Boss DM2 Analog Delay,'80s
This analog delay pedal is able to produce delay times ranging from 30 to 330 Milliseconds. It's got three dials with adjustments for Repeat Rate, Intensity, and Echo. This effect draws a lot of current so not all power supplies are able to power up this pedal. The vintage analog DM-2 is a very popular effect and prices are usually very high for a beat up but working pedal.
Version differences
There are at least 3 different versions of the DM-2. The first version was using
the MN3005 BBD. This was soon changed to the low current version of the same
circuit called MN3205. It is worth noting that the MN3005 has a SN ratio of 75
dB while the MN3205 is a little more noisy with its 67dB. The MN3205 only
produces 0.8% distortion compared to 1% for the MN3005.
The DM-2 can be approximately dated by reading the number on the compander IC NE570N. It should have a 4 digit number giving you the year and month of production in the form YYMM. Note that this is the production date of the integrated chip and not of the pedal but it's unlikely that the chips were stored for very long before used.
DM-2
Marking of PCB: ET-5214-510
BBD: MN3005
Clock Driver: MN3101
DM-2A
Marking of PCB: ET-5214-510A
BBD MN3205
Clock Driver: MN3102
DM-2B
Marking of PCB: ET-5214-510B
BBD: MN3205
Clock Driver: MN3102
Specifications
Labels
The DM-2 was sold from June 1981 to February 1984.