ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello everyone
I have recently managed to get hold of a beomaster 901 for a very reasonable price. However it being nearly 40 years old now it doesnt come without a few imperfections.
I hope someone can help me resolve these issues.
There is a 100 hz hum i the output. When the volume is set to 1/12th it is as loud as speech at that volume the hum doesnt increase with the volume. I have replaced all the electrolytic caps but that has´nt made a noticable difference.
The amp seems to start distorting the sound when the volume slider is past 3/12.the sound seems to lose some of its depth. Reducing the level in the input doesn´t seem to make any different, the sound is still noticeably different at 3 and 4 .
The veneer on one of the sides is missing. I was planning on replacing that as well when i get the other issues fixed. I know that it is said to be some kind of rosewood, perhaps there is anyone here that knows more specifically which species and finish was used.
I have made a good quality scan of the schematic that I found on the under side of the top cover. Hope this helps.
Welcome to Beoworld !
First thing I would check is the idle current settings. The trimmers go bad so replace them and readjust.
Martin