Thanks for this! I'm working on my own superfuzz clone, and I'm pretty happy so far using a mix of BC108B and 2N3904, all in the hfe range of 190-200. I'm planning to try some BC107As or 2N2222As to see if the sound changes significantly. Does the sound get less harsh when the octave is turned down...

Looks awesome. Have you tried it with bass at all? Not personally. I downsized my collection a few years ago out of necessity - my new wife insisted on sleeping in a bedroom instead of a project studio - so I had to sell my bass. A friend of my test tech has promised to bring in his bass so we can ...

We usually include schematics in the user manual. We weren't able to do that this time because the user manual had to be small enough to fit into a box only slightly bigger than the pedal, and the schematic would have been illegible at that scale. I'll eventually get around to uploading the schemati...

Is there an "octave off" switch mod worth doing? Sure. You'll need a DPDT switch. One pole should break the connection between the wiper of the expander pot and the electrolytic on the base of the 3rd transistor (the phase splitter). The other pole should break the connection between the ...

Yep, they do recommend that. Got that same app note. What they don't tell you is how to turn on and off a 100W incandescent bulb in 'way less than a millisecond so you can avoid polluting the measurement of the LDR rise/fall times with the rise/fall of the emittance and color temp of the bulb as it...

Getting a calibrated light source is *hard*. These are rarer than voltage reference sources. Back when I was doing this, I picked up some green LEDs, and decided that *this one, right here* was my reference source, whatever it did. This let me test LDRs on a relative basis, as they'd be different w...

I was also measuring many types of LDRs. I used the Uni-Vibe LFO and had my LDRs just sticked in and connected to a voltage divider with an output buffer. So i could measure them under the exactly same conditions as they are meant to be. I used oscilloscope with a transient recorder feature to see ...

Mate you have a big thank for the sacrifice. :hug: Can you please post a sound sample when the thing is back together? Also, when you measure the LDR's (i assume you use a voltage divider to get the LDR voltages -> resistance) keep on your mind that the oscilloscope probes are about 1M ohm and you ...

500 ohms trimmer (the bulb adjustement) and 100k for R37 makes perfect sense (helps to equal the volume of chorus and vibrato). 10n for C13 is a huge surprise indeed. There are a few other components that appear to have been swapped at some point. C24 in the power supply, for example, and a few oth...

Howdy. Sorry about resurrecting a zombie thread. 8) My introduction post is here: https://www.freestompboxes.org/viewtopic.php?p=152894#p152894 I thought my first contribution to this forum ought to be something useful, so here it is: A schematic of my Shin-ei/Univox Uni-Vibe, which I traced out mys...