Reply with quote #1
I've recently bought an AU-70 amp on ebay. The amp works, but not fine. I know this could be due to some caps which have to be replaced. I've seen a picture on sansui.us of an AU-70 before and after the recapping. Now I have located the caps, but I would like to know which kind of caps should I use. I can read "0.25 +- 10% - 400 WV - EM", which I think stands for 0.25 Mfarad, 400 V. The caps also have a big minus sign close to one of the ends. So can anyone help me in finding which caps should I put in?
Other people in a forum told me to check out which series my amp belongs to. I really do not know how to do this. S/N is not readable. Can anyone help me too in finding the series? Thanks in advance to all the people who will read this message. Luciano
Reply with quote #2
First of all, the coupling caps on 7189A should be those ones that read 0.3uF 250WV. Any coupling cap should not have polarity. The way to determine the version of the AU-70 is
Count the number of bias pots your amp has – older one has one pot per channel; newer one has one pot per 7189A. This means older version has two bias pots, and newer one has four. Check the size of 7189A coupling caps. The newest model has large coupling caps with of course, 4 bias pots.
Beside the coupling caps, I advice you to change all caps on cathodes that read 30uF 6WV.
Reply with quote #3
which type of cap should this amp ==paper in silverv paper in oil copper film in oil . of electrolic cap