Project 1B – The Skinny Gett

Like any sensible noise maker, I love cascading gain stages and strange tones. For a few years now, I’ve been using big fuzz tones with octave up and octave down, octave all over the shop.

Whilst working on the Fat Gett with its glitchy sub octave fun, I thought about pairing the Gett with an octave up instead of octave down. I know that there are a couple of ways of doing octave down in analogue electronics, but no way of doing true octave up without going digital. There is however a clever trick you can use to get a pseudo octave up effect.

Different transistors amplify different harmonics in the guitar signal. The shape of the circuit and how the transistors are biased also affect the timbre. The green ringer (I think the original is by Dan Armstrong, though it seems to have been gifted to the DIY community) works by putting the transistors in such an arrangement that the octave above the fundamental is emphasised and the fundamental is diminished, giving an octave up effect, but it’s not true octave up, and it doesn’t sound the same. Anyway, we love all octaves fairly equally here at Champion Leccy, so we thought we’d just go ahead anyway.

To great joy I remembered I had a green stinger (a tweaked version of the famous Dan Armstrong Green Ringer) PCB and a big muff PCB from Fuzzdog lying about, so I thought I’d give that a shot. I populated the green stinger and popped it in my prototyping demo enclosure, so I could try it out.

schematic
Green Stinger schematic taken from Fuzzdog’s website pedalparts.co.uk

I went with two 1N4148s, though I know people often use the Germanium  1N34A instead. I couldn’t tell you about how much difference the diode choice makes to the sound, but I can tell you the trick with the green ringer is matching the diodes as closely as possible. I got the multimeter out and measured the forward voltage over several several diodes, so I could get 2 that matched extreeeeeemly closely.

There is a nul option with the kit. The nul is there to help eliminate the fundamental. So I decided to go with a pot for the nul instead of the standard resistor, but after trying to tune it in, I couldn’t really hear any difference. Maybe because I matched those diodes so perfectly!

Being that I’m a bit of a numpty sometimes (learning from mistakes is good), I totally forgot to put in the AMZ style tone stack, and went with some old values that didn’t really work. That will be fixed, and you can watch some fantastic desoldering in BS8 – Nightmare! desoldering!

One great thing with the Fuzzdog Multi Muff PCB is the fact that it has a couple of switching options (clipping options for the second clipping stage and a pseudo tone bypass). I went with both just to give me a few more fun things to play around with. I also used an on-off-on switch for the clipping options, so in the centre position it’s the standard Gett circuit, the other clipping options are red LEDs and two 1N4148s. The Gett (my own take on the Big Muff) part of the circuit is close enough to the original that I could use the Fuzzdog PCB, the only difference was, I used a 25k pot instead of a switch and a 27k resistor for the mid boost, which is fine.

I used a painted enclosure for the first time, and again made a wee booboo, this time cos I was so excited to get it boxed up. So let this be a warning to you. When I drilled the enclosure I didn’t sweep up the aluminium shrapnel from previously drilled holes. This scratched the finish a little. This pedal is for my own use, so I’m not arsed, but I know for next time.

When I get a chance I’m going to hand paint the enclosure with posca pens. Check out BS7 – Finish Him! Hand-painting and coating enclosures.

This isn’t a pedal that’ll be putting up for sale, there’s already at least one more on the market that is basically a modded Big Muff with a green ringer (Earthquaker Devices Hoof Reaper), BUT! I did try putting the Green Ringer after the Fat Gett and it sounded mint! So I may well do a three footswitch version in the future.

I’ll add a video of the Skinny Gett after I’ve swapped out the tonestack and finished the paint job. Meanwhile just look at this plain enclosure.

sg-unpainted

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s