Dr Boogie problems

Started by littlephil, July 17, 2009, 04:50:07 AM

Previous topic - Next topic

littlephil

Hi guys,
I've built a Dr Boogie for my first project and I'm having a bit of trouble with it. I used the gaussmarkov layout PDF, and I'm pretty sure everything is soldered properly. I've double and triple checked it, but when I turn it on, I hardly get any volume, and the EQ knobs dont do anything as far as I can hear. The gain knob works, but none of the others do, and the signal is barely audible(far quieter than the bypassed signal)
Anyone have any ideas as to what could have gone wrong?
Thanks,
Phil

anchovie

Disconnect the tone stack and use an audio probe to see if you've got a nice healthy signal coming out of the end of the gain stages.
Bringing you yesterday's technology tomorrow.

Slade

Did you regulate the trimmers to get 4.5v at the Drain of the Jfets?

littlephil

I cant measure it as I dont have a multimeter, but i've tried adjusting all the trimpots for about half an hour and it cant get any louder than it already is. Besides, that wouldnt stop the volume and EQ pots working, would it?

anchovie

You need a multimeter. Not just for setting the trimmers, but also because there is obviously a problem with your tone and volume connections. You need to be able to measure resistance and check for shorts.
Bringing you yesterday's technology tomorrow.