Members of the Group DIY messageboard participated in group orders of the John Hardy 990C op amp and Cinemag CM-75101 and CMOQ-2S transformers during April - June of 2006. This coincided with the introduction of the DIY500 on that same messageboard. The list of parts below shows one way to correctly configure these devices as an excellent-sounding module.

Those components which remain constant for all circuits; R2, R3, the pushbutton switches, op amp pin sockets, and 1/4" connector; have not been listed.

Component designations refer to the DIY500 schematic and component explanations table.
------ means leave that component out.
zero ohm jumper resistors can be used for all shorts.
All resistors are 1% metal film, 1/4W, unless otherwise noted.

0.1µF (105J)
ComponentValueType
R1short
R4, R5680Ω
R6150Ω
R7------
R8150kΩ
R9short
R9a------
R10, R1110Ω, 1W
R1210kΩ
RV110kClarostat 388 Series potentiometer, RZ (reverse log)
R1320Ω
R1439Ω
R15100kΩ
R16------
R171k2Ω
D1, D2, D3short
J1short
J2------
C147µF/63V or greaterpolarized electrolytic
C2------
C3------
C4------
C5, C6220µF/25V or greaterpolarized electrolytic
C1, C5, C6 bypassfilm or metalized film
C791pF (101J)C0G/NP0 ceramic
C81000µF/6.3Velectrolytic, negative side facing front panel if polarized
C91000µF/16Velectrolytic, negative side facing edge connector if polarized
C8, C9 bypass------
C10------
A1John Hardy 990Cdiscrete op amp
T1Cinemag CM-75101APC1:10 microphone input transformer
T2Cinemag CMOQ-2Squadfilar steel-core output transformer, wired 1:2 (just follow the silkscreen)


Specifications subject to change without notice. GMT