Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: basschops1528 on April 20, 2016, 07:04:14 pm
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May be a silly question but has anyone made their own optos for fender trem/vibe circuits? They are so expensive for such a small part I'd like to make my own.
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May be a silly question but has anyone made their own optos for fender trem/vibe circuits? They are so expensive for such a small part I'd like to make my own.
messing with that for a epiphone/gibson futura/invader. i tried a CE distribution fender part and it failed miserably - it sucked off all the gain of stage it was modulating.
the a luna pvd-8006 looks promising. http://www.digikey.com/product-detail/en/luna-optoelectronics/PDV-P8006/PDV-P8006-ND/480607 (http://www.digikey.com/product-detail/en/luna-optoelectronics/PDV-P8006/PDV-P8006-ND/480607)
built it, but need to test it. i used a NE-2 bulb and ordered several types of CdS photocells.
--pete
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It's a matter of time vs money. I myself have no idea what the light output of whatever light they use in a roach is, nor do I know the sensitivity of the photocell. A neon lamp has poor light output, towards the red end of the spectrum which is low energy. And does not possess a gradual on-off characteristic, and dims suddenly to zero at the extinguishing voltage and requires a much higher than normal starting voltage. You need ~~~ 100 volts to start a neon and an oscillator that can swing let's say 40-50 volts is very unlikely to come out of a 12AT7; though it could, in a relaxation oscillator, but then those squirt noise all over the place. I don't think it would be a good choice. Me, I never build trem into my amps because I never use it so there you go.
Versus buying the part that gits 'er done.