Old TO-R s15u, Should i fix it?

[Jonas83]

This is one old beast, i cannot find much about it and my experinces with tubes are kind of limited. might this be any good? exterior is really good but the inside is worse, this will take some time to recondition. so my question is: do you guys think it is worth the effort?

TO-R s15u with tubes: ECC85, EF89, EF80, EM87, ECC83, ECLL800

Note, the black caps point soldered to the vol. pot are cracked... i have no idea why, as said... this one will eat time.

[Rundmaus]

Final stage using ECLL800 looks interesting, a triode as PI and two pentodes in one bottle.

If the outside looks nice, and the transformers are ok, I would probably try to refurbish it. Check availability of the tubes, though.

Regards,
Andreas

EDIT: Had those black caps in a lot of old tube radios, they're potted in some kind of tar and get leaky (in an electrical sense) with time, usually leading to their destruction, sometimes amongst other, innocent components. Change them all.

[Jonas83]

Thanks for your answer, this brings a little hope to it. I will tear out the transformers, test them out and take it from there then. caps are prone to fail with time (we all know) but it sounds good that this ones are extra "bad", after a closer look at it every black cap looks cracked.

//J

[Rundmaus]

I found them mostly in equipment from Eastern Germany, but the guys from the Netherlands seem to have used them as well...

Andreas

[Rundmaus]

If it is the first restoration project, keep in mind some safety issues:

* the unit seems to be connected to the mains without earthing, if there are any metal parts on the outside, there should be a safety ground connection

* there is a cap in the power supply part (C805?) which is directly connected between the mains and the power supply ground. Given the age of the unit, I wouldn't trust that cap - if it's leaky/shorted, it defeats the mains isolation provided by the power transformer.

Andreas

[tricomp]

Originally Posted by Rundmaus

.... but the guys from the Netherlands seem to have used them as well...

Andreas

This time the guys from the Netherlands are Danish, built in 1961

In any case those black cap's need to go. 25 years ago I replaced them on sight and I don't think they've improved since

Other than that I remember the tuner being fair to good but of course stereo only comes from the attached AF-sources like a tape-recorder (R-to-R) or a CD-player.

ECLL800 is pretty expensive so watch-out for that detail before digging in too deep.

rgds,

/tri-comp

[Jonas83]

Yes this will be my first ever tube amp, so there is a bit of basics around tubes that i need to "refresh" before i start. There is not much in this one i trust to function as it is supposed to, so safety first, allways. all lytics are given subjects to be changed. i will keep this thread updated when i get going with this one ECLL800 is kind of expensive but there is no way around that, hopefully it will give something back

thanks!

[planet10]

Could easily be simplied down to ECC85 + the ECLL800 (i have at least 4 of them). Your OPTs look more substantial then mine.

dave

[Jonas83]

Seems like the ECLL800 is kind of tricky to find.... not sure of their condition, probably bad.

[tricomp]

Originally Posted by Jonas83

.... not sure of their condition, probably bad.

Just measure the voltage at the common cathodes (Across the cathode bypass electrolytic). You should measure around 7 ~ 7,5V= with volume turned down if the ECLL's are OK.
Defective grid-1 cap's (C111/47nF & C108/22nF) may raise this voltage considerably and even destroy the ECLL's. Don't bother checking before replacing these cap's.

rgds,

/tri-comp