RCA (f) Inputs for Foot Switches <trem & reverb> ."Grounding Improper"

[frank666]

Sentura II '67-'68 .   The RCA (f) connectors for the Trem & Reverb foot switches are not grounded
properly.  It is assumed the ground strips on the dual connector are adequate enough to make contact
withe the chassis when assembled with screws to the back panel. (NOT !)
<I have seen this problem emerge on BOSE 901 Equalizers from the 70's - preamp IN / OUT connectors>
They are used for 'ease of assembly' and are sometimes 'pop riveted' in.
Suggestion :  for those who have these type of connectors, 'Hard-wire' the Ground tab to the chassis !

frank d.

[Ryan Phelps]

Frank,
I do agree that hardwiring the ground connection on RCA connectors is certainly better. Relying upon the bolted or pop-riveted connection to the chassis was quite common back in the day. And electronics had to be built to a price-point too. Certainly, if one is having a problem with a Sunn footswitch, this should certainly be checked .....we've all seen the surface corrosion on a Sunn chassis! However, I would not consider hardwire grounding of these jacks to be an imperative .....I've never had this problem with any of the Sunn amps I've repaired over the years. While it couldn't hurt, I prefer to only fix functional problems on vintage amps, leaving them as original as possible (within the parameters of safety). Just my 2 cents.

[Isaac]

On a similar note, I've had input jacks lose their ground due to corrosion of the chassis, and fixed that issue by soldering on a ground wire.