SD-9 just got worse HELP !!

Started by MartyMart, June 06, 2004, 06:50:05 AM

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MartyMart

Hi Guys,
I tried lots of suggestions, which i thank you for but my poor SD-9 is outputting NADA !!.
Checked Fet switch, op-amp, wiring, changed FET transistors ( thats when i even lost the distorted signal !! ) so i'm a bit stumped !.
Should i start changing caps/resistors ?  or call it a dead one ?
Any help would be great  :-(
Marty.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

RDV

If you lost your distorted signal when you changed the FETs you most probably have the pinouts wrong.

Regards

RDV

petemoore

Using heat sinks on actives or diodes when soldering them in...I just typed this...you probably already know this.
Convention creates following, following creates convention.

MartyMart

:(
Thanks, i installed the new FET transistors the same way as was, one side is "flat" like in a "half moon" way.
Could a similar spec FET be the opposite way around??
Thanks,
Marty.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

R.G.

QuoteCould a similar spec FET be the opposite way around??
Yes. Even the *same* type number sometimes comes with a different pinout from different manufacturers.

Before you start easter-egging parts out, go back to basics: Measure the DC voltage on all opamp and transistor pins in both bypass and effect mode and post them here.

There are very few "no operation at all" situations that cannot be found that way.

Better yet, read the Guitar Effects Debugging Page at GEO, and run through that first.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

MartyMart

:) Thanks RG, I'll do that asap, might take me 'til wednesday to find the time, then i'll post the result.
Even if i have to change all the parts, its only 15 bucks worth !!
Cheers,
Marty.
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

Eric H

Quote from: MartyMart:)
Even if i have to change all the parts, its only 15 bucks worth !!
Cheers,
Marty.
The knowledge you gain from systematically trouble-shooting it,  will be worth more than that .

-Eric
" I've had it with cheap cables..."
--DougH