First I'd like to state that I am trying to locate schematics for this amp, if anyone has them I would be grateful if you could send them my way.
Second, I have the following strange situation.
Everything on the amp basically works, I just did a bunch of "preventative' maintenance on it.
However, while working on it, I noticed that some of the resistor values just don't match up.
For example: I have the VC3112 schematic and it states that R60 & R61 should be 100ohm, the bands are brown/black/brown/gold as well... so last I check that should add up to 100ohm & 5% tolerance. R45 also is red/brown/red/gold which should be 2.1k. Well, that said... R60 and 61 are both around 50 and R45 is 2.6k? I was only taught one way of coding resistors and that way back in physics 2 though so maybe I missed something? A whole slew of others are like that.
Now my multimeter could also be horribly wrong but some new radio-shack 5.6k resistors are all reading around 5.5k on it.
The reason I bothered to check resistor values was a hunch that the power amp section or transformer may be off/going. I have brand new matched tubes in it and I can get the plates to glow if I crank it. Granted, it has no fan or air circulation and it throws heat like a toaster. One or more preamp tubes may be bad as well but even in a self-biased amp I'm not sure if that could effect the power tubes like this.
Any suggestions? I emailed 'enzo' on this forum as he seems to know a lot but I don't really want to impose on him out of the blue.
Thanks, Tim
Second, I have the following strange situation.
Everything on the amp basically works, I just did a bunch of "preventative' maintenance on it.
However, while working on it, I noticed that some of the resistor values just don't match up.
For example: I have the VC3112 schematic and it states that R60 & R61 should be 100ohm, the bands are brown/black/brown/gold as well... so last I check that should add up to 100ohm & 5% tolerance. R45 also is red/brown/red/gold which should be 2.1k. Well, that said... R60 and 61 are both around 50 and R45 is 2.6k? I was only taught one way of coding resistors and that way back in physics 2 though so maybe I missed something? A whole slew of others are like that.
Now my multimeter could also be horribly wrong but some new radio-shack 5.6k resistors are all reading around 5.5k on it.
The reason I bothered to check resistor values was a hunch that the power amp section or transformer may be off/going. I have brand new matched tubes in it and I can get the plates to glow if I crank it. Granted, it has no fan or air circulation and it throws heat like a toaster. One or more preamp tubes may be bad as well but even in a self-biased amp I'm not sure if that could effect the power tubes like this.
Any suggestions? I emailed 'enzo' on this forum as he seems to know a lot but I don't really want to impose on him out of the blue.
Thanks, Tim
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