UFN

Excellent, thanks! //UFN

I am struggling a bit to find a 787k high-voltage resistor for the bias-supply on my 450V PSU. The only thing I can find is Mouser p/n 594-HVR2500007873FR5. The voltage rating is fine (1.6 kV) but it is only rated 1/4W - is that enough? //UFN

Apologies for quoting myself, but in case anyone needs it: I ended up ordering LSKs from Micross in the UK. Postage was a bit steep at 15 pounds, but I ordered on Sunday and parts arrived Thursday, so no issues to report there at all //UFN

Yep, an all-black version would be great Apart from that - obviously an outstanding job as usual Spritzer //UFN

Geoff, I can see you use the LSK389, can I ask how you got those? I looked at trendsetter but they want nearly $65 to send $80 worth of transistors to EU and I thought that was a bit steep - do you have another option maybe? //UFN

That sounds normal if there is no load on the transformer as the voltage for any transformer is specified at full load. At idle, you should expect 5-15% higher voltage (percentage depends on the size and core type of the transformer). //UFN

I believe the pins are a jumper to enable/disable the DC servo. //UFN

Looks good Stop doing this to us - you know we always want the latest and greatest //UFN

Ahh, yes of course. I'll just stick with the FETs then. Cheers Kevin! //UFN

Simple question really: I am gathring parts for a KGSSHV and would I be able to use 2SA1831 I already have instead of the 2SA1968 for the current sources - or would I be better off just buying the IXYS FETs from mouser instead? //UFN

Impressive work indeed. //UFN

Now that is cool //UFN

Typical tolerance for large electrolytics is +/-20%, so 600uF is well within spec. //UFN

More listed now. //UFN

Applies here as well I think... //UFN

Haven't bought anything in there a while so shipping may have made it prohibitively expensive, but http://www.conradheatsinks.com/welcome.htm would be on my list. //UFN

That's where I bought mine from (as shown in ) and I now have some more on the way. However, the batch numbers in the listing picture and the ones I got are (very) different and the available quantity keeps changing. Most likely this is a seller buying up various leftover components from manufacturers in China and so there is some risk that you don't get what you pay for. Also, in my naivity I bought some 2SK389s from the same seller and they were clearly fake (tested as BJTs and not FETs) but the listing very clearly said "genuine Toshiba" so I would not unconditionally recommend this seller. //UFN

1) Yes, that should be the only difference. 2) Looks that way. //UFN

I believe it should be 280V and around 140-150mA, so complete min. specs for a custom wound would be: Pri: Whatever voltage(s) you need, power = 120VA or higher. Sec. 1: 280V/min. 40VA Sec. 2: 280V/min. 40VA Sec. 3: 15V/min. 10VA Sec. 4: 15V/min. 10VA Sec. 5: 6.3V/min. 10VA Sec. 6: 6.3V/min. 10VA You can go higher power if you want of course. The 15V windings can be higher voltage (16-18V) if you want but it should not be necessary given the dropout voltage of the LM78xx/79xx regulators. It can also be 15-0-15 center-tapped instead of two discrete secondaries if you prefer. //UFN

Same here, doesn't really seem worth the effort now. //UFN

I am in the process of gathering parts for a KGSSHV build and came across some 2SC4686a's at a reasonable price. Now, not the best picture in the world, but what do you think – are these genuine? Pin connections are consistent with the data sheet and hfe seems to be in range as well. Unfortunately I have no way of measuring the breakdown voltage. There’s no bar under the batch/lot number so either they are very old (pre-RoHS) or they have been remarked. Thanks, //UFN

Looks very good - only annoying thing is that I already ordered a couple of boards of the older version and the KGST amps I can see the amp board has been upgraded to v0.51 as well, can I ask what was changed? Oh, one minor error in the silkscreen by the way - one of the big caps is marked as 50V, not 500V. //UFN

Looks like they just gave you an extra core free of charge How are Keen Ocean's prices (and quality) compared to the toroidy audio grade transformers? //UFN

Another (online) Gerber viewer if anyone needs it: http://circuitpeople.com/ //UFN

Very impressive, but probably not really safe //UFN