Dharma Sound / Colorsound Distorter

Here is a forgotten oldie that has been requested ever since Colorsound released a small run of replicas in the fall of 2023. Dharma Sound was a small operation builder from Kent, OK, active in the 70s. 

The circuit design is pretty interesting; first a BJT input buffer. Then the signal is split into two parallel active fixed filters. The signal is then joined together before it hits the LM741 op amp with stacked clipping diodes to generate distortion. . Sound clips suggest that it sounds like a distortion with a cocked wah tone.

Schematic is avaiable HERE.

Oh, and this is post #1500! 

*Edit 24221* Verified by Henrik.

Colorsound Vocalizer

 A rare bird in the Colorsound range. Some additional mods can be made. Replace the 3,9k resistor with a 10k pot for a Freq control. And try a PNP Germanium for Q1 which smoothens the feel of the formant filter..

Schematic is avaiable HERE.

Colorsound Octivider

 Schematic is avaiable HERE.

Colorsound Overdriver MOJO layout

 

Colorsound Hybrid Tonebender 2018 Edition

Couldn't resist to draw a schematic and a layout for this interesting mutant of a circuit that just got traced. 

 First two gain stages is almost identical to a Jumbo Tonebender (except for one cap and one resistor value), the third gain stage is almost identical to the saturation stage in a Tonebender Mk. 3. Transistor bias is quite different with the zener diode, though. Tonestack is Big Muff style followed by a Volume control.

Note that earlier versions had 100nF or 470nF instead of 10nF so it might be worth socketing that cap.

 

 

 

 

 

Park Auto Wah

 Not an auto wah in a normal sense, more like an inductorless wah circuit driven by an LFO.

This must be one of the earliest modulation pedals and IMO it is a hidden gem. Lots of murky psychedelic madness can be found in this circuit, especially with a dirt box upfront. 

Rate and Depth controls is self explanatory but the Tone control really widens the ranges of tones. Clockwise you'll get normal wah wah sweeps, roll it back and you can dial in vowel and yuo-yuo sweeps. 

With the Depth control CCW, the LFO is disengaged and the unit acts as a eq / filter circuit.

Layout has some mods; power supply mod since original units was positive ground, CBE pinout for the transistors, power filer cap and protection diiode. As for the transistors, most low gain NPN silicons should work, I ended up with PN2222s in the 150Hfe ballpark. 

This is soon to be boxed but need to figure out how to add a rate LED first...

*Edit* Rate LED added with help from Radu.  Thanks!

Schematic is avaiable HERE

 

 

 

Colorsound Sustain Module 1 switch version

 Here is a rare old and quite unique circuit that hasn't been traced before. With lots of help from AlexS and cobyjoe we managed to trace it and a have a working clone.

So what is it? Not to be confused with the Supa Sustain, this is a quite gnarly and fat fuzz with lots of output on tap. Some parts of the circuit resembles to a Fuzzrite (Q2 and Q3) with a feedback path that that has lots of odd things happening (Q4, Q1, D1 D2). 

There is also a 2 switch version with an added switchable transistor stage but I haven't managed to trace it yet....

 

 

 

 

Colorsound Supa Sustain

 An old school, loud, dirty and sometimes noisy compressor that seems to be inspired by Roland Sustainer. The original runs on two 9v batteries for 18v operation so I included an onboard voltage doubler. It might be a good idea to socket both the LED and LDR to fine tune the the compression.

Colorsound Tremolo V2

DAM/Solasound Tonebender Mk II The Hybrid

Verified by AlexS

Colorsound Tremolo V1

Park Fuzz Sound 2-knob

Colorsound Power Boost

Now verified by Alex. Thanks mate!

Colorsound Bass Fuzz

Unverified

Colorsound Jumbo Tonebender

Solasound Tonebender Mk. 1,5

Colorsound Tonebender Mk. III pre 1972

Colorsound Fuzz Box

Solasound Tonebender Mk II

Solasound Tonebender Mk I