4. Triumph-made

Serial nos in the 2000s

5. Burndept-made

Serial nos in the 2000s

6. Solid state rectified

Serial nos in the 3000s

Details of a Mk 3 chassis

Serial no. in the 3000s

Brimistors

From Oct. 1965

7. Solid state rectified

Serial nos in the 4000s

AC50s with reverb

Various serial nos.

AC50 reverb unit

Made by Thomas Organ

Speaker cabs and wiring