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DIY Stompboxes => Building your own stompbox => Topic started by: MartyMart on June 06, 2004, 06:50:05 AM

Title: SD-9 just got worse HELP !!
Post by: MartyMart on June 06, 2004, 06:50:05 AM
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.
Title: SD-9 just got worse HELP !!
Post by: RDV on June 06, 2004, 08:40:43 AM
If you lost your distorted signal when you changed the FETs you most probably have the pinouts wrong.

Regards

RDV
Title: Suggestion
Post by: petemoore on June 06, 2004, 10:09:32 AM
Using heat sinks on actives or diodes when soldering them in...I just typed this...you probably already know this.
Title: SD-9 just got worse HELP !!
Post by: MartyMart on June 06, 2004, 11:27:16 AM
:(
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.
Title: SD-9 just got worse HELP !!
Post by: R.G. on June 06, 2004, 12:19:54 PM
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.
Title: SD-9 just got worse HELP !!
Post by: MartyMart on June 06, 2004, 12:42:28 PM
:) 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.
Title: SD-9 just got worse HELP !!
Post by: Eric H on June 06, 2004, 12:54:04 PM
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