Quad 33 Pre Amp Restoration and Upgrade 

UPDATE: I hooked it up to the QUAD 303 today and a couple of Denon speakers (the electrostatic speakers are next in my servicing list!). It works fantastically! Very pleased this is a living thing again. Some pics here: twitter.com/backofficeshow/status/1203634848348459009?s=19

It's called a Pre-Amp. The disc Adapter card is for various phone cartridge like Magnetic, Crystal, Ceramic etc.

I have two of these Quad 33 preamps and two of the matching Quad 303 power amps that were made to go with them. Production started in 1967 and the 33 continued until 1982, the 303 until about 1985. The 33 preamp has several common problems after so many years. Most notable are the input and filter switches which cannot be replaced anymore and the edge connectors which hold the vertical boards. These connectors were poorly designed and can become unusable after removing the boards several times. If you’d like to buy one, make sure you get one with serial number over 100,000 which will ensure it’s not as old and will have the better later edge connectors. The Quad 33 and 303 produce a wonderful warm sound via appropriate high impedance contemporary speakers, such as LS3/5a, Tannoys and Quad’s own ESL-57.

IT's A PRE-AMP! 4 differnt phono inputs on board

It's called a preamplifier.

I had one with the companion 303 power amplifier and FM3 tuner

All that work and you don’t even show it working at the end. That’s too bad, would have been nice to see that and hear your thoughts on any difference the upgrades made ?

Quad made the first audiophile electrostatic speaker

So British ..like Gerry Anderson's puppets . I have that unit and i love the looks.SO ahead of its time This company was doing analog buses .others were just doing crappy wiring

Nice video. But, remember to cut leads before soldering. You stress the solderpoint when cutting after. This might limit how long it will last

you could adjust the "slope" of the tone control

The Quad 33 Pre Amp was manufactured from 1967 till 1980

Do you still have the instructions from dada? They are no longer trading, and I just want to do some upgrades on a broken quad 33. They used to be freely available on their website, but unfortunately that also doesn’t function. Many thanks.

hi there i am just about to buy one , what caps did you use to replace them and how do thy sound now

usually these"kits" provide replacements for "failure-prone" components.

Maybe If I was going to put together a mainly vinyl/70's system I would consider one of these? I normally like odd looking minimal stuff but this really doesn't do it for me.

This is a really interesting video but I can’t help thinking that you’re being a little heavy handed - did you really need to change ALL of those components?

Hello there - why did you not check the existing components with a tester before changing them? at least you would of kept more of the original parts

Are you sure that C401 on the amp bards are the right direction at about 38 minute mark ? on the picture it shows positive at the bottom and you marked it at the top

Quad acoustical manufacturing, England

Why dont use desoldering pump?

measure it!

would you say that this upgrade leave, nothing for the Quad being a quad? i am not saying it not a beautiful pr-amp put it is not a Quand ... what is that sucker btw?

oh boy ........that , is a preamp .......leave it alone!

those aren't "schematics"