Thanks for reviewing this amp, I've been curious about it since its release.

Wondering if when you compared it with the H10 was that with the 49860's or 49710HA's? Could you describe the SQ differences you found between the two amps when running the HPA-3B fully-balanced?

I currently use a H10 with the stock opamps swapped for AD797's and 49720's but I'm looking to upgrade to a fully-balanced amp around $600 mark (but not Liquid Carbon as it will cost more like $850 in Canada). Cheers!

Hi Mate,
 
Same op-amps on both H10 & HPA-3B for comparison , In both amps, I found LME49710HA gives a better performance than others.
 
HPA-3B is clearly ahead in terms of sound quality when used fully balanced. First difference you notice compared to H10 is the soundstage, obviously expansive & airier in HPA-3B. Instruments separation, placement are pinpoint accurate. Detail retrieval is better, channel imbalance is gone, Clear Left & Right channels.
 
A more natural, expansive and fatigue-free sound quality on a balanced connection vs Unbalanced.
 
H10 has a slightly deeper & fuller bass than the HPA-3B, Mids are better textured, detailed & clear on HPA-3B, Highs extended, expansive & airy. As a bonus, HPA-3B also has superb balanced volume pot.
 
I can happily recommend you the HPA-3B over H10, if using a balanced connection. It costs around 400$ shipped, but dont forget the op-amps, get the LME49710HA & browndogs!

Hey thanks for the insight but just so I fully understand, you left the stock OPA134's in the H10 and swapped it's NE5532's for the LME49710HA's correct?

Yeah mate,
 
OPA134 is single channel op-amp, where as NE5532 is a dual one. First I swapped NE5532, for 2X LME49710HA  on browndogs & later took out the OPA134 too, and put in a single LME49710HA.
 
H10 amp scales really well with op-amps I can say. But still loses out to Balanced sound quality of HPA-3B in full balanced configurations.

Oh crazy, I didn't even realize the browndog adapters fit in the H10's i/v stage (XLR connector in the way), it must be a tight fit! Thanks again for your help.

Hey what dac are you using with this amp? I'm trying to decide on an amp and dac and you really made me consider the HPA-3U after reading your review but if the balanced version is THAT much better it might be something to consider, however the extra cost of a dac would be a little annoying. Thank you for the reviews!

Hi mate, Thanks for compliments!
 
I am using ODAC with the 3B, Its excellent match. plus you have to get a good quality RCA cable. So that sets you back 200$ more on a ODAC + RCA cable
 
Again headphones play an important role: If you have a moderate performing mid-level headphones, then 3U is a very good package. But if you have high-end reference headphones, then 3B is definitely worth spending on additional DAC cost.

Thank you for the answers. I have Oppo PM3 and Mr.Speakers Mad Dog both terminated with 1/4th so I think I might go with the 3U. I would have to pay quite a bit more to get them terminated with balanced so they could actually take advantage of the amp. Thank you for the information, I really appreciate it.

Hey have you tried the Gustard H10? If so how does it compare to the Matrix?

Is this guy for real?!?!

Oh wow.......I didn't even realize it was already in the review. Thanks for making me go back and read the review again natemact.

Nice review, thank you!
Please, take care of what OPAMPs you're rolling to HPA-3B, because this little beast is powered by NJM7818/7918 regulators delivering +/-18V. LME49710/49720 should be powered by no more than +/-17V (at least this is what manufacturer recommends). LME49990 and OPA2132 might be OK, but these OPAMPs have a max. recommended voltage of exactly +/-18V, so in long term might not be a good idea without a heatsink installed.

What I am curious of is the sound signature. The HP3 U is reportedly weighty down low full in the middle but strongly extended up top almost to a fault. 
 
What is the sound signature compared to the the H10. Which one is brighter, darker, had more or less bass etc...I thought it was an excellent review but it missed those aspects. I speed read so I could have missed it.....Sorry I worked very long hours today. 

Quite a great review could be found here: http://soundnews.ro/2015/09/23/matrix-m-stage-hpa-3b-review/. Feel free to use Google translate.

Any comparisons against the Liquid Carbon? Also, where did you get your LME49710HA + Browndog adaptors?