[sdiy] Banana vs. 1/4" question

[Trevor Page]

> The first synth gear that I built was based around banana jacks- 
> they were good because you could stack them on top of each other- 
> the problem was, I found that because they were not shielded, 
> they could pick up local radio very easily. 

As all electrical conductors do, and rather than relying upon screened
cables alone, one look at why the modular input might be prone to
amplifying and demodulating RF. A very high impedance node, e.g. op-amp
input, going straight to the socket might be your trouble.

> I often wonder if banana jack users ever get this prob. 
> Is there a way of getting rid of this problem? 

Maybe a resistive load in parallel with the input and ground would be
sufficient - 1M or something - and maybe some form of LPF, e.g. choke
(?)

/T