gepardcv

Right. I tend to lump BHSEs in the KG amp category, and my casual impressions from forums suggest that most end up in the US, with a handful in Europe. Add to that the other vendors who made and sold a few stat amps over the years — maybe another 50-100 units? They surface routinely at various meetups. (Excluding exotics like the HEV90.) But I saw exactly 0 non-Stax amps on a trip to Japan, even at a well-stocked retailer where I thought I'd see at least something (e-earphone, which carries nearly the entire Stax product line). Back to the T8000, I half-expected a miniaturized, mostly-SMT mostly-solid-state T2.

Does Stax care, or even know much about aftermarket amps for its headphones? I gather that the bulk of its buyers live in Japan, where KG amps are vanishingly rare. I can't imagine Stax sells more than a few thousand systems a year, and the third party amp market can't be more than a fraction of that.

Metrum Acoustics?

I asked that question on another thread: I haven't done this upgrade to my Carbon yet, though will likely get around to it eventually. The amp sounds excellent to me as is, so I don't feel any rush to make changes, and about a dozen other projects have higher priority. I kinda wish I just built it with a GRLV up-front to avoid reworking it, but that's almost certainly FOMO-driven nervosa speaking.

I just discovered that this exists: https://www.staxaudio.com/ Must be the new US distributor? Maybe @justin knows more? 009 pads listed for $150. No clue if shipping to Australia is possible from this seller, or how much it would cost. Prices for other products significantly lower than the defunct staxusa.com.

How's the headphone out on it?

I always bought regular "audio grade" from Toroidy. No hum from any of them on clean AC mains, though I have had hum when I plugged some other devices into the same line. Not sure if the "supreme" would have helped in this case. Keep in mind that the "supreme" ones are quite a bit larger.

I ordered the Gumby upgrade and am in the queue now. Since Gen 5 USB now comes standard on all non-entry-level Schiit DACs, not having the upgrade will destroy my unit's resale value (by more than $150, I suspect). Other than that, I, too, am exceedingly skeptical of the supposed evils of USB. Unfortunately, the details of the technical debate that I saw are way over my head. I just don't understand the nuances of digital electronics well enough to judge. @TMoney, what DAC do you use in your main (non-office?) rig these days? Or did you switch to vinyl and tape?

Sorta. You will need 2 Carbon amp boards and a GRHV PSU. As Soren explained, there are several options for the GRHV: single-board, split fat (two boards), and split skinny (also two boards). The right choice for you depends on how you plan to case up the finished product. I think the split fats are the most up-to-date since most people used those, but they should all work and one of the others may make more sense for you. Laying out the PCBs inside the case is part of the challenge if you have specific dimensions in mind. Keep in mind that all boards have several devices which must be attached to large external heatsinks. Look through the various build threads to see how others have done it for ideas. The board silkscreens are well-labeled, so you don't really need the Mouser BOMs, but they'll save you time figuring out what you need. You should always cross-reference the BOM with your board and make sure you order exactly what you need. Some things aren't super-obvious (like the exact LEDs you need), and the BOM will help out here.

I recently answered a similar "how to get started" question here: Definitely build a Carbon in lieu of a classic KGSSHV, unless you really don't want to deal with off-board heatsinks. I prefer my Carbon to my KGSSHV in every way. I'm sure someone has extra boards. No written full guide to a DIY electrostatic amp build exists, but all the knowledge you need is available on various threads here. I linked to the densest ones above. It's a lot of reading, and some has to do with debugging problems fixed in subsequent circuit and board revisions, but teaches a lot. Perhaps one day someone will write up something. I thought about doing it, but just don't have time now. Too many projects.

The Schiit Fulla 2 works okay. Build quality is meh, but the knob is one of the better ones in that price range. There's also the Audioquest Dragonfly. The original one had a horrible noise floor, but apparently newer versions work better. It's hard to beat its size and convenience.

I've been collecting T2 parts for nearly two years. Almost done with that phase. Hope to get to the build within the next year... just need to force myself to dive into it and be mentally prepared not emerge for a solid 2-3 weeks.

@P3t4: You generally mount boards on standoffs. You will need to drill the case, and heatsinks, to do this. Alternatively, make a CAD file and have a machine shop do that for you. Front Panel Express does this well and even provides a simple CAD program for doing this. Rather expensive, though. Modushop cases come only with the screws necessary to assemble them. You can also get a case at Cam Expert who I believe can also do customizations, but no idea about prices or heatsink availability. McMaster-Carr carries a wide selection of mounting hardware (and a million other things). For wire, I buy PTFE 600V-rated spools from Bulk Wire. Good for most builds. On that subject, though, do you know how to safely work with high-voltage electricity? You must have a grasp of safety technique. If you short-circuit one of these power supplies while touching a rail, it can stop your heart. That's why I suggested you start with a Dynalo+GRLV. You'll have to solve similar construction and wiring problems, but the circuit is much safer to work with.

v5 works. I think that's the one most of us used through group buys. v6 is the same, except slightly smaller and needs slightly smaller L brackets. Compare them with a Gerber viewer (like circuitpeople.com). Edit: Don't forget the power supplies. The one most people used for the Carbon is the GRHV, in either a split or single-board version. The files for the split PSU were kgsshvpssicfetsinglenewleftfat.zip and kgsshvpssicfetsinglenewrightfat.zip, but there are several others in the archive, with "s" and "sw" suffixes on the file names. I'm not sure what those are. A close look at the rendered Gerbers should prove enlightening. Finally, some builders chose to bypass the GRHV's built-in low voltage power supply in favor of the dedicated GRLV. If you go down that road, the file is goldenreference6.zip (no clue what 6d is, and I guess the ones with minus and plus in the file names must be split versions).

@P3t4: The board and schematic archives are in a transitional period right now (read the stax mafia circuit boards thread). If you're after the solid-state Carbon, I think this post has links to the schematics of the Carbon amp and the GRHV power supply. As for boards, you can get your own made (links to recent Gerbers should be floating around here somewhere), or buy from someone who has extras. It'll help to review this entire thread, as I think it covers every tricky point of the build. Other things to read, and think about: The original KGSSHV thread has great info on the basics of building an electrostatic amp. It's old and long, but well worth reading. A few more basics are covered in the old DIY electrostatic amp thread. If you decide to build an off-board heatsink design (like all Carbon variants), I hope you have access to at least a drill press. A full metal shop would be better. Depending on your experience with building high voltage circuits, starting with something non-electrostatic — like a Dynalo with GRLV — might be a good idea.

This is terrific work. I wonder if I have the SMT skills to stuff a board like that. ? Could you explain the heat sinking story here? I always made sure to attach GRLV's MJW21194 and 93 to an external sink or at least the chassis. Doesn't seem like you're doing that here. Is the expected dissipation need really low? Same question about all devices needing a sink on the HV side. Run them to a sink with wires, as Kevin suggested?

Boards came in today. They look great. Thanks again for the GB!

Shipping fees sent. Thanks!

Forndom — Flykt

No, both amps are fully powered up all the time. Which definitely contributes to potential heat problems, though the Dynalo (and honestly all three GRLVs) run quite cool. It does seem likely that a bias device has failed, because the bias across an entire bank of output devices (not sure if the + or - side) drops. Wish there was an easy(ish) way to figure out which one, though, to minimize desoldering and part replacement. At least I hope it wasn't an output device. I matched those fairly carefully, and don't have (matched) extras lying around.

Yes, this is the combined build. The Dynalo side works fine, as does the other Dynahi channel. I checked the PSUs, they all seem to put out the right rail voltages consistently. I've not tried to get it to happen on a cold start with the lid off, but it happens fairly consistently with the lid on. It's definitely a packed case with non-ideal airflow, but the heatsinks are pretty huge and the case feels cooler to the touch than my on-board heatsink KGSSHV. I don't have the right kind of grabbers, but I could order some and figure out a way to run a few wires out through the top vents. What do you think might be happening?

I tried several Schiit amps, both at home and at shows, and most had something unpleasant going on. Most run crazy hot to the touch (not at all surprised the Jotunheim cooked itself), some have awfully scratchy and noisy volume controls, and some have appalling noise floors (with the Valhalla I heard with an HD800, the hiss drowned out the music). I've always been surprised that they come so highly recommended. But the DACs always seemed pretty decent. What's objectionable about the Yggy? (I don't have one, so not defending it. Just curious.)

My Dynahi developed a problem on one channel: the offset jumps intermittently. It looks like the outer 8 output devices' bias drops from the ~0.40V I set it down to ~0.30V or lower. This causes noise, and, when the offset becomes sufficiently high, triggers the protection circuit and cuts off sound. The corresponding LED dims. The amp worked for weeks with no trouble, and developed this symptom a few days ago. The first time I opened it, the problem went away completely, and I suspected overheating. But it now occurs even after a cold start. Any tips on how to diagnose this problem?

I use this for all my builds: Schaffner FN1394-10-05-11 (out of stock at Mouser at the moment but available from other stores). It's a bit bulky, but has everything I want: solid switch, two-fuse holder, voltage selector (just flip the fuse drawer), and quick-connect terminals (five: one safety earth and two per primary winding). The wiring diagram is printed right on the unit and easy to follow.

@s_r: When you say no extra noise, do you mean that your T2 finally has a noise floor you're satisfied with?