[Beau Cauchemar]

Are you using the extension to mount the V5 horizontally in the case?

Yes. It's hanging off to the right side (the toroidal transformer side) floating above the mosfets but not touching anything. I should mention that this config was a rather tight fit. With the extension's socket going into the board's socket, the extension's wires are at a tight bend and touching the top vent. No room to spare really. A straight-into-board's-socket vertical install would require cutting a hole in the top case vent (or not having the cover on.) Although since this socket region seems to be a tad hotter than the surrounding areas, I wonder if it isn't better to have the V5 be hanging off the side of the opamp board.

Another interesting thing to note...the plate of capacitors was installed with the vertical heat sink towards the back, which is backwards compared to your pics (and other reviewers interior pics.) I switched it back around though so the heat sink was under the top vents instead. I even contacted Optomo to see if the change was intentional, but got a response back that "they didn't have any schematics to reference. Sorry." Huh... Well anyway, I hope I made the right move making my layout the same as your, earlier-assembled models.

 

[Armaegis]

Hopefully the extension leads are relatively short. I'd almost consider cutting a hole in the chassis to pop the V5's out the top.
 
That's rather worrisome that Optoma couldn't even figure out which way to install the board...

 

[Beau Cauchemar]

That's rather worrisome that Optoma couldn't even figure out which way to install the board... :blink:

That's what I thought. The interior was festooned with quality control stickers dated 2016 so it clearly was manufactured recently. It just didn't make sense to me that the heatsink for the chips (regulators?) should be located AWAY from a vent. Especially since the capacitors don't seem to generate much heat. Either way, the "new", corrected orientation paired with the V5 seems to be doing just fine (about 12 hours into burn in and a few hours of listening) although I don't have a temp reader to confirm anything. Definitely warm/hot to the touch on the vent above the opamp board, but not perceivably more so than without any mods.

Still feel as though the effort/money was well worth it with the V5. My one complaint with this unit is that (at least with my iPhone 7 > Cozoy Astrapi DAC line out setup) in order to get the Q701s to my preferred listening level, the volume on the HA200 (and DAC) is pretty much at maximum. I should mention that I don't notice any volume changes between the 2134 and V5. I don't exactly feel the need for much more volume, but sometimes on a quieter track/album, I wish I had the option for just a bit more headroom. Granted these particular headphones are known to be hard to drive so this doesn't come as too much of a surprise, but something worth considering if you're coming from an amp that pushes more volume or has a hi/lo gain switch (which the HA200 doesn't.)

Btw Armaegis...why did you hope that the extension leads are relatively short? What are the length concerns?

 

[Armaegis]

Try it with the case off so you can plug in the V5 without any adapters. Generally for pcb's and opamps especially, you want all circuit traces to be as short as possible. In very broad terms, the shorter the traces, the less change of interference or other garbage messing with the signal. Power supply capacitors also want to be as close to the opamp pins as possible.
 
There shouldn't be any volume change with swapping opamps. If there is, something is horribly horribly wrong in the circuit. Different tubes in an amp might change gain or output impedance, but opamps don't work like that.
 
That must be a very low level line output from the Astrapi if you can barely get loud enough with the AKG's.

 

[Beau Cauchemar]

Since the current config with the extensions doesn't seem to be degrading performance in any way, I'm going to leave it as-is for the moment. Maybe later on I'll mod the case for a direct, vertical placement. I'm sure Burson wouldn't sell the extensions if they were known to have fidelity issues anyway.

Are you saying that I should have left the capacitor board the way it was, with the caps facing the opamp board and the heatsink towards the back? I don't see why the capacitors would "want to be as close as possible" to the opamp pins. Especially when the heatsink would be better suited for an area under the vent with more airflow potential.

And yeah, the Astrapi, while a decent DAC, might have an issue with output volume. After all it's a tiny, device-powered unit so I'll have to test with a laptop/external sound card setup to see if I can get a bit more volume. In any case, I'm quite happy with the HA200 and have been enjoying it all day.

 

[peter123]

The V5i would probably also be an good option as it's much more well suited for smaller places.

 

[Armaegis]

Since the current config with the extensions doesn't seem to be degrading performance in any way, I'm going to leave it as-is for the moment. Maybe later on I'll mod the case for a direct, vertical placement. I'm sure Burson wouldn't sell the extensions if they were known to have fidelity issues anyway.

Are you saying that I should have left the capacitor board the way it was, with the caps facing the opamp board and the heatsink towards the back? I don't see why the capacitors would "want to be as close as possible" to the opamp pins. Especially when the heatsink would be better suited for an area under the vent with more airflow potential.

And yeah, the Astrapi, while a decent DAC, might have an issue with output volume. After all it's a tiny, device-powered unit so I'll have to test with a laptop/external sound card setup to see if I can get a bit more volume. In any case, I'm quite happy with the HA200 and have been enjoying it all day.

 
I'd wager a dozen donuts that the extension degrades noise/distortion performance, but perhaps only at an academic level.
 
As for Burson selling extensions... well, that's just part of their business practice to make their absurdly large opamps fit into tight spaces.
 
When I was talking about capacitor placement, I meant on the pcb near the opamps. Not the big power supply board.

 

[Beau Cauchemar]

UPDATE: The V5 is toast.

I was watching some TV last night on my sofa across from my headphone station until I was interrupted by a dreaded sound of static/pops/noise. Sure enough it was coming from my headphones. The amp had been on a continuous 14 or hours at this point so it was safe to say that the V5 had apparently lost to the levels of heat. Granted I was already concerned about this so my fears were pretty much confirmed at this point. The relatively loud static/pops/noise wouldn't stop at any volume and even with nothing plugged in, so it was easy to deduce that the opamp had met its demise. Making sure that it wasn't the extensions, I installed took the cover off and installed the V5 vertically, directly into the socket: problem persisted. I even turned the unit off to let it cool down for a while, but the problem returned immediately upon turning back on.

What an expensive lesson. Given the flawless operation beforehand I can pretty much say with certainty that the V5 is not compatible with the HA200 (provided the cover is put back on.) At least I might have saved some other people the cost with this experiment. What a shame though since he V5 sounded so good with this amp.

On the plus side, I had a spare OPA2107 that I had purchased before the Burson which I installed and, low and behold, perfect operation was restored. Granted the sound is a bit less to my liking coming from the V5, however, I'm also not too disappointed either. Now I'm wondering if I should bother with a Sparko SS3602 (size-wise it looks as though it will fit) since it seems to be the only other chip regarded as highly as the V5 but with better temp stats.

Operating Temp Max:

OPA2134: 125c
OPA2107: 85c
Burson V5: 50c
Sparko SS3602: 70c
MUSES02: 85c

HA-200 Temps (as measured by Armaegis):

On vent: 50-60c (60-65c for bottom one when stacked)
Inside vent: 48-76c

Based on these numbers, the Sparko might still be a gamble. Thoughts? I also wonder if there's any point contacting Burson on this issue.

 

[Armaegis]

Holy crap, the Burson only has a rated temperature of 50°C and you *still* put it inside?? Geez... don't show them this thread and maybe you'll get a warranty fix on them.

 

[Beau Cauchemar]

Holy crap, the Burson only has a rated temperature of 50°C and you *still* put it inside?? Geez... don't show them this thread and maybe you'll get a warranty fix on them.

I'm not going to bother since this amp is the only unit I have to put them in anyway so a replacement would be pointless. Very much doubt I could get a refund. I'm just going to measure to see if the SS3602 will fit and in the meantime enjoy the 2107s.

 

[Armaegis]

Well they do supposedly have a lifetime warranty...

 

[Beau Cauchemar]

Sorry for keeping this old thread alive, but I wanted to post an update for people curious about this amp...
 
Given the opamp clearance and temp concerns, I decided to swap out the OPA2107 for a MUSES02 (from Mouser at $46 currently) based on it being regarded as one of the best chips of this form factor. so far I'm quite impressed and enough so that I'm going to be keeping it installed. Compared to the Burson V5 and the 2107, this fits nicely in between (if not pretty much tied with the V5) in terms of overall SQ without any concerns in terms of overheating, compatible specs, or install clearances. 
 
I do feel like the synergy of the 2107 with the Q701 was quite nice given its mid-forward character and soundstage width, but the MUSES02 keeps a slightly better balance (especially with the treble range) while still keeping the pleasing holographic midrange and excellent imaging. Good shimmer, tight/extended bass with impact, full bodied, black floor, and just warm enough to give the slightly clinical Q701 a solid synergy.
 
If anyone is considering swapping opamps in this unit, I'd say that the MUSES02 should be at the top of your list. Btw given some measurements that I took, the Sparkos SS3602 would be a very difficult fit to the point of being incompatible. Not to mention the operating temp max being slightly lower than ideal for this amp (MUSES02 is 85c max, on par with the 2107 - please see above post for further comparison.)
 
Overall I'd say that the HA-200 with the MUSES02 is hitting well above it's price point and for me it would just be a matter of diminishing returns unless I had over $1000 to spend on a SS amp.
 
 
P.S. - I forgot to ask this, but does anyone have any idea why the HA-200 comes with 2 different versions of seemingly the same type of power cable?

 

[Armaegis]

Glad you're keeping the adventure alive! The next step of madness is to start exploring the soic options but you need yet another dip8 adapter to make them work

 

[gb21011971]

hooked up to a Wadia121 dac, custom made dual XLR3 to XLR4 adapter for my HE-6[/QUOTE]


Did you make the adapter yourself? I am planning to make my own, since I can't find any off the shelf. But I don't know how the 3 pin XLR's are wired. Any idea? Thanks.

 

[Armaegis]

Did you make the adapter yourself? I am planning to make my own, since I can't find any off the shelf. But I don't know how the 3 pin XLR's are wired. Any idea? Thanks.

Yes, I made the adapter myself.

On the XLR4:
pin1 = L+
pin2 = L-
pin3 = R+
pin4 = R-

On the XLR3's
pin1= nothing or shield
pin2 = positive
pin3 = negative