Turntable Experts

HippoPete

Knowing there are at least a couple of expert level people here, can I table a question.

I have a Pro-Ject Primary (entry level I know but the Linn Basic is in the loft and goodness knows how it's held up over the years). In a sudden bout of Pink Floyd inspire enthusiasm, decided to give DSOTM a spin. Unfortunately the arm is not lowering fully onto the platter.

It's not the hydraulic lowering lift, that is retracting. And it's not fiddling with the counterweight, this is locked in place with a hex key at the factory and cannot have been twiddled in the interim.

The TT has been dormant for a couple of years and if I didn't know better, I think that the bearings have stiffened up but I'm reading scuttlebutt around the net that this is pretty much unheard of.

I guess I'm just interested to see if I've encountered any kind of known issue before I drop a line to the Pro-Ject people.

I have ordered a simple balance to check and adjust tracking force but I fail to understand how this could have changed on it's own.

All the best,

boogieman

If it’s not the lift mechanism sticking (are you absolutely sure it’s not?) then I would suspect either the arm bearing is sticky or the counterbalance setting is wrong. Full disclosure, I’ve got a Linn deck and not a Pro Ject so I don’t know how they vary. 

blobb

Does it drop, but just not enough to reach the deck? The arm should move freely in all directions when you swing it around by hand, the lift mechanism should drop completely down out of the way to allow this. If it doesn't move freely it's bearings - they don't usually stick completely, they might feel a bit 'grainy' as you move it. If it moves freely but you just can get the arm low enough to rest on the platter it could be vertical tracking adjustment. I suspect this arm doesn't have an adjuster for vta but if it moves freely but doesn't hit the deck you either need to lift the deck or drop the arm base. 

crosstownvamp

Is the arm parallel to the turntable when lowered?

If it is the the entire arm assembly needs to drop (not sure if it's possible to move the arm on a ProJect - even though I've got one - but I've had arms than can do that). 

If the arm is pointing up slightly then the lift is sticking or the bearing is stuck. But you should be able to see from the side if there's a bit of gap between arm and lift.

AK99

Got any pics of the offending hinge mechanism ?

HippoPete

Many thanks for the prompt response all. I'm going to take a close look over the weekend with the deck on the bench where I can see it properly. No pics at the moment but there is very little to see to be honest. The counterweight is a simple weight ring fixed in position with the friction of a grub screw so not intended for casual adjustment such as you might see on a more upmarket tone arm.

The bearing housings appear to have a tiny cover plate with two minuscule holes which I suspect need a special tool or thin nose pliers to adjust the bearing preloading (assuming that it's even possible on an entry level turntable).

I'm beginning to remember why I was glad to see the back of such an archaic method of listening

Thanks again,

blobb

I'm sure you know but the idea with the counterweight is to unlock the screw, move the weight until it balances perfectly level, then bring it forward until the needle exerts the tracking force you want (buy a set of tracking scales). I presume this was preset at the factory to avoid having to adjust it out of the box. The problem with grub screw weights is that tightening the screw changes the position of the weight slightly so it can be a bit trial end error to get the force you want for the cartridge you are using. Don't be afraid the adjust it though It's not locked permanent. But even with the weight set wrong, or removed completely, you should still be able to move the arm freely about it's axis with your fingers. If you can't do that no weight position adjustment will change it.

Kittyfrisk

Air lock in the hydraulic oil of the arm lift/lowering mech.?

HippoPete

Thanks again for the additional contributions. Interesting development in that Henley Audio, the distributors, responded to my enquiry the same day inviting me to forward a video for further advice.

Irrespective of the outcome, this is great response on a £200 product. 

Arm lowering mechanism is definitely fully lowering. 

Cheers all

snowblind

Just thinking about the arm on my Technics 1200, there's a locking catch on there. Does your deck have anything similar which is preventing the counterweight side of the arm from moving up as far as it needs to? If the lifter is lowering to its fullest extent then the obvious next place to look is the other side of the balance point.

AK99

Im still not clear on the problem alas.

Is the arm free to move through an arc that will let the stylus down to the deck but it just wont stay there due to a balance issue, or is the movement of the arm restricted which prevents it from doing so ?

viz

Did you use to have a thicker platter? Or a thicker mat? 

HippoPete

Again, thanks for the contributions. Nothing has changed on this since the day it was lifted from its carton. Imagine if you will that the arm lowers 'normally' but hovers a few mm above the record platter.

I do hear you all shouting 'you're an idiot' adjust the tracking weight but here's the thing. it's locked in place at the factory for the standard cartridge and can't be adjusted without an Allen key. It's almost as though a few grams has evaporated off the counterweight !!!

It's not the end of the world just an interesting mechanical puzzle so I will report back, the solution to resolve the mystery. 

I did note, however, that even for this entry level turntable, you can purchase replacement bearings and bearing special tool so full marks to Pro-Ject supporting their products (at a price though).

The only thing I can't determine is whether the tone arm bearings use lubricant that may have dried up or whether they might be the sort of synthetic jewels used in mechanical watch movements. I'll be sending Pro-Ject some video over the weekend.

Al the best,

AK99

When you say hover, can you actually get it to go down to the record-surface, or is there a physical block preventing it ?

HippoPete

No physical block, you can gently (literally a feather touch) persuade the cartridge down onto the record surface but the merest bounce of the track will go back to "hover mode' as though you are tracking at about half a gram.

When the balance arrives, I might be able to measure the tracking force, if anything.

The TT was supplied with a 180G vinyl copy of Dark Side and the Missus has developed an unhealthy interest in all things PF and Dave Gilmour and is determined to hear them in all their crackly vinyl glory*

Being mischievous, we both spent too much on Linn / Arcam when younger and spent may hours 'courting' to our mutual record collection. Can you love records (or the memory of records) but remain a deep dislike of the technology? 

TheMarlin

It sounds like the counterweight needs adjusting.  Cartridges generally like 1.5-2.5g of force on the stylus - check the recommended weight for your particular cartridge.  I can send you a stylus weight gauge.    
if you were local, I'd do a service and full setup on the deck for you. for free. 

AK99

HippoPete said:

No physical block, you can gently (literally a feather touch) persuade the cartridge down onto the record surface but the merest bounce of the track will go back to "hover mode' as though you are tracking at about half a gram.

When the balance arrives, I might be able to measure the tracking force, if anything.

Linn fanboy here too - old LP12 / Briks and a handful of s/h amps. Still hard to beat (imho).

Yeah as Melin says, sounds like yours has to be a counterweighting issue.  If you can't wait for the balance you could go old school and stick a penny on top of the cartridge - sorted

HippoPete

Very kind offer Marlin but I've got an Ortofon balance gauge on the way, hopefully in tomorrow's post.

The old school kit was Linn Basic, Arcam Alpha (original) and Linn Index speakers (all still resident in the loft awaiting retirement and a room to put them in). The Linn TT needs the terrible motor board fix applied. There are a few tutorials around the net and I'm handy with a soldering iron (at least I was thirty years ago when I fixed things for a living).

boogieman

HippoPete said:

No physical block, you can gently (literally a feather touch) persuade the cartridge down onto the record surface but the merest bounce of the track will go back to "hover mode' as though you are tracking at about half a gram.

When the balance arrives, I might be able to measure the tracking force, if anything.

The TT was supplied with a 180G vinyl copy of Dark Side and the Missus has developed an unhealthy interest in all things PF and Dave Gilmour and is determined to hear them in all their crackly vinyl glory*

Being mischievous, we both spent too much on Linn / Arcam when younger and spent may hours 'courting' to our mutual record collection. Can you love records (or the memory of records) but remain a deep dislike of the technology? 

If you can “force” the stylus down onto the record with just a touch then it’s just a case of adjusting the counterweight to get the balance right. It’s got out of whack somehow, maybe it got disturbed when you put it into or out of storage? Should be easy enough to sort. 

I’ve kept my turntable and vinyl out of nostalgia for the most part, although I’ve got some albums that are irreplaceable or just too damn expensive to buy on cd. There is that little something extra about the ritual of getting a record out of the sleeve, lining up the track and dropping the stylus down but most of the time I can’t be arsed with all the rigmarole. 

Sounds like we have a similar set-up btw… mine’s a Linn Basik, Creek amp and Linn Index speakers. I bought it all in the late 80s and it’s still sounding great. I swapped the cd player out a few years back as the original Denon went kaput. 

TheMarlin

This is my main turntable setup. 

I have three others. 

boogieman

TheMarlin said:

This is my main turntable setup. 

I have three others. 

Blimey! Apologies for possible numpty question but what’s the advantage of having such a hugely tall  and bulky platter on the deck?