Wish I could offer more than this lone mention of the company:
Monogram Professional Audio
Company based in Hayes, Middlesex, England that as the name suggests manufactured products primarily intended for the pro-audio market and usually marketed their products under their initials:
MPA. We believe that the company was founded in the early 70’s and the products you are most likely to see on the second hand markets are amplifiers that were primarily sold to the club and pub market. But in 1977 introduced the
A+ line of rack mountable power amplifiers with the1 1/2U 3100 model, but these were unusual at the time in that they are fully Class A when run at low volumes but start working in Class A/B when higher power requirements kick in. A little later the company introduced a series of hi-fi products including a version of the A+ power amp intended for home usage called model 3050, an FM tuner called model 3600 FM and a cheaper integrated amplifier called Model 3000 slimline. Later in 1977 Monogram introduced the
MPA TD1 turntable. The company appears to have disappeared by 1980.
Not to be confused with Monolithic. Do you know if your has RCA or pro-style inputs on the back?