[jeff7742]

Well I guess this unit is going back. Just turned it on again and smoke started coming out of it. Now it won't turn on. Not good. Don't know if I should get a replacement or refund.

 

[canthearyou]

Well I guess this unit is going back. Just turned it on again and smoke started coming out of it. Now it won't turn on. Not good. Don't know if I should get a replacement or refund.

Was it set to the correct supply voltage?

 

[jeff7742]

Was it set to the correct supply voltage?

 
Yeah, it was. I haven't touched it. Worked for a few hours, them smoked when I turned it on again. Bad component somewhere, I guess. I just got the lemon this time.

 

[raoultrifan]

Sorry to hear that.
 
Anyway, it might worth checking the voltage, on the left side, though I'm pretty sure it's not from there the smoking part.
 
Unless you can get a Cavalli Carbon, the HPA-3B is a very good option.

 

[jeff7742]

Yes, I checked the voltage - it's at 115. It a good amp. From single-ended, the amp sounded a little more refined than than my VA2, but in A-B tests the VA2 is also quite good, just brighter. I would love to have heard it balanced, though.
 
I've read good and bad things about the Cavalli. Is it much better than the HPA-3B? 
 
For single-ended, I will also try the Beyerdynamic A20, which everyone seems to think is one of the best for the T1 and other Beyers (along with the A2).

 

[raoultrifan]

I'm not sure it's better, because I haven't tested, but Cavalli it's a higher grade design. Anyway, you can read all about it on it's Head-Fi forum.
 
All I know is that I wouldn't give up my HPA-3B for anything else unless I'll test it first, no matter it's Cavalli or anything else. Anyway, same HPA-3U design & schematic is also use in Audeze Deckard, so I really trust Matrix on HPA-3U and HPA-3B internal design, but I'm aware that improvements can be done.

 

[burdie]

  Well I guess this unit is going back. Just turned it on again and smoke started coming out of it. Now it won't turn on. Not good. Don't know if I should get a replacement or refund.

If i remembered correctly, it won't turn on if the opamps were burnt.

 

[canthearyou]

Now this is weird! I recently received the Fostex TH-X00 from Massdrop. I immediately installed SMC connectors and used my balanced cable.

The headphones have an audible hiss as soon as they are plugged into the amp. If I touch the brass connectors near the cups the hiss disappears completely. I thought maybe because of the metal construction of the headphones it was somehow causing a grounding issue. I went ahead and fully insluated the SMC connectors from the cups. The issue is still present. The hiss is not present when I use my SE cable.

But what's even more weird is if I switch my amp to high gain the hiss is gone. Only bad thing is I can only use about 20% of available volume control.

The headphones do sound great, though!

P.S. The cable/amp works perfect with my HE-500.

 

[raoultrifan]

That's odd, I know it may sound silly, but is this happening with default opamps too?
Also, mid gain is also affected?
 
I had issues with V5i (though original V5 was working perfectly), but only when using low-gain and the hiss was pretty loud, I wasn't able to actually listen to the music because of that. Anyway, now I'm using MUSES02, because the V5 are so big and are also heating too much for my taste.

 

[canthearyou]

It was there in mid gain but not as loud. I am using the v5i...hmmmmmm.
I will try the Sparkos and stock op-amps this evening.

 

[raoultrifan]

MUSES8820 is extremely low noise and is also wire with gain.
Anyway, looking for your reply after changing the opamps.

 

[canthearyou]

Installed the Sparkos and it's completely silent. Unless I flip it to high gain, then there is a slight hiss.

So it was the V5i causing the hiss at low gain.

That is the strangest thing!

I wonder since the HE-500 are less sensitive and higher resistance I never heard the hiss?

*I still don't understand how touching the exposed metal on the SMC connectors removed the hiss, though.

 

[raoultrifan]

It's most likely related to headphones impedance more than sensitivity, that is causing sort of oscillation when using the V5i. This was happening to myself too and I've seen on the V5i review pages/thread that was happening to another head-fier into a different amplifier (see the http://www.head-fi.org/t/784790/burson-supreme-sound-audio-v5-opa-d-v5-opa-s-review/120#post_12921569 and my reply too).
 
Anyway, the original SS-V5 sounds great inside Matrix HPA-3B, but with case closed I got opamp temps of around 70-72C (on outer plastic shell) and I'm not very pleased of this, this is why I removed them and got MUSES02 instead.
 
P.S.: I still need to say that best buck for the bang would remain MUSES8820 for VAS, LPF and OutputBuffer in all of my tested devices (Essence One, Objective2, Matrix HPA-3B).

 

[wildwestgoh]

Spoiler

Something came in today.

 

[raoultrifan]

Looks great! I found those opamps on eBay, but I'm not sure who's the manufacturer and what's the "scene name" for these.
In their specs the max. operating voltage would be +/-/22V, so there should be no problems to operate perfectly in HPA-3B.
 
Can you please measure the DC-output on single & balanced output plugs (without music playing and no source connected to inputs)? Also, any change of getting some scope plots or an RMAA, if possible please?
 
And ofc, how do they sound?