Thermionic Culture THE PHOENIX SB Stereo valve compressor - Manual (Page 9)

©Thermionic Culture Ltd, July 2011 8
4 Servicing & Maintenance
The unit comes with a 12 month warranty covering all
parts, including valves. It is essential that it is returned to
our factory or to the dealer from which it was purchased for
repairs to be carried out otherwise the warranty is
invalidated. There is, however, one important exception to
this rule:
4.1 Valves
It is quite safe for the user to change the valves, but
the unit must not be operated without all valves
plugged in
. If a fault occurs, it may be a valve, so
unplug the mains
and remove the top cover.
Looking from the front of the unit there is a row of 4
valves going from left to right and 2 smaller ones at
the back. Going from left, the 1st 2 are
input/compression, the next 2 are output. The 2 at the
back are in the side chain and almost never give any
problem. If a fault occurs on 1 channel try swapping
the 2 input valves over and if the fault (usually crackle
or level loss) changes side then you have located the
problem. If not, replace the valves where they were
and do the same with the output valves. Make sure
that the valves are put back in their original positions.
If a valve fault is located Thermionic Culture will
replace, under warranty if applicable. If an input valve
(PCC 85) is faulty, BOTH must be replaced as a
matched pair and they will be matched at our factory.
If an output valve is faulty, then the faulty one can be
replaced on its own, though it may be best to replace
both if more than 2 years old. Output valves must be
accurately matched so that the 2 halves of the valve
are equal, then soaked and re-tested. We do this with
all valves supplied.