JIMV wrote:

I have a tube buffer in my otherwise all solid state system. The buffer (Grant Fidelity) lists 3 different tubes that can work in it, the 6N8P, 65N7 and 6H8C...

Can anyone say what the differences in sound might be??

I trust you meant 6SN7. I think you will probably find there can be considerable differences, or shall we say trade-offs, among 6SN7 manufacturers. For example, one 6SN7 tube might provide a full, rich sound but lack the deepest bass. And one 6SN7 might be very dynamic but lack the high end extention of another. Overall, in my experience you really can't go wrong with NOS Sylvanias or RCAs.

Cheerio

Geoff Kait
Machina Dynamica