6H30 replacement

Not certain what the 6h30 does in this unit.

The 12ax7 is used for input/gain and wonder if the 6h30 is somehow used as a driver for the SS amp section, otherwise I don't understand why it's even there.

If it's run @ a lower bias than spec'd for the tube, then 6n6p may be a candidate as others have used it successfully as a sub in DAC's and some preamps in which the the 6h30 is ran @ lower values.

Also confused as to why the manufacturer cannot answer (what would seem to me) a simple query.

DeKay

to be honest, if it is a nice, expensive piece of tube gear, and the manufacturer or dealer won't give straight answers about how the tubes work in the circuit, and speak to reasonable substitutes (or lack thereof), it would be enough for me to move on to something else

The 12ax7 is used for input/gain and wonder if the 6h30 is somehow used as a driver for the SS amp section,

you are spot on, the X7 has a max gain of around 100 , runs at low current, (us around 1mA) and therefore has very poor driving ability, the 6H30 has a theoretical gain of around 16 and runs at a much higher current (us 15+mA), conferring excellent driving ability. It may even be configured in a cathode follower configuration, which sacrifices gain (only 0.9) for even greater grunt.. The max power dissipation of the 6H30 and 6N6P is 8watts both plates driven for both tubes, so I wouldn‘t be concerned about catastrophic failure if you made a substitution. The plate curves are somewhat different though, and the biasing would not be optimal, although the outcome might sound fine (you might still be in a fairly linear area of the plate curves).

A schematic would be great, and I would really pressure the manufacturer to get one.

@pesky_wabbit  I am trying :) with Pathos. Hopefully they will give  them up.

Just noticed that Upscale Audio carries Pathos.

Had a bit of a hissy fit/kerfuffle with Kevin Deal years ago (here I think), but we were both under "extreme family matter issues/pressure" @ the time so I'm over it, and also not blameless in the altercation.

Anyway, although I assume that you did not purchase the amp from him, you might direct your 6n6p query to him (Kevin Deal).

He's seems to be knowledgable about the lines that he carries, especially so for tube based gear as he also supplies aftermarket tubes for them.

DeKay