Colby Amplification MM12, MM50, MM22, MM100 Owner's Manual

Owner’s Manual

MM12/50, MM22/100

“MOD MACHINE”

Welcome to Colby Amplification. We share something in common; we care deeply about tone. After 40
years of playing guitar and a 40 year career based around guitar amplifiers, I started Colby Amplification
with a desire to produce the very best possible tube guitar amplifiers. Colby amplifiers have been
designed with tone as the number one focus, period. Everything possible is done to keep the signal path
pure, all tube, and sounding great. There is and will never be a compromise when it comes to tone.

The MOD MACHINE was conceived as an amp that could produce many great British sounds. I know
British amps. I worked for the US distributor of Marshall for 32 years and have been collecting amps for

longer than that. I’ve been to the UK many times and scoured music stores for vintage treasures. I also

had friends in the UK searching. I was lucky because I had an easy way to ship amps to the US (in
containers with the Marshalls we were distributing).

MOD MACHINE was tweaked for over a year until the goal was achieved: be able to produce everything
you want and need if you are looking for an amp that can recreate many of the big British sounds
produced by different designs starting from 1962. The MOD MACHINE is a single channel amp that
offers the full clean sound of an early to mid 1960s four input amp, the cutting clean sound from a 1970s
four input, and just about every overdriven sound from the 1960s to the Master Volume amps of the
1970s and 1980s to the higher gain amps of the 1990s and later. It’s got the right amount of detail,
compression, note body, smooth or aggressive overdrive all with the turn of a few knobs and front panel
switches.

The word MOD is a great adjective for this amp since it can be reconfigured to sound like so many
different amps with the turning of two front panel rotary switches and a few controls.

By incorporating a finely tuned additional gain stage (STAGE 2) the MOD MACHINE can go from super
clean to high gain overdrive and sound great at the extremes and in between. The addition of power
amp Pentode/Triode and Fixed/Cathode bias switches allows you to lower the power from maximum to
about ¼ of full power in four increments. These switches create differences we can use for greater
possible variation in tone and feel.

While designing we found that having two Master Volumes, each in a different spot in the circuit allows
you to dial in all sorts of satisfying overdriven sounds at any volume level. In addition, you can dial in just
the right setting so that the amp cleans up well using your guitar’s volume control.

I know you want to get going so here is the quick start guide:

1) Set the STAGE 2 switch to the down position and the Gain control to minimum

2) Set the LOOP switch to the down position

3) Plug in a speaker and set the rear panel impedance switch to the same setting of the speaker

4) Set the controls as per the attached picture (insert picture)

5) Set the back panel EFFECTS Send and Return level controls to 12:00

6) Set all MASTER controls to 12:00

7) Set the Volume control to 10:00 to 11:00 and the Treble, Mid and Bass controls to 12:00

8) Plug guitar in. Turn the amp on (Up) with the ON/OFF switch. Wait 45 seconds and turn the

STANDBY switch on (Up) and start playing!

Front Panel

The top row

EMPHASIS: This four way switch dials in different amount of pre-emphasis. Position 1 has none. Use this
setting for a mellow tone. Position 2 is like an early lead amp and is similar to a traditional bright switch
as used on a very popular American amp. Position 3 is an intermediate setting that is more aggressive.
This position is great for a more nasal, cutting type tone. Position 4 is like a later, more aggressive amp
and boosts everything from the mids and up. Use this for traditional rock/hard rock overdrive sounds.

(interesting note: in this setting, the Volume control works as a bass filter when set over half way. At the
half way point, you have almost maximum gain but the lows are cut. Turn the volume control higher to
add more lows)

Shift: This changes the mid content of the sound. Position 1 is slightly scooped. This has various uses. For

clean sounds this gives you something akin to a BF sound. Position 2 is the “normal setting” for 1960s

big British clean sounds. Position 3 gives you more mids and is the preferred setting for rock/hard rock
overdrive. (note: this switch is more effective with higher setting of the bass control and lower settings of
the mid control)

VOLUME, TREBLE, MID, and BASS controls work as you would expect