Main menu:
Quad 22 Stereo Valve System
22 Pre-
Quad 22 Stereo Valve System
22 Pre-Amp & 2 x II Power Amps
This system has just been re-built by a retired BBC audio engineer.
A lot of work has been carried out. The last picture shows the faulty parts which were removed from the two power-amps. The power amps have had all out of spec components and valves replaced and now contain two matched pairs of GEC KT66. Consequently, these power amps sound absolutely gorgeous - just as they should.
Prior to the power amps being re-built, the 22 control unit had resistors & capacitors replaced and was bench-tested for several hours, to ensure it’s working to spec.
For your reference, here are the notes sent to me by the ex-BBC tech guy:
“Hi John
Here's the list of work carried out on the Quad system:
Power Amps:
• Replace both sets of mismatched KT 66 with matched pairs from Watford valves
• Replace 1 x GZ32 with good used Mullard valve
• Replace 2 x noisy/low emission EF86 (Mullard) to improve driver stage balance
• Replace 1 x burnt out choke
• Replace HT electrolytic capacitors and install new mounts as previous replacements were of poor quality
• Replace 1 x cathode resistor and bypass capacitor
• Check all resistor values
• Check all capacitor values and check for leakage.
• Clean valve sockets
• Re jumper output taps for 8 ohm
Preamp:
• Check resistors and capacitors are in tolerance
• Clean valve-holder sockets
• Check switches and pots working correctly
• Check for excessive noise
• Check channel balance
• Run soak test - 5 watts @1 Khz into a dummy load for several hours. No overheating observed
• Re-make power input cable ends (2 pin socket) to power amps as in poor condition.
• Run EET ('PAT') test on whole system with earth added for test.
(Note that the 22 preamp and hence the whole system, is supplied as manufactured with a 2 pin connector and does not have a permanent 'CPC' or 'earth' connection. A 3 core connection with protective earthing should be employed).”
The pre-amp now has the correct mains cable connected, so the whole system is earthed correctly.
So……. Here is an opportunity to own the classic Quad valve system which has been expertly serviced, is working as it should and is in very nice condition.
This system comes with Bulgin mains cable (with earth connector) and user manual.
£1,850 (GBP).
Payment accepted via Credit/Debit Card, PayPal, Bank Transfer, Personal Cheque or cash on collection.
Economical worldwide shipping via UPS or FedEx – Expertly packed, tracked and insured.
Please contact us either by telephone on 01883 340073
or by sending and email to enquiries@retrotechaudio.co.uk
if you are interested in purchasing this item.
Linn, Quad, Tannoy, Revox, Arcam, Musical Fidelity, SME, Rogers, Spendor, Garrard, Leak, Thorens, KEF, Meridian, Lecson, Mission, Michell, Sudgen, Nakamichi, Radford, Armstrong, Bowers & Wilkins, Celestion, Exposure, Gale, IMF, Beard, Audio Innovations J.R., Etc…etc…