Introducing the xDuoo TA-66 OTL Tube Amplifier - Now Available on Apos Audio

[GenX]

Are there any Schiit Valhalla 2 owners that picked up the TA-66? If so, it would be great to hear your thoughts on how they compare. I currently use the Valhalla 2 as a pre-amp into a Violectric V222 with some really nice results, but ordered the TA-66 for comparison which I'd also be using exclusively as pre-amp. My headphones of preference are the low impedience LCD-XC's, so not a good match to use exclusively with an OTL Tube amp.

 

[Jasonovich]

I decided to change the Chinese 6N5P buffer power tube on my XDUOO TA-66 with Sovtek 6H13C tube. I suspect the original is already excellent sounding, there were 6AS7G(US)/6H13C(Russian)/6N5P(Chinese) generic tubes selling on AliExpress for £15(ish) but had no idea that these were going to be any better than the original. 6N5P can be directly swapped with 6AS7G/6H13C but there is always a small risk of incompatibility.

So I decided fork out the extra for a brand that's well known, Sovtek 6H13C. The cheapest I can find was from Jukebox Revival €64, including taxes and delivery. Hopefully it will deliver the desired results.

This will be less of a challenge than the preamp 6N2 tube, where an adapter/converter was necessary for the Psvane 6LS7 replacement tube.
I will happily feedback to you once it arrives from Germany. If it doesn't work out as expected, well at least I have a backup tube.

https://www.jukebox-revival.eu/en/p...bes-4955/tubevalve-6as7g-6h13c-sovtek-35765-p

 

[Jasonovich]

Are there any Schiit Valhalla 2 owners that picked up the TA-66? If so, it would be great to hear your thoughts on how they compare. I currently use the Valhalla 2 as a pre-amp into a Violectric V222 with some really nice results, but ordered the TA-66 for comparison which I'd also be using exclusively as pre-amp. My headphones of preference are the low impedience LCD-XC's, so not a good match to use exclusively with an OTL Tube amp.

Is a mighty fine tube amp, I can't see any direct comparisons with TA-66 on YouTube but there's one thing you can't do on the TA-66, you can't turn it around in one hand like you can with the Schiits Valhalla 2 . The XDUOO weighs a ton!

 

[Edward Ng]

The 6SN7 to 6N2 adapter came in and I have set it up with a Shuguang WE6SL7 Plus. It sounds great, BUT there is a low level buzz/hum when there are silent passages or nothing playing. Changing the volume does not affect the amplitude or frequency of the hum. I am going to try and see if I can live with it this way but in the mean time I will also order a cheaper 6SL7 tube to swap out and see if it’s my Shuguang tube or something else.

Looks quite nice, though. And sound is bigger, and also more detailed. Bass has more slam. Just wish there wasn’t the low level hum when there is supposed to be silence.

-Ed

 

[ycatsmot]

Looks quite nice, though. And sound is bigger, and also more detailed. Bass has more slam. Just wish there wasn’t the low level hum when there is supposed to be silence.

-Ed

The red base plays nice with the volume knob, as we just talked about!

 

[dudeduck]

The 6SN7 to 6N2 adapter came in and I have set it up with a Shuguang WE6SL7 Plus. It sounds great, BUT there is a low level buzz/hum when there are silent passages or nothing playing. Changing the volume does not affect the amplitude or frequency of the hum. I am going to try and see if I can live with it this way but in the mean time I will also order a cheaper 6SL7 tube to swap out and see if it’s my Shuguang tube or something else.



Looks quite nice, though. And sound is bigger, and also more detailed. Bass has more slam. Just wish there wasn’t the low level hum when there is supposed to be silence.

-Ed

I nullified all the noise in mine with a reinforced power cable from aliexpress, (my unit has stock tubes though).

Also can't make up my mind between the shuguang 6sl7 or the save 6sl7 (with jemosa adapter of course).any thoughts which to get?


As I see it both are an improvement but the psvane is cheaper and less noisy and the shuguang is expensiver (probably better sounding?) but also possibly noisy.

 

[Jasonovich]

I nullified all the noise in mine with a reinforced power cable from aliexpress, (my unit has stock tubes though).

Also can't make up my mind between the shuguang 6sl7 or the save 6sl7 (with jemosa adapter of course).any thoughts which to get?


As I see it both are an improvement but the psvane is cheaper and less noisy and the shuguang is expensiver (probably better sounding?) but also possibly noisy.

I'm not getting any noise from the Psvane, dead silent. Also I am using power mains filtering and quality cabling. This may sound obvious, if the tube isn't sitting in the adapter properly, this could emit noise.

 

[Jasonovich]

The 6SN7 to 6N2 adapter came in and I have set it up with a Shuguang WE6SL7 Plus. It sounds great, BUT there is a low level buzz/hum when there are silent passages or nothing playing. Changing the volume does not affect the amplitude or frequency of the hum. I am going to try and see if I can live with it this way but in the mean time I will also order a cheaper 6SL7 tube to swap out and see if it’s my Shuguang tube or something else.



Looks quite nice, though. And sound is bigger, and also more detailed. Bass has more slam. Just wish there wasn’t the low level hum when there is supposed to be silence.

-Ed

Ed
You could change the adapter for a better quality one, some of the materials used in the top end ones probably isolate the noise better but cost a little more. See link below

https://www.aliexpress.com/item/32948112617.html?spm=a2g0o.productlist.main.3.44d96cfd0XEuFL&algo_pvid=96f6bc5f-de21-4d94-9fb5-703cd174460c&algo_exp_id=96f6bc5f-de21-4d94-9fb5-703cd174460c-1&pdp_npi=4@dis!GBP!10.99!9.89!!!13.88!12.49!@211b617a17302902252955052eec34!66252234788!sea!UK!2022925542!X&curPageLogUid=hZc1ar08Wjj8&utparam-url=scene:search|query_from:

 

[Edward Ng]

Ed
You could change the adapter for a better quality one, some of the materials used in the top end ones probably isolate the noise better but cost a little more. See link below

https://www.aliexpress.com/item/32948112617.html?spm=a2g0o.productlist.main.3.44d96cfd0XEuFL&algo_pvid=96f6bc5f-de21-4d94-9fb5-703cd174460c&algo_exp_id=96f6bc5f-de21-4d94-9fb5-703cd174460c-1&pdp_npi=4@dis!GBP!10.99!9.89!!!13.88!12.49!@211b617a17302902252955052eec34!66252234788!sea!UK!2022925542!X&curPageLogUid=hZc1ar08Wjj8&utparam-url=scene:search|query_from:

Thanks! I’ll try a different tube first (already ordered) before I order another adapter.

I'm not getting any noise from the Psvane, dead silent. Also I am using power mains filtering and quality cabling. This may sound obvious, if the tube isn't sitting in the adapter properly, this could emit noise.

It is obvious, and that was the first thing I checked.

-Ed

 

[Madesu]

Interesting.
I am very happy right now with my config, which is:
- stock 6n5p tube (no noise from this one actually; my noise issues are only there with the GE JAN 6080 and the Svetlana 6AS7GA tubes)
- Jemosa 6n2 to 12ax7 with Genalex Gold Lion tube

No noise in this config, but as mentioned the replacements for the buffer both produce some low noise. The sound is very very enjoyable with HD650. The stock 6n5p has a bit more bass than the replacements and the replacements seemed a bit more open and refined, but i didn't do proper comparison. I'll send the one tube back, since I'm still in return period and eventually try one more replacement tube from a different store.
I really enjoy the setup and had a nice listening session yesterday.

@Edward Ng are you observing the noise in both channels or only one side? Left/ right?

 

[Edward Ng]

Interesting.
I am very happy right now with my config, which is:
- stock 6n5p tube (no noise from this one actually; my noise issues are only there with the GE JAN 6080 and the Svetlana 6AS7GA tubes)
- Jemosa 6n2 to 12ax7 with Genalex Gold Lion tube

No noise in this config, but as mentioned the replacements for the buffer both produce some low noise. The sound is very very enjoyable with HD650. The stock 6n5p has a bit more bass than the replacements and the replacements seemed a bit more open and refined, but i didn't do proper comparison. I'll send the one tube back, since I'm still in return period and eventually try one more replacement tube from a different store.
I really enjoy the setup and had a nice listening session yesterday.

@Edward Ng are you observing the noise in both channels or only one side? Left/ right?

It’s in both.

-Ed

 

[ycatsmot]

The 6SN7 to 6N2 adapter came in and I have set it up with a Shuguang WE6SL7 Plus. It sounds great, BUT there is a low level buzz/hum when there are silent passages or nothing playing.

I'm not at all unhappy with the Mullard 12ax7 that you recommended... but after seeing your photo, on looks alone, that Shuguang made me curious. I looked it up at Amazon, only one seller and it has 2 reviews. One has the same problem that you describe so it was returned, and the other is very vague from someone new to tubes.

 

[Edward Ng]

I'm not at all unhappy with the Mullard 12ax7 that you recommended... but after seeing your photo, on looks alone, that Shuguang made me curious. I looked it up at Amazon, only one seller and it has 2 reviews. One has the same problem that you describe so it was returned, and the other is very vague from someone new to tubes.

Thanks; I’ve initiated a return request on this tube. Highly disappointed, the first Shuguang tube I’ve ever tried, and was hoping for similar experience I’ve had with Psvane and Linlai, but apparently that is not to be.

-Edit

 

[jaexlee]

I just got a TA-66 today, and there is a lot of hiss and static on the right side, while the left is fine. Both sides play sound just fine. Is this a tube problem? Does it go away after being broken in? Or should I just return the unit?

 

[Jasonovich]

I just got a TA-66 today, and there is a lot of hiss and static on the right side, while the left is fine. Both sides play sound just fine. Is this a tube problem? Does it go away after being broken in? Or should I just return the unit?

First check everything is seated properly, i.e your interconnects are not loose, your tubes are rooted firmly in their sockets. If that doesn't work, switch the cables around, see if the static noise appears on the right side, if that is so, then the problem lies with the cables.