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Posts by mwhouston

I was given these prototype cct. brds. (populated) some years back but only recently have I started to listen to them. There was a K311 and now a K311B and I think there maybe a "C". I have the schematic but at this point will not publish it. The amp is by Oatley Electronics. It uses two 2SK170 jFets for amplification but a strange power FET push-pull config to drive the HPs. It burns a lot of current and the power FETs are mounted to on-board heat sinks. Strange. Lets...
Good work.
Both neat builds.
KT88: great work.
Very neat. Looks pro.
Neat
It is more of a driver (being emitter follower) than a preamp. Usually you would expect a preamp to have multiple inputs and be able to attenuated the signal and drive into low impedance. With most players putting out over 2V these days a small loss of this voltage should not hamper power amps from obtaining full power. There a some tranni based preamps and light speed style which do not amplifier the signal.   The preamp to me is more of a buffer also. Buffers usually...
I actually build this quite some time back but had it out the other day and was really enjoying it and thought I should post the project. This is something I designed myself and design work is not my strongest point. Probably, concept, layout and construction are I'm better at. No I do don't know how to direct couple the load to a single stage, singe transistor, single B+ voltage amp. I rap everything in the bituminised Al foil (flashing). Yes probably vibration and...
FrankCooter: Thanks for the nice comments. Two of the most over engineered power amps (a little off thread here) are my 300B I call "The Silver Dragon" and my 807 amp named "Luciano". The reason why they are so over engineered is they were designed by an electronics engineer in Seattle who works in high frequency electronics and designs and builds valve amps. The 300B (SE) cost my over $3K in parts and boasts 30W Hammond OPTs for a 6W output. That's just the start of...
Thanks for the nice comments (sort of). I guess that's the beauty of DIY is for the cost of parts only you can go nuts. Yes it is class A but all currents etc are low as this is not a power amp. no huge idles currents. I wanted the PS to be dead quiet and the only way to do that is careful layout and lots of good filtering. I used the ploys on the output because I didn't want to use electros NP or other. Compared to my tube headphone amp also posted on this site it does...
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