[hmscott]

Lifetime speaking, I've done enough parts choosing!

And, although I've looked into it, I'm not really interested in modifying my amps, or building from scratch, I've thought about building from kit - like an 300B/2A3 SE POWER AMP KIT [ TU-8900E ], but I don't need that right now.

I'm happy with the TA-20/TA-26 base design and build as they are right now. I selected the TA-20 as between the lower priced options I thought it was the best price to benefit choice for me. I could spend more, but probably not get much more, and I could spend less, but not get that Hybrid tube sound with SS compatibility with headphones.

I wanted more power, but I had the Topping D90 MQA so I didn't need another DAC, and so the TA-30 wasn't of interest with 3W vs the TA-20 2W. After months of enjoying music on the FiiO M15 and Topping D90/A90, I was ready to try the TA-20, and it has been a fine base to work from to reacquaint myself with tubey sound.

Right now I've got my 2nd wind with the TA-26, so I can continue to enjoy tube tuning, without changing the base builds, although when I settle on my "end game" tubes, I might pull out the specification sheets and re-wire the resistor/cap/inductor/transformer values to match the "final tube" selection(s).

Then again I'm just as likely to swap in a new base system and start over again with the tube rolling - I need somewhere to put all those extra "pairs" of tubes I'll have soon.

I would be interested in hearing what you get up to with TA-26/TA-20 modifications, and perhaps even try the changes that you feel make a positive difference, so please do carry on posting your progress.

Nice to meet you, I hope you hang around and get some good use out of your TA-20

PS: That is why I like using the Tung-Sol/Cetron 7236 Power tube, it has a transconductance rating of 12,500 uMhos, for a slightly lower output impedance, and they can be found without too much waiting for $35-$60 each. There are other choices as well, for both tube positions on the TA-26:

For 6AS7G tube rollers here .....
https://www.head-fi.org/threads/for-6as7g-tube-rollers-here.410326/post-5441008

The Reference 6SN7 Thread
https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/

Update: Forgot to mention about the Tube Week - AMP sound demos!! Listening with the TA-26 + 7236 + Kenrad VT-231 + Hifiman HE6SE V2...

TUBE AMP DEMO! // McIntosh Vs Xduoo Vs Miltra
​

 

[YanaMJ]

I've tried the stock tubes, JJ gold, Sylvania /Tung Sol US, Brimar UK and now Philips Heerlen and clearly theses tubes are my graal so in love with them

 

[-Darkstar-]

Totally agree, and for me the TA-20 sound kept improving all during the first couple of months of use, and that was about the time I found the Tung-Sol 12AU7 Black Glass tubes and stopped listening to the Topping A90 completely - except for specific comparisons to answer questions posed to me online. Now, the A90 is sitting unplugged under the TA-20...

I would expect the TA-30 to need as much burn-in time too.

For me the stock TA-26 was stuck on stock tubes for a couple of weeks until I could get new tubes plugged in, and I often went back to my TA-20 simply because I thought the TA-26 stock tubes as still new sounded too harsh - but, with the TA-26 wide sound stage and "airy tubiness" being much better than most TA-20 tubes sound, even while the harshness played out during burn-in.

The TA-30 was very rolled off and flat sounding at first. The bass was quite loose. This wasn't too objectionable with my Ananda's, but it quite bad with my TH900Mk2's. I ended up having to turn up the amp too much to bring out the mids and the bass would get completely out of control with some material, with terrible resonance off the cups. Now, it pairs quite well with everything, but I think the Ananda has the best synergy with it. I think I'm going to try out some Psvane tubes with it.

 

[hmscott]

The TA-30 was very rolled off and flat sounding at first. The bass was quite loose. This wasn't too objectionable with my Ananda's, but it quite bad with my TH900Mk2's. I ended up having to turn up the amp too much to bring out the mids and the bass would get completely out of control with some material, with terrible resonance off the cups. Now, it pairs quite well with everything, but I think the Ananda has the best synergy with it. I think I'm going to try out some Psvane tubes with it.

There are different "levels" of tube grades with PSVANE as with many manufacturers - as some wise person once said, they have to sell all of the tubes they make, even if they are really bad. It helps to learn the methods of how bad tubes are marketed and sold as well as how each detail of their history helps illuminate their achievements, and what they are and how to find them for purchase.

It helps to do some patient research, as there isn't always all of the models and information in one place, so I searched through various outlets for sales of PSVANE before putting together what I thought would be their best models, some kinds of their tubes there are lots of options like with the 6SN7, and some there are fewer.

Also it helps to know that PSVANE is really now Shuguang - as - briefly - some engineers split off from Shuguang to form PSVANE and then PSVANE ended up buying Shuguang and carrying on their less expensive lines of products as well - at some point the lines started to blur between the production lines - and I think the specialness of PSVANE tubes disappeared without their culling process and factory matching - those boxed matched tubes may be no more in their current lines but either they still make the old models in those boxed sets still, or they made a boatload of them and are still selling them - another adage, not everything "new" is designed to be "better".

What about the rectifier tube in the TA-30? Does it have an affect on the sound qualities of the TA-20? That is usually why a tube is brought in as a stage in the build of such amps, so what tube brand/models bring what kind of sound in the TA-30?

Some histories of PSVANE, it helps to look at the dates they were written:

WHO ARE PSVANE?
https://www.hificollective.co.uk/components/who-is-psvane.html

Who is Psvane?
https://premiumvacuumtubes.com/who-is-psvane/

Psvane Acme Series (new flagship series)
https://www.whatsbestforum.com/threads/psvane-acme-series-new-flagship-series.26395/post-532813

And, of course PSVANE has splinter groups that have grown up to make good products too.

About [LINLAI™ Global] – The official LINLAI™ EXPORT website
https://linlaiglobal.com/

If you find other accounts of any Chinese tube company history, please do post them.

I've found a lot of unexpected PSVANE models/packaging and variants via searches on Aliexpress.com
General match search
https://www.aliexpress.com/wholesale?catId=0&SearchText=psvane+tube
Focus on newest
https://www.aliexpress.com/wholesal...esale&SortType=create_desc&groupsort=1&page=1
Focus on lowest price
https://www.aliexpress.com/wholesal...olesale&SortType=price_asc&page=1&groupsort=1
Focus on highest price
https://www.aliexpress.com/wholesal...lesale&SortType=price_desc&page=1&groupsort=1
Focus on sales volume
https://www.aliexpress.com/wholesal...ortType=total_tranpro_desc&page=1&groupsort=1

Each one and summed together, helps me focus in on variations within tube types, pricing, which shops to Follow, etc.

 

[roderickvd]

And, although I've looked into it, I'm not really interested in modifying my amps, or building from scratch, I've thought about building from kit - like an 300B/2A3 SE POWER AMP KIT [ TU-8900E ], but I don't need that right now.

I'd love to build a kit! I looked at the Bottlehead options, but they're not cheap as they are, and then adding to that EU VAT and import taxes and it just starts getting out of hand. Pity. I didn't know about Elekit, but they seem to be shipping from the EU as well. Will check them out for sure.

From a very quick read on Google it seems that the headphone out of those units is drawn from the speaker output with a series resistor. Technically that's not the greatest way of doing things and usually indicative of "speaker first, headphones second" approach. With a 90Ω resistor, there may be damping issues, but I've also quickly seen great reviews when paired with headphones. Whatever works, works -- I'll do some further digging.

I wanted more power, but I had the Topping D90 MQA so I didn't need another DAC, and so the TA-30 wasn't of interest with 3W vs the TA-20 2W. After months of enjoying music on the FiiO M15 and Topping D90/A90, I was ready to try the TA-20, and it has been a fine base to work from to reacquaint myself with tubey sound.

Right now I've got my 2nd wind with the TA-26, so I can continue to enjoy tube tuning, without changing the base builds, although when I settle on my "end game" tubes, I might pull out the specification sheets and re-wire the resistor/cap/inductor/transformer values to match the "final tube" selection(s).

Then again I'm just as likely to swap in a new base system and start over again with the tube rolling - I need somewhere to put all those extra "pairs" of tubes I'll have soon.

I would be interested in hearing what you get up to with TA-26/TA-20 modifications, and perhaps even try the changes that you feel make a positive difference, so please do carry on posting your progress.

I'll think about rolling caps again once I've decided to keep this unit. They are 8.2µF, and there are four of them, so problem is that good caps get crazy expensive fast -- almost half the worth of the unit itself if you were to go the Mundorf SUPREME or EVO Oil route, or better. I do know from experience that this can really make a difference with removing any "veil" in the sound.

Nice to meet you, I hope you hang around and get some good use out of your TA-20

Likewise!

When investigating cap options, I also think I worked out the input impedance to be 20KΩ balanced or 10KΩ unbalanced. With 8.2µF caps, that would put the -3 dB crossover point at about 2 Hz for a more or less linear response from 20 Hz upwards. That's on the lowish side (for comparison: my AMB β22 is 1MΩ) but satisfactory even for highish output impedances.

The same holds for the TA-10. For the TA-26, I couldn't make out the capacitor values from the photos.

PS: That is why I like using the Tung-Sol/Cetron 7236 Power tube, it has a transconductance rating of 12,500 uMhos, for a slightly lower output impedance, and they can be found without too much waiting for $35-$60 each. There are other choices as well, for both tube positions on the TA-26:

Pretty good!

The TA-30 was very rolled off and flat sounding at first. The bass was quite loose. This wasn't too objectionable with my Ananda's, but it quite bad with my TH900Mk2's. I ended up having to turn up the amp too much to bring out the mids and the bass would get completely out of control with some material, with terrible resonance off the cups. Now, it pairs quite well with everything, but I think the Ananda has the best synergy with it. I think I'm going to try out some Psvane tubes with it.

Meanwhile I have received my Denafrips Ares II. After a few hours of listening purely over XLR yesterday evening, the TA-20 sounded much better than the night before! The grain was gone, but now I hear recessed vocals and a somewhat flat bass (lack of low end).

I'll try to post more listening impressions tonight, including a comparison of unbalanced versus balanced input, to see if this improvement is due to burn-in of the TA-20 and tubes, or the change to a balanced input. Easy enough to A/B test, with that input selector on the TA-20.

 

[roderickvd]

So... only a few days in and the TA-20 indeed does seem to be opening up and starting to shine!

Comparing RCA and XLR inputs from the same DAC, the XLR input does lift some of the veil that is present on the RCA. This is not a proper ABX test of course and not exactly level matched (although the RCA and XLR volumes are very close when set the same on the dial -- interesting!) but it's also no surprise that opamps touch the sound. So use XLR inputs when you can for maximum sound quality.

But to be honest, the change in SQ between RCA and XLR was much lower than I had expected. Indeed it seems that the biggest improvement comes from burn-in.

I even swapped to my reference AMB β22 and on a quick comparison I must say it sounds close. At this moment the β22 has some more authority at the bottom end still, but the TA-20 sounds more natural with instruments like flute. Not that the β22 sounds ragged by any means (!) but the TA-20 does seem to soften up the edges. As for attack and decay of transients, they sound very close. Impressive -- when this TA-20 continues going this way, it does look like it's going to be a keeper!

 

[Ufanco]

Been having a blast with trying out tubes this week. I bought a lot on ebay of semi used 12au7 most in the 80-90 range. There was a bunch of Westinghouse/Conn 12au7 untested in the lot. Checked them out and they work and sound great have some extras if anyone wants a set to play with PM me.
I found a thread on here that compares a bunch high end 12au7 tubes It’s definitely worth a look. Have to scroll down for the tube reviews.

https://www.head-fi.org/showcase/cypher-labs-prautes-headphone-amplifier.25706/

 

[hmscott]

Been having a blast with trying out tubes this week. I bought a lot on ebay of semi used 12au7 most in the 80-90 range. There was a bunch of Westinghouse/Conn 12au7 untested in the lot. Checked them out and they work and sound great have some extras if anyone wants a set to play with PM me.
I found a thread on here that compares a bunch high end 12au7 tubes It’s definitely worth a look. Have to scroll down for the tube reviews.

https://www.head-fi.org/showcase/cypher-labs-prautes-headphone-amplifier.25706/

As long as you don't use a headphone/IEM that shows "HISS" - caused by Cathode decay by-products being deposited on the Grid over time, then you will be able to use those tubes for quite a while.

I also did a similar buy of inexpensive used tubes at first with 85% as the "bottom", then when I heard "HISS" - a lot of it btw - a wall of HISS in my IEM's after switching from Headphones, I moved to hunting for cheap 95% Life remaining tubes, but even those have a low level of HISS already, so now I get 100%+/100%+ tubes - I don't buy as many tubes because they are much more expensive - unless you persist with watching/hunting for good prices, which I've been fortunate to find.

It is a lot of fun though getting all those tubes on the "cheap", and in headphones that don't detect the HISS background noise they can sound great - because they are "well burned-in".

Note: Found the place in the thread with all of the great tube info, search AS AN UPDATE AS OF 3-3-22 and you'll get there directly, as it is a long scroll to get there otherwise.

@roderickvd - I fixed the 12,500 uMhos 7236 Specifications sheet link posted in my last response to you:
https://frank.pocnet.net/sheets/127/7/7236.pdf

 

[-Darkstar-]

What about the rectifier tube in the TA-30? Does it have an affect on the sound qualities of the TA-20? That is usually why a tube is brought in as a stage in the build of such amps, so what tube brand/models bring what kind of sound in the TA-30?

A rectifier tube will most definitely affect the sound. A slower reacting one will soften and warm up the sound, compared to a quicker reacting one. This is one of the reasons I was intrigued by this amp, because you don't see too many tube rectified amps at this price range. I've had good results with new stock tubes from EH, SED and Gold Lion in the past, and I'm considering them, too. I also might go NOS but only at a certain price point.

 

[hmscott]

A rectifier tube will most definitely affect the sound. A slower reacting one will soften and warm up the sound, compared to a quicker reacting one. This is one of the reasons I was intrigued by this amp, because you don't see too many tube rectified amps at this price range. I've had good results with new stock tubes from EH, SED and Gold Lion in the past, and I'm considering them, too. I also might go NOS but only at a certain price point.

That's great!

I haven't any experience with that tube, but found this link that suggests a variant that might be easier to find in NOS:

"My own amp had a 5Z3P, which can be directly replaced with a 5U4G. This gave me a bit more output voltage and ability to add a slightly bigger R/C filter to the B+ rail. Don't think it made any major difference to the sound, but it looks better..."
https://www.diyaudio.com/community/...cements-for-chinese-tubes.110365/post-1329618

It looks like there are a wide range of 5U4G NOS options
https://www.ebay.com/sch/i.html?_nkw=5U4G&_sacat=0&_sop=16

A Western Electric 422A or 274B would be an awesome replacement - but a bit ridiculously priced

Listing at the bottom of the 1st page from the above ebay search are a couple of 110% testing RCA 5U4G's for only $59!, you only need one - one has a cracked base, not unusual in these very old tubes:

NOS new testing matched pair 5U4G made by RCA
https://www.ebay.com/itm/394006997428

GE 5U4G Coke Bottle RADIO/AMP RECTIFIER Vacuum Tube TESTED Vintage S.4173-D
https://www.ebay.com/itm/154556067571

There are others scattered over the first 1-4 pages, and even more if you consider $200 and below.

I would also ask Xduoo directly if they have any recommended variants for the 5Z3P that they have tried in the TA-30, and if any of those tubes above would work ok in the TA-30.

 

[ColSaulTigh]

Best inexpensive option is the BRIMAR 5Z4GY variant: https://www.ebay.com/itm/310653909306?hash=item48546a793a:g:fHcAAOSwJPph8-RM Big, Bold sound, incredibly fast, thick and meaty, plenty of airness in the top end. No sluggishness.....but it's a little nuclear reactor. It runs HOT!

Best $50 you'll spend...

 

[ColSaulTigh]

If you really want to go nuts - pop for a pair of these, too: https://www.ebay.com/itm/254301528939

This setup (currently in my bedroom) performs ALMOST as well as my Woo Audio WA6-SE stuff.

 

[hmscott]

Best inexpensive option is the BRIMAR 5Z4GY variant: https://www.ebay.com/itm/310653909306?hash=item48546a793a:g:fHcAAOSwJPph8-RM Big, Bold sound, incredibly fast, thick and meaty, plenty of airness in the top end. No sluggishness.....but it's a little nuclear reactor. It runs HOT!

Best $50 you'll spend...

That is awesome! Do you know if the any of the other 5U4G variants I linked above are compatible with the TA-30?

What other power tube variants have you heard are compatible with the TA-30?

I would ask Xduoo, but I already have a couple of unanswered questions in the queue with Xduoo. Sometimes they get so busy it takes a while to get an answer, but they always applogize (they don't need to!!) for their sometimes slow responses. I really appreciate their support

If you really want to go nuts - pop for a pair of these, too: https://www.ebay.com/itm/254301528939

This setup (currently in my bedroom) performs ALMOST as well as my Woo Audio WA6-SE stuff.

Yup, the E80CC's made in Heerlen, Holland (Netherlands) are in my top 5 favorites on the TA-20!

Do you have startup considerations with the TA-30 with the E80CC's installed?

In the TA-20 when the ambient gets much below 68F the TA-20 "errors" on startup because the E80CC's take longer than the built-in startup timer on the TA-20, but if I restart quickly 2-3x on the last power on the TA-20 works fine with the huge E80CC's.

Right now I have a pair of the Haltron E80CC's made in Heerlen, Netherlands installed and they start up without fail - it is warm enough now for them to heat up fast enough, before the TA-20 built-in startup timer expires.

 

[hmscott]

...Meanwhile I have received my Denafrips Ares II. After a few hours of listening purely over XLR yesterday evening, the TA-20 sounded much better than the night before! The grain was gone, but now I hear recessed vocals and a somewhat flat bass (lack of low end).

I'll try to post more listening impressions tonight, including a comparison of unbalanced versus balanced input, to see if this improvement is due to burn-in of the TA-20 and tubes, or the change to a balanced input. Easy enough to A/B test, with that input selector on the TA-20.

Awesome, congratulations on the new Denafrips Ares II - I'm assuming that needs about 100-200 hours of burn-in too?

Aha!, Denafrips does a 100 hour burn-in at the factory!:
https://www.denafrips.com/support#:~:text=All DENAFRIPS DACs are factory,tests performed prior packing & shipment.

"Factory Burn-In
All DENAFRIPS DACs are factory burn-in for at least 100 hours with comprehensive Audio Precision Tests, QAQC tests performed prior packing & shipment."

So... only a few days in and the TA-20 indeed does seem to be opening up and starting to shine!

Comparing RCA and XLR inputs from the same DAC, the XLR input does lift some of the veil that is present on the RCA. This is not a proper ABX test of course and not exactly level matched (although the RCA and XLR volumes are very close when set the same on the dial -- interesting!) but it's also no surprise that opamps touch the sound. So use XLR inputs when you can for maximum sound quality.

But to be honest, the change in SQ between RCA and XLR was much lower than I had expected. Indeed it seems that the biggest improvement comes from burn-in.

I even swapped to my reference AMB β22 and on a quick comparison I must say it sounds close. At this moment the β22 has some more authority at the bottom end still, but the TA-20 sounds more natural with instruments like flute. Not that the β22 sounds ragged by any means (!) but the TA-20 does seem to soften up the edges. As for attack and decay of transients, they sound very close. Impressive -- when this TA-20 continues going this way, it does look like it's going to be a keeper!

That is great! I'm happy for you that your TA-20 is ripening nicely!

The potential for tonality balance changes through tube rolling, and as those new tubes burn-in the mellowing and softening of their rough edges, provides an ever changing and engaging listening experience.

As I recall, I had about the same experience with my Topping A90 sounding more resolving than the Brand New out of the box TA-20 with stock tubes, but with burn-in time on the TA-20, and a few tube rolling's, my TA-20 soon matched and surpassed the Topping A90 in my resolution perception, and more importantly in listening enjoyment.

On my TA-20 the difference in perceived volume level differs by about 4-5 steps in the volume indicator. Listening to Tidal right now, and Balanced at 65 sounds the same as 70 on single-ended, listening with the Hifiman HE6SE V2.

Using the 6.35mm single-ended output I can go as high as 79-80 - it is too loud if I go any higher. Balanced is maxxed-out for me at 74-75.

As far as which is better?, I find the TA-20 4-pin Balanced output is more detailed and slams a bit harder, but I happily listen via 6.35mm/3.5mm single-ended often, and to me the single-ended 6.35mm output sounds great!

 

[roderickvd]

To be clear I was A/B testing RCA/XLR in, each time XLR out.

The more I'm leaning towards keeping it, the more I'm thinking about doing so with a good tube. I think my current Sylvania 6189W's may be a bit hi-fi sounding, and would perhaps welcome something warmer, lusher. I can get my hands on a matched pair of Philips Heerlen E80CC's (gold pins) for $75 including shipping... seems like a great deal?

I can get also get pairs of Philips SQ E80CC for even less, but not measured and so no guarantees about matching.