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Penfold Autowah file: 000046   1/24/102 4:46 am
This is an autowah construction article from Electronics and Music Maker (I think) that RG Keen was nice enough to send me some years ago, and I finally got around to scanning. I believe it is from somewhere in the very late 80's or early 90's. Haven't built it, but the parts are all there teasing me from their bins. Looks like a good design with some nice features, including initial frequency and resonance, as well as (apparently) low envelope ripple.

One of the key features is that it is a lowpass filter, which is good for bass. More conventional bandpass-type effects can also be gotten from it.

As with all these scans, I can't vouch for all PC layouts being exactly to scale. You may want to print it out and compare it against an IC to evaluate the amount of enlargement or reduction required,

Make your own battery snaps file:   DIY-snaps.pdf 000045   11/12/101 9:04 pm
This document illustrates and describes how to go about making your own heavy duty battery snaps, using parts from dead 9v batteries. Easy to do. You will need:
- a dead or very limp 9v battery
- some pliers or wire cutters
- some red and black 22awg multistrand hookup wire
- a hobby style glue gun and hot melt glue
- a soldering iron

Another perfboard build file:   tsf-pix.jpg 000044   11/12/101 3:41 pm
This is a blow by blow of my old warhorse modified Tube Sound Fuzz. The sequence of images is intended to let you see how the packaging occurs with a piece of free-standing perfboard. 1. Shows the leads coming from the board on one side. 2. Shows how the board is intended to fit in the chassis when packaged. 3. Shows a piece of foam (actually cheapo carpet underlay) tucked under the board so that nothing shorts out underneath. The same long narrow piece gets folded over the end of the board and onto the other side. 4. Shows the board safely tucked in place. The tail end of the foam keeps the battery from flopping around, although the wires help that mission too. 5. This is the musician side of the pedal. The "Gain" switch kicks the gain up in the first op-amp stage but sticks a resistor in series with the output level pot to keep volume level relatively constant. Adds more hair to the signal. The "Filter" switch goes between a passive 2-pole lowpass filter just ahead of the output level control (set around 2khz or so from what I remember), and another fixed resistor intended to keep perceived loudness about the same after the switch-over.

The choice of slider pots and rocker switches was an attempt to salvage a 1590BB I had originally machined for something for a keyboard player friend. As luck would have it, the spacing between the two rocker switches provides a nice little "nest" for the battery.

Just an example of what packaging a perf'd project can look like.

Mosfet Booster pix file:   mosfet.jpg 000043   11/12/101 5:11 am
Okay, so it's a vanity thing. Latest pedal - Jack Orman's MOSFET Booster project (available at

Electro-Harmonix Guitar Synth file:   EH-Guitar-Synth.ZIP 000042   10/26/101 8:46 pm
Once upon a time, Electro-Harmonix produced a REAL guitar synthesizer. Not a glorified octave divider/fuzz/autowah, but a real land-of-1000-knobs rack-mount with pitch-to-voltage conversion, multiple VCO's, envelope generators, the whole kit and kaboodle. It was clearly intended to compete with the Arp Avatar and the first Roland Guitar Synth. If you scroll down and look at the EH price list I posted, it wasn't cheap either.

Steve Giles was lucky enough to find the schematic, and gracious enough to send it to me. So here it is folks, 4 GIFs in a zipfile. It's about as accurate as we're likely to get 20 years on.

Enjoy.....and, uh, don't try this at home, kids.

B.B.Dementia file: 000041   10/9/101 7:34 pm
Matsushita-Mania has been replaced!!

By the grace of Mike Irwin, Kristian Schlager, Christian Landry, Manolo Dudes, and probably some other nice folks I've overlooked, this is becoming the single best source of info on BBD devices on the web. Most of the files in this 5.5M zipfile are in PDF format though some are zipfiles of JPG or GIFS. I have more datasheets at home which will get scanned in time. The files are organized here into categories for your perusal. There are probably many you never even knew existed.

Clock chips: Matsushita MN3101, MN3102, MN3105

Matsushita BBD chips:

MN3004 MN3204 MN3304
MN3005 MN3205 MN3305
MN3006 MN3206 MN3306
MN3007 MN3207 MN3307
MN3008 MN3208 MN3308
MN3009 MN3209 MN3309
MN3010 MN3210


SAD512 (8 and 16-pin versions)
Reticon product summary (including some limited data on R5xxx series chips)


Philips TDA1022

If you happen to have datasheets for any other BBD chips, please contact me at I'd like this file to be a complete package for anyone interested in BBD-based effects.

Pocket Rockit Practice Amp file:   PocketRockit.PDF 000040   9/13/101 7:19 pm
This is a project article by Jim Fiore appearing in Electronic Musician in 1987. It details construction of a small LM386-based headphone/practice amp that can produce surprising volume levels if connected to a small speaker and given enough battery juice.

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