IMPORTANT NOTE IF YOU ARE SENDING YOUR 33 FOR SERVICE: If your 33 has intermittent, missing, or low volume L or R channels or input source faults, it is probably due to mechanical failure of push button switch contacts or rear horizontal edge connectors. Unfortunately, we cannot replace these items with NOS items as they are no longer available. We may be able temporarily cure the problem by cleaning or re-tensioning the contacts (this is part of our standard service). If the contacts are too worn, we may be able to replace the part, by removing the item from another 33. It all depends on if we have one in stock at the time, with good parts! If this applies to your 33, we will inform you before we proceed, as unfortunately, an extra charge will apply. Please be aware; these mechanical parts are the ‘Achilles heel’ of an otherwise great sounding control unit. Please also bear in mind, the 33 is over 50 years old!, so it all depends on how much use they have had. This also applies to most other makes of vintage control unit. Please don’t expect us to repair faulty mechanical parts under warranty. It is up to you to ensure the mechanical parts on your 33 are good enough to warrant a service in the first place. It may be a better option, to seek out and buy a later, less used 33, with intact contacts, or buy a new control unit, unfortunately it wont’ be a Quad 33. Quad 33 Things to check before hooking up If you have just had your Quad 33 serviced, or you have purchased one on the internet, here are a few tips to ensure it works correctly. The great looking, sweet sounding, Quad 33 control unit has seven printed circuit boards. Two are fixed mother boards and five are slot in, edge connected, types. The horizontal mounting cards, are user configurable. These slot in horizontally at the rear of the 33. The other three slot vertically into the two motherboards inside the 33. See pics above. The plug-in design and lack of retaining springs, means the cards can easily work loose during transit. The main culprits are the internal, vertically mounted, cards. These often jump out of their slots and become wedged against the cover and their respective motherboards. When you first receive your 33 back from service, there are a few things to check prior to power up: 1. Unscrew the two rear slotted screws and withdraw the chassis from the sleeve and check that the three vertical slot-in board are pushed down firmly into their edge connectors (see the left picture above). 2. Refit the chassis into the sleeve and refit the screws. 3. Make sure the fuse thumb screw is tight and has not loosened in transit. 4. Make sure the power amplifier, 33 and other peripheral units are unplugged from the mains and connect the signal leads. Look at the rear of the 33 and ensure the index indent on each plug locates with the relevant socket index on the rear panel. (Shown as a red arrow on the lower picture above). Don’t try and plug them in just by ‘feel’! 5. When you have connected all the signal leads to their relevant units, connect the mains cables to the units before you finally connect to the mains wall socket. 6. If you are using a turntable and pick-up make sure the turntable earthing lead is connected to the thumb screw marked 'E' (shown on the rightmost picture). 7. Refer to the Quad 33/303 user manual. (Copy on our download page.) Note: If we serviced your 33, and you send a large enough box, the vertical cards are packed separately for you to fit.