SE/30 recapping: sound chip question

[Oberlehrer]

I'm currently preparing to recap a SE/30. First time for me so I'm taking some precautions.

Now most electrolytics go from a voltage rail to ground, in fact nearly all of them.

However there are a couple of electrolytics in the audio circuit as well. C3 and C4 are directly in the audio path so they're DC blocking caps (or coupling caps?). C5 goes from VREF for both sound chips to ground.

I faintly recall that tantalum caps are not often used in the audio path so perhaps it's a better idea to stick to electrolytics here?

What's got me stumped at the moment is C6 vs C24. C6 is 1u electrolytic, C24 is 0.1 ceramic. C6 goes from SND-R-A/D to ground, C24 from SND-L-A/D. So both essentially have the same function. So why the difference between those values?

 

[Oberlehrer]

Any takes on this?

I'm about to order caps this week; I'll probably stick to electrolytics. The lifespan of modern electrolytics is hopefully a bit longer so there's a chance I won't have to do it again in my lifetime.

Removing the old caps worked quite well; not a single pad lifted. I tried the "twist with pliers" method first but found it a bit unnerving. So I stuck to the "cut off the top" method that exposed the leads and the plastic part at the bottom. That part was so brittle that it was disintegrating with little force, leaving the leads on the pads. Those were easily removed then.

 

[bibilit]

All capacitors are 47 uf 16 v and one is 1 uf 50 V (smd)

you have got two axial ones also. 

I don’t see any 0,1 uf. 

You can go for electrolitics or tantalum, never had any issue with one type or another, they will work the same way. 

 

[Oberlehrer]

My point was: Is there a (known) reason why both audio channels use different values and types (1u electrolytic vs. 0.1u ceramic)? Just being curious here.