While restoring the Lans-alloy surrounds on some old JBL speakers of mine (an annual affair), I got to thinking about the MMC cartridges.

The JBL Lans-alloy speaker surrounds on the LE-14 woofer are of a rubber compound that hardens with age. Rather than replace the surrounds (which I probably should), I carefully coat them with Castrol DOT 4 brake fluid once a year. This application softens hardened surrounds, restoring the flexibility needed for woofer excursion.

My thought: Has anyone tried a CAREFUL application of something to soften old MMC stylus cantilever suspension grommets? I've heard these harden with age (before the stylus itself wears out). being as the option are wildly expensive (the SoundSmith 20CL replacement is, ummm, outrageously priced, though perhaps fairly priced considering the niche demand).

Any experience here along the lines of refreshing the suspension? Any thoughts? Is this just the Scot in me taking too much control?

 

Thanks in advance,

P.M. Summer
 

I suppose one problem is getting to it! I think Soundsmith have tried servicing MMCs so they probably have some expertise! It is a nich market as you say though. I don't know what is possible - a friend of mine has tried opening up MMC cartridges to repair them - usually electrical maladies with loose pins in MMC2s. He didn't have a very high success rate though he managed a few. Therefore possible though I would suggest new suspension would be preferable if you managed to get that far.

Have you actually needed to do this or are you just wondering if it's possible?  I'm asking because I sometimes wonder how much of an issue the suspension depredation really is.  Last year I bought a new sp12 cartridge still in the original plastic package.  There are quite a few people who would have said something like "it's junk anyway, because the suspension will be ruined from sitting in that package untouched for 30 years."  Nonetheless I plugged it in and the sound is perfect.  Last week I was playing a record for my cousins (they didn't happen to see me put the record on) who couldn't believe the sound was from a turntable and not a cd.  When I told them it was coming from a 30-year old turntable and cartridge one of them walked over to the system and just sat on the floor staring at the turntable for a couple minutes while it was playing.

 Austin
 

It seems very variable. I have a couple of SP cartridges which are completely fine. However I do think the suspension in cartridges ages. Th best test of this is the playing of CD4 records. This makes them track at up to 45 kHz. (Only useful in 6000s and CLs really!) None of my 6000s work well now (they used to) and the CLs vary.

What would be the symptoms of a failed suspension, lack of bass, treble, or distortion?
Just curious, as I just repaired a Beogram 1102 and the MMC 20s sounds perfect. Unless my untrained ear is missing something.

Abdy T.

Can cause any number of problems Andy, skating, distortion, lack of any sound at all the list is quite long. If your cartridge sounds fine then I'd say just leave it alone until it finally gives up the ghost. There doesn't seem to be any consistancy in why the suspension fails. I've seen it in new old stock items yet I have other well used cartridges which are absolutely fine.

 

Chris.