Tubes for the Io...
Since I am quite happy with the selected Philips Herleen 12ax7 NOS I bought for the first gain stage some months ago, I have asked the seller for two more pairs of NOS tubes, for the output buffer - V7 should have type 6922, V8 should have 6SN7 (see post #542).
The seller says he has a good pair of Philips (Heerlen factory) E88CC and a pair of RCA 6SN7GTB.
Two questions:
Have anyone tried these, in the Io? Or, generally, changing to NOS in the output buffer - is it worth it?
Are these the correct type? E88CC seems to be another name for 6922, so it should be ok. 6SN7 using 6SN7GTB - is probably ok also, but I am not sure.
Output buffer | V7 | 6922 | Buffer (no gain in V7) | | |
| V8 | 6SN7 | | | |