Recent content by temol

Before you swallow them? :) Sorry, I couldn't resist. Maybe you have a pedal where the opamp can be swapped? Single opamp.

If it works, why change? :) I've tried switching to Kicad several times and keep coming back to Eagle. Switching is difficult once you've developed Eagle habits.

Once you have the transistors matched, the fun begins with turning the bias trimmer, like a ham tuning a radio to a weak SSB station... left, right, left, right... nope. In fact, there are usually a few cool settings for a given set of transistors. There are different modulation patterns, and...

Testing the circuit on a breadboard now. three sets of matched JFETs. Same settings for the first three samples: speed, depth (max), color (zero). #1 J113 with vp around -1.75V #2 J113 with vp around -2.21V #3 MMBF5457 with vp arounf -1.6V Then #4, #5 and #6 in the same order but I played...

This yellow sulfur is quite good. Unfortunately, local suppliers only offer a powder with a smooth finish :(

@Robert - it's me again... I just wanted to make sure these are the correct connections for the dpdt. The connections in the schematic are identical, but is it possible that the A/B sections on your board are reversed?

C3 from 100n to 100u C5 from 2.2n to 22n

Thanks for the tip, I'll have to check them out. I only have versions R and Y.

The MMBF5458 is generally unavailable, but the Mouser website offers suggestions for similar transistors. For example, the 2SK932 (datasheet) or MMBF4117 (datasheet) Any experience with them? There is also TF412S but the SOT-833 package rather discourages its use.

I highly recommend two detailed tutorials from Phil's Lab on PCB design in Kicad9. They're quite long, but the amount of practical information and tips is enormous. part 1 - schematic part 2 - pcb

Almost there... 59 board is ready.

Correct. Lower cap value = less low freq content.

Some ltspice plots... Looks like C10 or C13 would be a good candidate.

https://forum.pedalpcb.com/threads/article-59-od-ics.27686/

Yes, I read about that. I only have Type 1 switch, but that means the switching should work like the original.