Colorsound - Power Boost (Vox)

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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brendon79
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Post by brendon79 »

I am going to build the 18V power boost with b169c. see attachment I have read that this circuit works best when the collectors are biased to 9V ( sound right??)
my question is which resistors would you tweak to bias the collector voltage for t2 and t3? (r6 and r 14) sorry its been a while since I too a electronics class

thanks
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Powerboost.jpg
Powerboost.jpg

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IvIark
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Post by IvIark »

Yes, R6 and R14
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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Electric Warrior
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Post by Electric Warrior »

brendon79 wrote:I am going to build the 18V power boost with b169c. see attachment I have read that this circuit works best when the collectors are biased to 9V ( sound right??)
my question is which resistors would you tweak to bias the collector voltage for t2 and t3? (r6 and r 14) sorry its been a while since I too a electronics class

thanks
More like 10V. The (factory?) schematic for the 9v version asks for 5V there.
Is getting these voltages there even a problem? I hear this circuit is fairly tolerant about transistor specs.. but no experience here. I was going to build one, but scored a vintage unit before I got to it :mrgreen:

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