Matrix HPA-3B a good choice?

[amirm]

I would be interested in reviewing it if someone gets it and loans it to me.

 

[pkane]

I would be interested in reviewing it if someone gets it and loans it to me.

I could, but mine is modified by the previous owner, so not sure if it will be if any value to anyone else but me to get it measured.

 

[amirm]

I could, but mine is modified by the previous owner, so not sure if it will be if any value to anyone else but me to get it measured.

What did he modify?

 

[pkane]

What did he modify?

Replaced voltage regulators to lower voltage to 15v from 18v and put in Burson V5i opamps.

 

[trl]

If you got the Sparkos regulators inside then the previous owner was "burdie" or "canthearyou" (L.E.) the headfier, quite a good amplifier
there. Mine is way too modded...sorry.

 

[pkane]

If you got the Sparkos regulators inside then the previous owner was "burdie" the headfier, quite a good amplifier
there. Mine is way too modded...sorry.

Yes, Sparkos regulators. Used their 5v version previously for another project, and they performed really well, low noise, well made, but on the expensive side with some cheaper alternatives out there. I'm a bit worried that with all the mods, the opamps are no longer class A biased. At some point I'll have to open her up and check

 

[trl]

I know it's off-topic, but I recommend you to swap the V5i with SS V6-Classic or with OPA1652. The latest is having the lowest noise from all op-amps I've tried with this headamp.

 

[maxxevv]

I know it's off-topic, but I recommend you to swap the V5i with SS V6-Classic or with OPA1652. The latest is having the lowest noise from all op-amps I've tried with this headamp.

Sure that the OPA1652 is correct ? Or are you referring to the OPA1612 instead ??

 

[pkane]

I know it's off-topic, but I recommend you to swap the V5i with SS V6-Classic or with OPA1652. The latest is having the lowest noise from all op-amps I've tried with this headamp.

You said in another thread that you may have some screen shots (measurements?) of V5i and V6 op-amps. Can you please share these?

 

[trl]

Sure that the OPA1652 is correct ? Or are you referring to the OPA1612 instead ??

OPA1652, FET-input opamp, was quite good for my HPA-3B.

You said in another thread that you may have some screen shots (measurements?) of V5i and V6 op-amps. Can you please share these?

I know about that thread, I've edited that post today actually (I misspelled something there), problem is all scope screenshots are looking identical (sinewaves and squarewaves only), no matter of opamp used, so all opamps perform admirable on my scope. The only difference is with RMAA on Burson PLAY when SNR showed couple of dB lower noise with MUSES8920 and AD8599 when compared with SS V6.

L.E.: https://audiosciencereview.com/forum/index.php?threads/burson-play-mods.3346/post-96303 - first column was done with SS V6 Classic, the second column represents MUSES8920 (I/V and LPF). So 3.1dB lower noise with MUSES8920 and 1.2dB gain in dynamics too.

L.E. 2: To clear things up, I'm starting a modding thread here: https://audiosciencereview.com/forum/index.php?threads/matrix-m-stage-hpa-3b-mods.4344/. Thanks!

 

[maxxevv]

OPA1652, FET-input opamp, was quite good for my HPA-3B.

Has it been measured somewhere? As being "lowest noise" its completely subjective if its purely your interpretation by ear.

Base on specs sheets, the OPA1612 is supposedly the cleaner dual channel opamp that goes up to +/- 18V.

 

[pkane]

I know it's off-topic, but I recommend you to swap the V5i with SS V6-Classic or with OPA1652. The latest is having the lowest noise from all op-amps I've tried with this headamp.

SS V6 Classic upgrade would cost me half of the price I paid for the whole amp! I doubt it's going to make a significant difference changing from v5i to v6, but some impressive measurements could help change my mind

 

[trl]

Has it been measured somewhere? As being "lowest noise" its completely subjective if its purely your interpretation by ear.

Base on specs sheets, the OPA1612 is supposedly the cleaner dual channel opamp that goes up to +/- 18V.

Totally subjective, I changed op-amp from only one channel in the HPA-3B, then used sensitive cans and difference was big enough (RCA inputs shorted, gain and volume to the max.)

L.E.: I don't have OPA1612 to test it. However, AD8599 is having even a lower noise and in HPA-3B provided a higher noise than OPA1652. I totally trust my ears when speaking about background noise and difference was big enough here.

L.E. 2: With FET-input opamps the output DC would be lower, especially with HPA-3B that has no DC-servo. Instead it has DC protection that stops audio when DC is too high (has no idea what's the max. DC level here).

 

[trl]

SS V6 Classic upgrade would cost me half of the price I paid for the whole amp! I doubt it's going to make a significant difference changing from v5i to v6, but some impressive measurements could help change my mind

V5i wasn't even compatible with my HPA-3B. I got a very strange noise and hiss when using higher gains. Also, there were pops & clicks when changing the gain and powering ON and OFF the amplifier, hence I've swapped them instantly.

 

[pkane]

V5i wasn't even compatible with my HPA-3B. I got a very strange noise and hiss when using higher gains. Also, there were pops & clicks when changing the gain and powering ON and OFF the amplifier, hence I've swapped them instantly.

Strange. Don't have any of these issues, except maybe for a very low background white noise at the highest (+20dB) gain setting, and only into HE560s headphone (no noise audible through HD650s). No noise at all at the other two gain settings. Did you try it with 15v or 18v supply? I think it's only rated for 15v.

 

[maxxevv]

Did you try it with 15v or 18v supply? I think it's only rated for 15v.

I was about to ask that too. Believe Burson rates it at 16V max (if I read one of the various forum threads and remembered the values correctly).

Though it should be nominally operating at 15V only.

 

[trl]

I did the 15V mod especially to test BURSON SS op-amps.
Maybe my V5i were pre-production, I don't know.
The hiss I was testing it with AKG K550 (balanced mod), Beats Solo2 and Superlux HD385 16-Ohms IEM's.

 

[xevman]

Well looks like DHL reckon my address doesn't exist and my postal code isn't valid even though I took a delivery from them to the exact same address a week prior. Guess I have to wait a little while longer for this amp.

 

[xevman]

Well the amp arrived today and count me impressed. No frills product but it does what it is supposed to do very well. Powers all my headphones effortlessly on the lowest gain setting and the noise floor is very low. To put it into context with my DX7s on mute with my Denon D7000s plugged into the balanced connector I turned the volume to max and I could barely catch the slightest hiss. Keep in mind these are 25ohm 108db/mw so extremely efficient. Only drawback is that I don't get much range of the volume control on very efficient headphones.

 

[trl]

Glad you received the amp, hope you enjoy it! I got no problems driving sesitive cans when lowest gain is used, however...single-ended output has a much lower volume and you might try the 6.3mm outlet for really sensitive headphones.