MATRIXSYNTH: Restored Vintage ARP 2600 with 3620 Duophonc Keyboard 4012 Ladder Filter

Sunday, November 10, 2019

Restored Vintage ARP 2600 with 3620 Duophonc Keyboard 4012 Ladder Filter

via this auction

"This particular 2600 is funky, deep, and's the real deal.

Just out of the shop from a full internal restoration, this ARP 2600 sounds and plays incredible. This one is a mid production model with the original lawsuit 4012 Moog style ladder filter. Comes with fully internally restored 3620 duophonic keyboard. Has the more coveted Accutronics reverb "long" tank and the original Belden "round 3 prong" power cord. Cosmetics on the 2600 and the 3620 metal faceplates are excellent as seen in the pics.

The recent restoration included swapping all sliders on the 2600 and the 3620 with replacements supplied by the Synthchaser. The keyboard also had a full bushing replacement, and the 2600 and 3620 keyboard were then fully calibrated.

The restoration was not cheap, With the parts, it cost nearly $3,000.
Well worth the money, this 2600 and 3620 plays and sounds as the day it was released from the ARP factory.

One of the 42 Ohm speakers was non-serviceable so the op amps were modified to accept new 8 Ohm speakers - 42 Ohm speakers are no longer produced and cannot be repaired. The original 42 Ohm speakers are included as extra still works fine. It is incredibly rare to find an ARP 2600 42 ohm speaker in working condition and it alone is really valuable.

The original Tolex is in good overall condition with some wear as seen in the photographs and was purposely not replaced. The handles and latches function perfectly.

Serviced and restored by Mike Jay, owner of Pro Audio Electronics in Tampa, FL. Mike is brilliant at restoring and servicing synthesizers, and he has many years of experience working with vintage ARP's, Oberheim's, Moog's, etc. His wisdom is vast and he is honest.

All original parts that were replaced in this restoration are included (see pics)."


  1. Don't believe everything you read here. 40-45ohm speakers with the required mounting ARE still available. Much better to get the right speakers than to increase the load on the already limited OEM ARP power supply. As seen here, it appears NOT to have been modified. Great synth, caveat emptor on the seller claims.

  2. If one wishes to use 8 ohm speakers, the proper solution is to install impedance matching transformers between the speakers and the internal power amp. As was done on the early ARP 2600's and as shown in the service manual.


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