MXR "M-104 Distorsion+ with Block Logo and Lead" (original of 1981) NOT BOX, NOT REISSUE (SOLD)

In the late '70s, the script logo on the classic MXR Distortion + changed to the thick, modern block logo. Though the script models are typically more highly sought, the MXR Distortion + with block logo gives you the same mild, crunchy distortion made famous by the likes of Randy Rhoads, Thom Yorke and Jerry Garcia. One op-amp and a pair of germanium diodes give the MXR Distortion + a simple but effective configuration that you can control using the Output and Distortion knobs.

The "Box Logo Period 1" began around 1975-6 and lasted until 1981, and is named for the writing on the front of the box. The “Box logo period 2" started in early 1981 and went until 1984, when the company stopped making pedals. The main change in this era was the addition of LEDs and A/C adaptor jacks. These pedals used 1/8" power jacks and had exactly the same circuit board as their pre-1981 box logo brothers.


IMPORTANT INFORMATION from the Analogman site

MXR used pots with EIA date codes on them. They usually start with 137 which is the manufacturer (137 = CTS), then the next digits are the year and week. For example, 137 7903 would be a CTS pot, made in the 3rd week of 1979. Sometimes there are only 6 digits, for example 304731 would be 304 (stackpole) 7=1947 or 1957, 31st week. 

Other manufacturer codes are : 
106 : Allen Bradley 
134 : Centralab 
137 : CTS 
140 : Clarostat 
220 : Jensen (speakers) 
304 : Stackpole 
328 : Utah/Oxford speakers 
381 : Bourns 
465 : Oxford speakers 
285 : Rola 
391 : Altec-Lansing 
649 : Electro-voice 
1098 : Pyle 
67 : Eminence