RCket Booster

Time for a plain old booster pedal, a clone of the Xotic RC Booster.

The RC Booster offers a super transparent 20db+ clean boost with an adjustable ±15dB two band active EQ which adds a wide range of harmonic content to your ideal sound. As a clean boost, it can enhance other pedals, such as “overdrive and distortion pedals”, or you can crank the gain for a “crunch” sound. But, the RC Booster is an extremely transparent, where many player’s find they leave it on all the time.


I wanted to build another Zendrive clone. The Koan Drive used an OPA2604 opamp but I thought I’d try a AD712 (from eBay). There isn’t much difference, if any, in the sound. But still, I love the pedal so much I wanted a spare.


Also…I found another way to seal the artwork decal on a pedal.

He says further down – “…inkjet clear sticker film with an extra sheet stuck over the printing for protection.”

I used this transparent sticker film as the top layer because that’s all I have right now –
So, I printed out the colour label and then stuck the clear layer over that and then cut the whole thing out and stuck it to the enclosure.
Then I did an experiment – I ran the whole lot under the hot tap. Then a gooey layer of the transparent film started to come off in small lumps (the top coat of the clear vinyl). After a bit of rinsing and a final rub down with meths it came up really shiny and smooth. And the fingernail grooves I put in (deliberately) disappeared. It looks great!


What was that Carpenters song?

“…and say goodbye to…Envirotex…”



Here you can see the edge of the decal, looks great.


The old RAT pedal uses an LM308 opamp. But I couldn’t find any genuine ones. So I did an experiment with LM301 and OP07 opamps. I think the later RATs use the OP07.

I built a RAT clone ( and ordered some LM301s from Tayda and tried the following:

– OP07 (no compensation cap)
– LM301 with 100pf compensation cap
– LM301 with 33pf compensation cap

I know it’s subjective but, for me, the last option won. Sounded a bit grittier.

(BTW – the Tayda LM301s are genuine as they squeal like a pig without the cap unlike the “LM308” I bought off eBay which was a repainted OP07)


The Giant Hogweed

When I first started building pedals my goal was to build the Giant Hogweed.

This one is more ambitious as it has two stomp switches and the input and output sockets are on the top. In fact, I could only just squeeze the pots in under the sockets. It took a lot of planning.

I couldn’t get a genuine LM308 opamp but I tried. The one from eBay was fake, probably an OP07. You can tell if it squeals by omitting the 30pF compensation cap between pins 1 and 8.

I spent some time researching LM308 vs OP07.

The tech sheet for the OP07 has pins 1 & 8 as an offset nulling option where it seems a variable resistor can be connected. Yet, on various forums discussing the ins and outs of OP07 vs LM308 some people swear that adding a compensation cap on 1 & 8 on the OP07 makes a difference to the sound (example –

So I ended up with a TL070 after trying different opamps (LM741). In the end though, it’s a bit squealy at higher settings.



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