Fred Briggs - Psychedelia Fuzz

Fred Briggs - Psychedelia Fuzz

This pedal is the realisation of a tone I once heard being produced by an old Marshall combo amp that a friend of mine had bought for "spares and repair" with a view to using it as a donor chassis to build up a "new old stock" Bluesbreaker.

He'd managed to buy the amp after the original owner had decided that it had become too temperamental to use live and too expensive to keep patching up. The amp was in a sorry state - the tolex was peeled and tobacco stained, the cabinet gouged and cracked, the chassis paint was scuffed and the output transformer had rusted to within an inch of it's life. One of the speakers had what looked like a cigarette burn through it's cone and the other was so worn out it was hanging to it's chassis by a thread. The output valves were horribly mis-matched and burnt to a crisp with the biasing a mess. Internally someone had performed a range of capacitor mods with all the tone controls  hard wired into a set position. The power section was struggling and producing a range of voltages that seemed completely random at any given point with fluctuations in rectified voltages occurring almost constantly.

I wasn't expecting much from it when he turned it on but while we waited for what seemed an age for it to heat up he explained I was in for a surprise - the tone was unbelievable. Though it certainly wasn't the stock Marshall tone it was something special. A lucky blend combining the magic of the classic circuit with the electronic and mechanical madness of the amp's current state. The low gains were sweet and syrupy while medium gains produced a softly compressed overdrive that ventured into a fuzzy octave effect as the amp was pushed harder. At full gain the amp produced the most wonderfully aggressive, fat and harmonically rich fuzz tone with smooth higher octaves springing out of the fretboard as you played. The sustain was unlike anything I've heard before with a myriad of harmonics and a howling, ringing feedback.

This circuit is my attempt at recreating that amp's tone: It's low gains are sweet and higher gain settings render a soft octave effect with a long trailing sustain. When stacked with other gain pedals it retains it's own character and even adds it's own personality to other dirt boxes placed after it in the signal chain. It's a great little circuit that can produce tones from low bluesy riffs through sweet overdrives and into full on Hendrix Star Spangled Banner fuzz madness.

Controls:

Volume - Sets the gain level of the pedal, from a syrupy boost through a range of overdrives all the way to octave laced distortion and fuzz tones.
Tone - As the amp I originally based this pedal on had it's Bass and Mid controls hard wired I chose to have the Tone control affect the high end content only. It's a highly flexible control allowing you a full frequency response at low gain levels with the ability to roll off more highs as the gain increases.
Master - Sets the master volume of the pedal.
Bias Switch - Switches between a more "traditional" mildly asymmetrical clipped tone (for all those lovely odd order harmonics!) and a more drastic asymmetrical clipping associated with mis-matched / mis-biased tubes. With the Bias switched to "mis" you will experience a more pronounced clipping with the octave effect becoming more prominent at higher gains. Switching the bias to "mat" produces a more open tone while at higher gains the octave effect is less prominent.

General Information and Instructions:

With the Volume set low and the Master set high the becomes a brilliant booster that adds it's own distinct colouration and character to your amp. Set your amp close to it's break up point and use the boost of the to push it over the top and listen to it sing! If you want more of the pedal's character in you sound increase the Volume control of the and reduce the Master a little, you'll here more of the unique voice present in your final tone. If you just want to rock the hell out set the Volume of the all the way to 11 and strum away until your ears/fingers bleed.

As is common to the JTM family of amplifiers the Psychedelia is voiced with a rich mid range alongside plenty of sparkling treble content. With Fender and vintage Vox amps (which are known for having a much more pronounced low-mid scoop than their Marshall counter parts) you will notice an increase in these frequencies which can be a very welcome addition to your tone. Don't forget to trim the treble response to a point which suits your amps and the manner in which you use them - more gain = less treble!

[EDIT] - Here's some terrible quick demos of the Psychedelia in action, they by no means illustrate all of the tones you can get from this thing but it gives you a good idea. I recorded them with a guitar that only had 5 strings at the time and a "no name" crappy mike - but don't let that fool you - the reason they sound so shoddy is my broken fingers playing ;-) : http://soundcloud.com/fred-briggs/sets/fred-briggs-psychedelia-fuzz