Sold Colby Mod Machine M22/100


Gold Supporting Member
Colby Mod Machine M22/100

I don't like calling any used amp Mint, but this is as close as they come.
You have complete access to a variety of Marshall tones in this guy.
I'm not going to go on & on about how incredible this amp sounds, so I'll just sum it up by saying .....
This amp will blow your mind!!!

  • Features
  • MOD MACHINE can morph from a “Plexi” to “Metal Panel” to a “Master Volume” to higher gain sounds
  • Four power amp modes
  • Comprehensive MASTER section
  • All tube circuit
  • All-tube FX loop
  • All hand wired
  • Multiple clean sounds, multiple OD sounds
  • Cleans up from your guitar’s volume control
  • Works great with pedals
  • Two speaker outputs with 4, 8 and 16 ohm selectable impedance
  • Four EL34 output tubes (MM22/100)
  • Custom power and output transformers
  • All components selected for TONE!

MOD MACHINE is the ONE amp that can be properly reconfigured to sound like many classic big sounding “M” style amps from different eras. If you are looking for a modded “plexi”, this may be the amp for you. The MODs include: four-way switchable bright switch (Emphasis), switchable cascaded gain stage, bypassable tube effects loop with level controls, Pre and Post Master Volume controls and others.

MOD MACHINE is a single channel amp with a “plexi” heart that is specifically designed to recreate a variety of classic British tones. Starting from a full, clean sounding 1960s circuit, the MOD MACHINE can morph to everything from an early “Plexi” to a “Metal Panel” to a “Master Volume” to somewhat higher gain sounds (however, please keep in mind that this is not a “high gain” amp). Check out the videos for examples of what this amp can do. The power section includes four different modes (Pentode/Triode/Cathode/Fixed) for additional tonal options and with corresponding power ratings from 22-100 watts. The all-tube FX loop has send and return level controls so you can hook up your favorite time based pedal and rack effects for maximum tone and flexibility. The comprehensive MASTER section includes Pre and Post Master Volume controls as well as Presence and Hi Trim controls so you can dial in the right settings for both low and high gains sounds and achieve the sound you are looking for at any volume level.

Other significant controls are the four-way Emphasis (bright cap), three-way Shift switch and a switchable extra gain stage (STAGE 2). The Emphasis switch reconfigures the front of the preamp from smooth to chimey to aggressive to full-on drive. The Shift switch reconfigures the mids from scooped to extra “push”. STAGE 2 adds a gain stage and reconfigures the preamp for a tonal shift to a more modern sound. STAGE 2 has its own Volume control which in conjunction with the Emphasis and Shift switches plus dual master volumes allows the user to dial in just about everything from clean to mean to scream.

Some people have asked why the Mod Machine is not channel switching. There is a good reason! I designed the Mod Machine to be the ultimate multi-voiced “M” style amp. It is capable of many different sounds and does it authentically. In order to accomplish that with accuracy many things have to be switched, some at the same time. That is very difficult to do in a hand-wired channel switching amp and if done, would have to incorporate an enormous amount of additional circuitry adding to cost, complexity and potential future reliability issues. This amp is for someone who likes many different sounds but usually uses a plug-and-play one-sound amp. If you can’t decide which “M” amp to get or you want all of the sounds but don’t want three different amps, this is the amp for you.

As with all Colby amps, the MOD MACHINE is built to the absolute highest quality standards and is 100% hand-built with care.

The MOD MACHINE has tone for days and is a lot of fun to play. It’s got multiple clean sounds, and multiple OD sounds. It cleans up from your guitar’s volume control and sounds great with external pedals whether you are using a compressor or OD in front of the amp or a delay or reverb in the all-tube fx loop.

  • Power: 22/45/65/100 Watts
  • Tubes: four 12AX7, four EL34
  • Front panel controls and switches: Volume, Treble, Mid, Bass, Stage 2 Volume, Pre Master Volume, Presence, Hi Trim, Post Master Volume, On/Off, Standby, Four-way pre Emphasis, Three-way mid Shift, Stage 2 On/Off, FX loop On/off


Back panel controls and switches: Mains and B+ fuses, Fixed/Cathode bias switch, Pentode/Triode switch, Main and Extension speaker outputs, Impedance Selector (4, 8 & 16), Send and Return Jacks, Send and Return level controls


Price - $Traded - Thanks Jeff! Shipped - Meticulously Packed & Fully Insured
Will split PayPal fee if that's your method of payment
No fee for cashiers/bank check postal money orders
Power cord included (not pictured)


Last edited:


I have a 50 watt version of this amp and it's the finest amp I've ever owned. It's incredible the variety of killer Marshall tones it will reproduce. The finest loop and master volume setup I've ever owned. Zero need for an attenuator or a loop buffer. No relation to the seller. Just amazed this amp is still for sale.

Trending Topics

Top Bottom