Duncan MacKinnon, founder of Stompnorth Pedals, knows a thing or two about valves in guitar pedals. Below, he dives into how they work and why we love them...
My introduction to building guitar pedals was a Build Your Own Clone – ESV Fuzz. The ESV stood for Extra Special Vintage on account of its Phillips Ac127/01 germanium transistors. Its sound is amazing and is indeed as old school as its name suggests, but I wanted to take "vintage" even further, so I started looking for valve kits and soon found a booster that used a single 12ax7 valve.
I loved the way it sounded and the response it gave, so I knew that valves were the way I wanted to go with my own projects. As a synth player first and foremost, I was used to manipulating waveforms and textures, but even from this hi-tech perspective I still found vintage hollow-state circuitry [i.e valves] offered more pleasing sounds and possibilities than the more modern solid-state, transistor and op-amp driven circuits - which, of course, are also tremendous.
The sensitivity and flexibility of a valve is, in my opinion, unrivalled in guitar pedal building where subtlety, response, transparency and sound quality (not necessarily fidelity) are the aim. A valve in low voltage "starved plate" mode offers a certain type of response and transparency which is different to the more full-on high voltage valve circuits. You can max-out a 12au7 pedal and still know which guitar you are playing. I also think they have a really pleasing and unique sound all of their own. This is the reason I designed one of my own pedals around a 12au7 running 9 volts.
The Stompnorth Clipshear Getter Drive combines a 12au7 valve with a MOSFET transistor and silicon and germanium clipping diodes.
How a Valve Works
A valve can be thought of as a glass tube, with an anode (plate) at the top, and a cathode at the bottom. Electricity in a valve flows in the opposite direction to the accepted norm of positive to negative, and it does so in a wash of electrons called space charge; this is the bit I love the most! When you turn a valve on, the cathode has to warm up, and then space charge is produced. This flows from the cathode to the plate through a vacuum. Not carried by radio, or wire of any kind, but literally floating through space, a tiny bit of outer space, (with flying saucers and ray guns), right there in your pedal.
Your guitar signal enters through another internal component, the grid, which sits in between the plate and cathode. When a signal with positive potential enters the grid it gets caught up in, amplified by, and carried in the flow of space charge all the way to the plate, then on into your amplifier in an awesome shower of tone-bearing electrons.
Another fascinating thing about valves is their sheer theatre. They are huge in comparison to other components - you can see the internal workings through the glass. Also, each one is slightly different inside. The getter flash (silver cap) is another brilliant factor of valves. The science is fascinating and they look great, but this subject is best saved for another occasion.
In short, I think valves are magnificent, eloquent, and beautiful pieces of engineering that have un-reinventable qualities, which I think is why they are still so commonplace in guitar gear (and high end audio gear) today. They were not replaced by the transistor as we were told they would be - valves are here to stay.
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I spent an obsessive amount of time checking out univibe pedals. I'm so glad that I purchased this one from Boost. It is simply fantastic! If you don't believe me, then check out some video demos. Thanks Jim! + JG
This is a fantastic drive pedal. There’s plenty of Plexi style pedals out there and I’ve owned a few, this one stood out for the switchable A/B-B/A switch. The boost side is nice and simple, much like an LPB-1. Not overly clean but a perfect partner to the drive side. The Plexi side is again nothing revolutionary but very good all the same and sounds great, on a par with far more expensive pedals.
The build quality is also top end, very neat and tidy. Squeezed into the single enclosure and with a lifetime warrantee I couldn’t ask for more. I don’t think this’ll be leaving my pedal board any time soon!
Lots of great sounds in this relatively-compact delay / reverb
I’m only just starting to scratch the surface of the KMA MACHINES Cirrus, but absolutely loving it so far. Very responsive to pick attack which means can really control the “ambience” with playing style. Really looking forward to exploring further.
Had a few vibes, absolutely loving this one, check the YT demos, lovely satisfying vibe with all the swirly goodness you could hope for. Beautifully made and reasonably priced. Highly recommended - and Jim at Boost is a top guy
I came across the Formula B Fuzz Rangers via online demos on Youtube, and they all sounded so good that I had to get one. Looking online I found the Boost Guitar Pedals website via the Formula B website as a listed UK stockist. Jim was excellent and the pedal arrived when he said it would and it was perfectly packaged. I would have no hesitation in buying any other product from Boost.
As for the Fuzz Rangers, it is a great pedal. I had to work at it a touch to get the sounds I liked from it, but it seems to react really well to different guitars and different amps with adjustments to volume and tone on the guitar and different amp settings. I found it works best into a slightly cranked amp, and volume roll-off on the guitar offers a great variety of sounds from clean to classic fuzz. Thoroughly enjoying the pedal. Well done Jim, great website and a great selection of interesting brands and pedals..... Which one next????
Having used a number of univibe clones over the years this one truly nails the sound for me, it comes with some clever additions in a pedal board friendly size and is excellent value for money. If you want the true sound of the original this pedal delivers.Special thanks to boost Guitar Pedals for putting this deal together so quickly..
I'm still working my way through all the sounds, but so far I'm loving them all.
Each time I think I've got a fav sound I flip the diode switch and there's another one. Great value for a four-in-one fuzz pedal!!
Both modes really useable. The first can get a wooly or starved/wolly sound or more nasally raw sound depending on how you dial it in.
Mode two can be more mid focused and with both switches down it's just a real nice deep, warm wall of fuzz. Great stuff.
Awesome pedal. Does everything from short slaps, to long endless delays, or echo-verb. The infinite delay feature on the button hold is interesting, though if you need a certain sound out of it like that, you have to be okay with the sound that those settings create when the infinite hold feature is off. I’m sure it will be great for recording some interesting textures, but I don’t think I’d use it live, as the infinite hold sounds glitchy and cuts off very quickly at some of the shorter, more subtle delay settings that I use. The art on the pedal is nice, and the build quality is solid. Comes with a carry bag, for some reason, but I can’t complain. A great unit by any standard, but especially good quality and features for the ticket price.