Original posting from the seller I bought the pedal from:
"From the Fryer:
The Mayday overdrive/distortion pedal has been designed to give the full volume overdriven Vox AC30 Brian May sound but at much lower overall volume levels. It is especially good for achieving the full volume harmonically rich sound at low practice levels or rehearsal levels.
The Mayday needs a treble booster first in line to drive it, and has been designed to suit the Fryer Treble Boosters: Touring, Super, Deluxe, Plus and Special.
The Mayday also sounds very good when used with other manufacturers treble boosters such as those made by Pete Cornish or KAT.
The Mayday has been designed for amps such as Vox AC30, Vox AC15, Vox Pathfinder, and will also sound good used with amps such as Roland, Fender and Marshall etc.
Background:
The 2015 Mayday circuit was originally my number 2 circuit for the 2005 version ‘Fryer Fuzz’ pedal. The Fryer Fuzz 4 transistor circuit used some very nice sounding Germanium components which later unfortunately became obsolete.
After I was asked by some guitarists in 2014 about making a replacement for the older Mayhem distortion pedal, I began looking at this no 2 circuit again and in 2015 did some revisions which have resulted in the current Mayday pedal.
The original Mayhem pedal 2000-2008 used germanium and silicone semiconductors and was designed mainly for home use and for lower volume band use. Its role was to provide the full volume overdriven AC30 Brian May sound but at lower volume levels using the Vox AC30 amp.
Many people choose to run the AC30 at full volume like Brian May and use an attenuator to get the overdriven BM sound at lower volume levels. This can give some very good sounds but is hard on the EL84 valves and circuitry and sometimes results in amp failure due to the amp being run flat out all the time. Even at very quiet home practice levels the new Mayday pedal gives exciting rich full volume BM style sounds.
What amps does the 2015 Mayday pedal suit?:
The original 2000-2008 Mayhem was designed to be best used when plugged into the AC30 Normal channel and the volume control set to 1/3 or less. There were many other amp types that it didn’t suit at all.
The new 2015 Mayday is also designed for use with the AC30 Normal channel, but the flexibility of its controls and circuit makes it equally useful when used with other amp types.
What guitars does the Mayday suit?:
The pedal has been designed for use primarily with the Brian May Red Special guitar, but sounds equally good with Gibson Les Pauls or any guitar with a Gibson style humbucking pickup.
How is the Mayday pedal powered?:
By a Boss PSA style 9V Adaptor 2.1mm dia jack negative centre."