Blueman2

HERE is what happens when you buy parts from eBay. Never, never, never again.

I had the same issue a couple years ago with my first amplifier build. I bought some 10m90s and DN2540 from ebay, with the result that my power supplies kept blowing up. I had no idea that there was enough money to be made selling fake parts. But I guess there is. Now everything is from Mouser or DigiKey.

Congratulations, @MartinC700!!! Really nice build. And thanks for given back to the community with the learnings. Enjoy!

mwl168, can you add 1 set of miniT2 to my order? Should be 2,1,1,1,1

I am with @gepardcv on probable cause. Issues after a week or several months tends to indication bad solder joint that finally fails due to thermal cycling. My KGSSHV Carbon worked fine for about 3 weeks, then the right channel started making big popping sound on turn on/off. Luckily, nothing blew so I just re-flowed the entire board solder by solder. That appeared to fix it and over a year later still running fine.

Thanks for putting this GB together! Please put me down for: 2x GRHVxxx 1x GRLV79xx 1x GRLV78xx 1x Main Board

Xenon, I am not sure what you are looking for, but here is a bunch of files that I had collected when building my Carbon. I think the BOM is on the first page and that link is still active, but I have included the version of the BOM I used based on Mouser availability. Also, note that there are various revisions of the board itself, and some components might change. This is the amp. You will also need power supply. I recommend the GRHV with its onboard LV supplies for simplicity. And don't kill yourself. Working with these voltages is dangerous and lethal. KGSSHV CARBON Misc Files.zip

Work of art!!!! I want to listen to music staring at that.

Nice work! Very small amp case, which is pretty neat. What holds the amp boards in place? They seem to be just attached by the silicon right now.

I was interested in the copper bar used to hold the silicon devices to the heat sink. Pretty neat idea I had not seen before. Of course, it requires a board layout that leaves room for that bar to avoid conflict with resistors, etc. Also requires that all devices under the bar are the same thickness which may not be the case when mixing different devices to the same heatsink. I does have the advantage of drawing heat away from both sides of the device. And no need for peek screws! I wonder if devices are even engineered to take compression like this, vs just being held down by the hole mounting built into the device?

I will chime in with a few thoughts to go along with Helium's. 1) Just use the Low Voltage section that is included on one of the GRHV boards. No need for a separate GRLV. You will notice there are "left" and "right" GRHV boards. One has the LV +/-15VDC on it (so no need for GRLV) and one has the 580V bias for the headphones. Simpler is better, and it makes the case less crowded. 2) Definitely do not put the ODAC into the case. Not a noise issue so much as a future proof issue. And on that note, I also recommend going with a quad volume control and using balanced connectors on the rear of the unit, and wire it to be balanced. At some point, you will upgrade to a balanced output DAC (like the Shiit Gumby, which I have). You can also add RCA jacks and a switch to ground the unused balanced input for your ODAC. 3) The Carbon does have opto servos in order to maintain proper voltage differential on the outputs. Not necessary for this very stable solid state amp, but very little cost to add it so I recommend populating the servos on the Carbon boards. 4) When building the GRHV boards, please carefully read the other threads about how to work with these very high voltages. Clean up the flux with electronics grade alcohol. Buy parts ONLY FROM REPUTABLE DEALER!! I tried buying parts from eBay at one point and it was the stupidest thing I ever did. Mouser or Digikey are best. These voltages can hurt or kill you. Treat them with respect!

Hard for me to say that I prefer one of my amps over another in general. Depends on what I am listening to. I tend to use the BH BJT the most, following by about equal usage of my Carbon and my SRX-Plus. But just as with children, I would never part with any of them! SRX-Plus remains my 'most admired' amp because 1) it was my first build, and 2) it is such a simple design yet sounds amazing.

Not sure if there are any real differences between SZ2 and SZ3. Both are still being sold by Stax. Perhaps region differences? My SZ2 which are about a year old have the silver Japan version color scheme.

if voltage is OK, then you probably dodged a bullet. The issue comes in melting the insulation on the secondary wiring loop. If you did burn off insulation, you would have nearby wires in the loop touching each other, which would create the effect of fewer loops of wire, which would in turn reduce voltage. In any case, I would go ahead and continue to use the transformer.

Essentially 100% of the wattage that goes into that amp will turn into heat. So just as efficient as a small space heater. But far more wonderful to look at, not to mention listen to. We should get carbon offset credits for creating wonderful music while heating our homes.

I can just see you hunched over with your forehead resting on a table between these 2 monoliths, enjoying the wonderful sound. My back hurts just thinking about it. I am in awe of your nerdiness.

I definitely tip my hat to you, bui510!!!! I get great personal satisfaction when I do something myself, but you have taken that to an entirely new level. And yes, pictures please as you continue with your DIY ES earspeakers. Bravo!!

bui501, I love the board placement and use of space. Well done. And the acrylic looks pretty darned cool to me. I would keep them. Maybe even an acrylic top too! Now what the HECK are those custom electrostatic drivers? Did you build those yourself?

Boards Arrived!!! Thanks so much again, @sbelyo!!!!

Use the STN9260. I did on my amp and it works just fine.

Here they come!!!!

Just wanted to say thanks again, @sbelyo, for leading up this group buy. Probably the largest and/or most complex group buy I have seen recently on this or other forums! Let us know when you have the shipping cost calculations complete!

I had this issue with my Blue Hawaii. It was drawing more power than the GRHV was set to output. As I recall, I changed the 5R1 resistor (the large 3W one) to 2R5 or thereabouts and that solved the issue. I just soldered another 5R1 on top of the existing one and it worked fine. The 5R1 sets the amount of current that the PSU will supply.

Great to hear you did not give up on the shunt PSU!! I have a SRX build that I want to use this PSU for, and I hope to build it point to point in the coming few months. Thanks, Jim!! And still loving your SRX Plus design using the current BHUltraMini PSU. Cheers!

Thanks for the updates. These group buys put a big load on the person who organizes them, and this one was the mother of all group buys. So don't sweat it. I certainly appreciate all your efforts on pulling this buy together!