Switch mode power supplies and single ended transistor amps can sound really good. There, I've said it! I'm currently using a 2n3055 / tip31 darlington SE amp powered by a modified atx supply - see http://www.mthain.dsl.pipex.com/mickey.html. Has anyone else tried this - Either my ears have gone faulty or I'm onto something interesting. Give it a try and let me know what you think
An externally hosted image should be here but it was not working when we last tested it.
Bill Fitzpatrick said:
Take off the period...
http://www.mthain.dsl.pipex.com/mickey.html
the link works for me
--
Brian
I did something along these lines 30 years ago.
Parallel LM741s driving a 2n3055 as an emitter follower with a 50 watt Dale wire wound resistor as the current source. The power supply was not a switcher but a big transformer with a CLC filter.
As I remember it sounded very good for a 4 watt amp burning up about 75 watts. It got so hot in about 20 minutes that you couldn't touch it. Fans would have helped a lot I'm sure.
Later BZ
Parallel LM741s driving a 2n3055 as an emitter follower with a 50 watt Dale wire wound resistor as the current source. The power supply was not a switcher but a big transformer with a CLC filter.
As I remember it sounded very good for a 4 watt amp burning up about 75 watts. It got so hot in about 20 minutes that you couldn't touch it. Fans would have helped a lot I'm sure.
Later BZ
Yes, It's very much along the Zen lite theme - the amp circuit isn't unusual at all, but building it with a computer power supply makes it very inexpensive and nice and quiet (apart from the fan noise that is). Just a bit of fun really but I have built a few for friends and it has to be one of the cheapest ways of getting into SE class A. A lot more musical that your average cheapie integrated amp in my opinion.
Since drawing the schematic I tried moving things around with the lamp between the emitter and ground and the collectors connected directly to +24v. Also replaced the existing bias components with a single 220k pot between 24v and the base of the tip31. Seems to sound a bit smoother this way.
Since drawing the schematic I tried moving things around with the lamp between the emitter and ground and the collectors connected directly to +24v. Also replaced the existing bias components with a single 220k pot between 24v and the base of the tip31. Seems to sound a bit smoother this way.
I should think that the lamp will be a non - linear load leading to distortion. You could use valve (tube) heaters instead of a lamp; - that would really confuse everyone who saw it. 😀
On your home page you say:
You know it's real if you weren't expecting it.
I know *exactly* what you mean. My memory of previous sound systems was that as a sound faded away it "crumbled" and deteriorated into dirty little pieces. I have had ~18 months of class A listening now, and the difference is that those decaying sounds are =absolutely= clean and detailed as they receed away into the ambience and the distance.
You know it's real if you weren't expecting it.
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