“Needlestein, if my MMC1 looks perfect under my microscope and if it doesn’t collapse at its standard 1.0g VTF, may I assume it’s ok? I recently noticed some distortion and I’m trying to track down the source”
First, I have to ask what “perfect” means, as I don’t want to assume that you are using a powerful enough microscope to actually see the wear flats. No offense, but just as a troubleshooting exercise, I would have to ask.
Now, assuming the diamond does look perfect the next suspect is the suspension. After a few decades, they just fail. That’s about it. I can sometimes “mend” the suspensions without opening up the cartridge and replacing the parts because I have not figured out what cement to use. Nothing I have tried thus far has worked well. Lately, I really haven’t had time to really investigate possible adhesives. B&O cartridges may in fact use two different adhesives as the rubber grommet has to bind to very smooth hard plastic on one surface and metal on the other surface.
The suspensions of the MMC5 models seem to fail a lot less often than the others. I assume that due to the lower compliance spec, they are made of a more stable, durable elastomer. I will often upgrade these with higher level cantilevers and diamonds to get close to the performance of the higher MMC cartridges. Customer response has been more than favorable. Other people will rebuild them, but I have heard mixed responses about rebuilt units which is why I recommend new Sound Smith when someone wants a rebuilt unit.