Sunday, 27 October 2013

Ampeg A3 Overdrive

From During MTI's ownership of Ampeg, everything was being built in Japan. Ampeg's most extensive line of pedals is no exception. In production during 1982 and 1983, the "A" series effects were housed in black steel boxes with brightly colored graphics in pinks, oranges, blues, yellows, etc., and included nine pedals and a "systems box".

From what i can tell from the prices i've seen - these are very collectible pedals. Might be a nice subject for building your own. The semiconductors are not mentioned (other than 4558 as opamp) on the schematic, but as the transistors are used as buffers, you should be fine with 2N3904, 2N5088 or similar. The clipper diodes are silicon, so 1N4148 should be very close to the original.

Friday, 25 October 2013

Monkee Music Satan Distortion

Been waiting a long time to post this one up. Yup. It is 1:1 with Rocktek DIR-01 Distortion. The schematic i found was missing a couple of values, so instead of guessing i got myself an original and checked them. My original just happens to be this beautiful japanese plastic thing. It doesn't quite reach the unity level, but there's one resistor determining the overall level. I marked that with an asterisk on the layout with a note, so you can swap it for something like 10K. This one is definitely nice platform for trying on some mods. Schematic is up at FSB.

While checking for additional info, i ran into this perfect demo video of later Rocktek unit. Priceless. Just Priceless.

Thursday, 24 October 2013

General Guitar Gadgets D-Verb

A nice simple reverb project that a few people have asked for, with this layout based around the BTDR-2H brick.  The short description from the GGG website:

This is a great sounding digital reverb project.  Based on the Belton Digital Reverb Brick.
This really is an excellent reverb and is also the base of some of the reverb units being built by Hermida Engineering, used by many big name guitarists.

I've left the original layout up, but this is one row smaller so thought it worth adding for anyone who wants to keep the size down:

Wednesday, 23 October 2013

EHX Axis / Guild Foxey Lady 2-knob

The circuit is exactly the same in Electro Harmonix Axis fuzz and Guild's 2-knobbed Foxey Lady. 2N5133 may and will be very hard and expensive to source, so i'd suggest trying out any low hFE NPN Si transistors. Or go wild and try on anything you like. The cap values of 50µ and 4µ is another issue. Go with 47µ and 4.7µ. Should be close enough. I've added polarity protection and pulldown resistor, but you could omit them and save a column in order to make it verbatim with the original.

Monday, 21 October 2013

Yerasov Gamma DS-1 Distortion

Old Yerasov Gamma series distortion. Box totally looks like a Boss rip off, but the insides are not.

Friday, 18 October 2013

ZVex Distortron

Don't bother asking for a schematic. One doesn't exist. This layout is based on FSB thread on the subject....  (yes, you'll need to log in to see it)
The thread at FSB got wind under its wings after this layout, so the questionable values are finally confirmed. Here's the final layout with updated values (56n -> 22n and 10n -> 100n).

Thursday, 17 October 2013

Ibanez CR5 Crunchy Rhythm

As requested. I happen to have an original unit in metal enclosure, and to my ears this is definitely one of the greatest Ibanez overdrives. This layout is with your standard transistor pinout and with input buffer omitted. Reason for omitting the buffer is quite obvious... It is big, but should fit in B-box without an issue. Clipping diodes are placed so that one can easily add a switch for them. I would personally probably go with two red LEDs and two (or four) 1N60Ps.

Edit: There were a few errors on the layout (transistor labeling, vref via 1M to wrong input, HF tamer cap location and a vref via 100k to discrete opamp). All of those are now fixed and the current layout is verified. A/B'd this circuit with my original unit, and the differences between the two are minimal. Still one of the greatest Ibanez overdrives!

Tuesday, 15 October 2013

Ibanez BS10 Bass Stack

There you go John. We'll never have enough bass designs... This one is basically a Rat for bass.

Thanks to John, this one is now verified. Which also means that the LM7 and FC10 should be safe to build.

Ibanez LM7 L.A. Metal (layout v2)

Another redux drawn from Dirk's schematic..

Monday, 14 October 2013

Ibanez FC10 Fatcat (layout v2)

Ok. As the original layout for this circuit was originally drawn from a bad schematic and altered later, i thought it would be a good idea to redraw this from a trusted (Dirk Hendrik's) schematic with original buffering in tact. I also removed the old one from the archives... As this Rat adaptation shares the original board with LM7 and BS10, those are on their way too.

Info from the database:
A wide range of distortion sounds, a fat sound, and plenty of sustain characterize the Fat-Cat Distortion. Unlike typical overdrive units, when high gain settings are used, the fatness remains, allowing the FC10 to be equally effective on lead or rhythm guitar.

Like the TS10 and DS10, the FC10 gives extreme level boosts to incoming signals, creating an overdrive distortion effect. Enough gain is available to overdrive even weak signals, such as single-coil type guitars and low sustain/fest decay tones (bringing them up to a high sustain level).

To get the Fat-Cat "growling" distortion sound, turn the distortion control up high, while keeping the level control low enough to limit additional overdrive at the input of the amp. The tone control can be used to add harmonics for brightness and controlled feedback. High tone settings increase attack articulation, especially helpful on guitars with humbucking pickups.

Thursday, 10 October 2013

DOD 555 Performer Distortion

The orginal unit uses two 9V batteries and electronic swithing. I removed the latter, but left the supply voltage wanting the 18V. With this, i also left the (possibly) destructive polarity protection method in tact. For the supply, one can use two batteries or add a small daughter board to pump the standard 9V voltage close to desired 18V. That pump would be something like this or this.

DOD Studio Bifet Preamp / 410

Without the pseudo-balanced output and adapted to work as a stompbox. Not really sure if this is worth a build as it is supposed to be not that loud. Simple design with low parts count, so it might be nice thing to experiment on... The pot tapers are not mentioned on the schematic i found, but i suspect that linear should work well enough for both.