• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Finally: The QUAD II and QUAD 22

I will start with the QII's, then continue with the 22. Will have a lot of time for this!
I've just ordered smoothing caps for the II's from Keith Snook. He makes authentic looking smoothing cans. My plan is to fire it up with those, and send the original to a friend to see if it could be reformed
 
I cleaned the QII's thoroughtly with a brush and a vacuum cleaner in and outside, and carefully washed off the tubes with a soapy watered cloth, just not to unintentionally wash of the factory marking on those. They shaked off years of dust a grime.


Here are the internals:
UNIT 1.JPGUNIT 2.JPG


With the Quad 22's, I managed to swap all the capacitors at the bottom of the unit, and 3 caps at the top.


Here, you can find before/after photos:
22 OLD_1.jpg22 NEW_1.jpg


22 OLD_2.jpg22 NEW_2.jpg


Managed to take off the top board, but access to that little cap at the top of the switchboard was a pain, but not even less the other side of the volume pot (the 0.1uF cap).
I accidentally burned some cables, and maybe applied a bit too much heat to the Styroflex and to the switcher's lugs but I hope they are all right...



22 OLD_6.jpg22 NEW_6.jpg22 NEW_3.jpg


And, here is a measurement of the C10 cap:
22 OLD_5.JPG
 
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Also, here is the measured values of the resistors. They are measured cold, in situ (in circuit) and with a UT33-D DVM



First, at the bottom of the 22's:


R30 - 54,2 kOhm
R31 - 58,8 kOhm

R28 - 1012 Ohm
R29 - 981 Ohm

R26 - 1,56MOhm
R27 - 1,67MOhm

R32 - 17,96kOhm
R25 - 29,4kOhm
R20 - 52,5kOhm

R14 - 2,88kOhm
R15 - 2,93kOhm

R12 - 1,68MOhm
R13 - 1,67MOhm

R18 - 1,68MOhm
R19 - 1,57MOhm
 
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They do look very original. Are they close in serial numbers?

I wouldn't bother reforming the smoothing caps if you plan to use the amps for serious listening; there comes a point where pre-emptive maintenance means you can do the job once and forget about it. It could be nice to re-stuff the square can to keep to the original look though. Mine were quite heavily modded before I got to grips with them (picture is the starting point), so it was easier to ignore aesthetics.
 

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My personal philosophy is that to be most sympathetic to the restoration you should use the parts that the originals might have used, if they had been available. Quad used good parts, but they were still built to a price point. It’s actually quite hard to find 10% resistors these days, and 1% aren’t significantly more expensive.
 
Not really, they are about 12.000 apart, but read somewhere, that this isn’t necessarily means anything, as these tags picked randomly by the women of QUAD 🙂
Apart from the writings on the transformers and the c5 cap (that is changed probalbly in the past), they look the same.
Keith Snook makes some authentic replacement smoothers for the QII, and I already ordered from him. He gave a set of caps for stuffing them in the 22s for free, so I will do this next time.
Also, ordered the pot adapter and some new old stock tubes. These were a fortune, but ok…

As for resistors, thank you for your guide. I will get together some 1% metal films (1/2W and 400V) for the 22s.
 
Meanwhile waiting for parts...


When I bought the 22 from eBay, the seller did not included the mains plug and cable, and found to be difficult to source this so called 'Vintage Bulgin 2 pole P29' plug for the amp. After some time, I had the luck to find one from an italian seller. Needless to say, I bought it immediately! Sold for a moderate price, not that horrible, but one's do not buy plugs for a price tag like this one had....



Anyway, the cable arrived today. My luck that the end of the cable was unable to fit into the socket (never saw a termination like this), so I bought a clothing iron's replacement cable, and made these:


IMG_9526.jpg IMG_9512.JPG


I managed to have the earth lead fly out of the gauge, and terminate it into a fork.


Also, I had some vintage Belling Lee silver plated banana plugs, so made another two cables for connecting the QII's with the ESL's


IMG_9517.JPG




Also, found a little company (Keith Snook helped me), that sells capacitor cans exactly the values for the 22's (16+16+16uF) in a slightly different outfit, so took out the HUNTS pack, and made some calculations, if a 18mm diameter tower could fit in...
It will not easily, anyway, as the hole is only 15,5mm...


aa2.jpgIMG_9499(1).jpg
 
Got my hand on these, the cap tower for the 22s will arrive tomorrow.

These blocks are beautifully made. My concern is that the values are 70 and 130, that is not 16 and 16
I assume the 70 is for C6, I hope the GZ32 will handle it.

7A7ABCFC-3EA4-4105-AF8F-F8899FB54E48.jpg
 
You are going to have to fit a glass bottom cover on these amps! ;-)

I thought it was quite useful keeping the real estate freeed up by not having the block capacitor, but if I had had the original block caps, then I think I would have tried to stuff them and see how that panned out.

Now you have started down the path of improvements! Won't be long before you are ditching the rectifier, changing the OPTs, switching to ECC83 driver, and reaching for that purple aerosol paint can ;-)
 
Thank you for your help!


@OldHector:
I hope I am not already done that, but I do not want to make 'Theseus's ship' out of these.
Simply, I will just sleep better with every old electrolitics are out. If you barn find an old Ferrari, you probably have to swap at least the tires, those deteriorated by this time. Hope, my analogy is correct.
So far I've done with the caps in the two monoblocks. I even managed no to break these beutiful 'tag cards' locking the new blocks.
I like the outcome, ornamentally.


QII Whole.jpgQII 400V.jpgQII 160V.jpgIMG_9756.jpgIMG_9770.jpg


Anyway, having these out of the system, I will try to send them to a friend who's have the apparatus to reform these, or simply just sell them. I got a request from Keith, that he could find them useful.

IMG_9772.JPG

I found some sticky stuff (?) under one capacitor block, that is rather beeswax than tar. I don't know if I had to do anything with this, so I left it in place.
IMG_9752.jpg

Here is a comparison of the blocks:
IMG_9747.JPGIMG_9749.JPG





If I have the captower tomorrow for the 22's, and have it somehow fit, I will do an initial test this weekend.
 
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