Tubes in your system?

[lorne]

I'm goin' back to tubes. But I have collected a big stack of monster Japanese, solid state, integrated amps that have separate feeds for Pre and Power sections. I will be able to mix and match tube components for comparisons.

Last week I dug out my old PAS-3x. And, there is my ol' ST-70 parked away in the same closet, along with a bag of new parts. Last week I fed the stock PAS into a Sansui alpha's power section. I got some encouragement, but, I suspect an impedance mismatch. So for now, I am going to partially restuff the PAS and feed the PHONO section into the Sansui's preamp. I managed to dig up all four of the original Telefunken 12AX-7's for it.

My long-term aim is to have a basically reconditioned Dyna system — PAS-3x, ST-70 and FM-3. This was my system 15 years ago, but with original parts. I might do the Van Alstine bandwidth limit mod on the ST-70. And it's current diode rectification will revert to tube. Otherwise I am not that excited about wildfire modding. The addition of two mica capacitors allows my FM-3 to correspond to the essential part of the Japanese FM bandwidth — a very sparse band in Northern Japan, but NHK can be good — sometimes.

I also have a triode tube headphone amp. It's a kit that was designed and distributed by Tri, a Tokyo company.

 

[jcmusic]

My main tube rig is:
Sophia Electra 300b MKII-2-S.E. 300b's, 2-Siemenns el34's, 2-rca 5u4g's, 2-sylvania 6sn7 vt231's.
Rogue Audio 99 Magnum 4-sylvania 6sn7gt's.

Backup rig:
Scott 299 2nd edition- 4- sylvania 5751's, 4- E.H. el84's, 2- original scott-6bl8's, 1-sovtek 5ar4.

SS rig:
Marantz 300dc amp
Marantz 3250 pre amp
Marantz 2100 am-fm tuner
Revox b77 tape deck
Sony rcd w500c

 

[bolly]

I'll be running 2 of these in about a weeks time!

 

[flintstone]

Preamp: (Audioprism Mantissa)...NOS 7308's and 5814's

Amps: (Rogue Audio M-120 Magnums) KT-88's, 12AX7's, 12AU7's

My speakers are a pair of Apogee Duetta Signatures and a pair of large VMPS subs...the Rogues drive the Apogees and a big old Krell (Ksa-250) drives the passive subs.


Dave

 

[jaymanaa]

I'll be running 2 of these in about a weeks time!

Nice Hat-Trick! :thmbsp:

 

[Billfort]

This is long and rambling but here’s some detail on the pieces and tubes that are currently making it into my system on a pretty regular basis. I don’t swap stuff very often, tend to know what I like and stick with it (Altec 604's for 6 years, Sony SCD-777ES for 5, Sota TT for maybe 20) but I do seem to change SET amps, pre’s and tube mix up a bit – I just like having a few flavors around.

Pre-amps;

The Audible Illusions has been shelved for 2 Counterpoints; a modded SA-2000 (Amperex SQ 6922, Telefunken EZ81) with an ASL Mini-phono (Tele or Sylvania Germany 12AX7’s) or an SA-3000 (all Amperex 6DJ8’s and Tele EZ81). The 3000 can take my low output Denon MC straight in but it means using a SS amp stage so I use the same Altec 4722 mic transformers into it’s tube MM phono stage – just sounds better that way.

I haven’t decided which I prefer yet but I’m leaning towards the 3000 and bet if it was modded along the same lines as the 2000 (resistor and cap upgrades) and taken a little further with better rca’s, bypassing the SS buffer stage and moving the 4722 transformers onboard, it would smoke the 2000/ASL. As they stand now, the 2000 is livelier, more extended and ‘impressive’ on first listen while the 3000 comes across as smoother and a little rolled off. When doing a quick swap between these I seem to prefer the 2000/ASL from a gee-wiz hi-fi perspective but the 3000 floats a nicer image and just connects you to the music better. Nice to have both around actually.

Amps;

DIY 2A3/45 (switch selectable) using a Western Electric 417A driver and Mullard GZ37 rectifier. When 2A3 my favorite so far is the RCA dual black-plate but the JAN Westinghouse I have are pretty nice too. For 45’s my favorite is the RCA 245 globe but Raytheon ST’s and TJ mesh aren’t bad – I’ve read there really isn’t a ‘bad’ 45 and so far I’d agree with that. I love this amp as a 45 but it’s just not enough power for 100db eff. Altecs in my room – 2A3 is more like it and I use that configuration the most.

I still slide my Golden Tube Audio SE300B-II in every now and then as there is just something about the 300B that pulls me back. Driver tubes could be better (JAN Phillips 6SL7, Svetlana EL34 and an Amperex GZ34 rectifier) but I love the WE 300B’s I grabbed years ago. I have some EML 300B’s to try but any of the other ‘new’ tubes I’ve used like the TJ-mesh, Valve-Art, etc. where not up there with the WE.

My DIY 300B’s are now a pile of parts awaiting a rebuild as C3m>300B. They where originally built as 6SJ7>300B but spent a bunch of time with 6SN7 drivers. Nice sounding amps that where a bitch to get quiet (I had to resort to DC heaters on the 300B’s) but once I heard a well built C3m version I decided to start again from scratch in that direction. Great learning experience and I went through a box full of 6SN7’s (and coupling caps), my favorites being CBS 5692’s (Jupiter caps) for AC heat and Brimar CV1988’s (AudioNote PIO caps) after the switch to DC heaters.

The 2A3’s get the most use right now but I suspect a really good 300B will suit me best with the Altec 604’s. The 45 may be my first choice when I get my next set of all horn-loaded Altecs complete which should be around 103db. eff. but I figure I’ll always have a 300B around for when I need that silky sweet midrange fix that it delivers so well.

Other;

I use a Scott 350-D tube tuner regularly and honestly don’t remember the tube mix in it. I just turn it on, tune into my favorite Jazz/Blues station and forget about it. An amazingly musical piece (with the right program material) that for me speaks volumes in the listening vs. spec-manship debate.

On the bench now is an AudioNote kit2.1 DAC that does no oversampling and uses a 6922 amp stage with a tube regulated/rectified power supply. This should be real interesting as I never got along with CD but did feel the entry level AN DAC kit-1 sounded quite nice when I tried it using my SCD-777 as a transport. Maybe tubes can get me to a place where I can listen to CD’s for more than a few songs without running in terror to the selector switch and turntable for relief.

 

[Kegger]

Nice rundown Bill, I'll get mine in here sooner or later!

 

[jcmusic]

Hey Bill,
I had a similar situation with my 300b's, I went to a sylvania 6SN7 Ahh the magic.

 

[Billfort]

I have a bunch of Sylvania 6SN7's as well, very nice.

 

[Kegger]

I also like the sylvania 6SN7, the chrome top jobbies!

I have used the russian 6H8C as well for them and in
the right system they are awfully tuff to beat! CHEAP TO!

 

[jaymanaa]

I find this talk of Sylvys interesting. I never really thought of Sylvania as a high end tube untill recently. Since building my first homebrew, I have become a tube rolling nut. It seems to me that SET really lets the different tube sounds come through. What I mean to say is the results are more dramatic. My ears aren't very good, but I can easily distinguish the different strenghts and weekness of different ones. So far in the 6SL7 spot nothing really comes close to Sylvania. I am currently using some brown base, black plate, chrome tops, but the Jan Black base bottom getter tubes were also very good (maybe a hair less depth in the bass dept). The RCA's were very "OK" IMO. In the EL34 spot however, RCA's really shined, until I actually bit the epay bullet and picked up some NOS Tele's :tears: These delivered still more bass (very clear bass). I wish I knew how all this really works, but it is sort of fun plugging in a tube and waiting to see what it does. I think the SS designers of early really screwed up when they soldered the transistors in place instead of using a socket. Think of the millions they left on the table. We could have NOS JAN Silver Case PNP NPN double dipped ceramic coated ni-kad impreggnated three hole transistors. :scratch2:

 

[jon_s]

For tubes, I have had a number of different amps/preamps in my system, but presently I listen to a JuicyMusic Peach and a pair of Radio Craftsmen 500a's. I must preface my tube discussion with the following disclaimer: I HATE TUBE ROLLING. There is nothing I loathe more than swapping tubes in hopes of finding a "goldilocks" combination for "just right" sonics. Maybe my speakers are just too neutral for happy use with tubes? Right now, I have the following combination:

JM Peach: Amperex/HP 6DJ8 -> JJ E88CC, RCA 12X4
RC 500a: EH 6SN7 -> RCA 6SN7GTB -> GT KT66, Sylvania 5U4GB

For the Peach, differences between 6DJ8s are frustratingly significant.

The Craftsmen amps I hate tube rolling even more, because the rectifier colors the tone as much as the 6SN7 drivers. When I get a combination that works I just don't mess with it until I get significantly bored.

For the KT66, I've narrowed it down to the Saratov KT66; it's the only one that sounds right. 6L6-family is just too glassy and bright in these amps.

With a good combination of neutral gain+driver+rectifier tubes in both pre and power amps, which can be painfully hard to achieve/maintain, my amps can approach that big, dark, deep, 3D, natural, open sound -- kinda like the classic/boring, 300B/AudioNote voicing, minus syrupy/sloppy wetness, with twice as much power, and a damping factor of 20.

When its time for the next step, I'm going to design and build from-scratch with the goal of tweaking tube flavoring out of the equation. Using "unrollable" new production tubes -- stuff like ECC99s, 6N1Ps, 6N30Ps, EH6SN7s, KT66 HPs, Svetlana 6D22S, etc. The fewer options the better . If this takes hours of tweaking operating points and multiple feeback loops, so be it!

 

[jaymanaa]

Great post Jon, You bring up an interesting and often overlooked area of tube rolling. The rectifier :scratch2: I had allways planned on trying several different ones, but have not as yet. I plan to try "different" 5*4 types, which could have significant results due to varying voltage drops. This will have to be done very carefully and with a variac. Now I'm wondering if different brands of say 5R4's would make a noticable change in tone etc. I've heard many different schools of thought on power supplys in general ranging from "they just supply clean DC" to "they are what we are listening to". Could you go into a little more detail about your experiences with different rectifier tubes? Thanks, Jay

 

[jon_s]

The rectifier :scratch2: I had allways planned on trying several different ones, but have not as yet. I plan to try "different" 5*4 types, which could have significant results due to varying voltage drops. This will have to be done very carefully and with a variac. Now I'm wondering if different brands of say 5R4's would make a noticable change in tone etc.

Jay, be careful, rectifier swapping makes me even more angry than signal-tube swapping. While some rectifiers clearly change the bias point and result in large differences in voltages, I find shocking differences between those that don't. I'd think everything relevant should be filtered by the power supply and canceled in the output stage, but plenty of, umm, something seems to shine through, at least in my amps.

Not that rectifiers have a universal "sound", but they definitely seem to contribute some coloration which is consistent between trials: Sylvania 5U4GBs tend to sound bassy, warm, dry, a bit veiled, and can be quite delightful if this is what suits the mood. Tung Sol 5U4GB sounds fast, glassy, colored, somehow incomplete. Tung Sol 5AS4A sounds fast, dry, incisive, slightly bright and washed out, with tons of controlled bass. RCA 5U4GB sounds like a Tung Sol with more brightness and an overall more "complete" presentation. YMMV, of course. The Svetlana 5U4G sounds very open and fast, but lacks bass, totally changes the voltages (I compensate by increasing line voltage), and can have a metallic top-end.

The actual cause of these differences... well, I dunno, but I find it quite irksome that a rectifier can contribute so much to the "sound". Rectifier swap at your peril!

 

[Kegger]

I can see how some may not like the rolling part and could get frustrated with it's
results but it's one of MY favorite things about tubes, changing tubes to change a
tone or slight change in depth or whatever, I love it.

Now when you design from the ground up and your the designer so you put specific
tubes in certain voltage ranges and have done the math on how linear they will be
the tube rolling may be less an issue but certainly can still be there if yu want.

 

[jon_s]

I can see how some may not like the rolling part and could get frustrated with it's
results but it's one of MY favorite things about tubes, changing tubes to change a
tone or slight change in depth or whatever, I love it.

Certainly tube rollin' has saved me a few times when I changed something else in the system and needed to compensate. And, it can be fun when picking up some droolworthy NOS tubes. But, mostly I just find it tedious... a necessary evil which I hope to someday circumvent

 

[shelby1420]

I now have three working pieces in my system that are tube run....the first is my 45 watt stereo VRD-ST junior from our very own NOSVALVES, the next one i built myself which is the Bottlehead Foreplaylll and this past weekend just completed the upgrade kit( lovin these new upgrades) and about 3 weeks ago I built a Bottlehead Seduction along with upgrades!!! Tubes used are as follows---Forplay(line stage- uses three 12AU7's 2 of these are NOS RCA Black plates and the third (Regulator) is a JJ.... the Seduction is run with two Phillips 6922's and the amp is run with 2 EI 12AX7'S and 2 Mullard (NOS) 12AU7's and finally the power tubes in the amp have just been replaced with Mullard re-issue EL34's........................... all and all I'm lovin the tubes!!!!

 

[jaymanaa]

As Allison Krauss would say, I've got a "New Favorite"

In the 6SL7 spot on the SET EL34 homebrew. Red base, tall black plate 5691's. Great on male voice (where I was struggling somewhat). I've been meaning to post about a "maybe overlooked" tube also. The GE black plate 12A series. Worth a listen IMHO, Jay

 

[ldatlof]

...The GE black plate 12A series. Worth a listen IMHO, Jay

Glad to hear that Jay as I just bought a pair of 12AU7s to use with my Foreplay III. I have tried Mullard, RCA Cleartops and Amperex (made in the Heerlen Plant) so far. I was wondering what to try next when I came across the BPs and since I don't have any tubes with BPs I thought what the heck.

FWIW, here is my rating from worst to best:

Mullard: they do a lot right: very nice midrange, bass is good but, the high end is rolled off some. A little too much if you ask me.

Cleartops: very nice and a really extended high end. Really noticable when compared to the Mullards. Good bass and a nice midrange. I thought this would be the winner until I heard...

Amperex: This tubes gives you the best of everything. The high end is really sweet and makes the Cleartops sound bright in comparison. Bass and midrange are excellent too. This tube just seems to get it right.

 

[jaymanaa]

The 12AU7 GE's are outstanding IMHO. The ones I have are made in Canada and have MT vertically next to the round GE trademark. I haven't found anything I like better in my pre, and I've tried a bunch including JAN Sylvy's (which are good, just not "as" good IMO) Hope you like them too, Jay

Edit- I need to try some Amperex :yes: Seem's like I allways get outbid :scratch2: