[Villy]

I just wanted to express my appreciation for what you've done here in this tread, and specifically the information on 3B. I have been considering it as an alternative to Gustard H10 (I wish it had balanced cans output), and I think of getting it - burdie's and raoultrifan's discussion is very informative and helpful, thank you guys for taking the time! It will take awhile until I receive the amp from China, but whenever that is I'll post my impressions as well.

 

[raoultrifan]

Thank you Villy, I'm sure you'll be pleased with the new 3B.
 
P.S.: I hope I'll be able to test this baby soon with a pair of V5's from Burson. I'll probably need to replace power regulators to adjust voltage to +/-15V for this.

 

[Villy]

I'm not sure the Bursons will withstand the voltage - they've been melting on H10 as it is.Granted, that was before Burson took steps to up the QC requirement and from 15V to 17V (the new batches according to a post on the Gustard trail were suppose to start coming out mid-February), but even at 17V I have some reservations they'll be safe for prolonged initial burning which I will certainly subject the amp to (I always put new equipment, whatever it might be - amps, dacs, cans, cables, everything for at least a week thru non-stop burning).
 
I'll check with Burson, as well as  Sparko's Labs (also I am eager to try their opamps, have great reviews) if there is a chance their modules will be ok with the amp's supply voltage. There is another descrete opamps maker I am also interested in - Sonic Imagery Labs. Each of these adds between $140 and $180 of additional cost, I'll swallow it though as long as any of these opamps can be a match.
 
Alternatively, I will try 4X LME49710HA, 2x on 2 browndogs, one on each socket as suggested by YoYo Jocker in his review of 3B. 

 

[raoultrifan]

Burson's V5 are not OK with either 17V or 18V, this is why I'll replace power regulators from my Matrix 3B to give them a test. I've already spoke with Burson and they confirmed that I'll need +/-15V for this test.

 

[Villy]

Here is the page on the H10 trail where Burson confirmed they'll start releasing the opamps with tolerance for +/-17 starting 2 weeks ago. In any event, if power regulator mod works that will be awesome. My soldering skills are pretty much nonexistent and my engineering knowledge just about the same, but I'm not afraid to tinker with my stuff and will no doubt go for it

 

[Villy]

Oops, the link:

http://www.head-fi.org/t/735828/gustard-h10-high-current-discrete-class-a-output-stage-headphone-amplifier/4125

 

[raoultrifan]

[..] In any event, if power regulator mod works that will be awesome. My soldering skills are pretty much nonexistent and my engineering knowledge just about the same, but I'm not afraid to tinker with my stuff and will no doubt go for it

 
Will get back here with news regarding Matrix HPA-3B and Burson V5's, if I'll grab a couple of V5s in Mars (I hope). All I need is a bit of time to do the tests.

 

[Villy]

Just saw this posted this on the Burson's blog: http://www.bursonaudio.com/ss-audio-discrete-op-amp-review-from-poland/
 
Here's the thing though - the test for the quoted review, as well as Burson's own test of V5 with the H10, did not emulate real-live, that is loooong sessions, including weeks-long really, when one burns in new equipment. That worries me a bit...more than bit actually. As they noted themselves, in their lab testing they didn't go for prolonged sessions, else it is likely they would have gotten a whiff of the issue causing the meltdowns in H10 (hope they have learned a lesson here; and btw, I've come across online comments in regards to Burson's QC, ranking them just about as low as HiFiMan...we'll see, regardless I'm always willing to take a plunge, for nothing ever happens if one just stays put).

 

[Villy]

In the end I decided to go with Yulong A18 as the balanced amp in my headphones chain. In the end of my research it came down to these two models, so I weighted, and weighted the pros and cons of each one, and in the end .... Yulong's overall package (design / built / performance / price), and to a great extend the fact that it utilizes OPA2604 opamp (lot easier to and more options for upgrade), won it for me. So that's the direction I'm going, and modding all of my cans to make them balanced, balanced all the way, and I'm sure once I get there the'll be no going back

 

[raoultrifan]

It would be great if you could borrow a Matrix M-Stage HPA-3B to make a direct compare with Yulong A18.
 
BTW, same OPA2604 can be used with success in Matrix HPA-3B.

 

[burdie]

  In the end I decided to go with Yulong A18 as the balanced amp in my headphones chain. In the end of my research it came down to these two models, so I weighted, and weighted the pros and cons of each one, and in the end .... Yulong's overall package (design / built / performance / price), and to a great extend the fact that it utilizes OPA2604 opamp (lot easier to and more options for upgrade), won it for me. So that's the direction I'm going, and modding all of my cans to make them balanced, balanced all the way, and I'm sure once I get there the'll be no going back

Yulong A18 is single ended amp, so you won't benefited from its balanced output as it just simply adding more power to balanced out and yet the signal processing still in single ended form.. Please refer to the following post on Yulong A28, the brother of A18 but with fully balanced implementation.
http://www.head-fi.org/t/699772/yulong-a28#post_10164154
I used to own A28 (heard other head-fier described it as more neutral than A18), but traded it as it cannot keep up with Schiit Mjolnir.
But when 3B was introduced, I was impressed with the specs, and proceed to get one for office use. And yes, it come very closed to Schiit Mjolnir (of course, after swap opamps).

 

[Villy]

Hi burdie, typo on my part, I actually meant A28, yes of course, A18 isn't balanced. Already have ordered it and the amp is on its way. You said it 'cannot keep up with Schiit Mjolnir', in what way? My DAC is Matrix's X-Sabre btw, which I think has an outstanding resolution (haven't heard many high-end DACs, but from those that I have it sounds better than Violectric's V800, to my ears that is).

 

[burdie]

Hi burdie, typo on my part, I actually meant A28, yes of course, A18 isn't balanced. Already have ordered it and the amp is on its way. You said it 'cannot keep up with Schiit Mjolnir', in what way? My DAC is Matrix's X-Sabre btw, which I think has an outstanding resolution (haven't heard many high-end DACs, but from those that I have it sounds better than Violectric's V800, to my ears that is).

It is just personal opinion that A28 cannot keep up with Schiit Mojo. My view is that A28 have enough power, it drive my HE500/LCD-2 very well, and I like the bass both delivered.
However, when I compare these two amps on K701 & T1, A28 just simply not on the same league with Mojo, especially on clarity, Furthermore, the bass is kind of muddy, I believed there is no perfect amp that can feeds all types of headphone well, since Mojo performed better than A28 (matching with my cans and to my ears) , I decided to let go A28. But, it is one of the great headphone amps.
My DAC is Matrix Mini-i Pro 2014 (but loaded with 2015 driver to support higher DSD/DXD), the SQ is quite closed to X-Sabre (my friend owns one, in fact my initial choice but it have no preamp function)
Though I prefer Schiit Mojo and 3B over A28, my favourite amp now is EL84 tube amp speaker out via resistor adaptor.

 

[Villy]

Thx for the input. I will replace the opamps with discrete ones, Sonic Imagery's 994enh to be precise (the most expensive option but by all accounts, a step above anything else out there), so that should pretty much take care of/resolve any shortcomings in the detail and clarity of A28. Plan to replace the voltage regulators with discrete too.  
 
It wasn't an easy decision for me, not to follow my instinct and go with HPA-3B, since I already have X-Sabre. It was almost done deal, but in the end I decided to go with Yulong even if it costs a bit more - just looking at both circuit boards, A28's built is more solid, I also like the fact it has more room in the box for EMI isolation, and also....it's Yulong (Matrix quality is just as good, but I always though Yulong edges it out when it comes to desing). Still, I think the main factor in influencing my decision was how easy it is to replace the opamps with discrete. There is a lot of talk about Burson's V5 around here when discussing discrete opamps. I researched extensively the subject though, as I can't really buy, burn and test them all, so I created my own wish list: Sonic Imagery comes on top, and Sparko's 2nd, Dexa and Burson coming next in that order though not really close to the first two. Which then would naturally be my choice and is where swapping opamps probably ends for me. And it happened so that my first choice Sonic 994enh's specs match A28 very, very well, and that sealed the deal. With that said, If I have an opportunity to get my hands on (relatively) cheap 3B, I'll swipe right away, certainly. That will be the real test then...maybe, some day.

 

[burdie]

  Thx for the input. I will replace the opamps with discrete ones, Sonic Imagery's 994enh to be precise (the most expensive option but by all accounts, a step above anything else out there), so that should pretty much take care of/resolve any shortcomings in the detail and clarity of A28. Plan to replace the voltage regulators with discrete too.  
 
It wasn't an easy decision for me, not to follow my instinct and go with HPA-3B, since I already have X-Sabre. It was almost done deal, but in the end I decided to go with Yulong even if it costs a bit more - just looking at both circuit boards, A28's built is more solid, I also like the fact it has more room in the box for EMI isolation, and also....it's Yulong (Matrix quality is just as good, but I always though Yulong edges it out when it comes to desing). Still, I think the main factor in influencing my decision was how easy it is to replace the opamps with discrete. There is a lot of talk about Burson's V5 around here when discussing discrete opamps. I researched extensively the subject though, as I can't really buy, burn and test them all, so I created my own wish list: Sonic Imagery comes on top, and Sparko's 2nd, Dexa and Burson coming next in that order though not really close to the first two. Which then would naturally be my choice and is where swapping opamps probably ends for me. And it happened so that my first choice Sonic 994enh's specs match A28 very, very well, and that sealed the deal. With that said, If I have an opportunity to get my hands on (relatively) cheap 3B, I'll swipe right away, certainly. That will be the real test then...maybe, some day.

Discrete opamps is one of the way to improve sound, but right now I am quite satisfied with LME49720 on 3B.
 
A little advise on A28, you can't find any info on impedance output online (3B have very low impedance output at 0.4 ohms), but I got a confirmation from Yulong (Xiao Long himself) that minimum headphone requirement for A28 is 16 ohms, this could be on the safe side, but better don't try those headphone with lower impedance than 16 ohms
.
I have no idea on how solid is A28 circuit board, but I do face one minor problem on on-board RCA female socket, one of the femae jack is 'bigger' than the other one, I need to wider the ring of male RCA on the interconnect and push very hard to fully 'inserted' into the female RCA. And another problem is opa2604 is soldered on the PCB, extra works to swap opamps and might void warranty.
 
If compare the body/case, I don't think Yulong is better than Matrix, especially on your X-Sabre, which is 1 big block of aluminium cut by CNC.
 
However, SQ decides everything.