"Nick Gorham" wrote in message

Arny Krueger wrote:
"Dave xxxx" wrote in message


Andy Evans wrote:

Dave xxxx wrote:

The 4PS1 valve is used in a headphone amplifier

But I can not find it or anything like it.


Has anyone any ideas ?

ta in advance

This is an unusual name for a valve. Is it Russian or
Chinese? P is R in russian, but Russian doesn't have an
S.

Its fitted to many Chinese head(phone) amplifiers.


There may be a typo in the OP, as 4P1S is a recognized
tube type. The 4P1S appears to be a loktal triode.



I have been trying to find references, I think Arny is
right, looking around I think they could be the same as
4N1N which are not that common either. I did find a
reference that made me think they were pentodes though.

The headphone amp that uses these things might be using triode-connected
pentodes. I found a spec sheet that seemed to be talking about triodes, but
that might have been the usage, not the device. If the 4P1S is based on a
legacy design, every legacy loktal power tube that I can find is either a
rectifier or a pentode.