Topics

A friend gave me a nice set of Accutronics spings, so I needed to build something with that. Doing some research, I learned that this particular tank is best used in connection with op-amps, so I settled on Craig Anderton's classic: the Stage Center Reverb. Doing some more research, I found discussions on DIYSB on the 'Mark Hammer mods', and implemented those in perhaps a bit extreme form: I used two modboards with rotaries from Nucleon FX (thanks Rockhorst!) to switch between alternative caps before and after the tank. This is a very effective way to change the sound (the tone knob doesn't do much).

There's a LT1054 to make a split power supply, extra filtering so I can use a salvaged 12V power supply, extra outputs (incl. regulated 9V) to power pedals from the reverb, and LM833 opamps which are comfortable driving the reverb tank (and can take higher voltages). The enclosure is from Musikding ... it is sold as a looper enclosure, but when I received it I found out it is actually a piece of wire gutter cut to size ... Kind of unexpected, but it actually works pretty well.




Gut shot (built on a prototyping board and some stripboard for the power filtering; not the cleanest build but I was making it up as I went along  ):


Action pic in front of my Champ (built from a kit), with a modified Timmy (real mosfet clipping rather than the body diodes that are so often used  ).


The sound is pretty okay, with some nice sproiiing and boiiing going on , though I wouldn't mind having a bit more sparkle in the highs. Low on hiss and hum, unless you turn it all the way up (which sounds horrible anyway). Nice extra: you can kick the tank to get a nice clang without hurting your amp. It's a different sound than the brick-based reverbs, which I would generally recommend for your pedalboard (though this spring reverb is more fun to build  ).

Here is my Mandroid build. I was really anticipating this project as I wanted to dive into noisemakers again  . And this one surely delivers! Many different sounds to be had: lo-fi gritty detuned nastiness (don't expect pristine pitch shifting), tunable ring-modulator, etc. In 'robot' mode (step 8 on the rotary), you get a sort of rhytmic drone that can be tuned with the warp control. However, both speed and pitch will change together. The possibility to blend in the dry signal is really useful, that's really what makes the circuit shine for me.

A somewhat serious limitation is that it needs its own isolated power supply, which is a pain for my pedalboard setup. The 'vibrato' is rather weird, so that fits well with the oddity of the rest of the pedal (but not something I particularly like at the moment). The splode is interesting in robot mode, but that is something I have to explore further.

For my taste, this pedal really comes alive when you feed it an already distorted signal. With the internal gain trimmer maxed, it is still not enough for me. More distortion really smoothes out the nastiness, and let's it blend in better. This circuit might benefit from more gain (larger trim pot perhaps, or other diodes?) or a built-in fuzz circuit at the front. For now, I simply put a dirt pedal in front of it.



Gut shot below. The unconnected wire with the tie wrap is a ground wire from one of the switch pads. Forgot to remove it, but will just leave it there as it might come in handy whenever I decide to mod this thing.



Oh, and if you want to scare your kids: connect a microphone to the input and sing a lullaby 

I am planning to build the Tapanator(ator), trying to undertand the schematic, and was wondering about the wiring of the trim pots 1-3. I was expecting a variable series resistor (to limit current) or a voltage divider with the LED on the wiper, but instead the 5V supply is on the wiper. If a trim pot is set to its minimal position, that would mean that there is only 330 Ohm resistance between 5V and ground. Seems like a waste of current ... So, is there a need for wiring the trimmers this way in this circuit?

I already started posting, and just now spotted that there was a section for introductions ...

I have been building pedals since 2007, starting with a BYOC tremolo kit; that looked simple enough to build without soldering or electronics experience. The thing worked, sounded great, and I got a new hobby (or better: addiction). At this point, I have built close to a hundred guitar pedals, ten amps, and a few bat detectors. By the way, if you have built more pedals already than you'll ever use, consider building a bat detector (if you're interested in wildlife, that is).

I mostly build for my own pleasures, but I have made (and modded/repaired) a number of pedals for close friends, and sold a few that I did not like enough (but were built sturdily enough not to embarrass me) on the internet. I try to cut down on building new stuff, but then I discover some new projects or schematics ...  (looking forward to the new VFE projects at MB).