kevin gilmore Posted November 16, 2012 Report Share Posted November 16, 2012 (edited) Both Birgir and I have wanted one of these for quite a while, and they never seem to show up. So with a little help from one of the members here we were able to reverse engineer this one. http://gilmore.chem....rn.edu/ksa5.pdf http://gilmore.chem....rn.edu/ksa5.jpg still have work to do on the power supply. All the parts are still available, but identical and compatible parts also available. mpsw06 and mpsw56 and lsk389 I think this one is fairly cheap to do. And easy to assemble. Single channel is 10 x 3.65 inches. Single ended not really a HE6 killer, but balanced, a HE6 heavyweight for sure. If you replace the servo opamp with opa445, then you can go up to +/-35v rails. Then its definitely a HE6 killer single ended. picture of the original http://gilmore.chem....du/ksa5orig.jpg single ended with +/-21 power supplies, it does 10 vrms into 4 ohms or more. balanced 20 vrms into 8 ohms or more. single ended with +/-35 power supplies, it does 16 vrms into 4 ohms or more. balanced 32 vrms into 8 ohms or more. Edited November 16, 2012 by kevin gilmore 1 Quote Link to comment Share on other sites More sharing options...
cobra_kai Posted November 16, 2012 Report Share Posted November 16, 2012 Cool Quote Link to comment Share on other sites More sharing options...
morphsci Posted November 16, 2012 Report Share Posted November 16, 2012 This topic definitely interests me. Subscribed! Quote Link to comment Share on other sites More sharing options...
deepak Posted November 16, 2012 Report Share Posted November 16, 2012 Curious did Dan D'agastino design this or someone else at Krell? Quote Link to comment Share on other sites More sharing options...
Emooze Posted November 16, 2012 Report Share Posted November 16, 2012 I'd definitely be interested in building a balanced version. Higher voltage of course. Quote Link to comment Share on other sites More sharing options...
RudeWolf Posted November 16, 2012 Report Share Posted November 16, 2012 Hmm... How suitable actually would this be for speaker duties? Most likely it would require a considerable bump in heat-sinking. Maybe even some meatier resistors. I could build one for computer speaker duties. Maybe get me a pair of those Hsu's. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted November 16, 2012 Author Report Share Posted November 16, 2012 The people at diy audio where i just posted this seem to think that Todd Eichenbaum actually designed it. I don't know, none of the people i knew at krell are still there so i have no way to verify. As a speaker amp, you probably want the most efficient horns you can get. Not a good idea. Quote Link to comment Share on other sites More sharing options...
RudeWolf Posted November 16, 2012 Report Share Posted November 16, 2012 Hmm... Maybe I had some mistakes converting vrms into power. In any case I still love my Dynalo and have a feeling that utility wise it would overlap with the KSA 5 (both being current happy). Still too lazy (and afraid what you'll say about the wiring) to do a proper post at the DIY build thread. Quote Link to comment Share on other sites More sharing options...
spritzer Posted November 16, 2012 Report Share Posted November 16, 2012 The Dynalo and KSA-5 are similar is many ways but that is a very good thing in my book. I wouldn't try to use this for speakers though as the amp was never intended to do that. The PSU will not like it one bit too. Huge thanks to Tom for his help on this and the reasons for me buying a HD-800 should be clear now. It should be quite cheap to build as all parts or subs are available but the electrolytic caps should add up quickly. This run balanced at +/-35V will be a beast to reckon with... Quote Link to comment Share on other sites More sharing options...
c12mech Posted November 16, 2012 Report Share Posted November 16, 2012 Why, oh Why do you guys keep coming up with these great clone builds. I have subscribed and will be looking forward to this one. Especially since parts are actually available for a reasonable price. Quote Link to comment Share on other sites More sharing options...
spritzer Posted November 16, 2012 Report Share Posted November 16, 2012 Because we can? Quote Link to comment Share on other sites More sharing options...
Horio Posted November 16, 2012 Report Share Posted November 16, 2012 Another very interesting thread. I'm just hoping a few of these projects actually make it to the board fab shop... Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted November 16, 2012 Author Report Share Posted November 16, 2012 (edited) Board files available to all Edited November 17, 2012 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
livewire Posted November 17, 2012 Report Share Posted November 17, 2012 The Q14 - Q23 thing has me confused Looking at the pic of the board, dont see Q23. Also what is the function of the relays and other components in the middle of the board, between the two channels? Startup delay? Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted November 17, 2012 Author Report Share Posted November 17, 2012 (edited) you need better eyes... http://gilmore.chem....u/ksa5orig2.jpg the relays are output relays driven by a simple delay circuit. no real protection. there evidently was an issue with 24v relays used on 21v. Q14 is the Vbe multiplier thermally tied to Q23 for output stage bias. Edited November 17, 2012 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted November 17, 2012 Report Share Posted November 17, 2012 Zettler relays are very nice. Quote Link to comment Share on other sites More sharing options...
livewire Posted November 17, 2012 Report Share Posted November 17, 2012 I see it now. I should a payed more attention to your overlay jpeg. Quote Link to comment Share on other sites More sharing options...
c12mech Posted November 17, 2012 Report Share Posted November 17, 2012 If anyone does a board run count me in. This looks like a pretty straight forward build compared to some of the others I am working on. Quote Link to comment Share on other sites More sharing options...
Currawong Posted November 20, 2012 Report Share Posted November 20, 2012 Subscribed. Quote Link to comment Share on other sites More sharing options...
qusp Posted November 20, 2012 Report Share Posted November 20, 2012 nice, I probably dont need the higher voltage balanced version, but maybe I should build it just in case =) saw it over at DIYA, should be fun, will make my own boards if need be, thanks for that Kevin! Quote Link to comment Share on other sites More sharing options...
robm321 Posted November 20, 2012 Report Share Posted November 20, 2012 (edited) Interested as well Edited November 20, 2012 by robm321 Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted November 20, 2012 Author Report Share Posted November 20, 2012 power supply board should be done by the end of this weekend. Quote Link to comment Share on other sites More sharing options...
T-Bird Posted November 20, 2012 Report Share Posted November 20, 2012 I would be interested if boards are made Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted November 22, 2012 Author Report Share Posted November 22, 2012 (edited) http://gilmore.chem....du/dsc_0177.jpg The blackgate caps and the dact are mikhail's handiwork. here are the schematics for the 2 power supplies. The first one is the original supply that tom owns. http://gilmore.chem.northwestern.edu/ksa5psschemold.pdf this is the newer version http://gilmore.chem.northwestern.edu/ksa5psschem.pdf I think we will be doing the new version. I'm sure they sound different. Edited November 22, 2012 by kevin gilmore Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted December 1, 2012 Author Report Share Posted December 1, 2012 mikhail's just awful hack job removed and correctly replaced http://gilmore.chem.northwestern.edu/dsc_0234.jpg Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.