PH16 Tube Family Question

Sorry if I couldn't find this info,

So the PH16 phono stage basically uses 6922's, at least that seems like the most common number that comes up.

7308's, and 6DJ8's should work OK as well I take it.

I saw in the PH16 instructions I think, that 6CG7's will also work, well but maybe only in the buffer stage. Apparently these are basically 6SN7's in a smaller package.

Is there a reason why these might be recommended for the buffer but not the input stage?

yes, only 6DJ8 or 6922 tubes (or equivilent sub, like 7308 or PCC88) in the first two stages, the RIAA EQ is fine tuned to the characteristics of these tubes,
which are way different than 6FQ7 types, but 6FQ7s can be used in the output buffer.

I see, thank you!

A well-made 7DJ8 (PCC189) also works just fine as a drop-in for the 6922. They run a 7-volt filament for reasons I have never understood, but theoretically are longer-lived with a 6-volt input. I have used both types and can't tell the difference in a PH-16. The beauty of the 7DJ8s is that they're dirt cheap because nobody knows about them, albeit they are as well-made and NOS by the same folks who made the best 6922s.

dp correct
for a great list of tubes you can use in the PH16, see this page .. .
https://www.upscaleaudio.com/collections/preamp-tubes/6922-6dj8-7308-pcc88

deepee99 wrote:A well-made 7DJ8 (PCC189) also works just fine as a drop-in for the 6922. They run a 7-volt filament for reasons I have never understood, but theoretically are longer-lived with a 6-volt input. I have used both types and can't tell the difference in a PH-16. The beauty of the 7DJ8s is that they're dirt cheap because nobody knows about them, albeit they are as well-made and NOS by the same folks who made the best 6922s.

The reason for 7 V filament is that it is made to draw 300mA and connected as series connected tubes.

All european tubes beginning with "P" draws 300mA filament current and are typically used
as series connected in TV-sets.

European tubes beginning with "E" uses 6.3V filament. Etc

Thanks for that info, Peterh. I was not aware of the European nomenclature.
Another point needs to be made here, and that is that a 7V filament tapped to the 6.3V xformer will not bother anything.

I have a PH14 which I believe is the same as the PH16 without the moving coil option.
Mine came to me with Sylvania 6922 (probably from the '80's). I switched to Bugle Boy 6DJ8 which were a bit better but then I switched to USA Amperex 7308 (about 1964) and they were quite an improvement.
I didn't feel the need to roll anymore tubes in it.