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

[Erick Muller]

Ikea! 20 bucks a pop, I've got 5 of em!
https://www.ikea.com/us/en/p/lanespelare-headset-stand-ash-veneer-80571524/

Thanks dude and apparently ikea ships to my country which I wasn't aware of, super nice!!!

 

[Erick Muller]

Experimentation. If one TA-66 sounds great, what would two in succession sound like? Perhaps even more "tubey"? The TA-66 is priced reasonably enough to merit keeping two if the daisychained pair is better than one on its own.

I'll run the daisychaining experiment tomorrow, and forego the L/R separation experiment given that I don't have a matching pair of both tubes.

Just be careful when you do the test, you might clip the amp or worse, damage something.

Generally people use tube amps to pre-amp another SS amp to bring some of that tube flavor, but tubing another tube amp might yield interesting results.

 

[poppy10]

Just be careful when you do the test, you might clip the amp or worse, damage something.

Generally people use tube amps to pre-amp another SS amp to bring some of that tube flavor, but tubing another tube amp might yield interesting results.

So I've determined that daisychaining two TA-66s adds even more colour and a little more depth, but at the expense of sound stage. Not sure if I like this compromise. I wanted depth, width and colour to all be enhanced.

EDIT: After some more break-in time, the staging has gotten a bit wider. I quite like this diasychaining combo!

 

[Nick76]

Thanks dude and apparently ikea ships to my country which I wasn't aware of, super nice!!!

Don't want to derail the thread too much, but quick tip if you get them: I didn't notice for a bit, but if your headphones headband is a bit too wide, the front screw thing actually unscrews to extend a bit more and should fit way more headbands. Great cheap stands

 

[Erick Muller]

Don't want to derail the thread too much, but quick tip if you get them: I didn't notice for a bit, but if your headphones headband is a bit too wide, the front screw thing actually unscrews to extend a bit more and should fit way more headbands. Great cheap stands

Thanks dude, super helpful, gonna have to buy a pair of this stands.

 

[DarktoreS]

I am a historical user of Beyer headphones, with the arrival of this Xduo TA-66 I wonder what it could give with a Beyerdynamic T1 Gen 2? The TA66 is not so powerful, with my simple DT990 pro special black in 250ohms I am already at 60/70% of the maximum volume. But the Beyer T1.2 has a better output of 102dB against 96dB for the 990. So my question is whether I will not lose power with the T1.2, or should I fall back on a DT1990 and its need for EQ or modding ?

 

[Erick Muller]

I am a historical user of Beyer headphones, with the arrival of this Xduo TA-66 I wonder what it could give with a Beyerdynamic T1 Gen 2? The TA66 is not so powerful, with my simple DT990 pro special black in 250ohms I am already at 60/70% of the maximum volume. But the Beyer T1.2 has a better output of 102dB against 96dB for the 990. So my question is whether I will not lose power with the T1.2, or should I fall back on a DT1990 and its need for EQ or modding ?

If power is a concern, the TA26s has more than double the power than this amp, tho some people say that after the 12 o clock position, the volume pot becomes unusable and it's start to distort, also people recommend highly that you change the stock tubes of the TA26s because they're meh at best and they really hold back this OTL tube amp in the sonic department, something that's not at issue on the TA66 from reports and impressions, the stock tubes are more than fine enough and you have a lot more range on the volume pot before distorting.

I have the TA-84 from the Drop and xDuoo colab and I can drive them just well my DT880 600ohm edition with balanced cable mod and bass boost mod from Custom Cans, tho I'm on high gain and at the 3 o clock position on my amp and I'm the cusp of distorting, but again, this amp has less than half the power than the TA66 has, so maybe this amp will be enough to drive those 600ohm beasts from Beyer, no problem, I also have no issues with either the HD800S nor the HD6XX with bass boost mod also from Custom Cans, so 300ohms DD cans are just fine with my less powerful tube amp, in theory and logically speaking, the TA66 should have no issues also.

 

[dudeduck]

I have a different xDuoo tube amp, it's the drop collab, tho it's significantly lower in power, I tried my LCD2Cs on it and it did power them, but the sound was way off, specially on the bass, planars on these more affordable chi-fi tube amps is a no-go in my opinion. My modded HD6XX and HD800s on the other hand, absolutely glorious sounding. Can also confirm that this TA-84 tube amp also powered and drove the OG Clears as well, the bass is a little bit boomy, but it's really relaxing and lay back and the shoutyness that sometimes can come forward on some tracks with some vocalist on this cans disappears completely

Given that I liked my tube amp so much, it make me curious about other offerings in the xDuoo line up of OTL tube amps and this one it's definitively on my radar, tho I think before I pull the trigger on the TA-66 I might as well pay around with some tube rolling on my TA-84 and see how much more performance I can squeeze out from it and also I'm waiting to see if xDuoo decides to bring to market a bigger, badder version of this amp or the TA-26s, that would be super cool.

If you want to use plannars with tubes you should go for a hybrid amp, something like the xduuo ta 22 or similar. Between the Ta 84 and 66 I wouldn't know wich sounds better since I only own Ta 26 but both are great otl amps, so it might be worth it to tube role the 84 before buying the 26 (which has great tubes out of the box), just be careful not to overspend on tube rolling. Believe me it's too easy to do

 

[Erick Muller]

If you want to use plannars with tubes you should go for a hybrid amp, something like the xduuo ta 22 or similar. Between the Ta 84 and 66 I wouldn't know wich sounds better since I only own Ta 26 but both are great otl amps, so it might be worth it to tube role the 84 before buying the 26 (which has great tubes out of the box), just be careful not to overspend on tube rolling. Believe me it's too easy to do

Oh yes, I'm already perusing some tubes from psvane and others on aliexpress and also the new tubes from Apos and yep, they can get quite expensive, specially for matched pairs, still I need to burn my tubes a little bit more in order to bring their full potential, I'm still in the middle of that process, so maybe in a couple of months I might pull the trigger on some new tubes for my amp, but I would also like to know if there's an specific thread on this forum for tube rolling where I can ask for suggestion and/or people can recommend to me some tubes to look to pair with my amp or if I pair of tubes that I'm looking at would be a good match or if they sound good at all.

 

[Nick76]

Okay as good as this amp sounds, I've had two borked units so far, and I'm done trying to fight it. First unit had crackling/sizzling in right channel in about 15 second intervals, I believe a tube swap would have probably fixed this. However, I purchased off amazon, so I just arranged for a replacement unit instead.

Second unit came in today: along the relay pot, there are volume steps where the left channel mutes while the right keeps playing. Sending this one back as well.

It was good while it lasted.

 

[Erick Muller]

Okay as good as this amp sounds, I've had two borked units so far, and I'm done trying to fight it. First unit had crackling/sizzling in right channel in about 15 second intervals, I believe a tube swap would have probably fixed this. However, I purchased off amazon, so I just arranged for a replacement unit instead.

Second unit came in today: along the relay pot, there are volume steps where the left channel mutes while the right keeps playing. Sending this one back as well.

It was good while it lasted.

OOOOFFFFF, that's really bad, two in a row is not a good sign.

I'll probably wait to see more reports from users to see what's the failure rate on this amp.

 

[Chris Simon]

If power is a concern, the TA26s has more than double the power than this amp, tho some people say that after the 12 o clock position, the volume pot becomes unusable and it's start to distort, also people recommend highly that you change the stock tubes of the TA26s because they're meh at best and they really hold back this OTL tube amp in the sonic department, something that's not at issue on the TA66 from reports and impressions, the stock tubes are more than fine enough and you have a lot more range on the volume pot before distorting.

I have the TA-84 from the Drop and xDuoo colab and I can drive them just well my DT880 600ohm edition with balanced cable mod and bass boost mod from Custom Cans, tho I'm on high gain and at the 3 o clock position on my amp and I'm the cusp of distorting, but again, this amp has less than half the power than the TA66 has, so maybe this amp will be enough to drive those 600ohm beasts from Beyer, no problem, I also have no issues with either the HD800S nor the HD6XX with bass boost mod also from Custom Cans, so 300ohms DD cans are just fine with my less powerful tube amp, in theory and logically speaking, the TA66 should have no issues also.

Just curious if you've experimented going back and forth between low and high gain and what you find the difference in sound to be. With my HD600s in high gain I'm often stuck between a step that is either too loud or too soft. In low gain with the volume pot farther up the dial the difference between the steps is a little narrower so it's a little easier to find the right volume level. High gain sounds just a bit tighter and brighter with low gain being just a bit warmer but still big and full sounding but it might just be my imagination.
Having said all that, my unit has a couple of glitchy steps where the left side of HPs cut out a bit if I don't fiddle around with it so I'm probably going to exchange it for another one. I've also been experimenting using the line out of my K5 pro AK4493 as a dac with the volume on the K5 nearly at max and fine tuning the level out for ideal volume settings. It works really well with the K5 dac sounding just as good to my ears as the internal one on the TA84.

 

[Erick Muller]

Just curious if you've experimented going back and forth between low and high gain and what you find the difference in sound to be. With my HD600s in high gain I'm often stuck between a step that is either too loud or too soft. In low gain with the volume pot farther up the dial the difference between the steps is a little narrower so it's a little easier to find the right volume level. High gain sounds just a bit tighter and brighter with low gain being just a bit warmer but still big and full sounding but it might just be my imagination.

With my TA-84, yes, all the freaking time, on low gain the volume is too low, it works fine enough for watching video content on Youtube via my active speakers from the aux out of this amp, this is mainly due to most youtubers don't give a rat's ass about properly normalizing the audio levels of their videos before uploading them and many are just a few dB from 0(which is godawful), but for headphone listening, low gain is unusable, have to crank it all the way up on the volume knob and I'm reaching the point of distortion on the amp so I have to go to high gain and the jumps between steps is just to much, that's because of the +16dB gain increase from low to high gain which is completely insane.

Having said all that, my unit has a couple of glitchy steps where the left side of HPs cut out a bit if I don't fiddle around with it so I'm probably going to exchange it for another one. I've also been experimenting using the line out of my K5 pro AK4493 as a dac with the volume on the K5 nearly at max and fine tuning the level out for ideal volume settings. It works really well with the K5 dac sounding just as good to my ears as the internal one on the TA84.

I'm feeding my TA-84 via the RCA outs of my Cyan 2, and the Cyan 2 just has a straight line out from both the single ended and balance analog outputs, so that's not an option for me at the moment. I could control the volume digitally from either windows or from the player that I'm using, but that's kind of inconvenient for me, I always going to prefer to control the volume from the amp itself.

It's not a deal breaker for me because this little OTL amps sounds so good. I haven't experience the channel imbalance you're talking about straight from it's headphone output or feeding my active speakers from the aux out of the TA-84, tho if I try pre-amping my S17 with the TA-84, there's something weird going on between the left and right channels that resembles a channel imbalance but not exactly, it could be a weird synergy issue or something else entirely.

 

[Chris Simon]

With my TA-84, yes, all the freaking time, on low gain the volume is too low, it works fine enough for watching video content on Youtube via my active speakers from the aux out of this amp, this is mainly due to most youtubers don't give a rat's ass about properly normalizing the audio levels of their videos before uploading them and many are just a few dB from 0(which is godawful), but for headphone listening, low gain is unusable, have to crank it all the way up on the volume knob and I'm reaching the point of distortion on the amp so I have to go to high gain and the jumps between steps is just to much, that's because of the +16dB gain increase from low to high gain which is completely insane.

I'm feeding my TA-84 via the RCA outs of my Cyan 2, and the Cyan 2 just has a straight line out from both the single ended and balance analog outputs, so that's not an option for me at the moment. I could control the volume digitally from either windows or from the player that I'm using, but that's kind of inconvenient for me, I always going to prefer to control the volume from the amp itself.

It's not a deal breaker for me because this little OTL amps sounds so good. I haven't experience the channel imbalance you're talking about straight from it's headphone output or feeding my active speakers from the aux out of the TA-84, tho if I try pre-amping my S17 with the TA-84, there's something weird going on between the left and right channels that resembles a channel imbalance but not exactly, it could be a weird synergy issue or something else entirely.

Good to know I'm not the only one having an issue with the volume steps! I listen comfortably on low gain at about 2-3 o'clock with my 600s with most recordings so I'm probably right on the edge of distortion there. I think the TA 66 is also +16 gain with no low/high gain switch so we would probably have the same problem with that. It might have a few more steps though, I'm not sure.
The whole point in getting this was because it was an all in one but using the K5 pro with it as a dac if I want to use it in high gain isn't that big a deal. Like you said, it does sound great.

Oh yeah, do you think it sounds any different between low and high gain at a similar moderate volume?

 

[Erick Muller]

Good to know I'm not the only one having an issue with the volume steps! I listen comfortably on low gain at about 2-3 o'clock with my 600s with most recordings so I'm probably right on the edge of distortion there. I think the TA 66 is also +16 gain with no low/high gain switch so we would probably have the same problem with that. It might have a few more steps though, I'm not sure.
The whole point in getting this was because it was an all in one but using the K5 pro with it as a dac if I want to use it in high gain isn't that big a deal. Like you said, it does sound great.

Oh yeah, do you think it sounds any different between low and high gain at a similar moderate volume?

3 o' clock is right at the cusp of distortion for this amp, just one more click and it starts sounding like the amp can't handle it.

It's hard to tell if it sounds better on low or high gain because low gain is not usable for me at all for the cans it's supposed to be used with like the HD6X0 series and high gain seems to add more weight to the sound, specially on the low end but it might be just an effect of the huge increase on volume because of the insane gain on this little amp. Making a proper comparison between the two gain levels is almost impossible for me without trying to matched perceive loudness via digital attenuation from the player, and that's to much of a chore for me.

I wasn't aware the TA-66 had a gain switch, good to know.