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Carl L
Carl L, Technician
Category: Home Cinema System
Satisfied Customers: 4058
Experience:  13+ Years of Computer and Electronics Experience.
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I have a B&O Beocenter 9000. Have only used the radio side

Customer Question

I have a B&O Beocenter 9000. Have only used the radio side for ages. On trying to play a record on the turntable I noticed the output was distorted. The same happended with the CD. I then tried the tape recorder but the brake on the supply reel would not release. The radio still provides good quality sound, therefore, I have dismissed a fault in the output amplifier section. I have a circuit diagram for the Beocenter 8500 & 9500 which appears to be the same. Can you advise, please.
Submitted: 4 years ago.
Category: Home Cinema System
Expert:  Carl L replied 4 years ago.
Hi and welcome to Just Answer, a Question and Answer Company. My name is Carl and I will be assisting you today.

You're definitely losing it in the preamp circuit and if both inputs are affected, it maybe a power issue. How did you test the Caps? Visual, Scope, ESR Meter, etc? I would replace ever cap in the preamp circuit and try it again.
Customer: replied 4 years ago.

Hi Carl,

Thank you for the info. I checked the electrolitics with an ESR meter and apart from those I have mentioned all appeared to read O.K.

If the trouble is in the preamp circuit how is it that the output from the radio side is crisp and clear, and would the trouble in the preamp circuit affect the brake solinoid on the supply reel of the tape recorder?


regards, Ron Jackson

Customer: replied 4 years ago.

Hi Carl L,


Unable to rate your advice as I am still waiting for a reply to my follow up from your original advice.


Ron Jackson

Expert:  Carl L replied 4 years ago.
Each input type has it's own preamp circuit that is then supplied one at a time to the final amplification stage. A tuner will have it's own preamp built in. We will need an O-Scope at this point to trace where the Audio Sine Wave is dipping out / clipping. It's ideal to have a service manual for test points at this part of the repair.
Customer: replied 4 years ago.

Thank you Carl L.

I will do as you say and get back to you once I have tried your advice.

It will probably take me some time as I don't get down to my workshop every day. Being retired and my wife is not well I have to bide my time when I can do these things. I have a fully equipped workshop for when I worked on TV, video and radio.


Ron Jackson

Expert:  Carl L replied 4 years ago.
Sounds great! Keep me posted.