chinsettawong

Hi Birgir, I've been thinking of the back wave blocking issue with KS phones. Do you think that it's possible from the way they put the dust covers on? From my experience, the dust cover on the back side of the driver affects the sound quite a bit. If not done right, it's better not to have it. I personally don't like to put it on. Wachara C.

Those black foams inside the cup are indeed not a good idea. Over time they'll deteriorate and become dust. Birgir, what material do you think the stators and spacers are made of?

I listened to KS once and I didn't like its bass either. I bet if you take out all the damping material and give it a lot more open area at the back, the sound will be very different in a pleasant way.

So do we need another regulated +300VDC power supply circuit?

Just got the package. All the PCBs look nice. Thanks Tran.

Birgir, how do you like the SR-Omega as compared to SR-007?

Nice work Kerry. By the way, the clear nail polish works.

Additional shipping cost sent.

Beautiful!!!

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?