Nonstandard tubes for audio? Quadrature grid chorus effect?

[m6tt]

I was wondering especially about the 6bn6 as well as the pentagrid mixer types. The quadrature output of this tube sounds like it's 90° out of phase, which would make a great chorus effect. I have seen circuits using this tube as a clipper, but I was wondering if this tube could provide simple and interesting effects processing in a guitar amp or pre-amp.

I also was wondering if a pentagrid mixer tube type could be used to sum channels in a multi-channel preamp. It's also possible that this doesn't make any sense, so I was wondering if anyone had used any of the multiple grid mixers etc or the multiple plate tubes to create any interesting effects at audio frequency.

(I just picked up a broken Western Royal superheterodyne, 6u5 and all, which I am going to convert into a very nice looking living room guitar amp. 11 tube sockets, all octal...finishing a super Kalamazoo Reverb 12-like amp with 6ca7 output, as opposed to the 6bq5s in the original)

[Robert McLean]

The pentagrid converter will multiply the signals rather than add them, at least that is what they do as set up in a radio. Never the less, they may be interesting to play with in an audio effects application.

For an additive mixer you can try a twin triode with seperate cathode resistors, but one common plate resistor.

[m6tt]

I do recall seeing some triodes with "dual control grids" in my RCA '47 receiving manual...I imagine that would be the same.

Would such a mixer avoid some the old "220k resistors from each source to the grid" techniques' loading and channel crosstalk problems?