[hmscott]

If I remember correctly, I have a Tung Sol 6SN7 and a SED wing 6AS7G. It has been a while sine I switched the default Chinese tubes.
Sound is really clean and crisp with the combination, just what I am after. Hope it helps you.

Nice, SED tubes are made in St. Petersburg - I'll have to try to find one

They look like the Winged C Svetlana tubes, but made more recently, ending production in 2012, where did you find yours?

Is your Tung Sol 6SN7 also a newer production tube? Is it a GT, GTA, or GTB? Where did you find it?

If I am keeping you from school work, please answer later

 

[alexeyi]

Nice, SED tubes are made in St. Petersburg - I'll have to try to find one

They look like the same Winged C Svetlana tubes, but made more recently, ending production in 2012, where did you find yours?

Is your Tung Sol 6SN7 also a newer production tube? Is it a GT, GTA, or GTB? Where did you find it?

If I am keeping you from school work, please answer later

No, no problem. I am at work now, just had a few spare minutes to answer.
I received them from my father, I don't know where he bought them form. He is an old-school tube guy, he has his ways of getting all kind of tubes for his home equipment. After I told him about the new purchase he just got me these tubes and told me to get rid of the stock ones

 

[PetFju]

The AKG K712 Pro's should be well driven by the TA-26. Did you set your source at 100% drive?, and modulate the drive from your DAC into the TA-26?

But if you have a bright headphone like the AKG 712 Pro, it might sound too thin - as you are reporting - to pre-attenuate using the DAC/source, so running the source chain at 100% and dealing with the "notch" for volume range, might provide the best sound right now. You could also try an iFi iEMatch+, see below, to allow more range on the volume dial of the TA-26.

It is what I am going to work on in the next month or two, depending on headphone sales, an HD600 300 ohm and an HD650 300 ohm, both might sound even better than my HD660s 150 ohm, but IDK how, as this HD660S pairs so well with the TA-26 already.

I'm going to start with the HD600 first, I've been told that is really the one to get for tube amplifiers, but others say they enjoy the HD650 the best, so perhaps I'll buy whichever is on the best discounted sale first.

I thought they would be well driven as well, which is why i was a bit let down by this. And yes, i did try different "volume options" to see if that changed anything; which it doesn't in this case.

Also, that he 712 sounds thin has got to be some sort of misconception related to people underamping them. The reason for this statement is that when i i drive them with the Atrox V2 they sound full bodied with good bass slam and extension. Just very good really.
They might brightly tuned in the high mids/highs, but most certainly are not thin sounding.

It simply sounds like the TA-26 is running out of steam, as i stated; similarly to trying to run planars. Anyways, i guess i'll just stick to using Sennheisers and Beyerdynamics on the TA-26 for the time being.

Thanx for the input on the 600-series cans. I'll try to wrap my head around it, but i guess the only real way to find out is to try..

 

[hmscott]

No, no problem. I am at work now, just had a few spare minutes to answer.
I received them from my father, I don't know where he bought them form. He is an old-school tube guy, he has his ways of getting all kind of tubes for his home equipment. After I told him about the new purchase he just got me these tubes and told me to get rid of the stock ones

Those are great tubes on the TA-26. I'm happy for you that you and your father can connect with a shared hobby too.

 

[hmscott]

I thought they would be well driven as well, which is why i was a bit let down by this. And yes, i did try different "volume options" to see if that changed anything; which it doesn't in this case.

Also, that he 712 sounds thin has got to be some sort of misconception related to people underamping them. The reason for this statement is that when i i drive them with the Atrox V2 they sound full bodied with good bass slam and extension. Just very good really.
They might brightly tuned in the high mids/highs, but most certainly are not thin sounding.

It simply sounds like the TA-26 is running out of steam, as i stated; similarly to trying to run planars. Anyways, i guess i'll just stick to using Sennheisers and Beyerdynamics on the TA-26 for the time being.

Thanx for the input on the 600-series cans. I'll try to wrap my head around it, but i guess the only real way to find out is to try..

Well, the amp / headphone impedance matching is important. The AKM 712 Pro wants power at 62 ohms, per that posting I linked at least 500mA @ 2V, most SS amps should hae no problem doing that, including Hybrid Tube amps like the TA-20 that match better across the whole impedance range. Headphone AMP's when they list their power output at serveral impedance measurements, can show where the amp is "happiest" to drive a load.

The AKM 712 needs to be driven at 62 ohms, and the TA-20 would do that well, but the TA-26 appears to drive higher impedances better. The TA-26 drives the Beyerdynamic 600 ohm headphones like no other headphone amp I've used, so that shows me the TA-26 is happiest with high impedance headphones.

My Beyerdynamic DT-770 16 ohm headphones sound thin and lifeless on the TA-26, on the TA-20 the 16 ohm DT-770 sounds awesome.

My Beyerdynamic DT-880/990 600 ohm hadphones sound great on the TA-20, but not as good as on the TA-26, as the TA-26 drives 600 ohm impedance headphones best...

IDK if there is a viable solution for driving low impedance headphones on the TA-26, some work fine, some don't, all we can do is try different things, or use them on other amps.

And, save the TA-26 for the high impedance headphones.

 

[PetFju]

Well, the amp / headphone impedance matching is important. The AKM 712 Pro wants power at 62 ohms, per that posting I linked at least 500mA @ 2V, most SS amps should hae no problem doing that, including Hybrid Tube amps like the TA-20 that match better across the whole impedance range. Headphone AMP's when they list their power output at serveral impedance measurements, can show where the amp is "happiest" to drive a load.

The AKM 712 needs to be driven at 62 ohms, and the TA-20 would do that well, but the TA-26 appears to drive higher impedances better. The TA-26 drives the Beyerdynamic 600 ohm headphones like no other headphone amp I've used, so that shows me the TA-26 is happiest with high impedance headphones.

My Beyerdynamic DT-770 16 ohm headphones sound thin and lifeless on the TA-26, on every SS output amp including that TA-20 the 16 ohm DT-770 sounds awesome.

My Beyerdynamic DT-880/990 sound great on the TA-20, but not as good as on the TA-26, as the TA-26 drives high impedance headphones best...

IDK if there is a viable solution for driving low impedance headphones, some work fine, some don't, all we can do is try different things, or use them on other amps.

And, save the TA-26 for the high impedance headphones.

Yeah, that seems to be the conclusion. Which is one of the reasons i want to try a different set of Sennheisers on the TA-26. As of right now i have a pair of 58X, a pair of 560S is on the way and i have yet to decide if 650 or 660S are the ones to get. So even the 560S at 120 ohms might be not be ideal for the TA-26.
But..I have yet to try it out as a pre. It is quite possible that the TA-26 as a pre is ideal for something like the Toping A90 (or Atrox for that matter), basically a low noise high power solid state amp. I'll try it out whenever i have the time and can be bothered.

Off topic:
As for the K712's, they are primarily being used for gaming, via both a Soundblaster X-Fi surround coupled to a Little Dot 1+ for amp duty , and a Sennheiser GSX1000 coupled to the Atrox v2 as amplification.
I'm having trouble deciding if the Soundblaster or the Sennheiser dac both warrant a place in the lineup (for different games), or if i am to keep just one of them. They are useless for music, but still interesting as a surround option for gaming, dependent on the genre of games.

 

[PetFju]

@hmscott Thanks for the detailed information by the way, that goes for most posts you make, answering questions for everyone in this thread. Very enlightening and informative, and nice to have in here for people that are later to the xDuoo party than we are

 

[hmscott]

Yeah, that seems to be the conclusion. Which is one of the reasons i want to try a different set of Sennheisers on the TA-26. As of right now i have a pair of 58X, a pair of 560S is on the way and i have yet to decide if 650 or 660S are the ones to get. So even the 560S at 120 ohms might be not be ideal for the TA-26.
But..I have yet to try it out as a pre. It is quite possible that the TA-26 as a pre is ideal for something like the Toping A90 (or Atrox for that matter), basically a low noise high power solid state amp. I'll try it out whenever i have the time and can be bothered.

Well, if I had heard the HD600/650 before I'd feel more comfortable recommending one over the other, but given the TA-26 preference for higher impedance headphones I think it is safe to recommend trying an HD600 or HD650 first - then fall back to the least expensive option, the HD600 to try first.

The HD660s is awesome, but I can tell that because of how "lit up" the 600 ohm Beyerdynamic headphones are on the TA-26 compared to the HD660s, I'd expect the HD600 and H650 with 300 ohm impedance will be as awesoe or likely more awesome than the HD660s... but IDK for sure, I've got a subset of the experience I need to know for sure.

The correct answer is to get all 3 of them, and then decide which one you like best and either return the others or keep them to stave off the boredom that comes with using the same headphone constantly - it helps to break things up - switch up for another great sound for a while so your favorite once again can seem special - I really find it helps to have more than one great headphone.

I've spent a lot time only listening to each of them, but even the most special gets old eventually - you have a bad day, the headphone seems off, you swap in another great headphone and that picks you up and things are a little brighter once again.

And, Sennheiser had the HD540 that released 600 ohm models in the '80's, long discontinued:

Sennheiser HD540 20 - February 2019
https://overearmania.com/2019/02/20/sennheiser-hd540/

600 ohm headphones
https://www.head-fi.org/threads/600-ohm-headphones.726817/post-10712625
https://www.head-fi.org/search/8530926/?q=600+ohm&c[title_only]=1&o=relevance

Off topic:
As for the K712's, they are primarily being used for gaming, via both a Soundblaster X-Fi surround coupled to a Little Dot 1+ for amp duty , and a Sennheiser GSX1000 coupled to the Atrox v2 as amplification.
I'm having trouble deciding if the Soundblaster or the Sennheiser dac both warrant a place in the lineup (for different games), or if i am to keep just one of them. They are useless for music, but still interesting as a surround option for gaming, dependent on the genre of games.

As I said, variety has it's own special value, even if the alternatives aren't your favorite, they can sound great as alternatives down the road.

I've had CP-1, CP-3, surround sound processors for several simultaneous home theaters, but even those magical instruments lose their magic and the world moves on.

Enjoy them while you have them, and the time to find the next thing will come soon enough.

 

[PetFju]

I have now tried hooking the TA-26 up as a preamp for the Atrox V2. I haven't really concluded yet, but first impressions are that it's just about all of the TA-26 sound, but with solid state class A power..
It plays beautifully on the AKG 712's. The sound is moist (don't you just love that word..lol) and fat but with heft and body. Very Sennheiser 58X-like, but with the clarity of the AKG's, which is what i had hoped the TA-26 could pull off on it's own. Now i'll have to try it with planars..dammit.
Does anyone know if xDuoo make a tube-pre?

Btw; The outputs (front and back) are not exclusive. They both play at the same time, and they affect each other. Plugin a headphone in the front changes the sound of the output on the other amp (not sure what it does really, but it's audible).

 

[Shane D]

I got my amp today. Ordered Jan. 25 and received Feb. 16. That is my first, last and only order with APOS.

The amp is cool and VERY small. Gave it a bit to warm up and now it is hooked up.
BF2 to Loki to switcher to MT-602. Nice sound. Not as full and detailed as the Pro iCAN, but c’mon, it is literally ten times the price.

I pulled my HE6se V2’s out of the iCAN and put them right into the MT-602. Not bad at all. Especially with the Loki adding EQ and some gain. I am at 1:00 and it is sounding pretty good. I had to drop down to 12:00 with a newish jazz album.

I had some channel imbalance that could be corrected by touching the tubes. I turned it off, pulled the tubes and then reset them. They ship already installed and I guess loosened in transit.


I am impressed with this little amp! I have two other sets of tubes to run through in the coming weeks. I fully expect my efficient 'phones to be a problem with this amp, but it is taking my bad boys in stride. Auditory memory sucks but I think this sounds better than when I tried to run these headphones through my Violectric V220, which I deemed a failure.



This is an amazing amp for this price. This will keep me busy for a few weeks.

 

[DJ LP]

Hello to everyone on this thread. I'm new on the thread. I have a question. I own the xDuoo X10T II Turntable, xDuoo Xd-05Plus, hooked up with a Audioquest carbon usb type c to type c and a HiFiman HM-650, with a mini box amp card. Oh, and HiFiMan Ananda headphones. I just ordered the xDuoo TA-10R. here's why. My HiFiMan HM-650 sounds lovely with the Ananda's but since there is no way I can adjust the sound, the bass is a little thin to me. I purchased the xDuoo stuff because I could add the missing bass and yes, it sounds good. Last night the battery on the XD-05Plus died. While it was charging I grabbed the HM-650. I haven't listened to it for a year. Man Oh man. When I started listening to it, I didn't realize how textured, detailed, velvety and organic sounding the HM-650 was. It was like I was listing to music inside of the music. Plus it had way more dynamic slam, minus the sub bass. It was there, just not as much as I wanted. How much of sound quality difference is there between the XD-05Plus and the TA-10R?Will I possibly get all that I got with the HM-650? I mean that thing really sounds good. Just no type of tone controls to make adjustments to the sound. Hopefully someone can help me.

 

[hmscott]

I have now tried hooking the TA-26 up as a preamp for the Atrox V2. I haven't really concluded yet, but first impressions are that it's just about all of the TA-26 sound, but with solid state class A power..
It plays beautifully on the AKG 712's. The sound is moist (don't you just love that word..lol) and fat but with heft and body. Very Sennheiser 58X-like, but with the clarity of the AKG's, which is what i had hoped the TA-26 could pull off on it's own. Now i'll have to try it with planars..dammit.
Does anyone know if xDuoo make a tube-pre?

Btw; The outputs (front and back) are not exclusive. They both play at the same time, and they affect each other. Plugin a headphone in the front changes the sound of the output on the other amp (not sure what it does really, but it's audible).

Yup, plugging together tha TA-26 + Atox V2 you've recreated the hybrid Tube+SS Xduoo TA-20, but with different tubes, and two components.

The TA-20 output is a passthrough of the input, the input signal doesn't go through the tubes or the SS before going directly to the AUX Out, so you cannot hook up the TA-20 like the TA-26 to add tube sound to your source chain.

I've been thinking of getting a nice SS power amp to drive with the TA-26 and power my Hifiman HE6SE V2 - as the TA-26 directly doesn't have enough power.

Xduoo hasn't produced a Tube Pre, yet

Update: @PetFju - Xduoo has added a tube Pre, the Xduoo MT-603

 

[Shane D]

Yup, plugging together tha TA-26 + Atox V2 you've recreated the hybrid Tube+SS Xduoo TA-20, but with different tubes, and two components.

The TA-20 output is a passthrough of the input, the input signal doesn't go through the tubes or the SS before going directly to the AUX Out, so you cannot hook up the TA-20 like the TA-26 to add tube sound to your source chain.

I've been thinking of getting a nice SS power amp to drive with the TA-26 and power my Hifiman HE6SE V2 - as the TA-26 directly doesn't have enough power.

Xduoo hasn't produced a Tube Pre, yet

I am not 100% sure what you are looking for but how about this?
https://xduoo.net/product/mt-603/

 

[hmscott]

I am not 100% sure what you are looking for but how about this?
https://xduoo.net/product/mt-603/

@PetFju

Hah, I hadn't seen that MT-603 before!

I thought all the MT series were variations on numbers of tubes in the design for headphone amps , but there it is an Xduoo Pre!

Xduoo classify it in their "Tube Headphone Amplifier" category => Home / Tube Headphone Amplifier / xDuoo MT-603 Pre-Amplifier - even though the MT-603 doesn't have a headphone jack.

It is a nice start Xduoo, please branch out in the Pre line, and please give the Pre-amplfier(s) their own category

 

[Shane D]

Hah, I hadn't seen that MT-603 before!

I thought all the MT series were variations on numbers of tubes in the design for headphone amps , but there it is an Xduoo Pre!

Xduoo classify it in their "Tube Headphone Amplifier" category => Home / Tube Headphone Amplifier / xDuoo MT-603 Pre-Amplifier

It is a nice start Xduoo, please branch out in the Pre line and give them their own category

I came across that a while back when I was deciding on MT-602 or MT-604.