Boss bypass mod

Got a dead Boss DS-1 on the bench for repair and modification. I just had to replace the fried opamp and it was up and running. I was also told to mod the pedal in anyway I liked. Ever since I made the T-rex Mudhoney 2:nd stage mod the idea has been there to try something similar on a Boss or Ibanez pedal. So here it is on a Boss DS-1 pedal, the feature to choose a latching or momentary bypass.

/Krister Östman

Colorsound Flanger

Now here’s a rare pedal I got on the bench, a Colorsound Flanger.

However in a no working condition, Looking at the guts I’d say there’s some work to be done if it will ever work again.

Beyond repair? Well normally I’d call it electronic junk but looking closer at the circuit board there’s is still one component that makes me want to give it a try, the rare Reticon SAD512D BBD IC.

If anyone sits on a schematic for this pedal and like to share it with me I’d be very happy.


T-Rex mudhoney mod completed

I found the time to get my mod for the Mudhoney done. First a gut shot of the pedal in its original state, nice and clean.

First thing was to remove the HEF4013 in order to take control of the bypass circuitry.

The new circuit board that will control the fet bypass circuitry and the boost.

Here’s a caption where I’ve mounted the footswitches for bypass and boost, two toggle switches for the momentary/latching option and a third one for the clipping diodes.

The clipping diodes a pair of AA144 germanium.

Time to do some wiring then. The effects circuit board has had the boost switch removed, the original clipping diodes lifted from the ground plane on the circuit board. The new pot for tuning the gain is also in place. Here’s a caption of it wired up.

And a short video in an earlier stage where I’m testing the switching options.

And a picture of the pedal when it’s all done.

Well what can you say, that turned out somewhat different compared to the original.

/Krister Östman

New T-Rex Mudhoney mod

Working on new mod for the T-Rex Mudhoney pedal. The plan is to use two stomp switches as in the mod I done before. One controlling the Boost on/off and the other one for bypass. What differs is the option to choose between latching and momentary action for the stomp switches.

Here’s the circuit board to be fitted.

/Krister Östman

Guyatone Rolly Phase Sonix PT2

Finally found the time to finish this phaser. Replaced the electrolytics,  adjusted bias for the fets and it sounds as good as new. I really like the off board wiring done to it. Shielded wires for everything in the signal path. 

The opamps have sanded but they are all seem to be LM1458:s. 

The bypass switch is a nice, non-clickinging type. Never encountered them before. It’s not wired for true bypass.

The pedal works of a 9VDC battery but also have a DC jack, though the circuit uses +/- 4,5VDC from the power source so it can’t be daisy chained.



It struck me during a recapping of an early -80: s effect pedal. Sizes has shrunk on the electrolytic capacitors throughout the years.

The left pair is a 16V47uF and a 35V47uf, the other pair is a 16V10uf and a 25V10uF.