Channel balance with NPC


#1

Hi folks, I have a constant channel imbalance with my ancient B&O 8002 turntable and it’s installed MMC-1 cartridge. Is it possible to adjust the NPCs input circuits to compensate for this imbalance? There is about a 3 to 4 db difference with the right channel being higher.

Thanks for any info you may have.

Joe


#2

Not to my knowledge.


#3

Firmly grasp both ends of the tonearm and twist until it bends - just be sure you do it in the right direction! (I am joking. Do not try this.)


#4
badbeef said

Firmly grasp both ends of the tonearm and twist until it bends - just be sure you do it in the right direction! (I am joking. Do not try this.)


I was able to correct the problem, however, by inserting a calibrated piece of attenuating cotton into my offendingly “hot” ear.

#5
Paul McGowan said

Not to my knowledge.


Thanks Paul. I may try to build an attenuator to take care of the hot output or simply replace the cartridge with one of new manufacture.

#6

Sometimes I hate computers, I wrote a nice reply only to be signed off between opening this thread, and checking the forum posts, where it showed I was signed on. Well, I’ll try again.

I was going to suggest you try adjusting your anti-skate, but after doing a search on your tt, you may not have access to that adjustment.

On one website they mentioned cleaning out the old grease on the worm gear. Depending on which channel it is, would tell you if you need more or less anti-skate. The outer groove is the right channel, inner is the left.

You can access the service manual at Vinylengine, see link.

https://www.vinylengine.com/library/bang-and-olufsen/beogram-8002.shtml

I would switch the cables to be sure it is the tt. If the imbalance is still in the same channel, then it isn’t the cartridge.

For playback you should be able to use your balance control to center the image, but that won’t help for digitizing LPs.

Once you verify it is the cartridge, if you can afford it, I would just replace or rebuild it. In my search a few people mentioned Soundsmith for B&O cartridges. https://www.sound-smith.com/lookup/bo-cartridges

There is also a bunch of good info on the Soundsmith page I linked to. Check out the troubleshooting page.