[Rhamnetin]

The first post needs info on opamps, or maybe a separate thread is needed.  I see four that can be replaced, am I missing any?  Does the H10 use single channel opamps, dual channel, or both?  Are OPA134PAs used throughout the unit?
 
Also those 16 2200uF capacitors don't seem to be the best quality.  A tad disappointing if true.  I suppose if they start to swell I can replace them with Nichicon KA series.  They look like 35v caps?
 
- EDIT: So the two opamps in the back are NE5532s.  Thanks to this post.
 
http://www.diyaudio.com/forums/blogs/rjm/1214-gustard-h10-headphone-amplifier.html
 
Looks like opamp replacement isn't really necessary then.  Interesting that some people think the H10 is improved over the Violectric V200 which this is seemingly based on/inspired by.

 

[genclaymore]

It uses two dual channel op-amps for the rear where the connectors are and two single channel op-amps on the long side of the unit.

 

[Twain250]

  It uses two dual channel op-amps for the rear where the connectors are and two single channel op-amps on the long side of the unit.

 
Or another way of putting it…
 
The H10 uses two dual channel op-amps for the input stages (located at the rear where the connectors are), and two single channel op-amps on the long side of the unit for the headphone output stages.

 

[olek]

Got my pair of AD797ANZ opamps in the mail today. Of course, I just had to pop the cover and put them in same evening.
 
I like what I hear so far.
 
Recently I started to prefer more neutral signature of DACmini to warmth of H10. It just was more precise. Difference between 44.1 and 96kHz encodings was more apparent, while H10 was smearing bass notes a bit - making for more musical but less accurate presentation (BH Crack is even farther on that spectrum - bass smearing is even more pronounced, but so is the increased musicality as well).
 
With 797's in, H10 moved quite a bit to the neutral side. Now its sound is more like DACmini CX. It is still a bit warmer, and it is definitely more musical (DACMini CX with 1 Ohm mod sounds is a bit analytical), but is closer now to neutral, and has more precision to it. Currently I am not hearing that familiar slight 'smearing'. And sound still maintains just hint of 'sweetness' to it. Lovely.
 
Of course, I do not trust my own impressions yet, they are so very early, but I like where it is going so far.

 
Ah, and one thing that is a fact and nobody mentioned here yet is that with AD797 overall gain increased a bit. What used to be 12:20pm became 11:50am.
 
Or, in other words, 300mV signal became 340mV. Not a major difference, but it is there.
 
And Eva Cassidy's Tall Trees in Georgia does sound amazing with this setup indeed.

 

[stuartmc]

Glad to hear your grooving on the AD797's Olek. I've got another mind blowing recording to test them out with. The artist is Patty Griffin and the album is "Downtown Church." It was recorded in the old Presbyterian church in downtown Nashville with limited micing and minimal mixing. Think Cowboy Junkies Trinity sessions without the overblown reverb and better spotlighting of vocals and individual instruments. Every track is a winner. It's guaranteed to make you sit bolt upright several times, and say, "no way!...Did I just hear that!" Just a phenomenal high resolution recording of gorgeous music.

 

[spaech]

My op-amps arrived a couple days ago, I got a pair of AD797BRZs and AD823ANZs. The 797s seem to have improved the fidelity of the amp somewhat, although without an A/B comparison it's hard to tell. With the 797s in place, I swapped the 823s in and out a few times because they just didn't sound right. The amp lost some musicality, smoothness and vocal presence, overall sounded worse and was hard to listen to. So I'm currently running the 797BRZs with the stock NE5532s. Sounds great.
 
One thing worth mentioning is that the BRZ version is a surface mount form factor IC, and I used a SOIC8 to DIP8 adapter. It needed some modifications to get it to fit (I had to saw some of the PCB off). The connection is poor and I needed to reset the position of the IC after moving the amp once or twice because it gets jostled out of place easily. So unless you're good at microscopic soldering, I wouldn't recommend the BRZ, just go with the ANZ version.
 
[edit] It's possible the 823s I got were fakes, I have some more on order from a different vendor so it'll be interesting to compare.

 

[genclaymore]

Well mine BRZ was already solder to the adapter by someone else and they didn't use what you linked but a different soic to dip-8 adapter. The adapter they used was smaller but it didn't get in the way or any thing. They used this https://www.sparkfun.com/products/13655 when they did it and it was audio_cjn that I got my AD797BRZ from.

 

[Rhamnetin]

  Got my pair of AD797ANZ opamps in the mail today. Of course, I just had to pop the cover and put them in same evening.
 
I like what I hear so far.
 
Recently I started to prefer more neutral signature of DACmini to warmth of H10. It just was more precise. Difference between 44.1 and 96kHz encodings was more apparent, while H10 was smearing bass notes a bit - making for more musical but less accurate presentation (BH Crack is even farther on that spectrum - bass smearing is even more pronounced, but so is the increased musicality as well).
 
With 797's in, H10 moved quite a bit to the neutral side. Now its sound is more like DACmini CX. It is still a bit warmer, and it is definitely more musical (DACMini CX with 1 Ohm mod sounds is a bit analytical), but is closer now to neutral, and has more precision to it. Currently I am not hearing that familiar slight 'smearing'. And sound still maintains just hint of 'sweetness' to it. Lovely.
 
Of course, I do not trust my own impressions yet, they are so very early, but I like where it is going so far.

 
Ah, and one thing that is a fact and nobody mentioned here yet is that with AD797 overall gain increased a bit. What used to be 12:20pm became 11:50am.
 
Or, in other words, 300mV signal became 340mV. Not a major difference, but it is there.
 
And Eva Cassidy's Tall Trees in Georgia does sound amazing with this setup indeed.

 
I like neutrality, thanks for the impressions.  I'll probably get a pair of AD797ANZ when I get the Gustard stack.  I'll probably try the TO-99 LME49710HA as well.
 
- EDIT: Pretty sure I have a pair of LME49710HAs lying around.  Those will be going in first.

 

[SearchOfSub]

Would the H10 be able to drive HE6?

 

[GioF71]

Just A/B them with the same high resolution source material and be sure to level match them. List your associated gear and we're good to go.

 
I just did the requested test!
Here: http://www.head-fi.org/t/752522/gustard-amplifiers-and-dacs/495#post_11915718
 
Cheers

 

[olek]

Would the H10 be able to drive HE6?

I think consensus here is that it will drive them, but not to the best of their ability - those headphones require even more ooomph to show their best (think speaker amp).
 
BTW - I could be totally wrong on that, no first-hand experience with HE6, just seem to remember some past comments...

 

[SearchOfSub]

thanks for the reply - I just had one question that's off topic. I have a Matrix Mstage UPA-2 that I plan on using as a preamp out to Gustard H10. - (For the very reason people saying sepeeate preamp is good vs. not good, so I want to hear it for myself if a seperate preamp would actualy improve sound quality.) Anyway, it's a technical question - do I just connect mstage to h10 using rca OUT from mstage to rca IN on h10 and everything would work fine as they should correct? I'd be able dial volume only through mstage, and h10 would only work as a amp without volume control. No need to fiddle with any other hardware settings? thanks,

 

[BassDigger]

Would the H10 be able to drive HE6?

From what I understand, the HE6 is as power hungry as headphones get; they need speaker amp power figures to work properly.
So the H10, being quite powerful, will make them work and perhaps do better than many headphone amps. But ultimately you'd need more power (and quality) for the HE6. I've no doubt.

 

[olek]

thanks for the reply - I just had one question that's off topic. I have a Matrix Mstage UPA-2 that I plan on using as a preamp out to Gustard H10. - (For the very reason people saying sepeeate preamp is good vs. not good, so I want to hear it for myself if a seperate preamp would actualy improve sound quality.) Anyway, it's a technical question - do I just connect mstage to h10 using rca OUT from mstage to rca IN on h10 and everything would work fine as they should correct? I'd be able dial volume only through mstage, and h10 would only work as a amp without volume control. No need to fiddle with any other hardware settings? thanks,

Ummm... Not sure about details of Matrix preamp, but volume control on H10 will ALWAYS be active. I feed my H10 most of the time from DACmini with variable RCA out mod, and I can control volume using either volume knob of the 2 available. Seems like an extra hassle, and it is, but it actually allows for better volume matching for some ABAB listening tests. Just be careful to not blow up your ears, maybe get in the habit of turning one of those knobs all the way down when you switch off the equipment.

 

[Liu Junyuan]

Which of the HiFiman can yields the best bass response from the H10? And what about MrSpeakers Mad Dog Pro or Alpha Primes - bass response with H10? Yes...closed back


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If you are talking pure bass response and from the H10, barring any other concerns such as balanced treble and mids, the original HE-400s are pretty hard to top, well above their price tier. I owned them for three weeks before painstakingly deciding to save for the HE-500, whose bass response is less visceral than that of the HE-400 but is more balanced all around. For even more neutrality with a brighter sig, higher resolution, and faster transients, save for the HE-560, which extends very low and clean, yet will not sound quite as thunderous in the bass as does the HE-400. The H10 should drive all admirably (I used the HE-500 with it to good effect), and dont forget to opamp roll. Not sure how the new HE-400s (with an "s") adds up to these, but it seems pretty well-received, especially for the price. I am doubting it reaches the bass-quality of the original 400 though.