Telefunken TL70 renovieren

Hello!
Think you that capacitors are defekt?What says the capacitor measuring instrument?
Well, i think the idea to replace the capacitors to Jantzen Cross cap ( MKT, MKP ) is good.But not for C1.This must definitely a electrolytic capacitor for subwoofers.

Hi arusha!

Is it a good idea to replace all capacitors to Jantzen Cross cap 400V?

No! Because:

I would like to hear the original sound of theese speakers.

You may replace the two Elkos with new devices of good quality, they rely on chemical processes and no one ever planned 40 years of lifetime for them. The other Caps may be measured, but life in a home speaker crossover is not very demanding, so they should be nearly like new.


Best: Detsi

Still I couldnt measured, but I think the Elkos lost capacity (some dried fluid on their), and I think c4 to, because the midrange/tweeter change different frequencys. C3 is WIMA MKS 100V, I think it is ok.

So I have to measured all capacitors.
The ELKOs( C1, C2) must change, C1 for subwoofer a good quality ELKO (jantzen electrolityc?), and C2 for midrange, a good quality foil, for example jantzen cross cap.
Other capacitors if they lost capacity, change their.

Subwoofer need electrolityc cap, because ESR effect is bigger on low frequencys? And missing ESR causes too much bass?

Thank you very much for your reply!

According to the schematic, C4 should be of same type as C3. Can you show some pics?

Elkos do have higher ESR than Foil-Caps, but this was already taken into account during the design of the crossover. If you change the types, you can't really expect the original sound. To which degree it will change can't be predicted, but don't think a "better" cap will make a better sound. It can make another sound (with very small changes), thats all.

Best: Detsi

C3, C4 are not same. C3 is red 4uF WIMA MKS 100V, C4 is green I think polipropilen 6,8uF 100v.
C1, C2 are the big gray Frolyt Elyt 50uF 20V electrolitic caps.
some better resolution pictures: https://www.flickr.c...et-72157633050837761

Yes, OK, they 're not exactly the same, but in this context, namely Elko vs. Foil, they are.

I can still not see any need to replace C4.

Best: Detsi