It's a bit odd that they first attenuate the input signal 7.6666... times with a voltage divider that has a quite high resistance and therefore a high thermal noise voltage, and then amplify it again. It's also strange that the tape output level depends on the loudspeaker output level.
Shorted, you mean? Otherwise there won't be any signal at all.
Shorted, you mean? Otherwise there won't be any signal at all.
On old stuff (vintage receivers and amps) from the 70s but even newer amp devices like Linn INTEK I replace elcaps between 0,1uF and 10uF in the signal pad always by small WIMA MKS, and if there a lot of space (mostly an exception) I use WIMA MKP. One fact one must have into account; scratched pots not always come from silver oxidation of the potentiometer itself.
Sometimes the unwanted scratching went away after replace the elcap at input (in front of the volume control) by a foil capacitor.
P.S.: what are the BG N series ? This one ? - go to
https://web.archive.org/web/20070219181953/http://www.blackgate.jp/ebg6.htm
https://www.thlaudio.com/bgcapitme.htm
This I can confirm. One of the best capacitors for this application from my experience in televisions from the 80s and 90s are this versions:
1) Dörrbeck (logo: "db" don't exist since a long time) - for images go to post #13 under
One of the best RIAA Network capacitor - for me unknown Brand
2) WIMA FKP-series
Impulskondensatoren made in Germany
Also excellent suited for audio application - e. g. RIAA equalizer in phono pre-amplifiers
Even in TV horizontal fly back stages (actually a SMPS) I haven't find this both brands as faulty part at those days.
P.S.: I am still looking for old data sheets and advertisements of "db" caps. Until now I haven't find any technical documents concerning specials. Maybe anywhere this is to find under the portal of wordradiohistory.
Thanks for contributing. Once I get the amp finished I'll start checking it out and making changes as I go along. The preamp does have reasonably high gain.
