That would be great! I believe I read that review when it came out. A good friend had a subscription. (He bought the Conrad Johnston.)
MELOS GK-1+1 Docs
- Thread starter lorne
- Start date
Good news! I will be very much looking forward to it.
Not a review
For what some want for a GK-1 I wished I'd spotted this:
http://www.ebay.com/itm/Melos-MA-33...D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
Same seller, another ad:
http://www.usaudiomart.com/details/...preamp-3-chassis-including-phono-silver-mint/
Well. I may summarize the Melos information. The Absolute Sound gave a bad review and there is a whole section called Controversy where the manufacturer and over half a dozen readers vent at the poor review.
For what some want for a GK-1 I wished I'd spotted this:
http://www.ebay.com/itm/Melos-MA-33...D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
Same seller, another ad:
http://www.usaudiomart.com/details/...preamp-3-chassis-including-phono-silver-mint/
Controversy
The reader's letters noted Jack English's very negative tone in the review and lack of use of low output MC, etc.. One makes the point that they've never of heard of English's Pro Reference Preamp and that the review should have compared the GK1 to its tube competition.
Jack English in this reply sounded the mating call of the loser, "the comparitive frame of reference to be used for evaluation is the sound of live, unamplified music performed in real physical space." This is more or less a license for technical incompetence. He claims to have been predisposed to like the Melos Gk-1 since he likes hybrids and was using an ARC SP-11mkii ($6000 hybrid preamp versus $1300 Melos which is not a hybrid, by the way, yet again another technical error on the Absolute Sound's part).
English claims to have heard 4 Gk-1's in various systems (not sure when he heard these in relation to review timing, but sounds like he had already decided he did not like the unit prior to getting the review sample.) "The Melos GK-1 lacks depth! Having heard four Gk-1's (in different states of update) in a number of very different systems, I cannot understand how this preamp could be describes as accurately portraying the depth of the original acoustic space. It does not. Similarly, the GK-1 does not reproduce sufficient inner detail, has a wooliness in the bass, and has an upper midrange hardness. It can play very loud, has a big, open sound, and is quite dynamic. .."
English states that readers who disagree with his assessment should either listen to the $6000 SP-11 or go listen to live music. Some more mating call action if you ask me and completely uninformative jibberish. The Absolute Sound claimed they would do a follow up interview, but I don't think they did. For an example of some of English's antics, see the postscript of the Scientific Fidelity Tesla review in Stereophile:
http://www.stereophile.com/content/...esla-loudspeaker-jack-english-adds-postscript
By the way this was one of biggest hatchet jobs in high end history as the Tesla was quite popular and selling well. This review crushed sales of the speaker. I suppose English was trying to compete with Corey Greenberg in entertaining the readers. I don't know if you can get more negative and unprofessional, though it is entertaining and communicates something.
Today the GK-1 would have been compared to some of its competition. (It really had none at its price point then.) The ARC SP10 was $3700 and could handle some low output MCs (requires frequent retubing of 4 ultra low noise selected 6dj8 in phono stage, maybe twice a year.) In fact, all tube preamps that can handle low output MC's are a rarity. I am sure reviewers today would also explore tubing options and discussed this in detail.
I don't think I'll seek out the original review (issue 46) and the five reader letters are overwhelmingly positive. Loren, what do you think of the quoted description above?
George Bischoff, president of Melos, starts the Controversy section with his letter. Bischoff identifies a huge shortcoming in the review which is the use of a MM cartridge with the GK-1 with its raison d'être being its low price for all tube amplification of low output MC cartridges. (I concur, this was a very moronic move on the Absolute Sound's part.) The other area of concern Bischoff voices is the tuning of the subwoofer in Jack English's system. English states in his reply that he must adjust his subwoofer and speaker placement for every component change. To me this suggests serious technical problems in the reviewers system as the level of the subwoofer and placement should only need to be adjusted when changing the main speaker's amplifiers. The main speakers should not need to be moved.
The reader's letters noted Jack English's very negative tone in the review and lack of use of low output MC, etc.. One makes the point that they've never of heard of English's Pro Reference Preamp and that the review should have compared the GK1 to its tube competition.
Jack English in this reply sounded the mating call of the loser, "the comparitive frame of reference to be used for evaluation is the sound of live, unamplified music performed in real physical space." This is more or less a license for technical incompetence. He claims to have been predisposed to like the Melos Gk-1 since he likes hybrids and was using an ARC SP-11mkii ($6000 hybrid preamp versus $1300 Melos which is not a hybrid, by the way, yet again another technical error on the Absolute Sound's part).
English claims to have heard 4 Gk-1's in various systems (not sure when he heard these in relation to review timing, but sounds like he had already decided he did not like the unit prior to getting the review sample.) "The Melos GK-1 lacks depth! Having heard four Gk-1's (in different states of update) in a number of very different systems, I cannot understand how this preamp could be describes as accurately portraying the depth of the original acoustic space. It does not. Similarly, the GK-1 does not reproduce sufficient inner detail, has a wooliness in the bass, and has an upper midrange hardness. It can play very loud, has a big, open sound, and is quite dynamic. .."
English states that readers who disagree with his assessment should either listen to the $6000 SP-11 or go listen to live music. Some more mating call action if you ask me and completely uninformative jibberish. The Absolute Sound claimed they would do a follow up interview, but I don't think they did. For an example of some of English's antics, see the postscript of the Scientific Fidelity Tesla review in Stereophile:
http://www.stereophile.com/content/...esla-loudspeaker-jack-english-adds-postscript
By the way this was one of biggest hatchet jobs in high end history as the Tesla was quite popular and selling well. This review crushed sales of the speaker. I suppose English was trying to compete with Corey Greenberg in entertaining the readers. I don't know if you can get more negative and unprofessional, though it is entertaining and communicates something.
Today the GK-1 would have been compared to some of its competition. (It really had none at its price point then.) The ARC SP10 was $3700 and could handle some low output MCs (requires frequent retubing of 4 ultra low noise selected 6dj8 in phono stage, maybe twice a year.) In fact, all tube preamps that can handle low output MC's are a rarity. I am sure reviewers today would also explore tubing options and discussed this in detail.
I don't think I'll seek out the original review (issue 46) and the five reader letters are overwhelmingly positive. Loren, what do you think of the quoted description above?
Firstly, thanks for the interesting synopsis. I appreciate the effort.
Over 25 years ago, my best friend and committed audio enthusiast was a subscriber to Absolute Sound. I used to borrow them and we shared some speculations about the publication: A-S relied on some very fancy advertising. The publication was not a quarterly pulp, or anything like Glass Audio. They reviewed a lot of very high-end stuff, and a lot of mojo, hype and audio alchemy were mixed in with the reviews. There were good antidotes such as van Alstine's Audio Basics, Glass Audio and when the internet came along Mr Elliottt's articles on the Elliott Sound Products pages. I was not a huge fan of A-S. It was out of my league. Perhaps it was better suited to the dapper "suits" reading the latest issue in Starbucks — the keys to their Porsches displayed next to their coffee. I was more the rusting, Datsun pickup type with a box of tools in the back.
Question: could A-S have been cherry picking victims for some negative reviewing? My friend and I thought so at the time. They appeared to be lenient on equipment that came from very hi-end advertisers who were paying for some serious money to advertise in glossy colour. Melos never quite joined that crowd — AFAIK — and may have been chosen as the blighted cherry.
My friend and I compared the C-J and the GK-1 directly on both my system and his. We decided that there were differences, but they amounted to a matter of taste, and natural predilection. AFAIK the C-J of the time was not universally trashed either. My friend bought the C-J and I bought the GK-1. They were close in price. The C-J had a smaller footprint, which was a good point for some people. The GK-1 used tubes that were inexpensive and readily available. And I just liked the sound of the Melos a little better. My friend felt the same towards the C-J.
1) Lack of depth: I've never had any reason to complain about the lack of depth. I expect that the Bentlys and Rolls Royces of the audio world might do better. In my current setup, good recordings have plenty of depth enough for my taste. Good synergy with your amplifier is essential, and perhaps Mr English stumbled in that area of his review. Recently I have run the GK's signal through the "Tape Out" RCA plugs and directly into the power amp section of a dead stock Sansui AU alpha717 Extra where the volume is controlled right on the power amp side of this integrated amp. The other night, I listened to Paul Simon's CD version of Graceland two or three times in succession. Lack of depth never crossed my mind.
2) In regards to realism and so on: I was actually remarking to myself how live and realistic the entire performance sounded. And yes, I agree with Mr English that the GK is dynamic.
3) Same recording in regards to woolliness in the bass: Graceland, as everyone will remember, is a stunning cornucopia for percussion from the African musicians who were the heart of this recording. 'Wooliness' is not a word that applies — at least not in this recording. In fact, bass percussion showed so much resolution and definition as to be quite startling at high, realistic volume.
4)"lack of inner detail..." What is inner detail? Maybe its just the not uncommon BS we read in reviews. If I have a complaint about detail it would be that on some recordings I don't quite get all the words. On vinyl, I could ask for less confusion. These are limitations that more properly belong to the whole of my system, not specifically the GK. In fact, I don't think I've ever had a system that fully exploited the GK's potential. Just a suspicion. I am playing Redbook CD on a second generation Yamaha CDX using a non-oversampling DAC module. That is not the last word in digital music reproduction, but like the GK-1 itself, it leaves me with an optimum lack of coloration that suits my budget. If I don't get everything, at the very least there is a very natural sound — something that Melos specifically claimed to strive for and was a foundation in their advertising. Pianos sound like pianos — not like electric keyboards. The human voice is quite amazing. Swings and round-a-bouts, people like me who have children and no Porsche keys on the vestibule have to compromise. Still, I don't think there is a lot of comprising to be trucked around in the GK-1.
5) I don't understand the whole criticism of the phono section — and neither do many, many other Melos fans who perhaps above anything else prize the phono section of the GK-1. There was a time when I used MC cartridges exclusively. The Denon DL-110 and DL-160 were pretty high output — the 110 in particular. But others were not, and yet I never wanted for volume in any of them. I simply don't know what English was writing about. Perhaps he did not read the manual in regards to the DIP switches. Or, maybe he misread them?
6) Upper mid-range hardness: maybe he has a point. At high volume settings, there could be a case for this. Tube rolling might sort some of this out. Again, my source has a lot to do with it. Years ago when the GK-1 was tied to a Dynaco ST-70 tube amp, mid-range hardness never seemed an issue. I was using vinyl on a decent TT with an MC cartridge exclusively at the time. Several speakers have passed through the lineup over the years, so I have a pretty good perspective on this issue. Currently, some hardness is not uncomfortable until the volume is high enough to set my wife's teeth to grinding downstairs.
In conclusion: going by your synopsis, I cannot agree with Mr English's review. Recent technology has created a whole new frontier in music reproduction. I am not familiar with it. But, if an enthusiast wants to stay with the classic or vintage big black box technology and spinning vinyl on decent players, you can't go wrong with the pre maps in the same class as the GK-1. For a few hundred dollars you can get some very decent sound that has enough depth, resolution, detail and just plain heart to move your emotions to all the places the artists were intent on doing. If you are a person with a set of Porsche keys, perhaps you will want to spend another $1K and buy one of the gemstones that cost $6000 back in the days.
Over 25 years ago, my best friend and committed audio enthusiast was a subscriber to Absolute Sound. I used to borrow them and we shared some speculations about the publication: A-S relied on some very fancy advertising. The publication was not a quarterly pulp, or anything like Glass Audio. They reviewed a lot of very high-end stuff, and a lot of mojo, hype and audio alchemy were mixed in with the reviews. There were good antidotes such as van Alstine's Audio Basics, Glass Audio and when the internet came along Mr Elliottt's articles on the Elliott Sound Products pages. I was not a huge fan of A-S. It was out of my league. Perhaps it was better suited to the dapper "suits" reading the latest issue in Starbucks — the keys to their Porsches displayed next to their coffee. I was more the rusting, Datsun pickup type with a box of tools in the back.
Question: could A-S have been cherry picking victims for some negative reviewing? My friend and I thought so at the time. They appeared to be lenient on equipment that came from very hi-end advertisers who were paying for some serious money to advertise in glossy colour. Melos never quite joined that crowd — AFAIK — and may have been chosen as the blighted cherry.
Well, you may have made the main point already. The GK1 was not a $6,000 preamplifier. Were there better preamps? Sure, why not? I've never owned one. Moreover, I don't expect to ever have the coin to get into the audio stratosphere. Millions of vintage audio fans are going be satisfied with something on par with the GK-1, such as the contemporary Conrad Johnson model.
My friend and I compared the C-J and the GK-1 directly on both my system and his. We decided that there were differences, but they amounted to a matter of taste, and natural predilection. AFAIK the C-J of the time was not universally trashed either. My friend bought the C-J and I bought the GK-1. They were close in price. The C-J had a smaller footprint, which was a good point for some people. The GK-1 used tubes that were inexpensive and readily available. And I just liked the sound of the Melos a little better. My friend felt the same towards the C-J.
1) Lack of depth: I've never had any reason to complain about the lack of depth. I expect that the Bentlys and Rolls Royces of the audio world might do better. In my current setup, good recordings have plenty of depth enough for my taste. Good synergy with your amplifier is essential, and perhaps Mr English stumbled in that area of his review. Recently I have run the GK's signal through the "Tape Out" RCA plugs and directly into the power amp section of a dead stock Sansui AU alpha717 Extra where the volume is controlled right on the power amp side of this integrated amp. The other night, I listened to Paul Simon's CD version of Graceland two or three times in succession. Lack of depth never crossed my mind.
2) In regards to realism and so on: I was actually remarking to myself how live and realistic the entire performance sounded. And yes, I agree with Mr English that the GK is dynamic.
3) Same recording in regards to woolliness in the bass: Graceland, as everyone will remember, is a stunning cornucopia for percussion from the African musicians who were the heart of this recording. 'Wooliness' is not a word that applies — at least not in this recording. In fact, bass percussion showed so much resolution and definition as to be quite startling at high, realistic volume.
4)"lack of inner detail..." What is inner detail? Maybe its just the not uncommon BS we read in reviews. If I have a complaint about detail it would be that on some recordings I don't quite get all the words. On vinyl, I could ask for less confusion. These are limitations that more properly belong to the whole of my system, not specifically the GK. In fact, I don't think I've ever had a system that fully exploited the GK's potential. Just a suspicion. I am playing Redbook CD on a second generation Yamaha CDX using a non-oversampling DAC module. That is not the last word in digital music reproduction, but like the GK-1 itself, it leaves me with an optimum lack of coloration that suits my budget. If I don't get everything, at the very least there is a very natural sound — something that Melos specifically claimed to strive for and was a foundation in their advertising. Pianos sound like pianos — not like electric keyboards. The human voice is quite amazing. Swings and round-a-bouts, people like me who have children and no Porsche keys on the vestibule have to compromise. Still, I don't think there is a lot of comprising to be trucked around in the GK-1.
5) I don't understand the whole criticism of the phono section — and neither do many, many other Melos fans who perhaps above anything else prize the phono section of the GK-1. There was a time when I used MC cartridges exclusively. The Denon DL-110 and DL-160 were pretty high output — the 110 in particular. But others were not, and yet I never wanted for volume in any of them. I simply don't know what English was writing about. Perhaps he did not read the manual in regards to the DIP switches. Or, maybe he misread them?
6) Upper mid-range hardness: maybe he has a point. At high volume settings, there could be a case for this. Tube rolling might sort some of this out. Again, my source has a lot to do with it. Years ago when the GK-1 was tied to a Dynaco ST-70 tube amp, mid-range hardness never seemed an issue. I was using vinyl on a decent TT with an MC cartridge exclusively at the time. Several speakers have passed through the lineup over the years, so I have a pretty good perspective on this issue. Currently, some hardness is not uncomfortable until the volume is high enough to set my wife's teeth to grinding downstairs.
In conclusion: going by your synopsis, I cannot agree with Mr English's review. Recent technology has created a whole new frontier in music reproduction. I am not familiar with it. But, if an enthusiast wants to stay with the classic or vintage big black box technology and spinning vinyl on decent players, you can't go wrong with the pre maps in the same class as the GK-1. For a few hundred dollars you can get some very decent sound that has enough depth, resolution, detail and just plain heart to move your emotions to all the places the artists were intent on doing. If you are a person with a set of Porsche keys, perhaps you will want to spend another $1K and buy one of the gemstones that cost $6000 back in the days.
Melos MA-333
I suppose high end audio does cost a lot of money. It used to be if you had something like the Melos GK-1 back in the day you had something and there were better units, but they were thinkable perhaps. Now we live in an era of boutique high end audio and its just outrageous. My system uses 9 power cords and 7 interconnect pairs. Take a look at boutique cable costs:
http://www.stealthaudiocables.com/pricing/
A great company I suppose and I've heard the Metacarbon in my system at recent audio club meeting. Who can afford this? Cabling my system would cost $135,000 for the top of the line and that does not include speaker cable (add $200,000 for that!). It is demented and these companies are surviving, so I think when the term the High End was coined in audio we had no idea.
Loren if you want a Mercedes or Porsche and you are crazy enough you can get one easily enough; just wait for one to depreciate after ten years and work on it yourself and drive it. Its obtainable if you have the desire. Not so with High End Audio. The stuff eventually depriciates, but still can easily get 1/3rd the outrageous retail price even after decades. It is a hobby that can create some class envy for sure.
And yes, all this stuff does make a difference, but the stakes are high when assembling such systems as you are often only as good as your weakest link. You can't buy happiness in audio, you have to know how to assemble a system and work with it, so we enthusiasts in the lower reaches of the high end can do just fine.:tresbon:
It didn't sell for that. It sold for $1600 on ebay. These units are trouble too. The volume conrol is call a light phontentiometer. I read that you cannot get replacement parts for this. I've not studied the unit closely, but I believe originally it was hybrid. One of the main engineers was doing service on Melos until his death ten years ago (Will.) I believe he upgraded some units replacing the boards or something so they were no longer hybrid and were instead all tube. That is a lot of carcas for the money at $1600 and it had had much restoration work done and I think the unit went for $8500 with a phono section.Hi meles: I'd love to have that Melos MA trio you cited above. But $2,500? No way for this dude.Cheers - Lorne
I suppose high end audio does cost a lot of money. It used to be if you had something like the Melos GK-1 back in the day you had something and there were better units, but they were thinkable perhaps. Now we live in an era of boutique high end audio and its just outrageous. My system uses 9 power cords and 7 interconnect pairs. Take a look at boutique cable costs:
http://www.stealthaudiocables.com/pricing/
A great company I suppose and I've heard the Metacarbon in my system at recent audio club meeting. Who can afford this? Cabling my system would cost $135,000 for the top of the line and that does not include speaker cable (add $200,000 for that!). It is demented and these companies are surviving, so I think when the term the High End was coined in audio we had no idea.
Loren if you want a Mercedes or Porsche and you are crazy enough you can get one easily enough; just wait for one to depreciate after ten years and work on it yourself and drive it. Its obtainable if you have the desire. Not so with High End Audio. The stuff eventually depriciates, but still can easily get 1/3rd the outrageous retail price even after decades. It is a hobby that can create some class envy for sure.
And yes, all this stuff does make a difference, but the stakes are high when assembling such systems as you are often only as good as your weakest link. You can't buy happiness in audio, you have to know how to assemble a system and work with it, so we enthusiasts in the lower reaches of the high end can do just fine.:tresbon:
GK-1+1 or bust!
High end audio has made its way into the world of Glass audio with boutique parts. Knowing where and what to use these is very important. Our older components have been superceded in many ways. Some things like diodes upgrades are tolerable, and some things like Teflon capacitors are intolerable (I've Russian ones though waiting in the wings.)
I just swung for the fences and got a Placette Remote Volume Control for $350 (at the price I couldn't lose because I could sell it for more). My Loesch design preamp has essentially a passive volume control at the end of it. I wired up the placette in place of 18 step 20K Daven attentuator (which has been shunted). The difference was jaw dropping and I expect this was thanks to the bulk foil resistors artfully used in the Placette. A giant increase in bass slam and dynamics and this was despite dropping the load down from about 15k (with shunting) to 9.5k. Conventional engineering techniques cannot explain the difference, so the art of boutique parting the right parts seems to be an important question these days.
I tend to think this is not normally the case. The editors of both magazines essentially did not participate in the lynching of these components. Would they have interceeded if the companies were major advertisers? No matter their protestations, it surely is a factor. I think if they were actively plotting the demise of company X we would have had some deep throat character coming out with the sordid details.
http://app.audiogon.com/listings/tu...-2015-02-15-preamplifiers-85254-scottsdale-az
(Its predecessor, the all tube low output capable SP10mk2 is a legend that sells for more than its original retail of $4000.)
Any decent hybrid is likely to have some advantages in these areas that English notes. They also will tend to bleach out the sound of ones beloved vintage vinyl. ARC knows what they are doing and I am sure the SP11 has quite the sound, but even they have largely left these hybrid designs. Not really the Absolute Sound it appears after all.
The GK-1+1 is highly appeailing for its inexpensive tube complement. A vintage ARC SP10 uses freaking 12 6DJ8s, and you are talking $1200 for nice NOS, and 4 of these would have to be low noise selected and replaced annually! (forget that) I think we are talking $5 a tube on the GK-1 or less for NOS. You don't get any more budget than that.
The GK-1+1 is an amazing unit on paper and I still want one badly. With some artful parts upgrades (and I've seen quite a bit of discussion of this online) I believe the unit can be modernized.
Keep your eyes peeled for me Loren. Its GK-1+1 or bust!
Well, I believe in the observational science in audio. It was a sad state of affairs before the likes of the Absolute Sound and others rolled around (equipment designed for specifications, THD, etc. with little regard to sound quality.) I've always like Glass Audio and the like, but building something from scratch is usually quite expensive in many cases. I prefer to get something used for cheap and then modify. Loudspeakers are perhaps the prime example where modification of an existing design is much cheaper and building a loudspeaker from scratch that is really good is not easy.
High end audio has made its way into the world of Glass audio with boutique parts. Knowing where and what to use these is very important. Our older components have been superceded in many ways. Some things like diodes upgrades are tolerable, and some things like Teflon capacitors are intolerable (I've Russian ones though waiting in the wings.)
I just swung for the fences and got a Placette Remote Volume Control for $350 (at the price I couldn't lose because I could sell it for more). My Loesch design preamp has essentially a passive volume control at the end of it. I wired up the placette in place of 18 step 20K Daven attentuator (which has been shunted). The difference was jaw dropping and I expect this was thanks to the bulk foil resistors artfully used in the Placette. A giant increase in bass slam and dynamics and this was despite dropping the load down from about 15k (with shunting) to 9.5k. Conventional engineering techniques cannot explain the difference, so the art of boutique parting the right parts seems to be an important question these days.
I've never thought this before, but it is possible. The Sci Fi Tesla got attacked at Stereophile. The Melos GK-1 was victimized by the Absolute Sound. Both were successful products on the market before these reviews.
I tend to think this is not normally the case. The editors of both magazines essentially did not participate in the lynching of these components. Would they have interceeded if the companies were major advertisers? No matter their protestations, it surely is a factor. I think if they were actively plotting the demise of company X we would have had some deep throat character coming out with the sordid details.
I think English tips his hand with his preference for the ARC SP-11:
http://app.audiogon.com/listings/tu...-2015-02-15-preamplifiers-85254-scottsdale-az
(Its predecessor, the all tube low output capable SP10mk2 is a legend that sells for more than its original retail of $4000.)
Any decent hybrid is likely to have some advantages in these areas that English notes. They also will tend to bleach out the sound of ones beloved vintage vinyl. ARC knows what they are doing and I am sure the SP11 has quite the sound, but even they have largely left these hybrid designs. Not really the Absolute Sound it appears after all.
I think the GK-1 is an amazing unit on paper. I prize an all tube sound. A good friend has brought over an exceptional tube preamp, but with a JFET to achieve low noise at the very front end of the phono stage. It is an impressive sound (and I could add a JFET to the front of my current Loesch phono stage to stabilize it). The JFET front end seems to really be a great match with the audiophile vinly of the last 20 years, but i don't like it. You just give up that magic tube sound which works so well with vintage LPs. The GK-1 I would expect can retain much of this magic. I don't believe a unit was sold for a lower retail price, that was all tube and could handle low output MC cartridges. I am not aware of anything at twice the price for that matter.
The GK-1+1 is highly appeailing for its inexpensive tube complement. A vintage ARC SP10 uses freaking 12 6DJ8s, and you are talking $1200 for nice NOS, and 4 of these would have to be low noise selected and replaced annually! (forget that) I think we are talking $5 a tube on the GK-1 or less for NOS. You don't get any more budget than that.
The GK-1+1 is an amazing unit on paper and I still want one badly. With some artful parts upgrades (and I've seen quite a bit of discussion of this online) I believe the unit can be modernized.
Keep your eyes peeled for me Loren. Its GK-1+1 or bust!
Hi meles Thanks very much for the very interesting comments about the Melos MA. I had no idea, and now I don't think I want one.
I don't want to steer this thread into thrash-out about hi-end and snake oil. SO ... just a quick note in response to your astonishing comments:
I don't go around preaching my preferences in audio. But I will say here that I have no interest in so-called hi-end stuff like what I saw on the 'Stealth Cables' web page you cited. I read and try to understand what engineers and technicians are saying to us.
The very,very best audio I ever heard was built by a Japanese technician who specialized in tube gear here in Sendai. His speaker cable was common Belden 9497 —16 AWG, 19 strand ordinary copper in open twisted style. Probably PVC insulation. I use it. If you can find any, it will be some of the cheapest stuff on the stock shelves. His interconnects were just the same bread and butter sort of stuff. The recording was of Billy Holiday performing in a nightclub. The sound was so good that a listener was virtually in the room with patrons at the next table.
By the way, Takahashi-san did a bit of work on my Melos GK-1+1 — something I couldn't figure out. He liked and said it had many excellent parts in it.
and ride a 23 year old single cylinder Yamaha SRX "cafe racer".:thmbsp:
I'll have a bit of time soon. I'll try to post up some more detail about the GK-1+1 power supply rebuild — parts lists and other stuff.
I don't want to steer this thread into thrash-out about hi-end and snake oil. SO ... just a quick note in response to your astonishing comments:
I don't go around preaching my preferences in audio. But I will say here that I have no interest in so-called hi-end stuff like what I saw on the 'Stealth Cables' web page you cited. I read and try to understand what engineers and technicians are saying to us.
The very,very best audio I ever heard was built by a Japanese technician who specialized in tube gear here in Sendai. His speaker cable was common Belden 9497 —16 AWG, 19 strand ordinary copper in open twisted style. Probably PVC insulation. I use it. If you can find any, it will be some of the cheapest stuff on the stock shelves. His interconnects were just the same bread and butter sort of stuff. The recording was of Billy Holiday performing in a nightclub. The sound was so good that a listener was virtually in the room with patrons at the next table.
By the way, Takahashi-san did a bit of work on my Melos GK-1+1 — something I couldn't figure out. He liked and said it had many excellent parts in it.
I build and restore vintage road racing bicycles
and ride a 23 year old single cylinder Yamaha SRX "cafe racer".:thmbsp:I'll have a bit of time soon. I'll try to post up some more detail about the GK-1+1 power supply rebuild — parts lists and other stuff.
Jealous
I have a big 1993 Mercedes 300sd which I run on waste vegetable oil, but I am not a huge gear head like you, hence my preference for modifying.
I am extremely jealous that you have Takahashi-san as a technical resource. I love tube sound, but nobody around here does the SET thing. I triamp with push pull 300b amp on midrange and 2a3 tweeter amp push pull. These Japanese cats and audiophiles are pretty crazy. My dream amp is a really cheap used Concert Fidelity 6B4G Fusion monoblocks (made in Japan.)
You can procrastinate in my book until someone who has a GK-1+1 begs (like me in the future.)Hi meles I don't go around preaching my preferences in audio. But I will say here that I have no interest in so-called hi-end stuff like what I saw on the 'Stealth Cables' web page you cited. I read and try to understand what engineers and technicians are saying to us.
The very,very best audio I ever heard was built by a Japanese technician who specialized in tube gear here in Sendai. His speaker cable was common Belden 9497 —16 AWG, 19 strand ordinary copper in open twisted style. Probably PVC insulation. I use it. If you can find any, it will be some of the cheapest stuff on the stock shelves. His interconnects were just the same bread and butter sort of stuff. The recording was of Billy Holiday performing in a nightclub. The sound was so good that a listener was virtually in the room with patrons at the next table.
By the way, Takahashi-san did a bit of work on my Melos GK-1+1 — something I couldn't figure out. He liked and said it had many excellent parts in it.
I build and restore vintage road racing bicycles
I'll have a bit of time soon. I'll try to post up some more detail about the GK-1+1 power supply rebuild — parts lists and other stuff.
I have a big 1993 Mercedes 300sd which I run on waste vegetable oil, but I am not a huge gear head like you, hence my preference for modifying.
I am extremely jealous that you have Takahashi-san as a technical resource. I love tube sound, but nobody around here does the SET thing. I triamp with push pull 300b amp on midrange and 2a3 tweeter amp push pull. These Japanese cats and audiophiles are pretty crazy. My dream amp is a really cheap used Concert Fidelity 6B4G Fusion monoblocks (made in Japan.)
Takahashi-san went into the industrial electronics field some years ago, and no one sees him anymore. I know where there is some very affordable used SET pieces, and if I had some more efficient speakers, I rush out tomorrow and buy one of them. Instead I have my ST-70 ready for some work. I don't think I could do what you are doing — tri-amping. I don't even have the space in this Japanese house. I sleep beside my work station.
I'll keep my senses open for the GK you want, but I don't expect it will ever come from Japan. No one here ever heard of Melos — not even in Akihabara, Tokyo — before it turned into otoku cafes.
Space
You need to get that ST-70 going with the Melos!
I had Dynaco Mkiii and MkVI briefly and nice yellow pas2 (hated ARC SP9mkii). I think that trilevel Melos MA-333 would not fit in my rack come to think of it, but I still want it and I don't think they are hybrid normally (perhaps some of the later ones were hybrid). These were also called Music Director later on.
You need to get that ST-70 going with the Melos!
I have a lot to learn about the Melos family. Thanks for some insight. And yes, the ST-70 has to be "go".
Would you believe it? I started out studying how to reconstruct my Dyna back in 1990. I collected parts for years under a very constrained budget. I'll be off topic if I get too detailed, but it will be basically a stock amp with a Triode Electronics internal board that replaces the selenium component and the quad cap. The PC-3 is a nice fiber-glass board that is merely a materials improvement over the stock board. And I have NOS 7199 driver tubes for it. Years ago — and I recommend this to anyone with a Melos GK — the marriage with the Dyna was perfect. Do not expect modern sound. But, do you want to hear Shostakovich so that you spill your vodka? Wanna learn what high art was about under Stalin? The ST-70/ GK-1 will show you! Promise!
That being said, the GK really likes the power side of my big Sansui.
Twin transformers
Here are some images from another plain GK-1. The transformers have the same coding, but otherwise they look completely different. One GK-1 owner stated he'd seen a total of 4 GK-1's and 1 GK-1+1. He didn't know the exact differences, but they were all different. It seems Melos changed their designs all the time.Here is the plan-form of the rebuilt unit. Not the best photo, I lost the light. There are parts on the underside. They showed very great heat distress and were replaced. The whole board had to get disconnected and lifted off the nylon standoffs, so the work was relatively easy on the bench. The hard part was trying to find parts and figuring out how to prevent such heat from reoccurring.
On the left are the major semiconductors. The transistor on the big heat-sink was originally in 'DO' form like the one just north and to the right of it.
The original heat-sink was tiny compared to the one in the picture. I consulted with my parts supplier when I sought a replacement. He took out a calculator and within about a minute pointed to this big chunk of alloy as being adequate. He was adamant that the original sink could not possibly handle the energy emanating from this power device.
Attachments
Converting GK-1 to GK-1+1
(NOTE: These are essentially notes I am making as I research this project.)
First, the obvious. You must have the larger, longer power supply to do this. The smaller box only has one transformer and will not work.
The longer power supply predates the GK-1+1 designation. Evidence of this is that Lorne's unit was upgraded from GK-1 to GK-1+1 status by Melos in distant past. Another unit on ebay has a later serial number than Lorne's, but is not a "+1". It has the same transformers it looks like (at least one is the same), but everything in between is totally different. The burning up and over heating thing which Lorne fixed may be endemic to the GK-1+1 only.
Another obvious difference is the GK-1 comes with 8 6GK5. As a tube roller extrordinaire who currently has a phono stage with a 6GK5, this is not a great thing. Mullard 6GK5s are very warm and tubey sounding. Four in a row would be some serious darkness. Hitachi 6GK5s are also nice, but have a very extended solid state sound. Four in a row would well, let's say that would be the most you could do to combat darkness in a preamp. I've found one other Japanese 6GK5 that strikes a happy medium, returning the tube magic of the Mullard while retaining some of the Hitachi's extension. By the way Westinghouse Japan 6GK5 were not made by Westinghouse, but were rebrands. Lorne has mentioned in this thread his unbranded tubes with uranium salts on them and we need to figure out the make. If you use the Melos for high gain the 6GK5s may not give low noise performance for very long, but they are blessedly cheap.
With a GK-1+1 the line stage tubes are different. They are not radical changes, but the 6FH5 and 6ER5 are not substitutes for a 6GK5. The 6FH5 is close to the 6GK5. It takes .2 amps heater current to .18 amps for 6GK5. In most cases it is probably safe to add this load with no problem, but it could cause failure. The 6FH5 has 2/3rds the transconductance and 2/3rds the amplification factor of 6GK5. So, if you are using phono stage for high gain with low output MC cartridges putting a 6FH5 in the phono stage might be a bad move. For example, in Lorne's case with a MM cartidge, he could roll the 6FH5s from his line stage into the phono stage (I'd try the second stage). Currently, Lorne is just using the tape monitor circuit and is not using the line stage per se. He could easily run the unit without the line stages tubes (which would take some stress off the supply and might just sound better) and then try the 6FH5 in the second phono position quite safely as the other tubes would not be loading the heater/filament supply. One can safely put a 6GK5 in place of a 6FH5. Try and listen. All of these tubes are ultra cheap.
The +1s 6ER5 is a tube that is designed to run at higher voltages. The 6ER5 actually has a slightly higher amplification factor than the 6GK5, but the lower transconductance means it won't have as good a noise performance and the 50% higher plate resistance means it won't drive the next stage or component as well. On paper, not as good as a 6GK5. If you put in a 6GK5 for a 6ER5 it probably will have a short lifespan since it will be running quite hard at the higher voltages. I don't see problems putting the 6ER5 in for a 6GK5, but I have my doubts as it seems the circuit would not be optimum. Melos did make this change so one presumes they might have heard promise in the unmodified circuit when first exploring this change.
As I write this, it seems likely that the 6ER5 might have liked higher voltage in the design and that may be one of the things unique about the +1 power suppply. This may also be the source of heat issues too. Our schematic in this thread shows 110 volts for first 6GK5, 130 volts for the 2nd, and 175 volts for both the 6ER5 and 6FH5. Again the only caution for substituting is the slightly higher heater current of the 6FH5.
The GK-1+1 tube complement is interesting as the improved tubes are on paper inferior to the 6GK5. I suspect much of the change was just because they liked the resulting sound. I see this as the major advantage of the +1. It has much better tube rolling possibilities and it would be possible to get a much more neutral, better balanced sound then will all 6GK5s.
Enough for this post...
(NOTE: These are essentially notes I am making as I research this project.)
First, the obvious. You must have the larger, longer power supply to do this. The smaller box only has one transformer and will not work.
The longer power supply predates the GK-1+1 designation. Evidence of this is that Lorne's unit was upgraded from GK-1 to GK-1+1 status by Melos in distant past. Another unit on ebay has a later serial number than Lorne's, but is not a "+1". It has the same transformers it looks like (at least one is the same), but everything in between is totally different. The burning up and over heating thing which Lorne fixed may be endemic to the GK-1+1 only.
Another obvious difference is the GK-1 comes with 8 6GK5. As a tube roller extrordinaire who currently has a phono stage with a 6GK5, this is not a great thing. Mullard 6GK5s are very warm and tubey sounding. Four in a row would be some serious darkness. Hitachi 6GK5s are also nice, but have a very extended solid state sound. Four in a row would well, let's say that would be the most you could do to combat darkness in a preamp. I've found one other Japanese 6GK5 that strikes a happy medium, returning the tube magic of the Mullard while retaining some of the Hitachi's extension. By the way Westinghouse Japan 6GK5 were not made by Westinghouse, but were rebrands. Lorne has mentioned in this thread his unbranded tubes with uranium salts on them and we need to figure out the make. If you use the Melos for high gain the 6GK5s may not give low noise performance for very long, but they are blessedly cheap.
With a GK-1+1 the line stage tubes are different. They are not radical changes, but the 6FH5 and 6ER5 are not substitutes for a 6GK5. The 6FH5 is close to the 6GK5. It takes .2 amps heater current to .18 amps for 6GK5. In most cases it is probably safe to add this load with no problem, but it could cause failure. The 6FH5 has 2/3rds the transconductance and 2/3rds the amplification factor of 6GK5. So, if you are using phono stage for high gain with low output MC cartridges putting a 6FH5 in the phono stage might be a bad move. For example, in Lorne's case with a MM cartidge, he could roll the 6FH5s from his line stage into the phono stage (I'd try the second stage). Currently, Lorne is just using the tape monitor circuit and is not using the line stage per se. He could easily run the unit without the line stages tubes (which would take some stress off the supply and might just sound better) and then try the 6FH5 in the second phono position quite safely as the other tubes would not be loading the heater/filament supply. One can safely put a 6GK5 in place of a 6FH5. Try and listen. All of these tubes are ultra cheap.
The +1s 6ER5 is a tube that is designed to run at higher voltages. The 6ER5 actually has a slightly higher amplification factor than the 6GK5, but the lower transconductance means it won't have as good a noise performance and the 50% higher plate resistance means it won't drive the next stage or component as well. On paper, not as good as a 6GK5. If you put in a 6GK5 for a 6ER5 it probably will have a short lifespan since it will be running quite hard at the higher voltages. I don't see problems putting the 6ER5 in for a 6GK5, but I have my doubts as it seems the circuit would not be optimum. Melos did make this change so one presumes they might have heard promise in the unmodified circuit when first exploring this change.
As I write this, it seems likely that the 6ER5 might have liked higher voltage in the design and that may be one of the things unique about the +1 power suppply. This may also be the source of heat issues too. Our schematic in this thread shows 110 volts for first 6GK5, 130 volts for the 2nd, and 175 volts for both the 6ER5 and 6FH5. Again the only caution for substituting is the slightly higher heater current of the 6FH5.
The GK-1+1 tube complement is interesting as the improved tubes are on paper inferior to the 6GK5. I suspect much of the change was just because they liked the resulting sound. I see this as the major advantage of the +1. It has much better tube rolling possibilities and it would be possible to get a much more neutral, better balanced sound then will all 6GK5s.
Enough for this post...
Some misinformation
Here is another Audiokarma thread (with a schematic Lorne!):
http://www.audiokarma.org/forums/showthread.php?t=225437&page=3
The knowledgeable user SicoAmp (who generally has some great advice on mods here) incorrectly states that the +1 is defined by the presence of the wide power supply and not to worry about the facia. This is not true as our pictures and discussion in the above posts prove. I think technically the small power supply is from the Melos PGK-1, a rare predecessor. Earlier GK-1 apparently have this smaller supply. Later Gk-1 have the wide power supply. The GK-1+1 ps is wide also, but with changes.
On the thread another user uploads some notes in a letter which I suspect is from the departed Will, lead tech at Melos:
"Designation: the +1 refers to factory performed update to the line driver and power supply circuits. The two preamps are indistinguishable from the face although the +1 should (!) have a white input connect area as opposed to the earlier models all black input area. All of these preamps are designated GK-1 on the back plate. Some +1 preamps also had the mute removed, I elected to leave it in."
SicoAmp's power supply pic matches up very well with Lorne's. Lorne claims his unit actually says GK-1+1 on the face (but maybe Melos did not always go to the trouble to change the marking). Let me search the internet for the white input area.... It was hard to find, but the earlier link to missed item on ebay had it. See attachments on this post for image. The image of the front clearly shows GK-1+1 which must have been added at the factory. The seller was using all 6GK5s. And I believe these are from Namikis whose images dropped off this thread:
http://www.audiokarma.org/forums/showthread.php?t=555024
(Quite the Melos GK-1 group in the Pittsburg area it seems so I am surprised this unit had the wrong tube complement.) I am not sure how the back plate is attached or even if it is a plate. Not sure if it makes a sonic difference somehow.
Zooming on the nice image of the board, we have nine wires coming out of the umbilical. So now, do we have nine wires with the regular GK-1's? .... Well it looks like seven to me, but perhaps an owner would confirm. I'd conclude that a new umbilical cord needs to be installed to allow the GK-1 to be changed to a +1, but I have no idea from the schematic or why this would be the case. It is definitely the case of 7 wires on standard GK-1 as relayed by chinacave:
"Blue + Orange / Switched power
Brown + Green + black - Ground
White - Filament 6.64VDC
Red - B+ 225VDC"
One can count the wires coming in on the attached image and see 9 on the +1.
It is interesting to think about the fact that the power switch is in the main unit. A hotrod of the unit would be to lose the power switch and all the wiring and just unplug the unit when not using. Easy, but those who must have a switch might relocate it to the power supply for a partial hot rod.
Namikis mentions, "the main case does not have 'side walls' in the GK1. The GK 1+1 has sidewalls, creating an aluminum 'cocoon' for the motherboard." The sonic lizard might need to confirm the "cocoon". I guess I do see that our nice close up shows sides with the lid off on the +1. In fact they appear to be aluminum. Most GK-1 chassis are black. I'd very interested if a magnet stick's to Lorne's lid if it is black. Lorne does your unit look just like the one in the attached images?
On the main board, I see resistor changes which makes sense. With the two specimens I have close ups of I see the most differences around the phono gain setting switches and the soft start relay. These may just have been small changes in design at the time of the manufacture. In short, it looks like with a lot of squinting at the online schematic and confirmation with the GK-1+1 high rez pic attached, one could make the resistor changes rather easily. They all must be done right. Its possible some could have changed in the phono EQ which would be a major problem if not done exactly.
While on the resistor front, the general quality of the resistors is the reasonable flame proof type. This circuit appears to have quite a few resistors in the signal path. In phono I see 47 ohm and 18k. In the line 2.2k and 47 ohm (cathode follower). Bulk foil resistors might be tried in a few of these spots if one is look for a faster more accurate crisp dynamic sound. Bulk foils are amazing in some of the most critical spots and at $15 a piece not the end of life of course unless you replace every single resistor in the unit.
The unit has nice polystyrene capacitors and I'd be loathe to touch those. They are all smaller values like 680pf (.00068uf) and you'll pay $8 a pop for the Relcap RTX which might alter sound somewhat. These style styrene caps are not very rugged and don't handle heat well, so there may be no going back if you lose a few on removal. I've got some rusky small value teflon I might toss in the less critical positions.
Speaking of critical capacitors you'll have to check these in the phono EQ. They look the same on the two examples I've been comparing, but if the resistors change in the phono some of these would have to change. I don't believe these types are straight forward to read in value.
I expect some of the diodes that in the power supply schematic will need to be changed, but the image is so blurry it may take some guess work. These are associated with the large power supply caps on each voltage leg which are bypassed by the big 4.0uf 400v yellow caps that some may have thought were coupling caps. Hopefully these can be deduced, but these are critical as they determine the different voltages each tube is run at.
Where are the coupling caps? They are in the Melos cans and I wouldn't touch them. :nono: If you must experiment, then just try upgrading the line stage coupling cap or the cap before the cathode follower in the line stage (smaller and cheaper to do). These are quality caps Melos had custom made, and please don't think they are electrolytics!
The only other must do upgrade in parts for me is the diodes in the Bridge rectifiers. To me diodes and electrolytic capacitors are the signature components of solid state. My system as solid state bass rectification and upgrading all of my caps to black gate helped the sound much and made my system sound much more like it only had tube amplification. The change from diode upgrades was of a similar flavor and equally compelling. Tighter more dynamic sound too while sounding more tube like for both of these upgrades. Diode upgrades are quite cheap and high voltage one amp diodes for the high voltage bridge can be had from Michael Percy Audio for like $1.25 a piece and the heater supply may be the most important and here some substitutes can be had for a similar price (low voltage, 5 amp rated here will do, but will cost more or take the easy route with the 20A IXYS hexfred bridge for $10.)
One GK-1 user did a lot of upgrades and reports on the results here:
http://www.audiokarma.org/forums/showthread.php?t=225437&page=3
I just took a look at his images and he absolutely has a GK-1+1 in a black box with 9 wires (different colors of course than what we have in our image, and the grounds seem to hook up in different places, which is really strange.)
As far as upgrades SiCo had this to say in short:
1. The Macron photoflash caps (10 big ones on board I think) sounded great versus SiCo attempts to replace them. After 30 years they tested great, so don't touch. Quite expensive too.
2. "There is a 1uf 100v cap in the line stage (cathode follower section)... a solid tantalum cap and it causes a lot of that "original sound". Also, so do the input caps coming off the RCA jacks in the phono section. The original GK-1 has usually two in parallel - one is blue and one is tan. These are also solid tantalum dipped caps. They actually make some sense since they are physically small and the signal is also small. Replacing the tantalum caps will go a long way to adding LOTS of detail ...... I have tried all kinds of caps in these locations and will be happy to make suggestions later." SiCo where are you?
3. SiCo replaced the special Melos caps (made by SCR who makes Solen) in the phono stage "with some AEON caps (basically the same as SCR and Solen), just to see what would happen. As one would guess, basically the same sound. ..... don't worry about the "gloopy" stuff holding down caps. CAT, Counterpoint and a bunch of other manufactures used this stuff and it is absolutely necessary for the SCR caps to stay in place." Don't touch the Melos caps unless you want to pour money in the GK-1+1 (I'm sure a couple pairs of $500 a piece Teflon caps might be interesting.)
Of course, SiCo thinks this is the best Melos preamp ever with some TLC, but I expect ultimately he could take the $8000 music director to the next level.
Almost done I think. In short, it seems quite feasible to upgrade to +1 status provided you have a wide chassis power supply with the two transformers. The 9 wire 7 wire thing can be figured out I hope and it may just be some odd ground wire setup. The +1's seem to run quite hot, so a rebuild of their power supply would seem a necessary measure. Upgrading the main chassis to +1 status should not cost much except in time.
One think I've not figured out is the variable 1k resistor in parallel with 180 ohms on the cathode of the 6FH5. I see this in the schematic, but do not detect it in the images. Perhaps it is some bias pot I can't see that allows these tubes to be balanced internally (Lorne has mentioned about having to match pairs of 6FH5 because they vary over a wide range.)
Here is another Audiokarma thread (with a schematic Lorne!):
http://www.audiokarma.org/forums/showthread.php?t=225437&page=3
The knowledgeable user SicoAmp (who generally has some great advice on mods here) incorrectly states that the +1 is defined by the presence of the wide power supply and not to worry about the facia. This is not true as our pictures and discussion in the above posts prove. I think technically the small power supply is from the Melos PGK-1, a rare predecessor. Earlier GK-1 apparently have this smaller supply. Later Gk-1 have the wide power supply. The GK-1+1 ps is wide also, but with changes.
On the thread another user uploads some notes in a letter which I suspect is from the departed Will, lead tech at Melos:
"Designation: the +1 refers to factory performed update to the line driver and power supply circuits. The two preamps are indistinguishable from the face although the +1 should (!) have a white input connect area as opposed to the earlier models all black input area. All of these preamps are designated GK-1 on the back plate. Some +1 preamps also had the mute removed, I elected to leave it in."
SicoAmp's power supply pic matches up very well with Lorne's. Lorne claims his unit actually says GK-1+1 on the face (but maybe Melos did not always go to the trouble to change the marking). Let me search the internet for the white input area.... It was hard to find, but the earlier link to missed item on ebay had it. See attachments on this post for image. The image of the front clearly shows GK-1+1 which must have been added at the factory. The seller was using all 6GK5s. And I believe these are from Namikis whose images dropped off this thread:
http://www.audiokarma.org/forums/showthread.php?t=555024
(Quite the Melos GK-1 group in the Pittsburg area it seems so I am surprised this unit had the wrong tube complement.) I am not sure how the back plate is attached or even if it is a plate. Not sure if it makes a sonic difference somehow.
Zooming on the nice image of the board, we have nine wires coming out of the umbilical. So now, do we have nine wires with the regular GK-1's? .... Well it looks like seven to me, but perhaps an owner would confirm. I'd conclude that a new umbilical cord needs to be installed to allow the GK-1 to be changed to a +1, but I have no idea from the schematic or why this would be the case. It is definitely the case of 7 wires on standard GK-1 as relayed by chinacave:
"Blue + Orange / Switched power
Brown + Green + black - Ground
White - Filament 6.64VDC
Red - B+ 225VDC"
One can count the wires coming in on the attached image and see 9 on the +1.
It is interesting to think about the fact that the power switch is in the main unit. A hotrod of the unit would be to lose the power switch and all the wiring and just unplug the unit when not using. Easy, but those who must have a switch might relocate it to the power supply for a partial hot rod.
Namikis mentions, "the main case does not have 'side walls' in the GK1. The GK 1+1 has sidewalls, creating an aluminum 'cocoon' for the motherboard." The sonic lizard might need to confirm the "cocoon". I guess I do see that our nice close up shows sides with the lid off on the +1. In fact they appear to be aluminum. Most GK-1 chassis are black. I'd very interested if a magnet stick's to Lorne's lid if it is black. Lorne does your unit look just like the one in the attached images?
On the main board, I see resistor changes which makes sense. With the two specimens I have close ups of I see the most differences around the phono gain setting switches and the soft start relay. These may just have been small changes in design at the time of the manufacture. In short, it looks like with a lot of squinting at the online schematic and confirmation with the GK-1+1 high rez pic attached, one could make the resistor changes rather easily. They all must be done right. Its possible some could have changed in the phono EQ which would be a major problem if not done exactly.
While on the resistor front, the general quality of the resistors is the reasonable flame proof type. This circuit appears to have quite a few resistors in the signal path. In phono I see 47 ohm and 18k. In the line 2.2k and 47 ohm (cathode follower). Bulk foil resistors might be tried in a few of these spots if one is look for a faster more accurate crisp dynamic sound. Bulk foils are amazing in some of the most critical spots and at $15 a piece not the end of life of course unless you replace every single resistor in the unit.
The unit has nice polystyrene capacitors and I'd be loathe to touch those. They are all smaller values like 680pf (.00068uf) and you'll pay $8 a pop for the Relcap RTX which might alter sound somewhat. These style styrene caps are not very rugged and don't handle heat well, so there may be no going back if you lose a few on removal. I've got some rusky small value teflon I might toss in the less critical positions.
Speaking of critical capacitors you'll have to check these in the phono EQ. They look the same on the two examples I've been comparing, but if the resistors change in the phono some of these would have to change. I don't believe these types are straight forward to read in value.
I expect some of the diodes that in the power supply schematic will need to be changed, but the image is so blurry it may take some guess work. These are associated with the large power supply caps on each voltage leg which are bypassed by the big 4.0uf 400v yellow caps that some may have thought were coupling caps. Hopefully these can be deduced, but these are critical as they determine the different voltages each tube is run at.
Where are the coupling caps? They are in the Melos cans and I wouldn't touch them. :nono: If you must experiment, then just try upgrading the line stage coupling cap or the cap before the cathode follower in the line stage (smaller and cheaper to do). These are quality caps Melos had custom made, and please don't think they are electrolytics!
The only other must do upgrade in parts for me is the diodes in the Bridge rectifiers. To me diodes and electrolytic capacitors are the signature components of solid state. My system as solid state bass rectification and upgrading all of my caps to black gate helped the sound much and made my system sound much more like it only had tube amplification. The change from diode upgrades was of a similar flavor and equally compelling. Tighter more dynamic sound too while sounding more tube like for both of these upgrades. Diode upgrades are quite cheap and high voltage one amp diodes for the high voltage bridge can be had from Michael Percy Audio for like $1.25 a piece and the heater supply may be the most important and here some substitutes can be had for a similar price (low voltage, 5 amp rated here will do, but will cost more or take the easy route with the 20A IXYS hexfred bridge for $10.)
One GK-1 user did a lot of upgrades and reports on the results here:
http://www.audiokarma.org/forums/showthread.php?t=225437&page=3
I just took a look at his images and he absolutely has a GK-1+1 in a black box with 9 wires (different colors of course than what we have in our image, and the grounds seem to hook up in different places, which is really strange.)
As far as upgrades SiCo had this to say in short:
1. The Macron photoflash caps (10 big ones on board I think) sounded great versus SiCo attempts to replace them. After 30 years they tested great, so don't touch. Quite expensive too.
2. "There is a 1uf 100v cap in the line stage (cathode follower section)... a solid tantalum cap and it causes a lot of that "original sound". Also, so do the input caps coming off the RCA jacks in the phono section. The original GK-1 has usually two in parallel - one is blue and one is tan. These are also solid tantalum dipped caps. They actually make some sense since they are physically small and the signal is also small. Replacing the tantalum caps will go a long way to adding LOTS of detail ...... I have tried all kinds of caps in these locations and will be happy to make suggestions later." SiCo where are you?
3. SiCo replaced the special Melos caps (made by SCR who makes Solen) in the phono stage "with some AEON caps (basically the same as SCR and Solen), just to see what would happen. As one would guess, basically the same sound. ..... don't worry about the "gloopy" stuff holding down caps. CAT, Counterpoint and a bunch of other manufactures used this stuff and it is absolutely necessary for the SCR caps to stay in place." Don't touch the Melos caps unless you want to pour money in the GK-1+1 (I'm sure a couple pairs of $500 a piece Teflon caps might be interesting.)
Of course, SiCo thinks this is the best Melos preamp ever with some TLC, but I expect ultimately he could take the $8000 music director to the next level.
Almost done I think. In short, it seems quite feasible to upgrade to +1 status provided you have a wide chassis power supply with the two transformers. The 9 wire 7 wire thing can be figured out I hope and it may just be some odd ground wire setup. The +1's seem to run quite hot, so a rebuild of their power supply would seem a necessary measure. Upgrading the main chassis to +1 status should not cost much except in time.
One think I've not figured out is the variable 1k resistor in parallel with 180 ohms on the cathode of the 6FH5. I see this in the schematic, but do not detect it in the images. Perhaps it is some bias pot I can't see that allows these tubes to be balanced internally (Lorne has mentioned about having to match pairs of 6FH5 because they vary over a wide range.)
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Hi meles: great detective work here. It will take me some time to catch up on your requests for crosschecks and information. I forget some of what I could have answered off the top of my head some years ago.
I have to pull down part of my system to check out the details. I'll be back— but right now I am listening to Tony Bennet and Lady Gaga doing a duet album
One thing:I do not have the white board on the rear of the amp. But my amp really is a GK 1+1 — for sure!
I have to pull down part of my system to check out the details. I'll be back— but right now I am listening to Tony Bennet and Lady Gaga doing a duet album
One thing:I do not have the white board on the rear of the amp. But my amp really is a GK 1+1 — for sure!
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Sonic Lizard Your Tubes
I think this is the substance. This looks like a bargain price:
http://www.2spi.com/catalog/chem/Uranyl_Nitrate.shtml
I believe this is the Uranium Salt on your tubes. Please don't lick them any more! I'd investigate this more before getting a $125 bottle of the stuff.
Uranyl Nitrate, Hexa-Hydrate
N2O8U•6H2O
I think this is the substance. This looks like a bargain price:
http://www.2spi.com/catalog/chem/Uranyl_Nitrate.shtml
I believe this is the Uranium Salt on your tubes. Please don't lick them any more! I'd investigate this more before getting a $125 bottle of the stuff.
Uranyl Nitrate, Hexa-Hydrate
N2O8U•6H2O
