BYOC Ross Compressor Clone

[duhvoodooman***]

For any of you Fretters considering a first-time foray into the world of DIY pedal making, here's a good one to consider. Buildyourownclone.com has a kit based upon the legendary Ross Compressor that many consider the best compressor pedal design of all time. It's one of their cheaper kits at $75, and quite an easy build. If you can solder moderately well and follow directions, you can build this pedal, without a doubt.

Additionally, the kit has some design flexibility. By leaving a couple of components out and swapping a couple of others (all the parts are provided) you can instead make the pedal into a clone of the MXR DynaComp, if that is your preference. And unlike either of these vintage pedals, the BYOC kit incorporates a third control they don't have. The "Attack" knob lets you control how quickly the compression kicks in and fades away at the end of the signal sustain.

About the only slightly tricky thing is that the circuit uses a "trimpot" that has to be adjusted when the pedal is first used to optimize the compression/sustain. Basically, it's a matter of repeatedly picking a note while s-l-o-w-l-y turning the trimpot screw until the maximum sustain is attained with the "Sustain" control dimed. You'll know it when you hear it! Through most of the pot's travel, you get a very thin, low volume output, so when you start to get into the "sweet spot", the tone fills out and gets much louder. If you go too far, it thins back out again.

Below are a couple of photos I took of the Ross clone I built this weekend. Actually, I didn't buy the BYOC kit, but just ordered the parts directly from several places where I get all my pedal components. This can reduce the cost vs. the kit price pretty substantially, but you have to be buying more than one pedal's worth of parts at a time. Otherwise, the combined shipping costs will kill you and you're better off just buying the BYOC kit.

The instructions for all the BYOC kits are posted on their website as PDF documents, and each includes a complete "bill of materials". This is what I've used to buy the parts directly from component suppliers. I have these BOM's broken down by supplier, part number and part cost for several of the BYOC kits. If you're ever looking for one, shoot me a PM and I'll let you know if I have it.

Here are the two pix. As you can see, I haven't applied the decal graphics yet (just labeled the top view image with MS Paint), and the battery snap hasn't been soldered in yet, either. But it's fully functional with a standard 9V AC adapter, and works like a charm. Full, rich tone and lots of sustain:

[Tone2TheBone]

That looks good Voo. Those old Ross compressors do the job. I'll bet you yours is much more transparent. My old unit has old parts that somewhat suck tone but it does make up for it when it's engaged. I used to use it exclusively on the Jubilee for Strat use. I'd play on the overdrive channel at breakup point and kick it in for soloing. It added the sustain and drive I wanted without adding gain. I like the looks of your pedal. I'm wondering how different they'd be in comparison.

[jasongins]

duhvoodooman,

This looks like a fun project. Though I can solder, I haven't done much soldering of small components onto printed circuit boards. Do you recommend using a soldering iron of a particular wattage, and is it necessary to use a heat sink on the components while soldering them?

[duhvoodooman***]

A 25W iron is perfect for this kind of fine solder work. The only component I've come across so far that requires the use of a heatsink is a 1N34A germanium diode. So I just clamp a small alligator clip between the diode body and the solder point, and I haven't had any problems. Just make sure the iron is fully heated and the tip is tinned & clean, and you should be able to make individual solder joints with only 2 or 3 seconds of tip contact.

[ShortBuSX]

Can I ask a really dumb question?

Why two different syle jacks? The "in" jack is obviously different than the "out"...I was just curious why? Im sure there is a simple answer that Im just not seein.

[duhvoodooman***]

Not a dumb question at all--a very good one, AAMOF!

This and many other pedals use a stereo jack on the input side as a means of connecting battery power into the pedal circuit. The negative terminal of the battery is soldered to the extra "ring" connector on the stereo jack, and the circuit is then completed when a cord is plugged in. That's why you have to unplug your guitar from most battery-powered effects to keep them from draining the battery when the pedal is not in use. (Unless you have an auto-bypass AC adapter jack and keep that connected to to a wall wart, in which case the battery is automatically disconnected. The BYOC designs all use such an AC adapter jack, so that you can leave a "back-up" battery in the pedal for times that AC power isn't readily available or convenient and not have to worry about it draining down.)