I'll use transistor switching really, Graham - the relay is metaphorical...

I can just about manage that...solid state 12AX7, no problem!

Martin  GW3UCJ.

~~~~~~~~~~~~~~~

Well that's the problem, we all know what the kit can do , but there are only a few who can tap the keys and make it perform ..

I think your keying relay would be OK for OP8 .as long as the pull in and release times are well matched to retain the envelope shape ..

I think pulse 'jitter' would be a problem on the higher (shorter) versions ...... could you not use blocking keying or a pin diode switch ?