Pioneer SX-348 - Service manual?

[keantoken]

Hello all.

I just got a pioneer SX-348, to test out and see how it sounds compared to my other stuff (It's all tubes!). I couldn't find the service manual so I don't have any clear way to fix it except replace caps and hope that works.

I need to order new caps for it probably though I haven't checked them yet. To my knowledge all the tubes are fine, but some caps have shorted and the output tubes glow cherry red, a good sign to turn it off.

I was wondering, if I might be able to use the phono preamp and tuner amp section if I just remove the output tubes. IIRC tube gear is generally designed to withstand being turned on without the tubes being in place, so a dead tube won't destroy the whole thing?

- keantoken

[keantoken]

I just went through, most of the oil caps measured 500-700Kohms, a few measured higher, into the megaohms. None measured a short.

- keantoken

[aardvarkash10]

...yeah, but thats applying an insignificant voltage to them. They may well measure drastically differently under a 300V supply...

[keantoken]

Okay, so a better way would be to go back to the tube shop, get that capacitor analyzer, clip one lead of the caps and test them that way?

Of course by then I might as well begin replacing them all.

- keantoken

[mashaffer]

I would just replace all electrolytic, paper and wax caps on principle.

[Eli Duttman]

KT,

Replace those OEM oil caps. with Soviet surplus K40 PIO (paper in oil) stock. I suspect you have the same issue of electrically leaking parts, just like the contemporary Sansui tubed units exhibit.

Mica and ceramic caps. tend to hold up, but ceramic caps. in the direct signal path is a "no no".

BTW, have you tried contacting Pioneer? Perhaps they have documentation in the archives.

[keantoken]

Okay, I just found a good page. Problem with this sort of thing is, I can never find a page that tells me what the caps look like. I've never found a page on how to identify different caps, I'm just supposed to know somehow.

The obvious ones are marked "suzuki oil jcp-a" at 400WV. Can I assume all film, mica and ceramic types are dipped package and lima bean types?

The shop I got it from recommended getting these caps:

Bob's Antique Radios - Supplies

Probably not like the soviet caps, but I have real budget issues. Maybe I could go more expensive if someone knows a good source?

- keantoken

[kenpeter]

Get me a list of cap needs. You could also use my B&K mutual conductance
tester, but you would have to get to Dallas. Have a Sico tester that checks
only for "emission". Basically wires all internal parts like a diode, and check
that is works like a diode. Mostly to see if the cathode coating still emits?
You can rig something like that fairly easy...

[Tom Bavis]

Could it be SX-34B? All the tubular caps are bad - count on it!

[kenpeter]

Same as Allied Radio "Knight 333"?