drabik@gt-eedsp.UUCP (Timothy J. Drabik) (05/02/88)
I very much enjoyed the preamp schematics posted a short while ago by Mark Johnson. I'd really like to see some good basic power amp designs as well. Does anyone have that sort of thing? Are there any back issues of The Audio Amateur that deal largely with power amps? It would also be interesting to see, apart from the amplifier circuit design, to what lengths designers have gone to obtain power supply noise rejection and decoupling, for example, electrochemical cells as power supply shunt filters, solid bars or copper braid as low-inductance supply conductors, and the like. Ditto for quiet cooling and efficiency, e. g. heat pipes, plumbing, switchable supply levels, or other wierd stuff. Regards, Tim Drabik Ga Tech Optical Computing
chan@thoth23.berkeley.edu (05/03/88)
In article <265@gt-eedsp.UUCP> drabik@gt-eedsp.UUCP (Timothy J. Drabik) writes: >issues of The Audio Amateur that deal largely with power amps? I have noticed that they have occasional plans for power amps but I have no references. > >It would also be interesting to see, apart from the amplifier circuit >design, to what lengths designers have gone to obtain power supply noise >rejection and decoupling, for example, electrochemical cells as power supply >shunt filters, solid bars or copper braid as low-inductance supply conductors, >and the like. Ditto for quiet cooling and efficiency, e. g. heat pipes, >plumbing, switchable supply levels, or other wierd stuff. > A PS audio amp I saw (forgot the model 1A?, cost ~1500) was built around a massive copper ground plane. This thing was really a copper bar, connected to the filter caps (and elsewhere I could not see). It seemed to be about a half inch thick and undoubtedly weighed several pounds. It was polished and appeared to be very pure. Not much resistance (or gound loops), I'd bet. Jeff C. chan@bartleby.berkeley.edu ucbvax!bartleby!chan
mbutts@mntgfx.mentor.com (Mike Butts) (05/06/88)
From article <265@gt-eedsp.UUCP>, by drabik@gt-eedsp.UUCP (Timothy J. Drabik): > > I very much enjoyed the preamp schematics posted a short while ago by > Mark Johnson. I'd really like to see some good basic power amp designs > as well. Does anyone have that sort of thing? Are there any back > issues of The Audio Amateur that deal largely with power amps? Yes, indeed!! I'd love to see some power amps. I posted a call for leads on power amp designs some months back, yielding no replies. I know it may not make much sense to build this sort of thing anymore, but I have flux fumes in my veins. Whatever happened to the Audio Amateur? Did it go out of print? Are back issues available anywhere? Are there any mail-order parts houses that specialize in audio construction? Power transistors, transformers, quiet transistors and ICs, that sort of thing... -- Mike Butts, Research Engineer KC7IT 503-626-1302 Mentor Graphics Corp., 8500 SW Creekside Place, Beaverton OR 97005 ...!{sequent,tessi,apollo}!mntgfx!mbutts OR mbutts@pdx.MENTOR.COM These are my opinions, & not necessarily those of Mentor Graphics.
rbl@nitrex.UUCP ( Dr. Robin Lake ) (05/10/88)
In article <265@gt-eedsp.UUCP> drabik@gt-eedsp.UUCP (Timothy J. Drabik) writes: > >... >It would also be interesting to see, apart from the amplifier circuit >design, to what lengths designers have gone to obtain power supply noise >rejection and decoupling, for example, electrochemical cells as power supply >shunt filters, solid bars or copper braid as low-inductance supply conductors, >and the like. Ditto for quiet cooling and efficiency, e. g. heat pipes, >plumbing, switchable supply levels, or other wierd stuff. > > Regards, > Tim Drabik > Ga Tech Optical Computing "We" make (or used to make) electrochemical cells as battery replacements and much of the key development talent is about. Why are these cells any better in power supply shunts? Are they supposed to be lower noise? Is there any data/information that anyone might want on these cells? If there is any interest, I have schematics for Dyna tube amps, including some higher powered (300W) ones that were not offered commercially. RSVP -- Rob Lake BP America Research and Development decvax!mandrill!nitrex!rbl mandrill.CWRU.EDU!nitrex!rbl
mjj@stda.jhuapl.edu (Marshall Jose) (05/10/88)
With regard to Mike Butts' question about parts companies
specializing in audio construction, I thought he might be interested in
Mark V Electronics. They don't sell individual parts, but they do sell
a remarkable variety of audio amp kits and other audio kits. Amp kits
range in power from 5 to 200 watts.
My preference is to homebrew my own, but parts acquisition is getting
to be the #1 hindrance to the hobby. Mark V seemed to be a good starting
point, since ther kits come with the heatsinks, the damn-hard-to-find power
transformer, etc. I reasoned that I could start with their design and
modify it if it was lacking. I was pleased with the results!
For those hobbyists who would prefer to wind their own transformers,
etc, I can't recommend much; but for the bloke who wants to get "on the air"
first and dink with the design later, Mark V seems the best bet. Their addr:
Mark V Electronics, Inc., P.O. Box 6610,
Alhambra, CA 91802 (818) 282-1196
Marshall Jose
mjj@aplvax.arpa || mjj@aplvax.jhuapl.edu || ...!bpa!cp1!aplcen!aplvax!mjj
Disclaimer: I have no pecuniary interest in Mark V; I'm just a satisfied
customer.