Just a sneak peek of the discrete front end to go into my HGF once I get them hauled back up to Skunkworx and disassembled. Nothing wrong with the onboard solution, but I just like to try stuff.. Those sticky-up adapter cards are loaded with Tantalum Nitride 1206 SMD's by TT Electronics. Passive's don't matter dum dum! (I know, but there it is..) Mark Levinson ad copy touts these things in critical spots (Levinson? never heard of 'em..) So the rest of it is quad K170's with zener referenced cascode on the input, bootstrapped VAS (flying rails), onboard RC rail filtering w/low ESR caps, 12db (4X) gain, blah, blah.. If it's crap EZ enough to switch back..
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I have had the amp cooking for a few 8 hour runs, heatsinks get warm but not toasty, bias at 1.5A, offset solid at a few mV. I did have a nasty experience the first time I hooked it up. I had been given a balanced dac for the test rig and initial offset was 8V DC, I shut it down and started to look what I could have done with final wiring to mess things up and something made me check the dac output (yes, I should have checked it before using it but it came from a trusted source and was said to be working), the dac output is seriously borked, luckily no obvious damage to the amp. Set up with my normal trusted SE source and it sounds amazing in the test rig. Plan to move it into my main system and let it sing for a while.
Thanks for a great project and look forward to playing with all the possibilities with this design.. dB
Thanks for a great project and look forward to playing with all the possibilities with this design.. dB