New overdrive pedal arrives. Behold the Blue Alpaca!

I posted recently about the overdrive pedal that my good friend, Alfie, had made for me. Today it arrived. In the flesh this thing is a real beauty; put together by a craftsman.

I hadn’t expected the personalised baseplate that Alfie added.

Nor was I prepared for the very clean way he added the LEDs to the case. When they’re off you can’t see the LED at all. Switch it on and they glow brightly through the bronze finish.

Of course, none of this beauty matters if it sounds crap, but that is certainly not the case. I’ve only played with it for an hour so far, but it is as close to my perfect overdrive as anything I’ve ever plugged into. It covers the bases from mild and creamy through to biting almost fuzz-like. The tone and hump controls are very subtle. The tone on most pedals leaves you with a 20-30% range of the adjustment between the extremes of what is usable. The tone of the Blue Alpaca is useable right through the range. As will be expected, I’ll be putting my recording where my mouth is, but I’m going to spend a day or two getting to know my new baby first. Patience is a virtue, right?

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New overdrive pedal is on its way

A few weeks ago I asked my good friend, Alfie, if he would consider building me an overdrive pedal. I was delighted when he said “yes”. Alfie is the man behind Sydney boutique pedal maker Alfalfasprout69 Custom Shop. Perhaps his best known pedal is a variation on the Way Huge Red Llama, that he calls the Blue Alpaca. Here is a demo of the original.

I’ve asked for a slight variation on the standard build – there is usually an internal trim pot that allows you to tune the EQ to suit a particular guitar. Because I’m hoping to use this with many different types of guitars and basses I asked if this could be moved to the top panel to give an additional level of control. Alfie calls it the “hump” control.

Today I received an email from Alfie telling me that it had just gone into the post, along with a couple of pictures of the pedal. I don’t know about you, but it is a long time since I’ve seen something quite as luscious as that.

Of course, as soon as it arrives I’ll report back with more pictures and sound clips.

A DIY valve overdrive pedal – Goldie

In an amongst the guitar building I decided to break out the soldering iron to build an overdrive pedal – as light relief. I had stumbled across the “Valvecaster” schematic and layout at Beavis Audio.

This is a very simple circuit that uses a 12AU7 valve, running at a low voltage. Because it is running at such low voltage it is very easy to overdrive.

The schematic specifies an operating voltage of 9v but I decided to bump it up to 12v to give a fraction more headroom. I chose one from the tangle of old wall-warts I have tucked away in a drawer. It could use a battery but I suspect that the current draw for heating the valve would suck a PP9 dry in a matter of minutes.

If you search for “valvecaster” at Youtube, you’ll find plenty of examples of the pedal in action. One of the common comments is that this is a naturally “dark” sounding pedal. This was not exactly what I was after and so I was going to experiment with different types of tone stacks. As laid out in the schematic it includes a simple treble cut tone control. Even turned up full this would only make the pedal darker, allowing treble frequencies to escape to earth. I decided, initially, to build it with no EQ, and then add it later. One of the results of this was that it is not a dark pedal at all. It is wonderfully balanced and punchy just as it is, and it’ll not be getting any additional EQ added. To remove the tone control I just eliminated the 10nF capacitor (C2) and the A100k potentiometer (VR2).

I reused an old enclosure I had laying around, which I shot with a coat of black nitro-cellulose and a very light top coat of gold (both left over from my Shaftesbury restoration). The gold coat is thin enough to allow just a hint of the black to show through.

The chemistry geeks amongst you may, by now, have worked out where the inspiration for the name and colour came from.

I have yet to print up and apply the decals for the pedal but there’s the standard 1/4″ input and output jacks round the back. The top has the valve, a true-bypass footswitch and the power toggle switch. On the front, left to right, are the gain, a dummy pot (filling up a surplus hole in the old enclosure) and the output volume.

When I was buying the parts for this I also got hold of a 12AT7 valve. This works well too. It is more subtle and has less gain, but in some ways is all the better for it; smoother, warmer and just a bit less wild.

You can listen to a quick demo of Goldie with the 12AU7, that I recorded for my friend Alfie Lanos, who was really helpful in helping me plan this one out.

It was recorded on my mobile phone so the sound quality is not the best, but gives you an idea of what the pedal does.

The Bullmastiff: A DIY Fuzz Pedal

I’ve finished my DIY fuzz pedal based on the Roger Mayer Classic Fuzz.

I found schematics for it at Fuzz Central and based on this and this, drafted my own version.

I made two key changes to the original schematic;

  1. I found the quality of the fuzz was very sensitive to the value of the resistor that sits between the battery negative and the collector of the first transistor, so I replaced the specified 5.6k ohm resistor with a 47k pot.
  2. I had a pair of silicon transistors available and so wired these in with a DPDT mini switch that allows me to switch between the germanium and silicon transistors. Amazing the difference this makes. The germanium sounds much smoother and “creamier” whereas the the silicon transistors have a real sharp edge to them.

I used veroboard (aka stripboard) for the circuit board and here are the details of the layout, should you wish to do something similar yourself.