Fender Blender 3 Knob

[anders]

This one is quite rare and shares almost no similarites with the 4 knob version except for the name and it is a fuzz.



Circuit analysis HERE

Verified vero


I used a 2N5457 for the FET, 2N5088 for Q2 and Q3 and PN2222 for Q4.

Not sure if I will box it since the fuzz part barely reaches up to unity.

Might tinker with the wiring and put the booster before the the fuzz section

[tabbycat]

thanks for the layout anders. i didn't even know there was another blender. i love the original (many thanks to mark whose layout from here i used).

your feedback seems not entirely convinced. if the output was pumped back up to unity would it be a keeper? obviously it's got to go some to keep up with the original, but does it have redeeming qualities or idiosyncrasies that you think are interesting?

[anders]

Yes, the 4 knob version is one of my favorites as well, it has that end of the world octave thing going on. The 3 knobber is nothing like that, more of a  fuzzy Distortion+/DOD250 OD with different filter settings.

You are right, I was a bit dissapointed but there is some things that might improve it.
The boost or "pre amp" is way much louder than the fuzz, might stick a trimpot or a pot between the boost and the rotary switch.
A boost before the fuzz section really improves the fuzz and gain, tried a LBP1 here but will try a SHO.
A recovery stage after the fuzz to bring the output above unity.

Compared to the 4 knobber it is quite tame and weak but with some mods it could be a quite interesting fuzzy OD/distortion

[nocentelli]

anders wrote

Not sure if I will box it since the fuzz part barely reaches up to unity.

I ditched the FET and the cap switching, and on the breadboard this sounds pretty nice:



definitely way above unity. There's a tiny hint of upper octave on the decay, not as scrambled as i sort of expected from the blender name. I just used 2N3904s and haven't tried anything else, but messing with the diodes in the feedback loop yields some cool results, sound best to my ears with the sustain cranked. well worth further investigation.

[Silver Blues]

This is pretty interesting actually, your simplified version. Definitely seems like a neat platform for some mods. Now that I have four months of free time, I'll play with this once the breadboard is free again.

Seems to me like it would be nice in germanium flavor

[nocentelli]

Silver Blues wrote

I'll play with this once the breadboard is free again.

You can also replace Q1 and 2 with a single darlington transistor, e.g. MPSA13.

[Silver Blues]

Indeed, I'll try both things.

[Neil mcNasty]

Just built the preamp as a standalone circuit, and it sounds amazing! Best clean booster I've ever built!
Highly recommended!

Here's a thought:
If you build this (the whole circuit), use a 3 way rotary, leaving the preamp out, and then you feed the fuzz trough the preamp at the end to increase the level.

Also: if you want to keep it like it is and raise the level of the fuzz section, simply remove the 27K connected to the rotary switch. This resistor attenuates the signal before entering the Level/Gain pot and is the main reason for the low volume...