Build Reports

Showing 6 build reports for the Helios project. Submit yours →

John Morgan-Evans
Score:
8

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Toxic Rat

Project: Helios (RAT Distortion)
Variant: High Quality Caps

Build description

This was a fairly standard build following the instructions. I did not install the softness trimpot because this pedal was going to be screwed down to a board. Germanium and silicon diodes were used, not LEDs.

Modifications or part substitutions

The only difference I made to the standard fit-out was to use film capacitors in every possible stage. Where electrolytics had to be used they are Nichicon audio caps. I used a huge polystyrene cap in C2 as I don’t like tantalums. I had to put this in a 1590BS case (slightly deeper than the 1590B) because with the pots mounted on the PCB it wouldn’t fit otherwise.

ChuckHDTV
Score:
8

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Evil RAT

Project: Helios (RAT Distortion)
Variant: Sweep control and clip switch

Build description

Nice and clean as usual with Auon’s PCB. It sound great. First try at etching with Ferric Chloride. Turned out great looking.

Modifications or part substitutions

lM308N chip, socketed the second set of LED. Deported the 3mm red LED in the eyes. This gives the “evil” look.

Mrav
Score:
6

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FAT RAT

Project: Helios (RAT Distortion)

Build description

I made this one straight by instructions. Choose an LM308N for op-amp, and 3mm green LEDs for second clipping. Black 1590b enclosure with graphics on the white water decal.
I’m very satisfied with the PCB quality, as with the sound of this pedal.

Robert Jackson
Score:
6

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The Legend of Rat-Boy!

Project: Helios (RAT Distortion)

Build description

I had a couple of things in mind with this build. First off, if you look at photos of the early hand-built Rat pedals, they had tantalum capacitors. Those were very expensive in the 70’s and they didn’t make it to the mass-produced version, but I wanted to go that route.

Also, I built this with a socket to try several op-amps. I actually wanted to prove that there’s no audible difference between the current Texas Instruments OP07DP and the original LM308, which I had in both the DIP8 and TO-99 packages. I figured the modern TI op-amp would be fine, since its slew rate is as low as the old LM308. It just doesn’t sound the same, though. Also, it turned out that the old TO-99 LM308 sounded MUCH better than the DIP-8 version I had. Which seems odd, but made me wonder if the DIP-8 version I bought was a counterfeit. On the alternate diode pads I set up asymmetric Boss-style silicon clipping and that turns out to be the setting I mostly use.

As always, this PCB was a delight to build. I love the work Aion does with these old circuits and the options offered for experimentation with nearly every project.

Modifications or part substitutions

Old-school LM308 in the TO-99 enclosure. I had to put a couple of drops of epoxy on the legs to make sure it didn’t pop out of the socket. Also, asymmetric clipping on the alternate diode pads.

Pat
Score:
3

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Rattus Maximus

Project: Helios (RAT Distortion)

Build description

This was a great chance to build a high quality Rat clone with extra features. I went with germanium diodes for the other clipping section. They help to produce more of a 60’s style fuzz that sounds looser snd softer than the stock silicon diodes. I used a LM308 chip, which is essential for authentic Rat tones. This one sounds as good as my vintage big box Rat.

M
Score:
3

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RAT LM308N

Project: Helios (RAT Distortion)

Build description

As always, really high quality pcb to use as a foundation for a tailored pedal. Clear points of reference for modifications. Compact size, but has enough room for a wide array of component choices. Yellow finish also adds a slick look to the internals. Kevin is an absolute legend. Love his commitment to putting out the best boards and the best projects.

Modifications or part substitutions

I wanted to figure out why O’Malley of Sunn O))))))))))) liked a modded RAT. As soon as I plugged the unit in, I understood. I don’t like stock RAT units very much, but if you do some digging you can get a great monolithic tonality from this circuit.