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
I just repaired my Beocord 7000 with new belts from Beopart-shop and it all worked and I can now tape my favorites from eg Spotify. At the same time I purchased belts for the Beogram 7000 and replaced. At the same time all parts needed cleaning and lubrication was done. Also adjusted the pickup hight and parallelism according to manual.. They were way out from the manual adjustments and have never been tampered with before. Everything is up running BUT the sound is bad. Looking at the pickup needle I feel that it is pushed sideways to far during playing. Feel that it is "pushed" to hard against the track in the record and that might be the reason for the strange sound. When lifting the needle I feel it jumps back and straighten out. I am not sure if this is the normal operation or not. I would think that the needle should be pretty much straight and that the sliding chassis should follow easy along. All rails are cleaned and it moves easy. Could anyone give me some ideas of what could be wrong and how to fix. Could mention that the parallelism of the pickup arm was a couple of mm off at the tip compared with the indicator arm. The height was also a couple of mm to low.
Yes, the arm should track tangentially to the record groove. There are adjustments for that as well as height in the service manual. Check it out at beomanuals.com.
Thanks for the reply. Could you specify what part of the manual that cover the tracking part. Is this a part that is electronic adjustment and need special equipment. I am not an electronic engineer so that could be a challenge for me. Mechanical parts are ok. Do you recommend to use a B&O service center to perform the tracking adjustment? I have performed all the mechanical adjustments according to the manual but I do not know what is actually controlling the tracking tangentially and what is controlling this feature.😊
There are adjustments for parallelism and photo control in 5-2 to the top of 5-4 of the service manual. First you adjust that the arm is physically parallel (5-2) and then you perform the photo-control adjustment (5-3/4) so that it tracks properly. These are all done with a simple screwdriver as described in the manual.
OKI. I have now become a silver member because I thought I could get some more manuals but nothing new there. Back to the adjustment. I do not have the test record so I used a regular record and lowered half way in. Is there a specific distance for cutting 5? I could not figure out how to lower the arm on a Stationary turntable as the manual says. I guess the table should not turn but if I take the belt of, the player will not start anything and no light on the photo mechanism. Is there a trick here?. The manual then say to adjust 1,5-2,5 turntable turn initially. Does that mean spinning by hand and check for the value. Anyway, since I could not manage spinning manually since I could not make it work in manual mode I adjusted so I received about one movement on the servo for each turn and can not see any more major force on the pickup needle. Is this ok or do I need to follow procedure that I could not figure out.
After testing there is still the same disturbance on the right hand speaker. Left one is ok. Playing other sources like the CD the speakers are ok, so nothing wrong with the speaker.
All other adjustments are ok. Any idea what can be the reason for not getting good sound on right channel. The player worked fine before I started messing with it😊
You do remove the belt and use the controls to position the tonearm over the stationary record. You then turn the record by hand. This can’t be done with the record turning at speed as once the servo starts Turning it will continue to keep up. What you are trying to control is the # of revolutions before it starts.
As to the issue with one channel, you will need to be far more descriptive as to what you are hearing in order for use to help. If the stylus has been offset for many hours that would cause greater suspension stress and stylus wear. One advantage of having a test record of single frequency tones is that it is easier to identify whether you are hearing distortion or a frequency imbalance.
Finally, you haven’t mentioned which cartridge model you are using and whether you have properly set its tracking force.
Ok. I will try what you propose and return with results. Regarding the cartridge it is a MMC2 that I got refurbished by a German guy a few years ago and have not many hours of operation. It did function good until I started messing with the new belt, lubrication and adjustments. After I have performed adjustment as you describe by hand and tested again will try to record the sound if it still is bad and attach to this thread. I have adjusted the force on the arm to 1 g but can not find the little piece to lower the arm onto to check the force, just relying on the numbers on the dial on the arm itself. Appreciate your responses to this issues and hope you continue to support me. I am not a new member because I joined back in 2009 but of some reason the site seems to have a new date for me joining the forum because it is a few years since I logged in. Will post update when I try to adjust tracking as proposed and test the sound thereafter. Note that the stylus was working fine before I messed with adjustments and by that I am pretty sure the stylus itself is ok still.
Well I think I managed to adjust the servo within the initial limit. Got 2 turns before it adjusted initially and thereafter checking when playing it adjusts once for each turn of the record that is within the value of 0,5 and 4 turn.
Then back to the noice in one speaker. I have adjusted to 1g on the arm and the sound is still bad on right speaker. If I increase the pressure to 1,8g the bad noise disapear. Then I start wondering if the adjuster does not show right. I need to find a weight to really check the actual pressure. But if the weight show that the 1g is correct value and I need double on the MMC2, could there be any other reason for the noise. Should I just carry on using double weight og would that damage the MMC2.
I do recall now that the weight was around 1,8g when I started the project and therefore I think that was the reason for having no noise (humming bass) before and that I created this by adjusting to 1g. Any comments to the pressure on the stylus?
It is not unusual for one channel to distort before the other if the tracking force is too light. My guess is that you are seeing your tracking scale off because the arm is not balanced to float when there is zero tracking force. Unfortunately, B&O changed the design so this is not set how it used to be so your best bet is to use a separate stylus force gauge where you can hold down the lift button for a few seconds and the arm will lower onto the gauge for measurement. If your refurbishing resulted in any change to the cartridge weight, for example, no flip down stylus guard, this will also require higher tracking to offset that missing weight.