| rdf |
My chassis is done but before soldering in the components, does anyone know the history of the two Mullard 3-3 schematics available online? Version A appears to be from the original article and B from some unspecified later date. I've prototyped both and A measured significantly less distortion, and I recall it sounding better too. Anyone know the origins of the B version?
Version A |
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| ray_moth |
| I have yet another schema, which I believe to be the same as in Mullard's publication: |
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| rdf |
| quote: | Originally posted by ray_moth
I have yet another schema, which I believe to be the same as in Mullard's publication: |
Thanks Ray, that's version B with tone controls. Is that from the 1959 'Mullard Tube Circuits for Audio Amplifiers'? Version A is from a Radio Constructors article dated roughly the early fifties. I'm trying to determine which is the newer and, if B, figure out why I found its performance inferior to A. |
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| ray_moth |
| quote: | | Is that from the 1959 'Mullard Tube Circuits for Audio Amplifiers'? |
Yes, I built this in 1963 as a record-player amplifier, using Mullard's book. It worked OK but it had only a small eliptical speaker and was driven from a crystal pickup (ugh!), so I wasn't able to evaluate it properly. |
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| rdf |
| Thanks again. Maybe the redesign was due to changes in tube parameters, field failures, or something else unrelated to raw performance. I think Version A's the one then. Some LTSpice results suggest a simple front end change can yield a big payback on A as well. Experiment time! |
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