Quad 303 Service
3O3 £110.00 service
includes: fault diagnosis and rectification, replacement of all electrolytic capacitors,
out of tolerance components, badly worn sockets, and a full performance test and adjustment.
Finally after a listening test we carry out
a 48 hour soak test followed by a PAT*. We also
and clean the case inside and out to revive the appearance. Even
better, if you have both your 3O3 and 33 serviced at the same time the combined
charge is from £220. On the majority of 33s & 3O3s we receive this is the
final cost + return carriage.
NOTE: Our standard price does not include the
cost of blown homotaxial output transistors. These are now becoming very scarce. The
cost of these if required will be added at £7.00 per transistor to a maximum of £28.00
extra if both channels are blown. We will inform you if you are unfortunate
enough to have faulty output devices. Alternatively
we can fit modern 150W epitaxial MJ15003 devices at £4.50 each, extra maximum
charge of £18.00. Fitting these can cause HF instability so we may have to add
Click here for more information
The images below show a typical full
service for £124 inc. two homotaxial power transistors.
fault rectification and refurbishment: right channel defunct, crackling on
left channel, two main smoothing capacitors leaking and there are several
faulty & out of
New smoothing and output capacitors are fitted in place
of the old style bracket mounting types.
In the featured repair; two new driver and
two output transistors were replaced during the fault rectification process.
In addition, five noisy preset resistors and a complete set of electrolytic
capacitors were fitted as standard.
On older 303s we fit a
tiny BIAS modification board in place of the crude diode
bias arrangement. This allows more precise adjustment of the output
transistor bias. The original 0.68-1uF electrolytic or tantalum coupling capacitors, are replaced with polypropylene/polyester
Some 3O3s we receive for service are
in a very poor state. e.g., rusty case, bottom plate and front panel. We can restore the overall
look by stripping and re-spraying these parts with primer and top coat. The
re-sprayed sections (cover and bottom panel) will be in two tone metallic
colours but will not be perfectly colour matched. The cost for stripping the
old paint, priming and re-spraying the cover, bottom and front moulding, if
applicable, is £70.00 extra.
To add value and enhance the functionality
of the 3O3 we can fit a professional steel powder coated front panel with
phono inputs, conformal loudspeaker terminal posts and a switched and fused
IEC mains socket. Instead of the old flickering mains neon we fit an led to
monitor the HT rail voltage. When the power is turned off the led
slowly dims indicating when the internal capacitors are fully discharged.
This is useful when you want to move the unit or disconnect / connect
FULL COMPONENT REPLACEMENT OPTIONS
If you want the ultimate (still a Quad 3O3) modification we also offer a
complete full component replacement option. We fit a new front panel as
above and strip the L & R signal and PSU boards and fit new
components throughout. No old electronic PCB components are used apart from
the bare boards if they are good, and the internal heat sinks. If the boards
are poor, we can replace these too for an additional £20.00. The
circuit is still Quad's original but with new components. The net
result is a more robust 3O3 with improved response, lower noise floor and
distortion and improved power handling capability. The well loved slightly
warm 'valve like' sound remains.
our completely new circuit upgrade option is available.
*PAT Portable Appliance Test. A conformal test
of the electrical safety of the appliance. This includes insulation test and
earth bonding test.
A PASS sticker is attached to the underside of the Quad 303
with the date of the test and the engineers signature.
In the event of a fail
(very unlikely), the owner will be informed before further work is carried out.