Socal50 / BC30 effects loop

[lespaul99]

I've read about this mod but I can't find the details, but as my Socal50 is currently on the bench undergoing mods I thought I would try something.

 

The reverb tank is goosed, probably from when the amp was dropped so I have removed it. This drop also broke the HT fuse holder and dented the chassis. (Note to Ebay seller....fixing HT fuseholders with blu-tack is cheating and just a little dangerous. Note to self....check the chassis of the next amp you buy off Ebay before you part with your cash.)

 

I jumped the reverb sockets with a simple phono lead and the reverb pot now becomes a variable boost control which can be made switchable. This is a trick I used to do safely on a Marshall JCM600's effects loop and it appears to work fine on the Socal.

 

However I am unsure whether this connection is safe or advisable even though it is transformer coupled. Are there any impedance or current issues here and where can I find the tried & tested effcts loop mod?

 

Col

[jefrs]

This is a valve reverb loop, so you are effectively connecting an 8ohm "speaker" output (albeit from an ECC83) straight into the front end of a valve, the signal levels are all wrong. You are feeding a high-level output into a low-level input. This is like taking a desktop computer speaker output and feeding it into the magnetic cartridge input of you record player, ouch! Whilst this might be reasonable to do with an SS fed reverb, this one is a bit of a no-no. A line-level output might be arranged before V3, it would have to be decoupled from the HT and attenuated to line level, the return into V5 might also need a an input voltage divider like the input to V1.

[lespaul99]

And so it was quickly undone. Thanks for the info.

 

Col