Traynor YBA-1

[Chuck H]

Does the first switch leave the circuit more or less original in the one position (and stacked channels in the other)?

Yup. And the second switch is just a "bright" switch. The cap is a lower value than the original "bright" channel cap. It should actually make for a more useful option. You'll need to locate the master volumes somewhere.?. It's important NOT to run long leads on these circuits.

If you do these mods you may find the need to add a "bleeder" circuit somewhere to bleed off some highs. I didn't arbitrarily include one because amps and tastes differ.

In the stacked position with the pre PI master up and using the post PI master as the volume control this circuit would be a gain monster at any volume. Flip the switch back to one channel and crank both masters up and the amp will be clean to it's full wattage.