For audio circuits like these poly's are nearly always the better option. Ceramics are cheap and often used in budget gear.
If you fit or replace any caps with tubular polystyrenes you can use the caps construction to shield against stray noise pickup. You will see one lead comes from the middle and one from the outer edge of the cap. The outer lead which is the start of the foil wrap on the outside of the cap can work as a shield if you connect it to the lowest impedance point of the two connections on the circuit.
For example if the cap is from the base of a transistor to ground then connecting the outer foil connection to ground lets the caps foil act as a shield. In this circuit the low impedance point is the collector of Q209.
If you are in the UK then have a look at CPC:
https://cpc.farnell.com/lcr-components/fsc-160v-22pf-1pf/capacitor-160v-22pf/dp/CA05848
The coloured end on these type is another way to determine the outer wrap of the foil.
Yeah...... rather cheaper. Now, if it had been an engineering fastener I would have had no problems at all in identifying the spec. and most cost effective replacement. Different strokes for different folks, 65 next time round, never stop learning, never stop being curious, never stop asking questions.
I use CPC quite alot, along with Farnell, and surprisingly a company called Cricklewood electronics who have alot of bits you can't get anywhere else sometimes
Ceramic under 1,000pFd are often as perfect as it gets. NP0 (En Pee Zero) especially because it is blended for zero tempco (about zero everything).
Ceramics much over 1,000pFd need to be "salted" to get high capacitance and that "soup-up" is not perfect.
At 22pFd, I would use Silver Mica because it sounds cool. Ooops, five bucks?? Then NP0 ceramic.
I don't think 22pFd is made in film?? 10 inches of phone-pair is about 22pFd but would be an antenna also.
So did you try parts-express or Parts Connextion or mouser or mcm electronics or digikey? I have a parts store buy me. What type of replacement Capacitor are you looking for? Maybe I missed it🤷🏻♂️? The valve and the voltage and what type poly? I don’t mind stopping at the local electrical store on the way home tomorrow to see if they have the one your looking for? It’s not out of my way and so have known the owners for years. Be safe. Jeff
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Update. So while I dithered about sending the Silver Micas back because they were overkill on the £££ side and the board needed driling for the thicker lead wires I found the cheapest 22pf radial capacitor in the world in my old student box and popped that in as a test. Worked fine. Returning the SMs and buying something else was 3 lots of postage down the tube so I gave up, drilled the board and used them. So now after many years of routing the turntable through a different amp just to use the phono input I can now use the 8000a MM stage as was intended. My very first discrete component level fault find and repair a success - wouldn't have managed it without the help on here though, especially Mooly, thanks all.
