Help with Beocord 9000

Hi guys,

I've got a little issue with my Beocord 9000. It plays and records beautifully and all functions are perfect apart from the PPMs. 

If I feed in a mono tone (tried both the AUX socket on the front and through the Beomaster 8000) and set the left and right record levels the same (ie 5) the PPMs aren't showing the same, the left one is slightly ahead of the right one. If I adjust the recording level (a tiny ammount) I can get them to match up properly... But surely they should be the same when the recording level is set the same...

Is there an internal adjustment I can make to get them to match up?

Thanks.

Lee

 

Have you checked with a mono source?

I'm not sure what you mean Chartz, I've played a mono record on the Beogram and a mono WAV file on my DAC ad fed this into the beocord. 

Hi Lee,

this is a delicate thing. I tried that myself years ago.

There are different ways to get a asymmetric display of the ppm: the tape may be already recorded that way, because the amplification was not set correctly but was displayed correctly, or during playback it's possible to have a perfect symmetric sound but different ppm readout or the other way round. For a perfect adjustment, you have to short left and right (input-)channel to get the same level and have to read some testpoints with a volt-meter and after that, you can set the peak of the ppm's for each channel. But that is not all. The peak depends on the detected (measured) tape (distortion, senibility, saturation,...) . Thats for the record circuit and for the playback circuit, it's similar. Some of the adjustments are done by the microcomputer automatically. Definitely you will need the service manual, a frequency generator and a true-rms-voltmeter or oscilloscope.

Chris

Thanks for your reply.

It's not playback that's the problem. Pre recorded cassettes light up the ppm correctly and evenly. It's when I'm recording that I have to set the levels asymmetrically.

It's only a tiny fraction out so I guess I could live with it. But it would be nice to correct.

Yes, once you know that, you always look at it. Perhaps that is the reason why most of the later products have only one line of LED's. I believe, you don't hear the "unbalance".

I think your right. My Beocord 5000 (80s version) had the same issue. And watching videos of the Beocord 9000 and 800x series recording they seem to behave in the same way... Bizzare