Colorsound Tremolo problems!

Started by superferrite, May 04, 2008, 04:41:34 PM

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superferrite

I build the Colorsound trem circuit that USED to be in Dragonfly's gallery, and it sure doesn't work right.  Sucks, because I executed the neatest box I had ever done on this one!  Almost looks like I know what I'm doing.
Anyhow, it looks like a few folks have made this circuit based on the magical Search function so I'm begging a moment of your time to help me get this bugger tremolo-ing.
I get a barely audible fluctuation in volume  and  a "fip fip fip" when the circuit is on, and it varies when the knobs are turned.  Bypass and my Millenium LED work fine.
Here goes:

Battery is at 8.18v
Battery in circuit is 8.18v
Q1 collector 5.01v, base 1.31v, emitter 0.80v
Q2 collector, base and emitter 0 volts (I admit this may be troubling)
Q3 collector 9.11v, base 0.50v, emitter 0.00v

Thanks and I'll start checking the obvious once again so I don't have to be a weenie.
Psychedelic Garage Metal

superferrite

I still haven't made any headway on this one, so I'll give it one bump before I move on...
Psychedelic Garage Metal

sfx1999

I find it kind of odd that the collector voltage on Q3 higher than your battery voltage. Also, you battery voltage is kind of low.

Is it optical? If so, is external light is hitting your LDR? Do you have the circuit in a box and shielded from light?

Paul Perry (Frostwave)

Statistically, it's most likely a short, or a transistor pinout mistake.
The figures you give support both these possibilities.
We've all been there, Mr Ferrite.. :icon_wink:

superferrite

Thanks guys--it was a pinout problem.  In the vero layout at http://www.diystompboxes.com/smfforum/index.php?topic=63442.0 the pinout for Q1 and Q2 should be reversed!!!!
Now she's tremming like a baby.
Thanks for your time,
T
Psychedelic Garage Metal