Sharon I definitely see what you're saying about the
transformer BUT the hum is penetrating the
line BEFORE where a
transformer would be put - in the short unbalanced run between the laptop and the box where all these resistors
etc are.
The
transformer won't do anything for the hum that's already there from up the
line.
*sighs* I have had enough of this. Thankyou all for your help.
Can I ask a few favours of my
ControlBooth saviours:
1) Can somebody provide me with a
circuit diagram, taking all the above into account, that will do the best job in the situation and explain why it will work.
2)This has worked fine before in other setups with the same amount of unbalanced run, even beside the dimmers and all - except normally just taking the left
channel cutting out the right and outputting it straight out into the
system. The old cable, as mentioned in my first post, put L and R onto pins 2 and 3 respectively without any sort of
resistor setup, making horrible sound and probably damaging the laptop unless I just inserted the
TRS minijack only halfway into the laptop (obtaining L
channel only).
I am starting to think Sharyn is right about there just being far too much resistance to the original signal.
The same amount of hum was probably always there (as with all unbalanced lines) - just there was such a huge amount of signal that the hum was miniscule.
If we could mix the best of both worlds (SharonF and Cutlunch), come to an agreement about the best
resistor size and obtain a final
circuit, I shall do it up and report back.
And finally, you guys are the BEST.