I’ve had this amp for c.6yrs. It has developed a fault due to a lifted track/bad connection on one of the coupling caps, which I could easily remedy with the new pcb I bought for this purpose. But, before I do this (merely to prepare it for sale) I wondered if anyone wanting to do a little DIY is interested in buying as is, including the pcb. The buyer could simply transfer the components (or install other preferred ones).
These are the changes I’ve made to the standard amp.
1 It’s wired as a power amp with flying leads (and therefore has no volume control or selector switch). Running the KEL84 is recommended to minimise hum.
2. Virtually all components have been changed:
a. Power supply caps are 2 x Rifa 470uF and 1 x BHC ALC 10 220uF
b. Many resistors are Kiwame, some silver mica
c. Coupling caps are 4 x Jensen paper-in-oil, 2 x AudioNote (aluminium foil, silver lead-out) paper-in-oil
d. Small electrolytics are ELNA Silmic II
e. C22 is an LCR electrolytic
3. Most of the mods recommended on the WAD or WD forum have been done, along with others:
a Bridge rectifier replaced by 4 x IN5822 soft recovery rectifiers
b Diodes 1-4 are now STTA512D ultra-fast high voltage
c improved DC heater supply
d lowered feedback
e 4 x 100pF silver micas caps across R16/17/18/19
f many caps by-passed, eg with Vishay Roederstein MKP 1837
4. Valves are 2 x Mullard E80CF (an improved version of the ECF80 that came as standard); 4 x Russian EL84 (6P14P) which I prefer to the supplied Edicron and matched quad of Ei EL84 I previously used. Sale includes the matched quad of Ei EL84s and 2 JJEL84s
There's a fair bit of expensive componentry in the amp, and some raesonably expensive E80CFs.
Offers?
Adrian