jboehle

Very hard to come up with 5 desert island albums. The only ones I know for sure: 1. Weezer - Blue Album 2. Nirvana - Unplugged 3. Tool - Aenima Would have to add something from the White Stripes for sure. Also maybe some kind of rap for variety.

Thanks Kevin. I am a little worried about accidentally touching the heatsinks either with a probe or to a part of the case but I will just try to be careful. I couldn't find any Thermasil ones stocked at Digi-Key or Mouser. BTW the ones you spec'd in the - "thermal washer 739-A15038003 2" - are for TO-220, not TO-3. The TO-3 insulators I was able to find in stock at Mouser are 534-4662 (mica), 534-4667 (mica), 534-4636 (mica), 567-175-6-310P (Kapton), and 739-A15036002 (Tgard 500 - some kind of thick silicone one). Also, are the MJF1503x in the new PSU supposed to have any heatsinking? It doesn't look like they did in your pic but thought I would make sure.

I am making more progress on my power supply & amp boards. I checked to make sure the TO-3 insulators in the PSU were doing their job and the TO-3 cases were not connected to the big heatsinks, unfortunately my meter shows .3 ohm (it shows .2 ohm shorting the leads together), doh! I guess some of the jaggies from the heatsink poked through the (absurdly thin) mica insulators I got? What TO-3 insulators do you guys use? Unfortunately I was a dumbass and already soldered the TO-3 leads so I'm going to have to desolder those to replace the insulators, ugh.

CRUSHER. That's amazing. Love it!

Did the bottom of any of the original PSUs or amp have vents?

Yes it's more expensive than off the shelf units, but I could not find anywhere to get a 2x27V toroidal transformer off the shelf. I'm only going to build this once. I think earlier in the thread someone got a 2x27V tx from SumR that was not encapsulated for $54 + shipping if you don't need it encapsulated.

http://www.sumr.com/custom.htm You have to call or email them since the 27v is custom. I emailed them, Richard was great to deal with. Email address is [email protected]

Thanks Kevin I am going to try to trim/file down the leads tonight. For the .1uF cap next to the op amps on the new power supply can I use the .1uF film caps that are used on the amp board or does it need to be a ceramic cap? If it needs to be ceramic would this one work?

Looking through my Mouser order. I ordered 4x OPA227P from Mouser for the PS & amp. Will these work okay? I also mistakenly ordered 3x OPA445AU from Mouser. Should I use 2x of these instead in the PS or amp, or just return them? They are almost 2x the cost of the OPA227P...worth it for this use case?

FYI shielded & encapsulated 120v/2x27v/50VA tx from SumR was $79US + shipping.

Do the MJF1503x transistors need to be attached to the big heat sinks in some way?

What kind of cap is needed for the .1uF on the new power supply board?

Thanks, I've got some tiny heatshrink so I think I will do that as well, good idea.

Got the newer power supply board started tonight. Found out a couple things. I forgot to order the .1uF caps, ugh. Also, the snap in 4700uF caps I ordered do not fit fully through the holes, here are some pics. Will these be okay like this? http://imgur.com/Lb88JpV,lOdDtBe#0 http://imgur.com/Lb88JpV,lOdDtBe#1

Thanks, just placed orders at Newark & Mouser for most of the parts. Not sure what I will do for a case yet. Did the power switch on the original switch the +/-21vdc from the psu, and psu was always on when plugged in, or did the switch run through the 9-pin cable to switch the psu on and off? EDIT: nevermind I missed that in the pic on the first page, I just looked and the wires going to the power switch at the amp face are labeled -21 V +21 V

I got a set of boards (amp + new & old PSU) from a member that decided not to build theirs. Ouch, the shipping for 2x LSK389 from Trendsetter is more than the chips themselves. Was the "new" power supply used with the real KSA5 as well or was it used for some other Krell product? Is it worth ordering extra transistors for matching or not? I see earlier in the thread that not much luck was being had in matching.

Are there still boards for this available?