Here’s why you’re experiencing this problem: The output impedance of your guitar is quite high and the output impedance of the synth is quite low. when these outputs are paralleled (by being passively combined when the “Y” switch connects them together), the lower output impedance of the synth looks like a short circuit to the guitar output and thus the level of the guitar is reduced. If you inserted a buffer (even a boss tuner pedal buffers the signal) between the guitar and the “Y” switch, you’d have a better match to the output impedance of the synth and the signal level wouldn’t drop as much. It’s generally not considered a good idea to combine two outputs directly in they manner because of these loading effects, which in addition to the level changes you’ve experienced, can also produce distortion as the output of the connected devices are running out of current trying to drive a near short circuit.
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On Jul 31, 2014, at 16:44, Michael Peters <firstname.lastname@example.org> wrote:
non-loop related question:
I want to use either-or or both of two sound sources (guitar, and guitar controlled synth), so I plug them both into an y-switch feeding my amp.
That seems to work fine at first, I can switch between guitar and synth without problems, both are loud and clear, but when I set the switch to "both at once", the guitar is suddenly very low in volume while the keyboard is as loud as it was. Why is that? is there a remedy?