I have 'my' 33/303 back and hope to be able to afford to keep them (I need to pay the chap who was 'keeping' them for me - cough...). I don't care if the absolute standard isn't up to date, because even the (Dada updated) 33 makes the music so believable to me. I can listen to both together, or the 303 when passive preamp fed, and forget their age and limited (in today's world) abilities.

As above, more please...

Ah - if only it had been that simple

Back from the Brink
(the saga continues....)

I retired two years ago and near the top of my ‘to do’ list after some pressing domestic chores was finally getting the Quads fettled. I had already done quite a bit of web research in the interim and this had steered me towards electrolytic capacitor aging as the likely culprit. Sure enough, opening both boxes confirmed this with a couple of caps already in pieces and quite a few others badly split. Having toyed with various options, including sourcing all replacements myself or sending off to Quad for a service, I opted for DADA kits for both units as the most viable (and affordable) solution. I did consider the Net Audio route but some aspects seemed a bit too radical and I was concerned not to lose the Quad signature sound that I bought them for in the first place.

Replacing all the capacitors may sound like a daunting task but those familiar with these early Quad amps will know that the design includes mainly ‘pull out’ circuit boards making access quite easy. Carrying out the work was therefore relatively straightforward, helped in no small part by the detailed instructions provided by DADA and a copy of the original schematics. The only part of the process I initially held off on was the changes required to upgrade the 33 pre-amp to 16v operation, although I did replace the power supply caps with ‘like for like’ equivalents sourced separately. After a few evening's work and with some trepidation I finally set it all up and switched on for the first time in six years….and was more than rewarded with a sound that was definitely back to the glorious beauty I had always revelled in – RESULT !! - or so I thought ….

(to be continued)

To be honest Dave - at this time I was more concerned with getting the damn thing running properly again and this is not the end of the saga by a long chalk. I did come across this mod though and added it to my scrapbook for future reference but have never gotten around to it, glad you reminded me

That you Andr'e? I'd have taken your mint Quads and 'kept' them for you had I been able. The speaker manufacturer who bought an F307 from you had it on show when trying to suggest that all good dealers must have an oscilloscope so they can check if their demo amps are clipping or not - or something like that. 'Your' F307 asymmetrically clipped a CD player source at around 10 o'clock on the volume control I seem to remember.

I love that they are so many different approaches

With mine, I thought it was the beadle that was on it's way out causing fluctuations of the copper field, and the eventual sad demise of the unit. With no music to entertain, the house was bleak that night, I can tell you.

My mate Barnaby Rudge was of a totally different mind as to why it had expired, however.

With opinions Noah Claypoles apart, we enlisted the help of our mutual friend the wacky Ford Squeers who is in gainful employment at Dombey & Son Hi-Fi.

My imagination ran-out at that point.

God Bless Tiny Tim.

The Thot Plickens


The jubilation was short lived; although the overall SQ had improved significantly there was a still a hum, albeit fainter, but worse still the grumble on start up returned intermittently over the next day or two. As part of a parallel project, I had built a ‘home-brew’ passive (a basic voltage divider) so was able to check the 303 which showed an apparently clean bill of health – pointing a finger at the 33 as the likely malingerer. I was sorely tempted to stick with a passive and even considered buying a Tilsbury given it’s glowing reviews; unfortunately this would necessitate buying a phone stage for my Braun deck and this was a route I had no passion for (I am more than happy with the stage built into the 33 and would also miss the presence of little fella greatly.) An added complication was the need to feed my headphone amp (I do a lot of listening on an evening) which I normally achieve via the 33 tape output; with a passive this would require some form of switch box on the line out adding to the clutter and cable spaghetti littering my desktop.

More internet queries followed; by this time I had joined AoS as there seemed to be quite a few experienced Quad users who might help. My enquiries there yielded some useful suggestions pointing to the possibility of imminent transistor death or failure of the suppressor capacitor that I hadn’t thought to replace and strangely isn’t included in the DADA kit. Belt and braces pushed me to tackle both. I pulled all the transistors and replaced them with equivalents suggested by DADA (the BC550, a very cheap mod now included with the DADA kit) and also fitted a new RIFA suppressor. Unfortunately, despite all this effort, the start up problem persisted.

By now I was close to giving up and in fact sourced another (already recapped) 33 relatively cheaply - working fine but a bit scruffy, and relegated the other to the naughty step indefinitely. The replacement at least confirmed the problem definitely wasn’t with the 303 and I had pretty much decided to leave it at that … but that would be admitting defeat and that just ain’t in my nature. So after a week or so respite the errant box was opened again, this time with the intention of carrying out the 16v upgrade that I hadn’t done before in the thinking that perhaps this upgrade might be the final brick that would finish the wall. It was at this point that I discovered that the foundations were very possibly the culprit all along… when I desoldered the two wires connecting the PSU board to the power sockets one of them literally fell off, the connection at the other end being tenuous to say the least.



Obviously, it was a simple job to fix this during the refit of the power supply after replacing all components and making the necessary adjustments to other boards.


Finally all back together; all seemed well and inward smiles filled my hours … until a familiar but completely unexpected monster reared it’s ugly head shortly after…




(to be continued)

The story so far:
I have an old Quad 33 that started being naughty and wouldn’t stop no matter how stern I was - so after a final act of defiance I reckoned it was time to get down and dirty with drills, snips and a soldering iron to teach it a lesson….

DISCLAIMER: Probably best if any purists who flinch in horror at the sight of wanton violence committed on vulnerable specimens of endangered species look away now and read no further – a butchered Quad 33 is not a pretty sight ☹ For those of a more adventurous spirit I hope the following penultimate chapter is of some mild interest…


Alien Resurrection

All my efforts to eradicate the grumbling had been in vain … it came back with a vengeance, not only when I turned it on but also randomly and without warning when turning the volume pot - until suddenly the volume pot wouldn’t turn – stopping at half volume and refusing to budge. The box was opened for the umpteeth time and the pot removed, the back plate was prised off and sure enough, the thing was truly knackered. If you’re not familiar with the 33 it has the power switch mounted on the axle of the volume pot and in this case it had decided the time had come to fall to bits. Attempts to locate a suitable replacement were in vain; DADA sell a substitute but were sold out with no indication of when they would restock, there is an ebayer seller who has them occasionally but priced at a premium for what they are; searches of other suppliers drew a blank. At this point I pretty much lost interest in retaining any sense of originality or authenticity and decided to have some fun. I had the other 33 for insurance if things went pear shaped so what the hell….


I considered using an Alps pot and simply using a power switch mounted on the rear panel but space is very limited on the 33 casing and this was proving to be a headache. One of the more obscure (but noted) comments on AoS related to off-boarding the power supply to an external PSU. I had an unemployed variable regulated supply in the garage that I built from a kit some years ago and after dusting it off checked it for functionality – it worked fine. I also had a 50k Alps pot in the passive so what followed was simply rigging the two up temporarily to the 33 and trying it out with a separate mains lead to feed the 303. I ran it like this for a few days and with great relief noted no problems whatsoever; in fact I convinced myself that it actually sounded better for it (no doubt a subconscious placebo effect). With new confidence I bit the bullet, removed the inbuilt power supply and hard wired a socket fitted to the hole used by the fuse (later moved).


Once I’d done this I was pretty much on a roll and decided it was time to tackle the real bugbear I have with older kit – 5 pin Din sockets. All the gear I have is RCA – the only other legacy kit being my Braun TT and I converted this to RCA pretty much as soon as I got it way back in the ‘80s. As I had chucked originality out the window with the external PSU it was also time to take on this challenge and dispense with the annoying plethora of adapters I had accumulated over the years.

I did a mock up of the rear panel in Photoshop and crosschecked with the interior layout to avoid any unpleasant surprises and sure enough – it would work. For reasons of space I retained the Din Disc input and the 4 pin line out but these may be changed through a more radical redesign of the back at a later date. The only real obstacle I encountered was that the 33 Din sockets are all riveted to the chassis and only accessible to drill out by removing the characteristic plastic backplate. This is held on by metal push clips mounted to plastic pins molded into the backplate and I could find no way to release these other than prying them out as best I could and cutting off the pins with a craft knife. After removing the sockets I mounted the RCA replacements on some Perspex off cuts I had in a sympathetic colour (Ivory) and bolted them into the existing holes. The layout was determined by the space in the metal panel behind the backplate which I was loath to start cutting into without complete removal from the main body of the amp (something of a daunting task). This meant sacrificing one of the two radio inputs but as I never use both this was not an issue.
This was the result:




As a side project I also swapped out the still pristine front plate with the tatty one from the 33 I had acquired and gave it a bare metal strip down and respray. The original Quad finish is a very close match to BS381-389, aka Camouflage Beige, which is readily available from local auto supply shops – but only in matt finish (who would want a glossy tank?). In the end I opted for Ford Oyster Gold - a great colour match if a shade lighter than the original:





The only question remaining is ‘did it work’ … for the answer to this and the other eternal question of just how shit lead-free solder really is, tune in tomorrow for the absolutely final and gripping installment of this seemingly never ending story…

(to be continued)