Cheers mate, I actually downloaded this one yesterday. Tried to do a simple circuit today and had to give up. So much to look out for and so much going on. I don't know how you do it mate, top job!!
I've wanted to have something like this to mix in standard guitar effects with a bass signal for awhile, so very excited to build this one. This one can be tagged as verified, works great, but there are a few issues:
- The Amount, Master Volume and Tone pots operate "backwards". They should be wired as "1 2&3 instead of "1&2 3".
- The mix works fine, but is reversed from the demos I have seen of the original Juggernaut.
- In all the Rat schematics I've ever seen, the 1K resister precedes the 10uF cap at the output of the LM308. I wouldn't think this Rat circuit would be any different, so the 1K should be connected to pin 1 of IC2 (jumper from B2 to B1), then cut a trace at A12 and move the 10uF across it, negative side toward D1/D2 and Tone 3. It probably won't sound any different, but however….
This isn't an issue so much as an observation, but the crazy number of 47 ohm resisters and 100uF caps in the power section mean that there's a substantial wait as this thing powers-up. That's something like 600uF! That'll clean up the filthiest of power supplies, for sure.
Mods: I think, to make this better for bass guitar, I'll up the 22n at the input to pass more lower frequency signal. I'm also going to replace IC1 with a cleaner dual op-amp to keep the bass signal pristine. Do not touch the grungy MC1458 IC2, however; that crappy op-amp, like the even crappier LM308 in the original Rat, is integral to the sound. And since this is a Rat, those diodes can be switched out with LED's, germanium diodes, etc. I also think the effects loop will be important for my needs, so I'm going to wire those jacks between pin 8 of the distortion 3PDT and where it's supposed to connect to the 22nf at L24. Just keep in mind that if the inserted effect changes the phase, the "mix" will have some strange frequency subtraction.
Anyway, this is going to be a great pedal when I'm finished tinkering.
Thanks for verifying, spotting the pot issues and your suggestions for mods.
I hate when lpot lug numbers isn't marked in schematics, I easlly get confused about it unless about it is a simple voltage divider. ... The layout is updated and tagged and I switched the posistions of the 10uF/1k before the clipping diodes. It won't make a difference but, hey....
Once again, thanks and I would love to hear about the mods you will settle on.
Hey Anders, what software do you use to create layouts. Cheers :)
ReplyDeleteDIYLC.
Deletehttps://bancika.github.io/diy-layout-creator/
Cheers mate, I actually downloaded this one yesterday. Tried to do a simple circuit today and had to give up. So much to look out for and so much going on. I don't know how you do it mate, top job!!
DeleteI've wanted to have something like this to mix in standard guitar effects with a bass signal for awhile, so very excited to build this one. This one can be tagged as verified, works great, but there are a few issues:
ReplyDelete- The Amount, Master Volume and Tone pots operate "backwards". They should be wired as "1 2&3 instead of "1&2 3".
- The mix works fine, but is reversed from the demos I have seen of the original Juggernaut.
- In all the Rat schematics I've ever seen, the 1K resister precedes the 10uF cap at the output of the LM308. I wouldn't think this Rat circuit would be any different, so the 1K should be connected to pin 1 of IC2 (jumper from B2 to B1), then cut a trace at A12 and move the 10uF across it, negative side toward D1/D2 and Tone 3. It probably won't sound any different, but however….
This isn't an issue so much as an observation, but the crazy number of 47 ohm resisters and 100uF caps in the power section mean that there's a substantial wait as this thing powers-up. That's something like 600uF! That'll clean up the filthiest of power supplies, for sure.
Mods:
I think, to make this better for bass guitar, I'll up the 22n at the input to pass more lower frequency signal. I'm also going to replace IC1 with a cleaner dual op-amp to keep the bass signal pristine. Do not touch the grungy MC1458 IC2, however; that crappy op-amp, like the even crappier LM308 in the original Rat, is integral to the sound. And since this is a Rat, those diodes can be switched out with LED's, germanium diodes, etc. I also think the effects loop will be important for my needs, so I'm going to wire those jacks between pin 8 of the distortion 3PDT and where it's supposed to connect to the 22nf at L24. Just keep in mind that if the inserted effect changes the phase, the "mix" will have some strange frequency subtraction.
Anyway, this is going to be a great pedal when I'm finished tinkering.
Thanks for verifying, spotting the pot issues and your suggestions for mods.
DeleteI hate when lpot lug numbers isn't marked in schematics, I easlly get confused about it unless about it is a simple voltage divider. ...
The layout is updated and tagged and I switched the posistions of the 10uF/1k before the clipping diodes. It won't make a difference but, hey....
Once again, thanks and I would love to hear about the mods you will settle on.
Is there any way to remove the distortion switch?
ReplyDelete