Tuesday 30 June 2020

Earthquaker Devices Hoof Reaper

With an added mod from Fuzzdog which took the octave control  from EQD Life Pedal so you can dial in the amount of octave up as you desire.
Schematic and info HERE




Kod DS-4 Distortion

An old polish distortion which seems to have a few things common with a Rat but more things that differs from it so I thought it was a worthy addition. The transistors is buffers so you can use most NPN silicons in there.


Friday 19 June 2020

Roland AG-5 Funny Cat

Slightly modernized version of a the old wierdo Roland AG-5 Funny Cat. Original had discrete op amps and a transistor emitter follower which for this layout has been changed to regular op amps.
It is also modified for true bypass.
Schematic and info HERE





Way Huge Swollen Pickle Mk. I

There hasn't been a Big muff in a while.... Layout of Way Huge Swollen Pickle Mk. 1 with pads for transistors instead of the the transistor array of the original. There is also a switch that has toggles betwen the stock 47nf low pass filter cap in the tonestack which gives a very mid scopped raesponse. The other position has a more flat response with a 3n3nF cap to ground.


Friday 12 June 2020

The Gristleizer

Quite wild voltage controlled modulation and filter circuit by Roy Gwinn dated back in 1975. The most famous user was probably Chris Carter from Throbbing Gristle.

Some mods have been done for this layout  to make more compact and reduce ticking and hiss which is a common problem. Many thanks should go to mictester from FSB and Fuzzdog.

Original had five LM741 single op amps which is merged into a quad and a dual op amp. The dual op amp is in the audio signal path so low noise devices is used like NE5532 or LM833. The quad op amp handles the LFO and a LM324 is reported to have the lowest noise from ticking.

Other mods includes a higher value of resistor connecting to pin 2 of IC1 for higher input impendance and Level control value is reduced from 100k to 10k.

More info about setting the trimmers, schematics and even more mods at FSB , MusicPCB 
and Fuzzdog Pedal Parts

The layout is verified and working really good although there is still some faint ticking, especially in square wave mode.

 

Thursday 11 June 2020