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P a g e
have worn out through extended use or have become microphonic or noisy over
time.
Many issues relating to valves can be cured simply by re-tensioning the valve bases.
Over time, the valve sockets, which are constantly heating up, cooling down,
expanding and contracting may become a bit ‘loose’ and not hold the valve pins as
tight as they should. This can lead to noise and more commonly, sudden drops in
volume or complete lack of sound.
It is impossible to put a life expectancy on a valve but generally, if it lasts for the
first few weeks of use, a preamp valve can still give good performance for 3-15
years. Output valves tend to wear out much faster and with regular use, rehearsing,
practicing and gigging we would expect them to last between 1-2 years. We
recommend changing older output valves periodically as preventative maintenance,
i.e. before they fail and potentially cause more serious issues or pack-up mid-gig.
Victory ‘burn
-
in’ all amplifiers for a period of 2 hours at full power into dummy
loads to wheedle out any valves that are not up to the job. This is in addition to
around 90 minutes of electronic and audio test & measurement including a live test
at full volume in a sound-proof environment. This extensive testing catches most
problematic valves but a small percentage do fail in the first few weeks of use. If
you suspect a valve failure, please contact our service department who will advice
on the best course of action and invariably, replace these valves under warranty.
It is an easy task to re-tension the valve sockets and this can be done with a small
flat blade screwdriver such as this, (inexpensive watch-makers type):
Important! Please ensure the amplifier is not plugged into the mains and has been
off for at least 30 minutes before removing any valves so all of the high voltages
have dissipated. Carefully remove each valve in turn. The pre-amp valves have a
sprung-loaded screening can fitted over each one so twist this through 90 degrees
or so until it pops off. Then using the slow circular motion, pull the valve from the
socket. The output valves are retained by spring clips which need to be lifted up
and over the top glass nipple on the valves to facilitate their removal.
Please ensure that the valves go back into the same sockets as they are optimized
at the factory for best position relating to gain, noise, & microphony. This is easily