Kerry

That's fine. That was a print from LTSpice. I've used the 2SC2240 in the active battery component of the power supply (KGSSHV) and wasn't able to measure the noise unless I shield my apartment. Low noise and matched are both good things.

Here's the version with the active batteries to translate down to the bottom rail... Here's my build of one channel to test it out... EDIT: I built this using 425V rails instead of 500V. It simplified a number of things

Here's what I had posted a while back... This version uses the KGSS front end and the output servo from the T2 - pretty much a blue Hawaii otherwise. I built a version on bread board using the T2 style batteries and a modified input stage as well. I'll look around for that too.

Definitely alive I've been out of pocket, but will get back on the design over the weekend.

I've been out-of-pocket a bit on a new consulting gig and traveling as well. Will get to the multiamp next week. Just playing with the servos at this point. I've built it with the THAT bjt's but I'll try the jfets just to make sure.

I was out on vacation and came back to a ton of work. I'll have some time to finish playing with the servos next week and hopefully we'll be good.

Nice work Victor! Yeah, a CNC

I've looked at the liquidware site. The unit doesn't have the ethernet/wifi option bundled so would be additional. I'd love to get some more options to evaluate for an all-in-one. I've seen a few things that include wifi and the display, but haven't found the perfect package yet. My thought above was that if we have a good remote (iPad, etc) option, then maybe only use an encoder/OLED on the amp with no touch. Wanted to see if this was worth exploring.

I'll take a look at the rasberry pi. I've got experence with the Arduino stuff (very simple to make a board) and I could easily do something with Windows embedded as well. Not as much a of a Linux programmer, though I'm not against learning if needed. The thing is to define what's required in-amp vs. on the controller. I like the idea of separating the functions and having a rich interface on a smart device, but I'd also like to have a simple rotarty encoder with push button in the amp and menus to drive an OLED. This way you can control the amp stand alone. Just simple and basic functionality using the OLED. In terms of the smart device, I wouldn't mind playing with some HTML 5. Would need to think through where to host the html. It would make sense to put it in the amp, but not required and it would definitely complicate the amp side. I'm open to thoughts and suggestions here, but ultimately need to keep this relatively simple to make it easy on everyone putting this together.

Good luck Doug. When you power up the new board, you can check each supply independently. Just the +/-15V, then just +HV, then just the -HV. If you can put each under load that would be a good thing as well. I agree, that you should be looking for a failure condition that is common to the affected supplies. As far as beginners luck goes, it only goes so far and then you need to learn how to debug these beasts. It's a great skill to have so as un-fun as it is to desolder parts, there is a reward to getting everything up and running again. I took care to blow up my first power supply which lead to countless hours of research, etc. It was a good thing in retrospect.

Love the tigers-eye knob.

Nice How's the stability since the ski trip? I remember Inu's powder coating looking very nice and Kevin's warning about doing things like that. Two days on the couch... might be worse for me -> <- wife

I'm going to be helping out on the software side, but I haven't really started yet. Need to get some of the hardware in place first.

Nice looking build I'm all about smaller these days so love that it fit it a 2U case.

I've got the BH running around 24mA x 4 and about +/- 405V. The heatsinks run just under 130 deg. F.

I thought the KGSSHV was much closer to the BH than the KGSS. Sound stage was nice and open, but the BH still sits a notch above for me. When I build my KGSSHV, I think i'm going to play with the bias current. I'll likely try something around 12mA x 4 for the current (will want to experiment with this a bit).

Just had a chance to hear T-Money's KGSSHV. I was very impressed with the results Were there any other changes to the new board layout besides giving the local feedback option?

Great news! Also, just to answer your earlier question regarding the function of Q34 - Q36, they form a servo referencing the bottom of the batteries to set the where the input tubes sit. A defective Q26 can definitely have an impact on that servo. It's all one big system - very slick.

You probably have a few issues, but I agree, check why the batteries are not sitting at +200V on the top. Look at Q4 & Q5 to see the gate (~ 200V) and drain (~ 250V) voltages. If the gates are around 200V then Q4 / Q5 are likely at fault, if the gate is sitting near 10V then Q1 - Q3 are likely having issues and possibly D1 though the diode is is less likely. Another thing you can try is to use a diode tester against all the combinations of the three pins per device. Check from the good channel to the bad channel. You will likely see differences (shorts, leakage or non-conductive issues) on the bad channel. If anything looks different between the good and bad channels, then replace that device in the bad channel.

LOL

Drinking... Working... Listening to high-end stats on a great amp That sounds like a great plan

Shame about the crack, but I agree it looks f'in awesome

Nice! We'll definitely have to schedule some time to do some comparisons

That looks beautiful Can't wait to see the final result.

Merry Christmas everyone. I just finished putting on about 5 lbs