It really comes down to the fact that this pre amp requires a voltage at the tube plate that most NOS or common 6DJ8, 6922, 7308 types cannot handle.
Many fine NOS types or current 6922 typically have plate voltage ratings of anywhere from 95 or 110V, and even some have over 135V. The problem is that AA will burn through these in short order if used, despite how nice the sound may be.
The EH 6922 can handle the requirement and the best tube Iv'e personally found is the 6h23n-eb labeled Reflektor or Russian 6H23P-ev labled with Russian military code.
They were made in the former Soviet Union and are from the 80's typically. This tube has a plate voltage rating near 300V, thus it will endure and last in these pre-amps. They also sound very good and IMO better than the current EH (type 2) offering an even warmer and bigger soundstage. The best part is how inexpensive they relative to NOS types.
FWIW.. I have tried the Cryo version of this tube, but prefer the stock 6h23N-eb tubes sound.
Many fine NOS types or current 6922 typically have plate voltage ratings of anywhere from 95 or 110V, and even some have over 135V. The problem is that AA will burn through these in short order if used, despite how nice the sound may be.
The EH 6922 can handle the requirement and the best tube Iv'e personally found is the 6h23n-eb labeled Reflektor or Russian 6H23P-ev labled with Russian military code.
They were made in the former Soviet Union and are from the 80's typically. This tube has a plate voltage rating near 300V, thus it will endure and last in these pre-amps. They also sound very good and IMO better than the current EH (type 2) offering an even warmer and bigger soundstage. The best part is how inexpensive they relative to NOS types.
FWIW.. I have tried the Cryo version of this tube, but prefer the stock 6h23N-eb tubes sound.