Victor Chew

Some infomation about my build. Powered up the psu just now. Voltages were sitting as per spec. both at the +ve and -ve 500vdc and 15vdc. Then power up the amps. Balancing was perfect. However, I was not able to get the dc offset down to 0v Max I got was about +60vdc and was out of turns. Kevin suggested to either decrease the value of R26 or increase the value of R12 and R19, citing that the IXYS part was pulling too much current and is out of spec. Can't understand why the IXYS which is from mouser would do that. Anyway, Kevin said to change R26 from 2k to 1.5k. Didn't have that in hand so used a 1.2k. Hurray! Was able to balance and get the DC offset to roughly zero. What fuse rating would be good for this amp? The KGSShv pulls 5.5ma x 4. http://www.head-fi.org/t/582518/electrostatic-amplifiers-voltage-ratings

Nice work eggil.

Eggil, have you powered up yet?

Some holes for the bottom and plenty more on top arranged in the form of some design, a bit like the BHSE perhaps.

Some progress. My custom casing made from 3mm thick 4 inch and 5 inch plates. Bones are half inch. Its 15 x 11 x 4 in dimension. It was hard work tapping and drilling all the holes to precision. Took me about 4 days to get this case up from scratch. Need another for the amp portion. Good thing is that it costs US50 for both the casings and the tools (drill bits and taps). With all the metal it weighs close to 4 kg per box.

Yes indeed, my spec sheet shows off load at 480.7v and 16.3v but my actual reading is 490v and 18v x 2 = 36v hence my slight concern. Will test it again when loaded. In anycase, thank you all for the replies.

Just got my transformers from sumR. It was spec as follows: 100VA / Dual 117V primary ( 2 x 117V) 2 x 450V (@125mA output/ each secondary). 1 x 30VCT (15V-0-15V) 10VA secondary Core band Static shields Decided to measure the secondaries. Got 490v x 2 and 36vct. This is about 20percent above spec. Is this normal? Getting all the others parts together now. Local shop is helping me with that and might be able to save on some shipping costs. The sumR transformer shipping costs to Singapore was more than the costs of the transformer.

I will certainly be doing what you have just advised Dr Gilmore. However, on top of stuffing the boards, I am a little worried about wiring it up for testing and actual wiring as one wrong connection can mean a whole load of charred parts and not to mention the spraks flying around. Is it possible to have a wiring diagram for double checking purposes to mininise wiring mistakes? Thank you to the experts in advance.

Thank you Dr. Gilmore. On a separate note could you advise whether it is ok to mount the onboard version on the side of the casing to fit everything into one box, assuming that the box is tall enough to accept the boards, as I understand that off board version is more challenging to build due to the mounting of the side mount heatsinks?

Ok tks. I must looking at an older schematic. A little confusing for me as there have been changes along the way. I will wait for my actual boards to arrive.

I am looking at the schematics of the psu from lil knight's bom (dont have my boards yet)- the zener on top of the 15k beside beside the zener 1n4007 has not been marked? Can someone enlighten me which value it is please?

Nice work cobra_kai.

I was scammed US$2000 by this Robert Morewood fellow. I have put him on as many scammer list as I can so far. Anything else I can do to kick his ass? His other emails include: [email protected] [email protected]