Fuzzbox, Distortion, Phaser, Chorus, Echo and other Guitar Effects Info

The AMZ V-Dub pc boards have arrived. This is an updated circuit for a 9v-to-18v converter that has more features and improved design. The old V-Dub articles can be found here and here.

Read more about the new circuit and order a board!

Be sure to check out the 50 interconnected guitar effects pedals in this art exhibit:

Rose Cypher AUAM09

I found a factory schematic of an ancient EH pedal called The Silencer. It has been in my old notebook of FX schematics since the 80s. I scanned the page and put it in the schematics archive. Go to the AMZ home page for the link:

AMZ Home Page

I don’t know what the part number is for the jfet. Note that this is a buffered bypass pedal.

While reviewing some very old schematics in a notebook I found stored in a box in my barn, I realized that the new multi-purpose opamp pc board could be used to make a fuzz box with many of the characteristics of the old MXR Distortion Plus, or the EH Muff Fuzz. I have now added the parts list and schematic to the info that is sent to everyone who orders one of these boards:

Multi-Purpose Opamp PCB

The new AMZ Multi-Purpose Opamp pc board can be used to build one of several projects, including a guitar direct box. Read more about this versatile pc board and the projects that are available for it:

Multi-Purpose Opamp PCB

While doing some clean up work on this site, I happened to look at the old AMZ Guestbook, which preceded this blog. Some of the links that were posted there are dead but there are plenty of interesting and informative items still available. It would be worth your time to look through this archive of information.

AMZ Guestbook

Enjoy!

If I had ten cents for every time that someone posted on a guitar pedal forum that it was bad to place a buffer in front of a fuzz pedal, I could go to Starbucks every day for a month.

First, they is no universal agreement as to what specifically defines a fuzz pedal. Even the effects manufacturers are not in agreement about it. However, most everyone agrees that the fuzzface design is indeed a fuzz, and that placing a buffer in front of one will change the sound. I concur.

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Last week, I saw a picture of the inside of a custom pedal, with extremely neat wiring. All the wires were routed in orderly parallel rows to the switch, jacks and pots. Very neat and a beautiful construction job.

However, in my opinion, it is a poor method of construction for most pedals. The spaghetti wiring method with wires taking short paths to their destination is much preferred.

In audio circuits (like pedals) we are dealing with low signal level and high impedance. This is a recipe for problems if the wiring layout is not done properly.

Parallel strands of solid core wire can lead to extra stray capacitance, induced noise and oscillation problems that could be avoided with a different wiring method. Two solid wires next to each other will form a capacitor – Craig Anderton used this method in one of his designs to form a low value capacitor (5pF as I recall) to filter out noise. Conductors in a guitar cable run in parallel and the capacitance can be as much as 100pF per foot! This stray capacitance could be avoided by not having wires bundled or in parallel rows.

The spaghetti wiring method has no wires running parallel and many cross at right angles, which is preferred to reduce crosstalk and induced signals, which may cause feedback oscillations. Keep the wires short and direct.