Revisiting Tube Recommendations for Cayin TA-30


My appologies if this has already been beaten to death! :)

I hope you all are up for this post! I'll owe you all big time!

I have a Cayin TA-30 (purchased in '03) with mods from Paul that included the sub out. It has been connected to B&W Nautilus 803's and a B&W ASW800. I have a Sony XA9000ES as my cd/sacd player.

I replaced them all once from Paul with EL34's, 12AU7's, and 12AX7's tubes, from EH. Simply put, the TA-30 just doesn't come close to sounding as good as the stock tubes did. It, to me, sounds so flat and not open like it used to. I bias the tubes about every 90 days to keep them running at their best.

So now come the questions.

1st. The broad question I have is I need to replace the tubes again, and I want to replace them all, but there are soooo many options and choices and I'm really not interested in "tube rolling", though I know I really should be. Where does one start? I'm overwhelmed!

2nd. The TA-30, I see, can accommodate my types of tubes. Is a KT88 "brighter" or better, or should I stay with EL34's like it's called for? Should optional tubes be used on the front end? Is the TA-30 "pushed" to much using these other tubes?

3rd. Since I have the TA-30 connected to the sub, should I focus only on mids and highs for tubes?

4th. Is there a source out there where I can get this information without bothering you all? I googled some variations, but just haven't had luck. Is it just me, or are all the tube reviews done on guitar amps, not home audio amps?

Well, wasn't that a mess??? :)

Thanks in advance to you all! I hope this thread can become a resource for all us TA-30 users!

Regards,
Bob
bstromberg1
Oh My ...

Paul Grzybek of tubeaudiodesign.com formerly Bizzy Bee Audio, passed away on or about March 20, 2012. Some might have known him for his restoration of Fisher 400/500/800 Receivers.

Paul was 48 years old when he passed away. A great loss to the 2 channnel and tube community. Too Young ...

Got this from Huhuru on another site ... I'll miss Paul too - he was a great guy with a passion for audio
This is from a print out I did a while back on biasing a TA-30 ...

"You will need a tiny screwdriver and the supplied digital voltmeter to set the 4 output tube bias adjustments. Switch the amplifier on. Let it warm up for at least a few minutes. Plug the digital voltmeter Black lead into the Black tip jack and the Red lead into one of the Red jacks. (turn meter on, set meter to the marked 2000mV range). MEASURE WITH THE VOLUME ALL THE WAY DOWN - NO MUSIC PLAYING. You should see a reading on the meter. Turn the corresponding 25-turn small adjustment screw for each red tip jack you are measuring till the meter reads 350 (mV). Now move the red probe to the next tip jack and adjust the next corresponding adjustment screw. Repeat all 4 adjustments a few times till all are reading 350 (mV) +/- 10%. Super easy! The bias should be checked immediately when new tubes are installed, then every 6 months there after. Unusual readings (after initial adjustment - very high or very low compared to the other tubes indicate a tube failure. Output tubes generally last around 3000 hours. So every 1-3 years you will need replacements. A computer matched quad is the best choice - but not absolutely necessary in this separate tube bias design."

*** NOTE FOR KT-88 TUBES *** Bias to 400

Bias into class A - using tubes 1 & 3 (pull 2 & 4 out) - set bias to 700(mV) (assuming 800(mV) for KT-88)
This will convert the PP amp to single ended

I hope Paul is doing ok - looks like the web site is down - has anyone heard anything?
Thank you for getting back to me, so you are saying the 6L6 is the same as the 6n3ce setting? Have you tried the 6n3ce tubes? Thank you
Johnbonn,
Read my input from koiman 4 lines above. I put the bias values for the TA-30 and the stock EL-34 plus other tubes.
Lee
Yeh rub it in guys unfortunately I have an older one that is me biasing. If anyone has input on the bias setting I would really appreciate the input. And if anyone is running them in the older unit please give me your thoughts. Thank you
Mikirob,
If you have one of pauls modified Cayin TA-30 it's a very simple to Bias. Check his site.

http://www.angelfire.com/biz/bizzyb/TA30ADJUSTMENTS.html
Johnbonn,
I think Koiman/Paul may have this right, in fact the 6n3ce run cool and will last a very, very long time. I did see one spec that said 410 mV, but that was for a different amp by a person in Europe. At any rate I love the auto-bias feature. I think the Cayin bias procedure is a tough go from what I read. This whole process should be a lot easier.
Did he mention the 6n3ce? Anyone try them in a Cayin TA30 if so what are you biasing too. How do they sound and what tubes for the front end? Thank you
Bob,
Paul stated about a year you can use EL-34 Bias to 350 mV + or - 10% KT-88, 6550, KT-90, or 6L6 all Bias to 400 mV + or - 10%.
Mikirob thank you for all the information, a lot of information! Jim got back to me and said he has no idea if they would be compatible. So maybe someone part of the audiogon group will have some experience with the tubes. Thank you
Johnbonn, do not use me as authority. I'd strongly suggest waiting for a reply from Jim McShane or email Jeff Day, his reply may be quicker. Best.
I believe 450v/DC is correct: 6P3S, 6P3S-E 6n3ce

My Primaluna Dialogue 1 is auto-bias, makes it a snap to roll tubes.

(6n3C, 6n3C-E)

General
Tetrode, used in output stages of low frequency amplifiers.
Envelope: glass, with octal base.
Mass 70 g.

General characteristics:

Type 6P3S 6P3S-E 6n3ce
Filament voltage, Volt 6.3 6.3
Anode voltage, Volt 250 250
1st grid voltage, Volt -14 -14
2nd grid voltage, Volt 250 250
Type 6P3S 6P3S-E
Filament (heater) current, mA 900±90 880±40
Anode current, mA 72±18 73±13
2nd grid current, mA no more than 9 no more than 6
1st grid reverse current, mkA £ 3 £ 0.5
Cathode current, mA no less than 275 -
Output power, W no less than 5.4 no less than 5.8
Mutual conductance, mA/V 5.2 to 6.8 5.2 to 6.8
Internal resistance, kΩ 25 no more than 65
Inter electrode capacitance, pF:    
input 11±2 11
output 8.2±1.5 6.7
transfer no more than 1 no more than 1
Operation time, h ³ 1000 ³ 5000
Limited operating values:

Type 6P3S 6P3S-E
Filament voltage, V 5,7-7 6-6.6
Anode voltage, V 375 250
2nd grid voltage, V 300 250
Cathode - heater voltage, V 100 90 / -200
Cathode current, mA - 90
Anode dissipation, W 20 20.5
2nd grid dissipation, W 2.75 2
Resistance in 1st grid circuit, kΩ 500 150
Operating environmental conditions :

Type 6P3S 6P3S-E
Acceleration of vibration loads, g 1.5 3
by frequencies, Hz 50 5 to 300
Acceleration of multiple impacts, g - 12
Acceleration of single impact, g - 100
Continuos acceleration, g - 100
Ambient temperature, °С -60 to +70 -60 to +160
Relative humidity at up to 40°C, % 98 98
Plate and plate-grid curves

Mikirob what did you bias them to? And is there a specific brand? I got up with Jim and he said he would get back to me in a week or so. Sounds like exactly what I am after. Appreciate the input. Thank you
Johnbonn, the Amperex 12au7 Bugle Boy and Sylvania 1957 NOS Sylvania black plate 3 mica in combo with the 6n3c-e magically transformed my Primaluna Dialogue 1. Big, open killer midrange, tighter, more tuneful bass, the top end is sweet, yet airy, no more violin etch, piano to die for, when in the recording, wall-to-wall wide soundstage, deep and layered, rich, wet, weighty, correct saturated tone, flutes and woodwinds also to kill for; and, oh my, Ella Fitzgerald and other female singers are there in room, all in wonderful size and scale. Guitars, guitars, WOW!
Mikirob thank you for looking that up for me. I will check your sources and information. Really hope so from what I have seen everyone really likes the 6n3c-e tubes. I have the front end sounding great and have tried all kinds of EL34 tubes and really enjoy what I am hearing but like all of us if it can get better that is what I am after. And if there is anyone out there using them in the Cayin with first hand experience please let me know. Thank you
Johnbonn, I just looked up the Cayin TA 30 to refresh my memory, and yes, it does accept the 6L6 tube among others, so, I'm now positive the 6n3ce should be a direct substitute, but please double-check per my references. By-the-way, the Cayin TA 30 looks like a Primaluna Prologue, especially the transformers look to be identical?
Mikirob thank you for the information I will check it out. Anyone out there using the 6n3c-e in an unmodified Cayin TA30 I would like to hear your takes. Thank you
Johnbonn, I should have stated the 6n3ce is a direct replacement for almost all 6L6, EL34s, 5881s, etc.
Johnbonn, for many amplifiers the 6n3ce is a direct replacement. I'm not sure about your amp. Please let me refer you to Jeff Days blog, jeffsplace.me/wordpress/ he writes for Positive Feedback and 6 Moons as well as others. I was originally turned on to this tube via his blog and found that his comments to be true in my Primaluna Dialogue 1 and Cary v12. Go to section where he talks about the 6n3ce in his Leben amps against various EL34, other 6L6 variants, KT 66, KT77, KT88, KT90s and so on. Another good source for information is Tube Guru Jim McShane who is authority on this tube and has them in stock, though supplies are dwindling fast. So, I'm cutting my own throat here with the recommend, but I believe I bought a lifetime supply. Best.
Bob,
In the past I talked to paul and he said the orinigal tubes were a valve art el34 which are very easy to find and they a inexpensive.
Lee
Mikirob educate me on the 6n3c-e tubes? Are they direct replacement? What bias do you run them? Can they be run in the older non bybee modded integrateds mine you have to pull the bottom plate off to bias, heard the modified ones have more adjustment for other tubes than EL34's? Anything else have to be done to run them? Can they be run in single ended mode? How many watts is it then? Thank you
I've had about a dozen or more amplifiers in the past that included Symphonic Line, BAT VK 200, Leak and Ayon Spirit II to name a few and this one stands out as one of the best I've owned. Mine too is modified by Paul.

I have a question, can you drive another amplifier using the Cayin subwoofer output? How's the sound?
Here is my advice: John Bonn is right on, use Amperex Bugle Boys 12au7, Sylvania 5751 3 mica with the 6n3c-e also known as 6p3s-e, you won't be sorry and never look back.
You may want to try the NOS 6p3s-e tubes from Jim McShane. They are cheaper than the EH 6CA7's and sound better.
In the ax slots try the Sylvania 5751 3 mica's with either the bugle boys or RFT's in the au slots. EL34's for single ended winged c's well for all use winged c's are a good choice unless you want to spend some bucks for Mullards NOS or RFT's..... Enjoy the music!
I, too, had the very same amp you have and only sold it because it got too hot in my upstairs apartment. That was one great sounding amp.
If its tubes you're looking for and good advice to go with it, try Brent Jessee at his site. He is most accommodating and knowledgeable in all things tube. His selections are extensive and he has prices to match.
He got me a '71 Mazda RTC 6922 that transformed my Music Hall DAC to the point where I just stopped considering swapping out the opamps.
I used to have one of these and should have kept it. But that is another story. Anyway I tried all kind of tubes and found I like the JJ kt77 power tubes alot. I also like the RCA cleartops12au7 and the GE blackplate 5751's . This combination was I think my favorite. UMMV.