[hmscott]

Hi, if you turn up the volume of the video you will hear between a tick between a hook and the other of the tube.

Does the same "tick" sound happen when installing in the other tube socket? And, does the sound happen when you swap the tubes - try the other tube in the "noisy" socket?

I can't get close enough to my TA-20 to hear much of any sound from tube insertion/removal - I don't hear the "tick".

Does anyone else hear a "tick" when inserting a tube in their TA-20?

 

[cirodts]

it ticks only on the right side of the ta-20 even if I switch the valves.

 

[hmscott]

it ticks only on the right side of the ta-20 even if I switch the valves.

It's likely a tube socket riser board support fastener not tightened fully, I don't see one, but a "ring clip" not fastened properly with room to move can also "tick" as the pressure exerted meets the bottom of the travel and is transferred to the attachment clip.

Without taking it apart and tightening all the fasteners on that side - I wouldn't have anything else to recommend right now.

Perhaps there is also a "clip" used to lock the socket in place for soldering - there might be a physical attachment to hold the socket in place before soldering it - although the friction of the 9 pins might be enough to hold them in place for soldering.

There should be no travel possible after soldering all 9 pins - no movement of the socket possible - so I am back to the fasteners at the edge of the PCB on that side or underneath - if there is mid-span support for that socket PCB.

I wouldn't worry about it, but if it bugs you, see if you can RMA it to the dealer/Xduoo for inspection - or if you can still return it to the seller, best option, then return it and swap it for another new one. That's what I would do myself if it bothered me enough.

Happy Holidays!

 

[hmscott]

It's normal, I hear the pop too every time I turn it off.

Thanks, so is it better to unplug headphone first before turning off?

My 602 also has a nasty pop when you turn the unit off, I unplug my headphones every time I remember. I don't understand why this wasn't addressed by Xduoo during development/production of this amp. Long term affects of the pop and the extra unplugging and plugging of the headphones...

Thanks for that, @hmscott. Really helpful stuff! I actually already have an IEMatch but hadn't thought about using it with this amp until you mentioned it. I've just plugged it in (set to ultra) so we'll see what happens when it's time to flip the power switch in a bit. At the very least, it has expanded my usable volume from just below 9 o'clock with a significant decrease in source volume to boot, to 12 o'clock and only a minor decrease in source volume. A small win, eh!

I received a reply from Xduoo:

"Hi, Scott
Here is an article on how to solve this problem：
https://www.audiosciencereview.com/...gging-in-headphones-dc-offset-tutorial.25470/
We also noticed this problem and solved it
Best Regards"

After reading through the procedure, I would feel comfortable doing the adjustment myself, but I wouldn't recommend to anyone else to take that on unless you are an experienced professional - there are too many things that can be unknown to someone the first time they work on live voltage bare components.

Also, I wouldn't use a screw driver to make the adjustment, too easy to slip and zap yourself. Instead get a non-conducting tuning tool.

I've sent an email to Xduoo...

 

[Galapac]

I received a reply from Xduoo:

"Hi, Scott
Here is an article on how to solve this problem：
https://www.audiosciencereview.com/...gging-in-headphones-dc-offset-tutorial.25470/
We also noticed this problem and solved it
Best Regards"

After reading through the procedure, I would feel comfortable doing the adjustment myself, but I wouldn't recommend to anyone else to take that on unless you are an experienced professional - there are too many things that can be unknown to someone the first time they work on live voltage bare components.

Also, I wouldn't use a screw driver to make the adjustment, too easy to slip and zap yourself. Instead get a non-conducting tuning tool.

I've sent an email to Xduoo...

Good advice. I personally poke around with a chopstick myself.
Always unplug your unit and let it rest for at least a half hour.
Never use 2 hands to poke around inside, best to leave one hand in your pocket. You could create a ground and stop your heart, seriously.
If you know how you can always discharge your caps with a multi meter connected to a resistor to safely discharge.
Many YouTube’s vids on this procedure and safer once the caps have no juice.
Wear rubber soled shoes.
Remove any jewelry beforehand.

If I scared you a bit then I did my job as electricity is nothing to fool with.

If you do decide to open the amp up, read/watch instructional videos first until you feel comfortable or entrust it to someone with experience.

 

[cirodts]

It's likely a fastener not tightened fully, I don't see one, but a "ring clip" not fastened properly with room to move can also "tick" as the pressure exerted meets the bottom of the travel and is transferred to the attachment clip.

Without taking it apart and tightening all the fasteners on that side, perhaps there is also a "clip" used to lock the socket in place for soldering - there might be a physical attachment to hold the socket in place before soldering it - although the friction of the 9 pins might be enough. But, there should be no travel possible after soldering all 9 pins - no movement of the socket possible - so I am back to the fasteners at the edge of the PCB on that side or underneath - if there is mid-span support for that socket PCB.

I wouldn't worry about it, but if it bugs you, see if you can RMA it to the dealer/Xduoo for inspection - or if you can still return it to the seller, best option, then return it and swap it for another new one. That's what I would do myself if it bothered me enough.

Happy Holidays!

thanks, Happy Holidays.

 

[hmscott]

Well, tube only amps will give more "tubey" sound, but I've found the 12AT7 Mullard's of the links I've shared, in my TA-20, have given the widest sound stage and most focused sound for directionality - instrument and "enemy" placement, while being not too expensive.

I've ordered these Mullard E180CC tubes, and will report back when I hear them, I'm hoping they are the 12AT7 version of the E80CC tubes:

Matched Pair E180CC NOS Mullard Holland Valve Tubes
https://www.ebay.com/itm/111861807456

They also have unmatched single tubes for less:

E180CC 5965 12AV7 NOS Mullard Holland Valve Tubes
https://www.ebay.com/itm/112112339682

I've also seen Mullard E80CC tubes, maybe next month

A quick after Xmas update - What I got for Xmas this year.

The 5 - E180CC Mullard tubes arrived at the local Post Office (From Great Britain), Dec 25th... sigh...expecting delivery on Dec 27th

I had a nice surprise in an email from Xduoo Nov 27th:

"Hi, Hmscott
yes, thanks.
As a feedback, I can give you a TA-26, if you like it
Best Regards,"

I hadn't asked for anything, they simply offered it as thanks for my feedback. Of course, I said YES!!

I received the TA-26 on the 23rd and opened it yesterday evening...and here are my first impressions:

After digging through my headphone bags/boxes, I found my 6.35mm cables, removed the 4.4mm balanced cables, and tried out the TA-26 using the Topping D90 MQA.

At first it was "different", these are new tubes - they look like the standard China tubes Xduoo is famous for, and after swapping headphones around for a while:

Hifiman HE6SE V2, almost but not quite enough power - up to 80% on the TA-26 volume dial - The TA-20 delivers better power and experience.

Hifiman Ananda, wow, even at first play - I had to turn down the volume to 25% - the sound is full and encompassing, initially with some sharp tinges, but those went away after a few hours of listening.

Beyerdynamics DT770 Pro 16 ohm, that impedance is too low for the TA-26 - 60ohm-600ohm - so I'll try my DT880/600ohm and DT990/600ohm later and report back.

The Hifiman Ananda sounded so amazing on the TA-26 even with the stock tubes, that I didn't want to swap the Ananda out for any other headphones/IEM's. And, that was on movies (HBOMAX - Matrix Resurrections) and Youtube videos, but then when I listened on Tidal is when I was truly in appreciation of the TA-26 sound. The TA-26 SLAM! is unlike the TA-20, far more impactful and the "airy" sound I enjoy comes through on the Ananda's in excess to what I hear on the TA-20. And, that is with the stock tubes...

And, yes, of course I've already spec'd out a couple of new Mullard's for the TA-26, but before I pull the trigger on them does anyone with the TA-26 have any suggestions for tube pairings? I'll go back in this thread and start researching elsewhere for TA-26 tube ideas. I'll update here on what I find and enjoy.
Right when I thought I'd found the last tubes I'd need for my TA-20, Xduoo sucks me back in with the TA-26; I see what you did there.

Thanks to Xduoo for their kind gesture, and you can all be sure I'll not go too easy on Xduoo from here on out.

Update: Setting -12.0dB output on the Topping D90 MQA DAC, and the sharpness is gone and the TA-26 sounds Sweet

New Update: after listening in both -12dB and -0.0dB, I enjoy both at different times. It is nice with -12dB to be able to have more Volume Control range on the dial when I want to rock out, but the 0.0dB stock setting is also useful, but not when I want to increase volume gradually - there isn't enough Volume Control movement room.

Update: The TA-26 is an upgraded/modernized Darkvoice homage, using the same tubes: Darkvoice 336i & 336SE Tuberolling PartII

Update: The Mullard Holland made E180CC tubes arrived and are installed in the TA-20, WOW! More later...

 

[cirodts]

A quick after Xmas update - What I got for Xmas this year.

The 5 - E180CC Mullard tubes arrived at the local Post Office (From Great Britain), Dec 25th... sigh...

I had a nice surprise in an email from Xduoo Nov 27th:

"Hi, Hmscott
yes, thanks.
As a feedback, I can give you a TA-26, if you like it
Best Regards,"

I hadn't asked for anything, they simply offered it as thanks for my feedback. Of course, I said YES!!

I received the TA-26 on the 23rd and opened it yesterday evening...and here are my first impressions:

After digging through my headphone bags/boxes, I found my 6.35mm cables, removed the 4.4mm balanced cables, and tried out the TA-26 using the Topping D90 MQA.

At first it was "different", these are new tubes - they look like the standard China tubes Xduoo is famous for, and after swapping headphones around for a while:

Hifiman HE6SE V2, almost but not quite enough power - up to 80% on the TA-26 volume dial - The TA-20 delivers better power and experience.

Hifiman Ananda, wow, even at first play - I had to turn down the volume to 25% - the sound is full and encompassing, initially with some sharp tinges, but those went away after a few hours of listening.

Beyerdynamics DT770 Pro 16 ohm, that impedance is too low for the TA-26 - 60ohm-600ohm - so I'll try my DT880/600ohm and DT990/600ohm later and report back.

The Hifiman Ananda sounded so amazing on the TA-26 even with the stock tubes, that I didn't want to swap the Ananda out for any other headphones/IEM's. And, that was on movies (HBOMAX - Matrix Resurrections) and Youtube videos, but then when I listened on Tidal is when I was truly in appreciation of the TA-26 sound. The TA-26 SLAM! is unlike the TA-20, far more impactful and the "airy" sound I enjoy comes through on the Ananda's in excess to what I hear on the TA-20. And, that is with the stock tubes...

And, yes, of course I've already spec'd out a couple of new Mullard's for the TA-26, but before I pull the trigger on them does anyone with the TA-26 have any suggestions for tube pairings? I'll go back in this thread and start researching elsewhere for TA-26 tube ideas. I'll update here on what I find and enjoy.
Right when I thought I'd found the last tubes I'd need for my TA-20, Xduoo sucks me back in with the TA-26; I see what you did there.

Thanks to Xduoo for their kind gesture, and you can all be sure I'll not go too easy on Xduoo from here on out.

you can try the ta-20 IN full BALANCED compared to the ta-26 who sounds better?

 

[hmscott]

you can try the ta-20 IN full BALANCED compared to the ta-26 who sounds better?

Too early to tell, and until I get the Mullards or other NOS tubes in the TA-26 it is an unfair comparison overall.

I will say they both sound very different, the TA-20 SS amp section reduces the "airy-ness" on the TA-20, while the TA-26 is pure tube bliss... with the sharp edges of new tubes keeping my from declaring the TA-26 over the TA-20, in anything. -- It turns out I was overdriving the TA-26 with my D90, adding -12dB attenuation cleaned up the TA-26 audio completely, now it is smooth and sweet--Now, I don't need to reduce the D90 output, I guess the tubes "warmed up"

The stock tubes on both the TA-20 and TA-26 are too sharp out of the gate, and need burn in, the longer the better - I've read/heard 50-200 hours. At least that is what others report that stick with the stock tubes long enough to reap the rewards.

I bought new issue tubes for the TA-20 so when it arrived I could swap out the stock tubes. For the TA-26 it will be a couple of weeks before I select/order/receive replacements, so I will endure the stock tubes, I am enjoying the TA-26 that much.

But, at this stage, I'd say there are definite headphones/IEM's that won't be compatible with the TA-26 due to impedance - as I've already found, which is why I selected the TA-20 Balanced Tube with SS output for wide impedance compatibility, and there will likely be music / source material I'll still prefer on the TA-20 Tube/SS vs Tube only - but that could eventually lean in the TA-26's direction with better pairings of NOS tubes.

Like I said, too early to tell

 

[cirodts]

Isn't the balanced ta-20 as airy as the unbalanced ta-26 with both having stock tubes?

 

[hmscott]

Isn't the balanced ta-20 as airy as the unbalanced ta-26 with both having stock tubes?

No, the TA-20 stock tubes weren't airy, it was more SS than Tube sound - I did immensely enjoy the stock tubes compared to my Topping A90, and when I swapped in the first PSVANE 12AU7 matched pair, that was it, I was hooked on the TA-20.

So I ordered new issue 12AU7 tubes, a couple PSVANE series, Genalex Gold pin, JJ Electronics regular and gold pin, Telefunken - all 12AU7's, and then started into finding NOS tubes, gradually finding my footing through talking with friendly Tube dealers - until I decided to try a 12AT7

That was another turning point for me, the 12AT7 really bumps up the air and Slam from the TA-20, with the 12AX7 being a bit too "Hot".

The stock tubes on both the TA-20 and TA-26 are good for confirming functionality after delivery, and provide an increasingly enjoyable listening experience - time / burn-in for the tubes and electronics mellows the sound as reported by others, but I am too interested in hearing the best both headphone amps can provide to keep the stock tubes running long enough to give them their due.

I will say I am happy I heard the stock tubes, then did the gradual incremental listening experience of going through all the intermediate steps / tubes over the last year+. I don't think I'd recommend "jumping in with both feet" right away - give yourself the enjoyment of the full longer term listening experience of gradually trying many NIB/NOS tubes, starting with 12AU7/equivalents then 12AT7/equivalents.

Or, order some NIB/NOS 12AT7 Mullards that I've linked before a few times, and jump right to the best tubes I've found so far for the TA-20. There are lots of dealers on ebay and elsewhere that sell those same NIB/NOS Mullard 12AT7 tubes - from the 50's-80's - they aren't difficult to find - the 50's/60's built Mullard 12AT7's sound great to me - and you can also skip the intermediate expenses of purchasing all those other tubes I've tried on the path to the Mullards.

The TA-26 stock tubes are extremely airy in comparison to the Mullard 12AT7's on the TA-20, but are a bit sharp as new out of the box, it would take a lot of run time to then judge those tubes against equally run NIB/NOS tubes in a fair comparison.

Again, all too early to tell, I've only got about 6-8 hours on the TA-26!

Update: Started looking for video reviews / tube rolling advice for the TA-26 (Darkvoice uses same exact Chinese stock tubes), and DMS has a good start on the path for tube rolling the Darkvoice and a Little Dot tube headphone amp that kind of echoes my thoughts on the stock TA-20 tubes vs stock TA-26 tubes. Every little bit of info gathered from others experience can provide help on finding what you will really enjoy.

I did try what DMS suggested for using the D90 on the Darkvoice (same tubes as the TA-26), to turn down the D90's output a bit, I've attenuated it by -15dB, and the sound is less sharp - suggesting the D90 4V is overdriving the TA-26 input; that reduction in drive requires moving the volume dial on the TA-26 from 25% to 35% - I'll ask Xudoo what the maximum recommended input drive voltage is for the TA-26.

When I asked Xduoo the same question about the TA-20, Xduoo replied that the TA-20 can take 8V on the inputs, and the D90 is 4V, so I ran/run the D90 at full output for the TA-20:

January 4, 2020, relayed through Hifigo from Xduoo:
"Hello, Scott, sorry for late reply, they have 3days holiday here.
Xduoo reply below 8V is all no problem. if it is above 8v, it will cause distortion."

I'll report back what Xduoo recommends for the maximum input voltage for the TA-26

 

[cirodts]

the 12AT7 and 12AX7 are not suitable for the TA-20 or am I wrong?
I only use 12au7 for safety.

 

[hmscott]

the 12AT7 and 12AX7 are not suitable for the TA-20 or am I wrong?
I only use 12au7 for safety.

Xduoo has confirmed that the 12AT7 and 12AX7 were ok to use in the TA-20 before I tried it myself. You could email service@xduoo.net to ask the same question so you can hear it direct from Xduoo.

December 14, 2020, relayed through Hifigo from Xduoo:
"Hi Scott, sorry for late reply.
...is it possible to substitute the 12AU7 with 12AT7 or 12AX7 : Xdoo reply yes no problem."

I also confirmed with Xduoo that the E80CC is compatible before I plugged in a pair of E80CC's. I was concerned because the E80CC, even though it is a 12AU7 variant the E80CC draws 2x the heater current of the 12AU7, and Xduoo said:

August 4, 2021, relayed through Hifigo from Xduoo:
"Hello, Scott,
Sorry for late reply. E80CC ( 6085 ) is ok to match with TA20 and TA30 xduoo replied, and they thank you for your questions and testing.
If you have any futher questions, pls let me know.
Best regard ~ "

The TA-20 runs warmer with the E80CC's, but not as hot as the stock tubes on the TA-26, I guess I should post what the temps are on the TA-26:

The TA-26 6N8P Preamp tube measures 115F, the 6N5P "buffer" measures 143.8F - the front panel measures 86.7F, the top of the Transformer box measures 90.2F - Ambient temperature is 72F, using an infrared thermometer set to measure "Objects" / not "Bodies".

I've already posted the TA-20 temps, and it is powered off right now...

Update: Settling on -12.0dB output on the Topping D90, the Stones sound Sweet on the TA-26 + Hifiman Ananda, volume set to 35%-50% on the TA-26...

Rolling Stones - Beggars Banquet - 1968
https://tidal.com/browse/album/77735208

Crosby, Stills, & Nash - 1969
https://tidal.com/browse/album/306604

Diana Krall - The Girl in the Other Room - 2004
https://tidal.com/browse/album/64325935

Diana Krall - California Dreamin' - 2013
https://tidal.com/browse/track/51070811
https://tidal.com/browse/album/51070810

Diana Krall - The Look of Love - 2001
https://tidal.com/browse/track/576622
https://tidal.com/browse/album/576613

Diana Krall - This Dream of You - 2020
https://tidal.com/browse/album/155663945

Update: A nice review of the TA-26 here on head-fi: xDuoo TA-26: a perfect match for my Sennheiser HD 650, and more posts in that thread.

Update: Zeos's Xduoo T26 Comparisons/Reviews...:
Xduoo TA-26 _(Z Reviews)_ --Start of Tube Week--
Miltra OTL PCL86 _(Z Reviews) (vs TA-26, and Zeos keeps favoring the TA-26)

 

[PetFju]

@hmscott ; You seem to have had a lucky strike there with xduoo Happy for you, and that is an awesome thing for them to do!
I am interested in trying a "full tube" myself, so it is interesting hearing your impressions and opinions on the matter
Btw; I did order another set of tubes for the TA-20, Tung Sol Black glass 12AU7. Looking forward to testing them, but i think that'll be it for a while. I have spent more on tubes than the amp at this point..lol

 

[hmscott]

@hmscott ; You seem to have had a lucky strike there with xduoo Happy for you, and that is an awesome thing for them to do!

Thank you! Xduoo are awesome

I am interested in trying a "full tube" myself, so it is interesting hearing your impressions and opinions on the matter

I'd say go for it. Even the TA-26 stock tubes sound great now that I've reduced the output drive from the Topping D90 MQA DAC to -12dB, before - to me - it sounded overdriven with the full output of the D90 MQA into the TA-26, it made the TA-26 "sharp" which I was attributing to the new tubes. Now they sound Sweet

I'm finding I enjoy both the Hybrid Tube/SS TA-20 along with the TA-26. They complement each other for listening with different headphones / IEM's, and their sound characteristics are different enough there is no "sameness" comparing similar material side by side.

Btw; I did order another set of tubes for the TA-20, Tung Sol Black glass 12AU7. Looking forward to testing them, but i think that'll be it for a while. I have spent more on tubes than the amp at this point..lol

Wow!, that's awesome, Congratulations - those Tung-sol Black Glass 12AU7's are tough to find new @ 100%!