While I haven't actually tested it, it should be fine. The delay and reverb chips have their own voltage regulators, so they will always get the same voltage no matter the voltage of the power supply. And the rest of the signal path circuitry should run just fine up to 32V. The only possible problem is that it might make unity gain off a little bit. Higher voltage increases headroom, but it will also make them slightly louder. If they op amps were set to a gain of 1, it wouldn't matter. But in both cases, the input buffer op amp is boosting the signal and the output buffer is a gain reducer. It probably won't make any difference, but there is that possibility.
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*patience is a virtue*
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