DEFX Blur

[Fuzzonaut]

To round off my recent DEFX trilogy, here comes the BLUR, a clone of the Adenture Audio Fuzz Peaks II.

It's a Muff at heart, with a clean blend, 2 clipping options, Mids on a 3-way toggle and a feedback loop on a momentary footswitch (Peak).
I replaced the resistor (R31) that defines the range of the BIAS knob with a trimpot. (BIAS is on Q4).
Currently there are 4x BC574B in there, as suggested. I might try other transistors one of these days.

Very cool circuit, I just wish the clean signal would be louder, maybe my fault? I'm not smart enough to figure out (for certain) how I could get more clean volume ... but, it's not really a problem, my clean bass signal has it's own stack anyway.

LP Cover for graphics.

 

[Feral Feline]

I love how the hands form a triangle around the LED.

R14 on the clean blend is 100k, so you could try 91k, 82k, 75k, 68k...

 

[Fuzzonaut]

Thanks a lot @Feral Feline ... I'll try R14 then ...

 

[Feral Feline]

re R14 Maybe go with 51k in series with a 50k-trimmer, then you'll have the ability to dial it in Goldilocks-style: "jussst rrrright".
If the trimmer ever fails, you'll still have minimum resistance (it'll still go loud if the trimmer does fail).

 

[Fuzzonaut]

re R14 Maybe go with 51k in series with a 50k-trimmer, then you'll have the ability to dial it in Goldilocks-style: "jussst rrrright".
If the trimmer ever fails, you'll still have minimum resistance (it'll still go loud if the trimmer does fail).

Yeah, I was also thinking about a trimmer, maybe I'll just try some values in parallel to R14 first, without risking to butcher anything in place. That should get me an idea where my sweet spot is.

 

[Feral Feline]

Great idea.
You might be able to get some alligator clips on R14 (couldn't tell for sure as C12 in your gutshot blocked my view) and hook up a 100k pot parallel to the alligator-clips, dial it in then measure the pot and stick in the closest value parallel-resistor that gets the dialled-in setting.

Geeze I need to shut off the computer and get more sleep, I'm not sure I'm making any sense and I'm posting all over the forum right now.

 

[Fuzzonaut]

Great idea.
You might be able to get some alligator clips on R14 (couldn't tell for sure as C12 in your gutshot blocked my view) and hook up a 100k pot parallel to the alligator-clips, dial it in then measure the pot and stick in the closest value parallel-resistor that gets the dialled-in setting.

Geeze I need to shut off the computer and get more sleep, I'm not sure I'm making any sense and I'm posting all over the forum right now.

You're making sense, alright, kinda

 

[DeadAirMD]

@Fuzzonaut did you ever end up using @Feral Feline clean blend resistor suggestions? Very interested in building this if you were able to get a better clean blend signal out of the adjustments. Either way I'm definitely getting some JMK Panner/Paralyzer boards/building vero Paralyzer.

 

[Fuzzonaut]

@Fuzzonaut did you ever end up using @Feral Feline clean blend resistor suggestions? Very interested in building this if you were able to get a better clean blend signal out of the adjustments. Either way I'm definitely getting some JMK Panner/Paralyzer boards/building vero Paralyzer.

No, not yet, I've been very busy, but I plan to ... Maybe in 1-2 weeks. I can post my experiences here.