chinsettawong

Those boards look really nice, Kerry.

I had a chance to listen to KS with its tube amp earlier this week. The overall sound wasn't that bad, but I didn't quite like its bass. There's bass but it's different from Stax or mine DIY phones. It's rather difficult for me to describe it. But, I think the open area at the back side of the drivers is not enough or there is too much damping material. The bass just doesn't sound as "open". I also don't like its headband. It's just too small for my head.

The off-board one is running fine. It's possible that I had a little cut on the insulation paint over those spot and overtime they shorted. Thicker insulation paint would help a lot, IMO.

Just about 2-3 hours. I really don't think it's the cap problem. I think it's PCB problem. Wachara C.

My power supply board was making popping sounds yesterday. A close look showed that there were two short circuit spots. One underneath a capacitor and the other one near the diode. I think the insulation varnish on the PCB is too thin for 500VDC or the copper traces are too close to the ground plain. I clean the spots up, cover them with nail clear coat, and now it's working fine.

Happy Birthday!!!

My rather messy point to point wiring version:

I have my transformers made locally. The maker learned it the hard way when I asked them to make the transformers for my DIY T2. In total, we burnt 5 transformers. So now when I ask them to build me transformers for electrostatic amps, they know that that have to over specs everything. Wachara C.

Oh yes! I actually forgot about the +500V that is readily to use. Thanks very much for pointing that out. About the 1000Vp-p, I guess I'll just have to be very careful with that. Wachara C.

Thanks guys. This amp will take Stax and HE90. I've put an additional 5M resistor for HE90 bias. Should I make another 500V bias voltage for HE90 or will it be OK with 580V? Wachara C.

My second KGSSHV is done. Still need to tidy up all the wirings though. Wachara C.

No problem, Lil Knight.

Nicely done GeorgeP.

Happy Birthday, Birgir.

Happy Birthday!

Hi Tran, What is the size of your bottom plate?

I want some, Lil Knight!

Things like that happen. Hope all go well now.

Very nice, Kerry!

My SR202 sounds as good as my SR407, IMO.

Happy Father's Day!!

The meeting looks like a lot of fun. The photos are great.

Very nice!

Nice pictures. Thanks for sharing Purk. Wachara C.

Nice!