CHAMP ELECTRONICS -" THE VINTAGE VALVE
AMP HOSPITAL"
NOTTINGHAM, ENGLAND
SERVICING OF A HIWATT CUSTOM 50
COMBO AMPLIFIER
Not a
fantastic amount to say
about this one really…..just a few interesting points. This
is
basically the standard 50 watt Hiwatt chassis, mounted upside-down with
most of the labelling reversed to accommodate the upside-down mounting.
But not all….check-out the voltage selector & speaker
impedance
plugs’ labelling…still the wrong way up!)
A base-plate piece of wood has been fixed to the four original
mountings, overhanging on each side of the chassis by about half an
inch or so.
It
really disappoints me when reputable amp manufacturers revert to
PCB’s but…….I have voiced my opinion on
this a few
times before on the site so….there’s no point in
going
over old-ground.
Underside, right-hand viewed from the back.
Underside, left-hand viewed from the back.
Here the main
chassis is slid
back into place, resting on the two overhangs (left & right) as
described earlier. However, notice at the top/centre the piece of wood
screwed into the amps’ added wooden base. Also (though
out-of-sight) there are two more wood screws, toshed-up from the bottom
at a 45 degree angle into the top wood section of the amp. This is to
hold the rear section securely in place. I cannot for the life of me
see why Hiwatt didn’t just simply adopt the usual way of
fixing
an amp upside-down; i.e. with four long screws & cup-washers,
from
the top of the cabinet into the existing four captivated
nuts…….like many other manufacturers?
Now
we are really going “cheap-tack!” Here you can see
a block
of wood used between the front speaker baffle & amp
chassis…..to hold the front of the chassis up & in
place!
I’m not impressed at this bodging……..to
say the
least!
And
now to something funny! This is a close-up of the output transformer.
This isn’t a Hiwatt issue but a problem caused by the company
that were making the transformers for Hiwatt at this point in time.
Please let me explain. Most transformer laminations for valve (tube)
amps generally come in two kinds. One type are called
“T’s and U’s” whilst the other type are referred
too as
“E’s and I’s”. The later
being the most used.
This output transformer typically use “E’s and I’s.
Nevertheless, someone (probably an apprentice?) has put some of the
“I’s” in this transformer the wrong way
around! It
wouldn’t really make any difference to the performance of the
said transformer, but……..this is still
“poor
quality control”! God, you just can’t get the staff
these
days!
