Farfisa gs42r spring reverb

A rare beast.

I recently found this beautiful spring reverb at the flea market. There is almost nothing on the internet regarding this spring reverb. apart from the traces of one being sold at auction for quite a lot of money.

A little inspection showed that it was full of old electrolytic capacitors that were literally leaking their dried up contents. It contained a number of spiders, quite a bit of sawdust and years of dust buildup. There was a bit of exposed mains wiring and an old 10a italian power connector.

I decided to recap the whole thing to avoid nasty surprises. During this procedure i tested the Capacitors as i took them out, and surprisingly about half of them were still good (in terms of both capacitance and ESR). I'm not sure how long they would have lasted though, it's a fairly hot circuit, the power supply is basically a couple of zener diodes and a couple of voltage dividers with big fat power resistors.

A Dub Monster

Apart from just being a Spring Reverb the GS42R has, channel a has a 4 band LCR filter based eq with full cut and a Vactrol based Tremelo circuit, Channel b has a less aggressive 2 band RC filter EQ, both channels can use the spring reverb.

Farf GS42R_sch.pdf