Boost pedal halp!

insomniac2295 · July 30, 2012, 05:36:19 PM

I built this http://diy-layout.com/66 and can get the boost and high boost to work, but I can't seem to get the low boost section to work. It still has sound when engaged, but no bass boost. I've tried it at higher boost levels to see if I'm just not hearing it, and it's simply not there. I'm just looking for some guidance in which parts to check out while debugging. For what ever reason I can't seem to make a whole lot of sense of the schematic, so any help would be great. Thanks all

insomniac2295 · July 31, 2012, 05:51:15 PM

Anyone? I'll post the layout here so you don't exactly have to click on the link:

JRC4558D · July 31, 2012, 06:25:41 PM

Hi,

First of all, does your amp/speaker cab have the freq. response to cover those frequencies that should be boosted? If your answer is yes, then you should post pics of front and back of your PCB to see if you did something wrong.

I am not familiar with this particular pedal but I could have a look to see if there is somethig you've ommited by mistake, sometimes that happens.

cheers.

insomniac2295 · July 31, 2012, 07:11:29 PM

Thanks! Yup, it's a bass rig, so I'm covered. I'll post some pics in a bit.

insomniac2295 · August 03, 2012, 08:40:24 PM

Here's some pics. Sorry for the delay.

As you can see, I used 2 SPDT switches instead of a DIP.

insomniac2295 · August 05, 2012, 07:10:05 AM

Anyone?

rockhorst · August 05, 2012, 07:30:23 AM

If you've got a DMM then take a few voltage measurements and such. See the Debugging sticky thread. And an audio probe (search Google) is a real godsend for stuff like this. If you've got a guitar cable that's not intermittent but otherwise you don't care for, snap it in two and attach a capacitor to hot lead. Start at the beginning of the schematic and follow the audio path. You can put something like an iPod playing a tune at the input of the effect, to have a test signal. This is a very effective way to isolate in what area the problem is. Be careful though, volume jumps will be huge between amplifier staged, so be careful with your equipment and ears each time you probe the output of for instancence a transistor.

nascarbean_97 · August 05, 2012, 04:33:26 PM

Dang, that's neat. Do you have a hairthin iron tip?

And, your pot looks like it's wired backwards.

Go do the stuff in the debugging thread, someone will help you out after you do it.

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Boost pedal halp!