mono
1000+ Head-Fier
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Quote:
This design is already capable of more current than the typical A47, ignoring variables like the supply voltage. If you meant doubling up the opamp (voltage gain stage), it wouldn't be a benefit for a headamp, AFAIK. You just raise the gain if you want, err, higher gain, or choose a different complimentary pair of transistors for more current handling. BC327/337 are just nice for a TO-92 package but something like 2N5087/2N5088 might be nice, or step up to TO-126 sized transitors, a couple common around here are BD139/BD140.
I would suggest just building it in a basic version first, which can be done in short order and relatively inexpensively. If you had some 2N3904/2N3906 or whatever lying around it would give you an idea and you can take it from there. Just note the pinout of the transistors you choose, those Sijosae used (BC327/337) are CBE pinout (COllector, Base, Emitter), while many are instead EBC, so they'd be rotated 180' from the picture.
Originally Posted by ozshadow Any guesses how it would affect the output if you doubled the amplification stage like this into an A47-type layout ? |
This design is already capable of more current than the typical A47, ignoring variables like the supply voltage. If you meant doubling up the opamp (voltage gain stage), it wouldn't be a benefit for a headamp, AFAIK. You just raise the gain if you want, err, higher gain, or choose a different complimentary pair of transistors for more current handling. BC327/337 are just nice for a TO-92 package but something like 2N5087/2N5088 might be nice, or step up to TO-126 sized transitors, a couple common around here are BD139/BD140.
I would suggest just building it in a basic version first, which can be done in short order and relatively inexpensively. If you had some 2N3904/2N3906 or whatever lying around it would give you an idea and you can take it from there. Just note the pinout of the transistors you choose, those Sijosae used (BC327/337) are CBE pinout (COllector, Base, Emitter), while many are instead EBC, so they'd be rotated 180' from the picture.