Big Bill
Summertime Rolls.....
Hello Pio, you think these would be an improvement?
DIY High or Low Ouput Moving Coil Phono Stage
- Thread starter HypnoToad
- Start date
Hello Pio, you think these would be an improvement?
The two Panasonics I mentioned are polypropylene's, I tried the polyesters but found that even though they are very revealing they are also harsh, where the polypropylene's I settled on are detailed and smooth like I said.
I have also looked at those high priced audio caps but for the money I doubt you could beat the Panasonic's.
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bobrown14
Super Member
Is this the thread that started the CNC card? I'm listening to mine right now (CNC) while Irene blows her nasty breath and drenching us with A LOT of rain and wind.. Oh the wind and rain.
Sounds super, listening to Dengue Fever (Escape from Dragonhouse - green lp listen to the last track first side mmm WAY low bass) and the vocals sound SOOOO clean and clear. The vinyl was DIRTY out of the box for a new LP. I mean REAL dirty... still picking up grunge after 3 plays. Now its all good. I will be swapping out OP-AMPS here shortly, If I still have power.
There's a break in peroid on this phono pre ...for me about 20hrs. Now I'm impressed.... go go Toad. My tube amp tranny is getting hot with the low frequencies.
Cheers,
Bob
Sounds super, listening to Dengue Fever (Escape from Dragonhouse - green lp listen to the last track first side mmm WAY low bass) and the vocals sound SOOOO clean and clear. The vinyl was DIRTY out of the box for a new LP. I mean REAL dirty... still picking up grunge after 3 plays. Now its all good. I will be swapping out OP-AMPS here shortly, If I still have power.
There's a break in peroid on this phono pre ...for me about 20hrs. Now I'm impressed.... go go Toad. My tube amp tranny is getting hot with the low frequencies.
Cheers,
Bob
Big Bill
Summertime Rolls.....
No it isn't, its an entirely different board designed for use with moving coil cartridges only.
sachu888
Spare the tigers, kill me
Cnc
HI Bob,
Even I find my CNC better than any budget phonos I heard.Please post your pics in CNC thread.Thanks again to Hypnotoad,Bigbill and Fasterdamnit for making CNC a hit.
Regards,
Sachin
HI Bob,
Even I find my CNC better than any budget phonos I heard.Please post your pics in CNC thread.Thanks again to Hypnotoad,Bigbill and Fasterdamnit for making CNC a hit.
Regards,
Sachin
They do that on the 640P's, might be worth a try, thanks Steve.
I picked up on this thread a day or two ago. Looking I don't see a source for PCBs, info on RJM and ordering? I see a schematic in post #18, no parts list, maybe from RJM? . . . . And now I found the link. 
I think some attachments might have been deleted since the thread started (nope, it was my browser).
This should be fun.
BTW, I just bought The Beatles Love album, vinyl, after reading about it.
I think some attachments might have been deleted since the thread started (nope, it was my browser).
This should be fun.
BTW, I just bought The Beatles Love album, vinyl, after reading about it.
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Just email Richard at
rjm003.geo@yahoo.com
and tell him you want a pair of Phonoclone 3 boards, he will email you a PayPal invoice, that's what he did me.
NO AFFILIATION
Glad you like the Love album, it's one of my favorites.
Just had to say this, I'll be waiting for Love . . . . I ebayed it.
Thanks for the address. I'll do it soon.
Great thread. I have a Denon DL-103C I bought from Fat Julian's about 1986. It is still in good condition but well used. This will allow me to sell the Denon SUT that came with it way back then.
Thanks for the address. I'll do it soon.
Great thread. I have a Denon DL-103C I bought from Fat Julian's about 1986. It is still in good condition but well used. This will allow me to sell the Denon SUT that came with it way back then.
I have had a number of people contacting me regarding PCB's for this project.
Unfortunately there will not be a group buy of PCB's for what I made, it is conflicting with another forum at DIYAudio.
Richard from RJM Audio sells them rjm003.geo@yahoo.com, also Peter Daniels from Audio Sector sells a similar design phdaniel@sympatico.ca. No Affiliation.
I was hoping it would be for the benefit of AK'ers so they could get a high end stage at a fraction of new price, but as some have pointed out I would be stepping on others toes, so it's not to be.
It's up to anyone who wants to build this project to source their own parts and use the schematics provided by Richard or purchase boards from him.
The construction guide is here: http://phonoclone.com/diy-guide.html
People are welcome to ask me about tweak's I made to the circuit and the outcome. Especially the different output capacitors I tried. Bigger caps may be worthwhile also if you are running it with batteries, maybe others can elaborate more on this. Steve had a great idea for current limiting resistors on the op amp rails as well.
Good luck, it's well worth it IMO.
Unfortunately there will not be a group buy of PCB's for what I made, it is conflicting with another forum at DIYAudio.
Richard from RJM Audio sells them rjm003.geo@yahoo.com, also Peter Daniels from Audio Sector sells a similar design phdaniel@sympatico.ca. No Affiliation.
I was hoping it would be for the benefit of AK'ers so they could get a high end stage at a fraction of new price, but as some have pointed out I would be stepping on others toes, so it's not to be.
It's up to anyone who wants to build this project to source their own parts and use the schematics provided by Richard or purchase boards from him.
The construction guide is here: http://phonoclone.com/diy-guide.html
People are welcome to ask me about tweak's I made to the circuit and the outcome. Especially the different output capacitors I tried. Bigger caps may be worthwhile also if you are running it with batteries, maybe others can elaborate more on this. Steve had a great idea for current limiting resistors on the op amp rails as well.
Good luck, it's well worth it IMO.
Big Bill
Summertime Rolls.....
Hagerman Bugle-LOMC phono pre shoot out.
Hello Gang, as luck would have it, it turns out I did have a spare 5AR4 rectifier. It was hiding on a shelf in the workshop in an old broken down Scott integrated amplifier. This allowed me to get my reference amplifier/passive pre back up and running for a proper review of the LOMC phono pre. My wife and I spent several hours this evening doing an A/B comparison between the new board and my Hagerman Bugle phone pre. We listened to several pieces of reference vinyl, taking time to switch between phono pre’s before and after each song. As a result, I’ve have drawn these conclusions: While the super-wide sound stage that I found in the Hagerman bugle (using three OPA2134A Burr Brown OP amps) is wonderful, I’ve now learned as a direct comparison of the two phono pre’s it had been at the expense of truly accurate stereophonic imaging. The new pre gives me laser sharp imaging with only the slightest decrease in width of sound stage. The new pre has qualities one would normally think of when evaluating phono cartridges; i.e., this pre has a homogenous quality neither adding to nor subtracting from the source signal. It’s very detailed without being exaggerated. My wife says that it’s “pleasant” to listen to, which is as good a word as any I can think of to describe the experience. In short, this phono pre tells the truth.
I’m using the same OPA27GP Burr Brown OP amps as HypnoToad used for his review (per his request), but I intend to order the mono versions (OPA134 Burr Brown) of the OP amps that I’m currently running in my Hagerman bugle for the new pre in order to give a “fairer” review between the two. I will post again as soon as I have done so.
Bill.:thmbsp:
Hello Gang, as luck would have it, it turns out I did have a spare 5AR4 rectifier. It was hiding on a shelf in the workshop in an old broken down Scott integrated amplifier. This allowed me to get my reference amplifier/passive pre back up and running for a proper review of the LOMC phono pre. My wife and I spent several hours this evening doing an A/B comparison between the new board and my Hagerman Bugle phone pre. We listened to several pieces of reference vinyl, taking time to switch between phono pre’s before and after each song. As a result, I’ve have drawn these conclusions: While the super-wide sound stage that I found in the Hagerman bugle (using three OPA2134A Burr Brown OP amps) is wonderful, I’ve now learned as a direct comparison of the two phono pre’s it had been at the expense of truly accurate stereophonic imaging. The new pre gives me laser sharp imaging with only the slightest decrease in width of sound stage. The new pre has qualities one would normally think of when evaluating phono cartridges; i.e., this pre has a homogenous quality neither adding to nor subtracting from the source signal. It’s very detailed without being exaggerated. My wife says that it’s “pleasant” to listen to, which is as good a word as any I can think of to describe the experience. In short, this phono pre tells the truth.
I’m using the same OPA27GP Burr Brown OP amps as HypnoToad used for his review (per his request), but I intend to order the mono versions (OPA134 Burr Brown) of the OP amps that I’m currently running in my Hagerman bugle for the new pre in order to give a “fairer” review between the two. I will post again as soon as I have done so.
Bill.:thmbsp:
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Fasterdamnit
Super Member
Great review!
FYI-
We found the widest soundstage on the Bugle when we went to a pair of LME49990 surface mount op-amps on an adapter in the input position followed by two OPA2134's. I believe that is what is in yours at the moment.
FYI-
We found the widest soundstage on the Bugle when we went to a pair of LME49990 surface mount op-amps on an adapter in the input position followed by two OPA2134's. I believe that is what is in yours at the moment.
Big Bill
Summertime Rolls.....
Au contraire........
Yes this is true however, I removed the 49990's and reinstalled the OPA2134 in the first position on the Bugle for the purpose of this review/shoot out.:yes:
Yes this is true however, I removed the 49990's and reinstalled the OPA2134 in the first position on the Bugle for the purpose of this review/shoot out.:yes:
Did you find a difference with the 0.1uf bypass caps?
Without them I found that it was a warm tube like sound, with them a perfect balance for me at least but my hearings not the best anymore.
It will be interesting to hear what it's like with the OPA134's.
OPA637APs can be used in the second stage, they are cheaper at Mouser at the moment. But you may have problems with these higher bandwidth op-amps oscillating in the first stage, a capacitor across R2 would be needed, 33pf hopefully should do it.
AD797's are one of my favorites, they love low impedance inputs, but would definitely need taming with a capacitor.
AD843's are a contender as well
The LME49710NA is low noise and cheap to buy as well.
The possibilities are endless, IMO this is the best DIY MC phono stage out there. And if any of these op amps sound better than the OPA27GP it will make this into one of the best phono stages regardless of cost.
Now where did I put those plans for my next creation.
Yes, I don't expect to replace the TQ-3 any time soon. But the 103-C is on an old Dual 1219 (1229? I'll check) I have. The stylus is in good shape but I could afford a retip sometime before the first of the year. Retirement is kicking in soon.
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Big Bill and I have been talking. And I brought this up to him, so I'm posting too.
I was reading through RJM's site and looking at the schematics. I know it might be seen like semantics, I think it is a misnomer. The input impedance of an OpAmp is infinite not zero.
On the site the point made was that a LOMC is a voltage source with a source resistance (the same resistance that the + input has to ground, or signal common). Anyone who has shorted a car battery, another voltage source knows that you should never short a voltage source. That is which a zero input impedance would do. It would burn and open the coils in the MC cartridge.
Since the Op-Amp essentially draws no current into itself there are no non-lilearities in the frequency response due to any capacitance or inductance there. The resistor from the + input to ground gives both inputs the same "resistance" to ground. Op-Amps produce an output voltage that achieves the same voltage at the + and - inputs. I would expect having the same load on both is helpful, lowering noise.
I think it is a brilliant design. So far I don't see this circuit in my 1981 edition of Jung's IC Op-Amp Cookbook. I don't expect it is there, but I might find something like it.
I was reading through RJM's site and looking at the schematics. I know it might be seen like semantics, I think it is a misnomer. The input impedance of an OpAmp is infinite not zero.
On the site the point made was that a LOMC is a voltage source with a source resistance (the same resistance that the + input has to ground, or signal common). Anyone who has shorted a car battery, another voltage source knows that you should never short a voltage source. That is which a zero input impedance would do. It would burn and open the coils in the MC cartridge.
Since the Op-Amp essentially draws no current into itself there are no non-lilearities in the frequency response due to any capacitance or inductance there. The resistor from the + input to ground gives both inputs the same "resistance" to ground. Op-Amps produce an output voltage that achieves the same voltage at the + and - inputs. I would expect having the same load on both is helpful, lowering noise.
I think it is a brilliant design. So far I don't see this circuit in my 1981 edition of Jung's IC Op-Amp Cookbook. I don't expect it is there, but I might find something like it.
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