PICaudio Posted June 13, 2013 Report Posted June 13, 2013 I didn't fare any better with the output devices but this amp will be as close to stock as is possible. +1 -- o -- Rodrigo
spritzer Posted June 13, 2013 Report Posted June 13, 2013 Krell used Motorola sand in the stock amp but they should be identical to the current ON Semi stuff.
PICaudio Posted June 13, 2013 Report Posted June 13, 2013 Many thanks for the info Birgir -- o -- Rodrigo
zorning Posted June 13, 2013 Report Posted June 13, 2013 I didn't fare any better with the output devices but this amp will be as close to stock as is possible. Most of that doesn't make any sense to me. Rolling caps which look mostly vintage... why would anybody do that? someone over at a Chinese DIY site has a working KSA5 clone based on the schematic Kevin posted. He used his own boards, replaced mpsa06/mpsa56 with BC546/BC556, and changed the cap values a bit. He seems to like the sound (obviously.) Right now.. he is playing with different caps. Here is the link. Chinese diyers use vintage caps because they can get them at a very low price. you can get used UCC 81d 8200uf as low as $1 each.
kevin gilmore Posted June 13, 2013 Author Report Posted June 13, 2013 That's a riot. Bet they are on ebay soon.
spritzer Posted June 13, 2013 Report Posted June 13, 2013 Chinese diyers use vintage caps because they can get them at a very low price. you can get used UCC 81d 8200uf as low as $1 each. I get that but it doesn't change the fact that an electrolytic capacitor only has a shelf life of about 20 years. Doesn't matter if it is used or not... There is also the small matter of the massive improvements in capacitor technology over the last 20 years.
kevin gilmore Posted June 13, 2013 Author Report Posted June 13, 2013 i would love to do a version with NOS non polarized black gates, no chance of that now. not even for stupid amounts of money.
spritzer Posted June 13, 2013 Report Posted June 13, 2013 Some progress on my end but now I have to wait for the panels to be laser marked.
kevin gilmore Posted June 13, 2013 Author Report Posted June 13, 2013 (edited) so that's what a correctly assembled amb power supply looks like. I sure know what an incorrectly assembled one looks like. Edited June 13, 2013 by kevin gilmore
morphsci Posted June 13, 2013 Report Posted June 13, 2013 This thread makes me want to be more DIY adept
zorning Posted June 13, 2013 Report Posted June 13, 2013 hoping that the pcb layout file can be released eventually or someone have extra board, so that i dont need to use perfborad to build one.
trident900fi Posted June 13, 2013 Report Posted June 13, 2013 hoping that the pcb layout file can be released eventually or someone have extra board, so that i dont need to use perfborad to build one. Asks Kevin, he is really very friendly and will give you everything you need
spritzer Posted June 13, 2013 Report Posted June 13, 2013 Anybody who wants to order unproven PCB's is free to do so but none of these have been operational yet.
kevin gilmore Posted June 13, 2013 Author Report Posted June 13, 2013 http://gilmore.chem.northwestern.edu/ksa5ampfinal.zip but you should probably wait till we are finished testing.
spritzer Posted June 13, 2013 Report Posted June 13, 2013 Sketched up front and back panels for the KSA-5V just now: They will naturally not be colored like that...
spritzer Posted June 13, 2013 Report Posted June 13, 2013 A balanced version of this would be very, very big so that is the first major issue. There are also a lot of parts needed and to match all of them. Not under 2K$ with free labor would be my guess built to our standards. For a balanced amp the Dynalo Mk2 would be a better fit as it is cheaper to build, it's super symmetry so you can use either a SE or balanced source for balanced output and it's performance should be on par or even superior to the KSA-5.
jwzhan Posted June 13, 2013 Report Posted June 13, 2013 but it's not a Krell. I'm planning to build a SE version just to see how good krell is and also for fun of course. I'll keep it simple, not fancy engraving, just the very basic, and the cost should be under $600 total.
spritzer Posted June 14, 2013 Report Posted June 14, 2013 That is true but they are more similar than not minus the usual Krell overindulgence. They really are transistor mad, didn't the old CDP's have something like 200+ transistors in the output stage?
luvdunhill Posted June 14, 2013 Report Posted June 14, 2013 That is true but they are more similar than not minus the usual Krell overindulgence. They really are transistor mad, didn't the old CDP's have something like 200+ transistors in the output stage? Old? Hasn't changed. Most of this is due to everything being SMD. Not paralleling transistors and using larger dies is probably better. I think Kevin's design is better, imho.
eggil Posted June 15, 2013 Report Posted June 15, 2013 Audiogon has one now x 3750.00 USD. that's crazy. http://app.audiogon.com/listings/amplifiers-krell-ksa-5-headphone-amplifier-2013-06-03-headphones-10598
trident900fi Posted June 15, 2013 Report Posted June 15, 2013 Audiogon has one now x 3750.00 USD. that's crazy.http://app.audiogon.com/listings/amplifiers-krell-ksa-5-headphone-amplifier-2013-06-03-headphones-10598 It's the same as the one from EBay last week...
morphsci Posted June 15, 2013 Report Posted June 15, 2013 I've pretty much given up on finding one at a reasonable price. If I had reasonable DIY skills I would build the clone.
luvdunhill Posted June 15, 2013 Report Posted June 15, 2013 I've pretty much given up on finding one at a reasonable price. If I had reasonable DIY skills I would build the clone. Perhaps take a trip up to Ann Arbor? I bet we could do it in a day and I could walk you through the process
kevin gilmore Posted June 15, 2013 Author Report Posted June 15, 2013 i'm sure you could probably get it done in a day if you have all the parts and a pre-punched chassis. No high voltages to cause any grief.
morphsci Posted June 15, 2013 Report Posted June 15, 2013 Maybe a fall trip up to Ann Arbor is in order. I hear they also have beer up there. If I give a seminar at Michigan I can probably even get the trip paid for.
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