I’ve been fascinated by the Stompboxology and Stompbox Cookbook projects for a long time. I’ve only built a few and many of the ideas are hit and miss. The concepts presented are compelling none the less.

The Distort-o-matic VI for example, uses a very off the wall concept. The input signal is imposed on a 40k carrier wave. The carrier is a square wave generated by a 555. This signal is then fed to a high frequency transducer. The device has a high frequency receiver to pick up the signal from the transducer. The high frequency signal is filtered to leave the original input signal. Who thought of this? And what was going through their mind at time? This is so nutty!

Not sure what it will sound like. Figure you have to built it and find out. This is where we get to the hit and miss quality of the Stompboxology projects. Stay tuned for some sound samples…

I ordered all the parts to build this thing a long time ago and never got around to building it till now. Joe had the idea that we should explore the 555 and find some new things to do with it. So I dug the Stompbox Cookbook and found the Distort-o-matic VI. I etched up two boards and drilled them.

Here’s a picture of an Ugly Face I made recently. For the graphics on this I used PnP. Not sure how this is going to work out. This is second effect I did with this method. This one came out better than the fist.

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Shocktave Build

This worked right after I found a small solder bridge grounding the input cap. The PCB layout I posted has some very small traces that are very close to the ground plane. I thought this was going to be a nightmare to solder. It was actually not too hard. I found careful application of small amounts of solder worked well.

I had to sub a 2n5089 for a 2n5088. Since I only 4 2n5089s on hand. I picked the Q1 as the substitute.

My first impression was wow this is so distorted I’m not even sure that it’s working. After some testing I notice there is a very nice octave that comes out at times. Seems playing single notes around the 12th fret really brings out the octave, go figure. The octave sounds very nice under the right conditions.

Chords throw everything out the window. Playing a chord seems to make the sound explode into a barrage of noise, and not very musical noise at that.

Could be good for something. The mix is useful. Turning it down you can mix the octave to a pleasing level. Turning the mix all the way up produces a random arpeggiated note sort of distortion. This has some potential, but is hard to control. Q4 and 5 form an oscillator that is driven by the input signal. I wonder if  there were a control control the frequency of the oscillator if some more interesting sounds would come out.

The oscillator portion of the circuit stumps me. I don’t understand how this works and have not been able to find anything similar for reference.

I have been thinking about making Joe Davidson’s Shocktave for many years now. I have yet to build it, the PCB in this post is unverified so far. I’m finally getting around to it.

I had built a BSIAB II while back that had all of the transistors in a row. This made for a fun layout. It also made it convenient to use a single 15 peg milmax header as a socket for all the transistors. This worked out well, so I thought I’d try the same idea here. It works out especially nice since all the transistors are the same and face the same way. Hard to put the wrong one in the wrong place or backwards. Not that I would ever do that.

I’m sorry the values are hard to read to in the layout. I’m a beginner with Eagle. If anyone knows how to arrange the values are part names individually please post a comment and let me know.

This is the classic route to distortion. It seems to be included in many designs. Clipping diodes to ground have many different configurations and choices of diodes. Here’s a great thread talking about clipping diodes to ground.

http://www.diystompboxes.com/smfforum/index.php?topic=82764.0

Here’s a project that I built up some years ago. This never found it’s way into a box. I dug it out and decided to try and box it up. Difficult with the number of switches and knobs. I think I have a viable plan to shoehorn it into a BB sized. box.

This is a pretty interesting distortion box. It’s sort of a Tube Screamer, Rat, Distortion +, with an Octave up. When I finish it up it should be all of those things in one box.

This was built using the layout generously provided by R.G. Keen of GEOFEX fame.

Here’s my take on the Ugly Face/Crash Sync. I took my favorite parts of both and a few suggestions from RunOffGroove and the DIYStompboxes forum.

This version uses a different input buffer, which more closely resembles the input of the Crash Sync. Though it has a greater gain. I found this gave more sustain. The Ugly Face has a gain of about 200. The Revolting Visage uses a gain of about 1000.

I took the envelope from the Ugly Face which is simple and elegant and seems to work well for this design.

I also borrowed the Threshold from the Ugly Face. Which allows for self Oscillation.

These last two features do not exist on the Crash Sync. But, are a lot of fun to play with.

I changed the output to be directly taken from pin 3 of the 7555. The Ugly Face used a strange arrangement that was also connected to pin 7. The pin 3 arrangement makes more sense to me and is simpler.

I like the Tim Escobedo’s Ugly Face I’ve built about 7 now. This is a really fun pedal. Total Sonic Mayhem. Not for Jazz, though I’m hoping someone will take that as a challenge…

Something that is not really a problem, but has always bothered me is the volume. The Ugly Face is extremely loud. The output swings about 0 to 9V. Which leaves a small usable range on the volume knob.

Lately I have been adding a 68K resistor in series between the volume pot and the output from the circuit. My measurements seemed to suggest an 80K would be better but I had 68K on hand. The the thing is still way loud. But now at least volume pot seems to have a more usable range.

Built Jack Orman’s Son of Screamer last night. Fired up the first time and sounds pretty good. I have not owned a Tube Screamer before. After building this I’m understanding the complaints about the “mid hump” in the sound. The sound is very focused in the mid range.

There seem to be many mods for this floating about. So I thought I’d build a second one to compare to the first. I picked out the LovePedal Eternity. There is a good thread about this one here.

From the schematic it looks like the Son of Screamer with a few changes in parts values. From what I can see it seems the Eternity just increases the lows as described in this article Muzique.com.

Of course the next step is make the RunOffGroove Tube Reamer for a final comparison. Looks like the Tube Reamer adds event more.

It looks C2 is increased from .047 to .1, from SOS to Eternity, and doubled again to .22 in the Tube Reamer.

This is an interesting distortion effect with an octave and wah like tone control. I redrew this schem from an issues of Stompboxology.