[2241] Mod Box Distortion

Date: July 12th, 2017 | Comments : [5] | Categories: DIY.

Mod Box schematic

I found this old distortion project while searching through a magazine archive.

Back in the late 1990s, Thomas Henry and I collaborated on a number of articles for consumer magazines. One of those projects was a distortion pedal that was published in Radio Electronics in May 1997.



[2233] Boss SD1 More Mids

Date: July 7th, 2017 | Comments : [1] | Categories: DIY.

SD-1 tone control

This is the basic tone control section of the classic Boss SD-1 distortion pedal.


[2227] SD-1 vs. TS-808 Response

Date: June 10th, 2017 | Comments : none | Categories: DIY.

SD-1 and TS-808 response

After reading a recent forum post, I got interested in the basic frequency response of the SD-1 compared to the classic TS-808.


[2213] Effects Pedal Circuits Can be Patented

Date: April 11th, 2017 | Comments : [4] | Categories: DIY.

For about the third time in less than a week, I have seen someone post in an online forum, the erroneous information that pedal circuits cannot be patented.

Yes, they can be patented, and many classic circuits started out being protected by patents. Tom Scholz, for example, had numerous patents related to his Rockman devices.

Here is a page with some pedal related patents:

50 Audio and Effects Pedal Patents


[2187] Second Source Transistors

Date: January 25th, 2017 | Comments : none | Categories: DIY.

In 1957, Valvo-Berichte introduced the original OC81 germanium transistor (first source) which means that any other versions of the part are second sourced (Philips, Mullard, DSI, etc). It has long been a common practice for other manufacturers to offer their own version of parts, sometimes via a license but often just as an alternate work-alike.

Just because a part is second sourced does not mean that it is a fake, as mistakenly posted occasionally in online forums. Many semiconductors are made by companies other than the original producer, and more often than not, perform just as well.

Along that same line, in opamps, a Signetics NE5532 would be first source and the TI 5532 chip would be a second source. The 7660 charge pump is another example and there are numerous copies of it available. Also, the 4558 opamp is made by just about everyone, and no one says they are fake just because the specific 4558 is not produced by the company that first introduced it (Raytheon).

The spec of the OC81d is similar to the AC128, which is sometimes listed as a substitute.



[2197] Voltage Doubler Module

Date: January 20th, 2017 | Comments : [2] | Categories: DIY.

Voltage Doubler module

Voltage Doubler assembled module
The charge-pump voltage booster module. Fully assembled and ready for installation in your pedal or project. Boosts 9v DC to almost 18v. Also provides −9v for PNP fuzz pedals and other circuits that require a negative voltage.

Order the module from the AMZ Catalog Page.



[1665] Good Band Names

Date: January 18th, 2017 | Comments : [3] | Categories: DIY.

I’ve updated the page of FREE Band Names… check it out if you need a name for your rock-n-roll ensemble!

Good Free Band Names


[2190] Tone Report Weekly Issue 159

Date: January 11th, 2017 | Comments : [1] | Categories: DIY.

Tone Report Issue 159

Issue No. 159 of Tone Report magazine has an article on how to DIY my mosfet booster. The author was very complimentary of both me and the circuit, which I greatly appreciate. If you don’t like working with stripboard, as shown in the article, there are pc boards and completely assembled modules available on my catalog page so you can build your own mosfet boost.

The pcb and modules have a refined version of the circuit that improves performance slightly.



AMZ Home Page

Guitar FX PCBs