Re-Engineering A four-switch footpedal |
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My friend Ed bought a used Crate GTX3500H amplifier but it didn't have the footpedal with it. After he got nowhere trying to buy one online I re-engineered a Boss BE-5 four-switch footswitch to provide the same functionality as the original. |
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The original Boss BE-5 footpedal, mostly
non-functional. |
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The Crate GTX3500H footswitch logic put a
higher voltage (or perhaps runs a constant current) through the LED that
shows a given channel to be "on". The difficulty interfacing the
Boss footswitch came up when the footswitch LEDs dragged down the
Crate's in-amp LED voltages preventing them from illuminating properly.
The Crate's "off" channels were still putting out enough voltage that
the footswitch LEDs wouldn't turn completely off when their channels
weren't selected. Some experimentation showed that the Boss's
native LEDs would work if put in series with a 5.1V zener and a 1.8K
ohms resistor. |
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Here's a forum/blog on replacements for the Crate GTX3500H footswitch. The Crate GTX3500H Manual (PDF). |
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