Kyocera A-710 restoration project

[churchill127]

Hello Akers,

I recently bought a Kyocera A-710 integrated amplifier. This is a wonderful amplifier, but it needs a little love, I think there is a slight volume imbalance between channels. I want to restore the power supply and power amplifier boards beyond just a standard recap of all the electrolytics. I have a few questions I wanted to ask the community before I go about this:

1. Is there any reason why I should not replace the transistors and diodes as well as the capacitors and resistors?

Power Supply

• churchill127
• Jan 17, 2022

I don't have alot of experience using modern day replacements for transistors, so do these transistor replacements make sense for a power supply?

2SD880 -> KSD880O (https://www.digikey.com/en/products/detail/onsemi/KSD880O/1052497)
2SC1815 -> KSC1815YTA (https://www.digikey.com/en/products/detail/onsemi/KSC1815YTA/3908203)
2SA1015 -> KSA1015YTA (https://www.digikey.com/en/products/detail/onsemi/KSA1015YTA/4213843)
2SC2235 -> ???

2. From what I have read on AK, zener diodes are worth replacing, but silicon diodes are usually ok to leave? And to replace zener diodes you just need to find a zener with at least the same voltage and max power?

There are two large capacitors that I assume are part of the capacitor-coupled voltage transformer (not marked on power supply list) which are 20,000 uf / 63V. I have heard that some people increase the capacitance and power rating of these capacitors when restoring vintage equipment. Is there a good rule of thumb for doing so?

Thanks!

 

[churchill127]

Anyone think they can give me advice on a good replacement for the 2SC2235? Saw a thread where someone suggested the KSC2383.

 

[churchill127]

hello all, bumping this thread. I have found answers for most of the questions I asked, but would really appreciate some help with the 2SC2235 transistor replacement and whether it is generally ok to leave the silicon diodes in place.

thanks!