HomeBrew Electronics-Detox EQ (SCHEMATIC INSIDE)

[zosotone]

Finally, this is the schematic from PedalPCB. It's a EQ pedal, perfect for clean up your overdrive amp, like a second channel footswitch.

[zosotone]

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[squirrels]

Thanks for the layout. I built this one up today and it isn’t working. I looked over the layout and schematic and it seems OK, nothing seemed like an obvious error in the layout but I could have easily missed something myself. I’ve been building for a few years now but never really tried too hard to compare a schematic to a layout or learn why these things actually work. My voltages  with a 9.25 volt power supply are:

1: .95
2: .95
3: .31
4: 0
5: 9.25
6: .47
7: .47
8: .99

If anything seems wrong I can tweak my build to try to get this one working. The Detox seems like it may be a nice addition to many people rigs. Thanks.

[induction]

The pin-numbering convention for 8-pin dual inline IC's goes like this:

    1    8
    2    7
    3    6
    4    5

I believe that has some significance to our problem.

[squirrels]

That’s how I measured them. I tried two different JRC4558s as well.

[squirrels]

There are also 16 cuts on the layout.

[induction]

squirrels wrote

That’s how I measured them. I tried two different JRC4558s as well.

The problem is in the layout. The connections for pins 5-8 are reversed.

[squirrels]

Thanks Induction. Would making a little daughter board and swapping the connections work? I don’t think I can tweak my existing board to fix this.

[induction]

A daughter board won't work, I'm afraid. Your existing vero could be rejiggered with some work, but it may be easier to start from scratch with a modified layout.

[zosotone]

It's my fault, sorry about that. I'm making a new layout with the corrections...

[squirrels]

No worries. I’ll give it a shot when it’s ready. Thanks for making the layout.

[zosotone]

Corrected.

[squirrels]

Great, I’ll get started on it when I get a chance. Thanks again for the layout.

[squirrels]

Ok. Verified. Works like it should but it’s not going to add a sparkly clean second channel to a dirty single channel amp. My OR15 is set for a pretty dirty base tone, maybe cleaning the amp up will help but it’s not what I want to do. I’ll have to experiment with it some more but it seems like it will add some flexibility. I was thinking of adding a pregain control but I don’t think it would help much. Thanks again for the layout zosotone.

[zosotone]

Nice! thanks to you.

Well, I have not tried this one yet but my MP Underdrive with les paul+plexi head works really good. It's a similar typology. I think it is necessary to experiment with the controls, maybe a buffer in front or after can help and also use it with 18v...

Anyway I want to compare it with my Underdrive.

[squirrels]

It can run on 18v? I’ll have to build a charge pump. Thanks for the tip.

[zosotone]

You can run it at 18v if your caps are rated 25v or so.

[squirrels]

I haven’t tried it at 18 volts but this thing works great. I found that it really works well in front of my Colossus and Pharaoh from a more “traditional” Muff tone through my OR15. Definitely a worth while build if using a single channel amp. Thanks again zosotone.

[zosotone]

Thanks to you squirrels for verified it. I run my Underdrive at 18v for more headroom in the beginning before my overdrives and fuzzes too.