Tone arm drops too fast. Not sure how to sort this.

[unclemack]

I have a Pioneer PL 7L turntable with electronically controlled arm lift. Over the years the arm has increased in speed which seems like it lacks damping. I don’t know if this is a mechanical issue or an electronic issue. I’ve taken a couple of pics of the lift mechanism for reference. Does anyone have any ideas? Cheers, M 

 

 

[Jakeyb77_Redux]

@metal beat or @Doppelganger might know the workings of that table/arm mate 

[Doppelganger]

I had the PL-7L for a few years though I never had an issue with the cuing being too quick. My assumption is that it would need some viscous damping applied to the cuing rod. Initially, worth trying to do this without opening it up by just lifting the mechanism and smearing some 60,000 Cst silicon gel on the vertical part of the rod and then moving it up and down a few times to get the coating even. If this doesn’t work, you may need to remove the arm to get access but that should be a last resort. Good luck with it!

Edited July 16, 2024 by Doppelganger

[andyr]

58 minutes ago, unclemack said:

I have a Pioneer PL 7L turntable with electronically controlled arm lift. Over the years the arm has increased in speed which seems like it lacks damping. I don’t know if this is a mechanical issue or an electronic issue. I’ve taken a couple of pics of the lift mechanism for reference. Does anyone have any ideas? Cheers, M 

 

How fascinating - I can't imagine why the Pioneer engineers felt they had to have an "electronically controlled" arm lift ... as distinct from a 'normal' one (which, btw, I have no idea how it works ... to gently lower the arm).

 

[tubularbells]

47 minutes ago, Doppelganger said:

I had the PL-7L for a few years though I never had an issue with the cuing being too quickly. My assumption is that it would need some viscous damping applied to the cuing rod. Initially, worth trying to do this without opening it up by just lifting the mechanism and smearing some 60,000 Cst silicon gel on the vertical part of the rod and then moving it up and down a few times to get the coating even. If this doesn’t work, you may need to remove the arm to get access but that should be a last resort. Good luck with it!

 

Dopps beat me to it, not familiar with the TT but even if the lower/lift mech is electronic I bet its some sort of open/close solenoid letting the viscous fluid to do the "damping". Ive got a litre of the stuff if you need some.

Edited July 16, 2024 by tubularbells
spelling

[unclemack]

25 minutes ago, tubularbells said:

 

Dopps beat me to it, not familiar with the TT but even if the lower/lift mech is electronic I bet its some sort of open/close solenoid letting the viscous fluid to do the "damping". Ive got a litre of the stuff if you need some.

Thanks mate. I thought that some kind of damping fluid or grease would be needed, just not confident of accessing where it needs to be applied.  Cheers. M

[unclemack]

I’ve just discovered this little cap that came off to reveal a hole that might be a reservoir for damping fluid. Does this make sense? Let’s see what Google says. 

[andyr]

1 hour ago, unclemack said:

Thanks mate. I thought that some kind of damping fluid or grease would be needed, just not confident of accessing where it needs to be applied.  Cheers. M

 

Yeah but surely ... damping fluid is used in a "normal" tone-arm lift mechanism?  The "electronically controlled" arm lift mechanism would surely have a different setup?  

 

[unclemack]

22 minutes ago, andyr said:

 

Yeah but surely ... damping fluid is used in a "normal" tone-arm lift mechanism?  The "electronically controlled" arm lift mechanism would surely have a different setup?  

 

That’s exactly what is confusing me. 

[andyr]

9 minutes ago, unclemack said:

That’s exactly what is confusing me. 

 

We need Pioneer (or its Oz importer) to chip in,  here.

 

[Jakeyb77_Redux]

PL-90 is meant to be the same apparently 

ve_pioneer_pl-90_en.pdf ve_pioneer_pl-90_service_en.pdf

[Jakeyb77_Redux]

Stick a cotton bud in that hole @unclemackand see if silicone gunk comes out. 
Or you can also move the lifter up and down a few times, if the electronic function allows and this can sometimes free up the silicone fluid up the piston again 

[Jakeyb77_Redux]

This guy seems to work on them and sells an upgrade kit.

I’d ask him if there is an electronic fix for the Tonearm and explain the issue. He will probably provide you with a decent answer mate. It’s always worth a shot 
https://www.ebay.com.au/itm/266781865322

[Doppelganger]

16 hours ago, andyr said:

 

Yeah but surely ... damping fluid is used in a "normal" tone-arm lift mechanism?  The "electronically controlled" arm lift mechanism would surely have a different setup?  

 

My understanding is that the electronic control was implemented as part of the auto-lift functionality. The speed at which the arm lifts or lowers following the electronic signal is still influenced by mechanical resistance in the form of damping fluid.

[andyr]

34 minutes ago, Doppelganger said:

My understanding is that the electronic control was implemented as part of the auto-lift functionality. The speed at which the arm lifts or lowers following the electronic signal is still influenced by mechanical resistance in the form of damping fluid.

 

Aah, yeah ... that makes sense!   

 

[tubularbells]

Couldn't see anything in the service manual relating to this unfortunately but Jakey's made some good suggestions so id give these a go first otherwise whenever your in the area next I could take a look at it for you.

[SonicArt]

look at the exploded view of the arm,  it's a lift with spring,  so likely silicon fluid is needed to provide the drag on the shaft as mentioned.

[Jakeyb77_Redux]

From info online Pioneer use 300k silicon 

[Luc]

I'd be looking at the Shimano graded reel oils. I know of two guys using the oils for their lifts and I know it'll upset the Linn nutters infesting this place but it's been used on Cirkus as well.

[unclemack]

Thanks for all the replies guys. I’ll get in touch with the guy on @Jakeyb77_Redux s suggestion and see how that goes.   
cheers, M