SX737 Control Amp capacitor discrepancy

[spctrlhrmny]

Hey there. Attempting my first receiver rebuild on a Pioneer SX-737, and I am preliminarily checking components on the boards to the specs in the manual before I start testing, purchasing, and repalcing.

Ran into an issue on the control amplifier assembly board. Specifically, C1 + C2 and C23 + C24. These capacitors are listed as electrolytic, and according to the manual:
C1 - 1 uF 25V
C2 - 1 uF 25V
C23 - 2.2 uF 25V
C24 - 2.2 uF 25V

I have located them but they're unlike any I've seen before. C23+C24 are red and tan with a white spot and C1+C2 are orange/red, black, and tan with a white spot.
Can anyone shed some light on this? Pictures attached

 

[dups68]

They sorta look like tantalums to me (but I'll defer to those with more knowledge than myself). From reading some threads on here they should probably be pulled and replaced. I beleieve they can short and become "capistors". You could probably go with some film caps or some low leakage caps as replacements.

 

[spctrlhrmny]

film caps as a replacement??

 

[dups68]

This thread has a pretty good walk through on caps to be used for a SX737 recap (https://audiokarma.org/forums/index.php?threads/sx-737-rebuild.644391/)

Films are nice to use since they're non-polar so you don't have track of positive or negative legs when installing and should last and stay in spec much longer than an electrolytic cap. WIMA MKS2 or Kemet R82s are typically what I use. The only downsides is that they can be a bit bigger than a comparably sized electrolytic and they get expense when you start getting over 3.3 or 4.7 uF.

 

[gslikker]

https://www.oldradios.co.nz/data/index2.html

This one tells it all, s it looks the real ones are according the parts list.

 

[Super Noob]

Project: SX-7730 (SX-737)

As the saga continues, I had an opportunity to pick up a couple of vintage Pioneers locally. As you know my flavor is Pioneer, and here is what landed in the garage. A euro 737 and SA-8800. The 7730 had two noticeable issues.... glass was replaced with Lexan & tuning needle was not...

audiokarma.org

 

[EastPoint]

Those are tantalum caps. Replace with Wima film or Nichicon KL.