ARP 2600 Identification chart


This list is based on CMS's considerable database of ARP 2600's we have worked on in the past 25 years.

© 2007 all rights reserved CMS/ Phil Cirocco

model   circa         exterior changes     paint / screen   internal changes, comments    





2600P V1.0


2600P V2.0


2600P V3.0


2601 V1.0


2601 V2.0


2601 V3.0


2601 V4.0


early 1971






late 71-72








1977 - 1979




The Blue Marvin, all metal case & matching metal 3604 keyboard


The Gray Meanie, all metal case & matching metal 3604C keyboard


Wood / tolex suitcase & 3604P kbd, early silkscreen w Tonus logo, short panel


no external changes, Serial # restart using 26XXX format - Nov 1971


Panel increased to 15.5", New silkscreen & ARP logo - early 1973


3620 duophonic keyboard, smaller trim holes, serial # restart: 2601-XXX


No cosmetic changes


New front panel colors with matching 3620 keyboard


Late suitcase, strap type top handle & latches similar to Solus


blue / white


gray / white


gray / white


gray / white


gray / white


gray / white


gray / white


black / org&wht


black / org&wht

Very rare, great VCOs, great audio path, phenolic boards


Rare, great VCOs, great audio path, fiberglass boards


Easier service - great VCOs (4017), great audio path


4027 VCO (still good), audio path change to LM301


4027-1 VCO, hissy, poor slew rates, 1974 -small tank


Better input jacks, PCB mounts, better slider feel, hissy


4072 filter with error, submodules unencapsulated, hissy


No significant internal design changes


Avatar power supply, the last of the 2600's - rare

CMS reserves the right to change and update this info at our discretion. This info is based on our extensive database of units we have serviced over the years. Also thanks to Alan R. Pearlman for help compiling this data.

Estimated production numbers:

2600 - 25 units (light blue metal case with matching metal case keyboard)

2600C - 35 units (light gray metal case with matching metal case keyboard)

2600P - 1700 units (standard suitcase 2600)

2601 - 1000 units (standard suitcase 2600 with input jack update)


2600 production peaked in 1973-74.

The 2600P v3.0 is the version that was produced in the greatest quantity.

The later model 220v european version carries the 2602 designation. There were relatively small numbers of these sold, but they are electrically identical to the 2601.

The best 2600 to look for?

Chronologically, 2600's got more reliable and serviceable as production progressed throughout the 1970's. The biggest change was the 2601 update that replaced all the input jacks with a more reliable type of jack. However, this improvement required that each jack be hand wired to the circuit boards, pushing up the labor costs considerably. The printed circuit boards were fitted with additional supports that improved the tactile feel of the sliders and also improved mechanical reliability. The retail price of a 2601/3620 was $3300.00 in 1975.

It's also obvious that 2600's got progressively worse in the audio department. The best sounding units being the very first ones, and the worst sounding units being the last. All units made from 1972 onward sound very muddy, hissy and thumpy straight from the factory.

Probably the best course would be to find a late model (2601) and get the audio upgraded here at CMS. The earlier units do sound better from the factory, but the numerous mechanical problems can add up to a hefty repair bill especially if the 2600 in question, has been exposed to moisture for long periods.

Extensive road use is obviously another cause for concern. Indications are a yellowish silkscreen (tobacco) and a worn silkscreen in the filter mixer and ADSR sections.

See the 2600 page for upgrading your late model 2600 to original audio specifications.


Other interesting info:

The 4012 filter was used for all 2600's from the very beginning through 1976.

The all metal cabinet version of the 2600 appeared in 2 colors, light blue (2600) and gray (2600C).

The Blue Marvin is freaking bright blue! It's not "blue gray"!

It's not called a Blue Meanie! - Source: Alan R. Pearlman

The "Gray Meanie" nickname appeared in the late 80's probably as a result of the Blue Marvin misconception. It's real name is the 2600C. Lately, there have been several people selling 2600Ps on ebay billing them as "Gray Meanies". This is somewhat misleading since most experts and dealers classify a Gray Meanie as an all metal cabinet, gray 2600 - no wood or tolex whatsoever on either the synth or keyboard!


©2006/2007 Phil Cirocco / CMS