Lenco L75 Refurbishment

[Dowser]

Thanks - the big decision for me will be when I need to think about a plinth. I have a spare RB250 to try it with first, so do I cut just the corner off the top plate, or do a full cut job?

I don't really like the PTPs, as I like the idea of maintaining the on/off switch to disengage the idler.

Need to get active over on LH.

Richard

 

[PaulMB]

If you have yet to build a plinth, and you want to use non-stock arms (I tried running the stock arm, but the crudeness of its engineering was a bit depressing) is to turn the whole turntable clockwise by 90 degrees. Then you can mount whatever arm you like to the plinth rather than the top plate of the TT. It also helps the problem of the Lenco TT being very low, since you gain/lose about 4mm of height. Sawing off a part of the top plate might be a pity, and you would lose one of the 4 threads underneath that can be used to bolt it down to the plinth.

 

[Dowser]

Thanks Paul - yes, it seems a shame to destroy the top plate, but I also have concerns over how flexible it is with those 4 fixings. Can it be damped effectively? Or is it not a real world concern?

For my first build a 90 degree rotation is probably the best approach, thanks

 

[Chops54]

+1 for turning the chassis through 90 degrees. The Lenco always sounds better with the arm mounted on the plinth rather than on the chassis.
There is another way though. I built a 75 up for a friend and using a hole saw I cut an 80mm hole in the top right hand corner which just took up the holes where the original arm was. I then mounted a Jelco type arm directly on the plinth through this large hole in the chassis. I'm in the process of doing another one so as soon as I get some free time I'll post it here.
The chassis can be firmly fixed to the plinth by using packing pieces under the flat areas of the chassis so as to gain as much contact with the plinth as possible when the screws are tightened. The pan under the platter can be screwed to the plinth in several places again using packing pieces to get around the rods and levers.

 

[Dowser]

Thanks Chops, that's what I was considering too (along with car audio dampening material) - good to know it works.

Think I try like this initially, if good then I can fill stock mounting hole and paint top plate.

First I need to plug it into main system and listen...which will mean I need to unpack all the Abba albums for my young girls to dance to

Richard

 

[PaulMB]

I used some self-adhesive strips of black neoprene, the kind sometimes used to seal windows or other things. I bought it about 2mm thicker than the edge of the TT pan, so when I screwed it down the neoprene compressed and the edges of the pan pressed down onto the wood.
Didn't worry much about the possible sonic effects, I must confess, just the solidity of the whole thing.

 

[Mignun]

I believe that Jean Nantais fills the top plate with epoxy resin. This also neatly fills in the holes left by the arm, lift/lower mechanism etc.., which can then be sanded down and painted over. I have one of my Lencos stripped and ready to do just this. However, there are just too many other things taking up time right now so it's making slow progress..

 

[Dowser]

Thanks - easiest for me is the car audio damping stick on bitcumen (sp?) pads filled by draught excluder type foam so that when I tighten mounting bolts a bit of pressure is put on top plate - all items in stock in my cellar

Richard

 

[Dowser]

Coming back to this - I did finally try the L75 with stock arm and plinth in my main system...it was rubbish and went back in the cellar

My thoughts were that the music centre plinth was too flimsy, and the stock arm is crap. I have since collected an Ortofon AS-212 and Linn Basik as alternatives, and then finally a decent quality stock plinth came along last week thanks to a Lenco Heaven member.

This is a stock plinth, but is pretty decent quality IMO. I will take the sprung base off and use rubber feet for the first test.

So far I have just cleaned the plinth with wire wool and white spirits (don't want to dig too deep, not sure how thick veneer is), now I need to treat it with wax or oil.

I also pulled the bearing apart - it was pretty much dry! So I will also strip/clean/relubricate the motor and idler wheel before trying it with either the Linn or Orftofon arm. I think Linn first as it drops straight in, but I suspect the AS-212 is the better arm? It requires a bit more work to fit the AS-212 and maintain an arm lift mechanism.

Photos below. Could some kind admin update the thread title please? "Lenco L75 refurbishment" please, thanks.

Richard

Plinth cleaned with wire wool and white spirits

Bearing

 

[Chops54]

I recently bought a rather nice Dynatron with GL78. I stripped out the tuner/amplifier and stripped all the auto crap from the deck and fitted a Syrinx LE1. I can't do any more with it until I get back on my feet but the plan is to leave it in the original box with wood lid and build ply layers up inside the box to make a heavy plinth.
I forgot to say Richard that you can buy a threaded sleeve just like the one that Lenco use for their own arm that will allow the Ortofon to drop straight in. It is the better arm imo and looks nicer too.

 

[mark121211]

I have a GL55 in slate running a heavy platter. Rather than turn the plinth around I welded up the holes and re-drilled the tonearm mounts.
As mine was a light platter deck to start with I have less of a height issue than say the GL75 with it's recessed platter.
The top plate on all Lenco's are less than ideal. I am going to machine a delrin (or other like material) spacer that will sit between the top plate and plinth + look at better ways to brace the main bearing.

 

[Dowser]

I recently bought a rather nice Dynatron with GL78. I stripped out the tuner/amplifier and stripped all the auto crap from the deck and fitted a Syrinx LE1. I can't do any more with it until I get back on my feet but the plan is to leave it in the original box with wood lid and build ply layers up inside the box to make a heavy plinth.
I forgot to say Richard that you can buy a threaded sleeve just like the one that Lenco use for their own arm that will allow the Ortofon to drop straight in. It is the better arm imo and looks nicer too.

Thanks Si - any idea where I can get the collar from? I'd wondered about something like this, but haven't even tried offering up the Ortofon yet to have a look.

Yes, internally built up mass is what I am considering if the current plinth cleans up well.

Cheers, Richard

 

[Dowser]

At the end of the day, if I like what the Lenco does, then I do not mind going overboard - was it Nick on here who built up a slate PTP Lenco, with a separate slate armboard? I loved the look of that

But first I want to give it a fighting chance against the LP12.

Richard

 

[Dowser]

Thanks Si - any idea where I can get the collar from? I'd wondered about something like this one? Too expensive for me, double what I paid for the 75

Richard

 

[Chops54]

That's it Richard but I've seen another in aluminium that's much cheaper.
What's the diameter of the Ortofon pillar? 20mm comes to mind. You could machine a sleeve that fits tightly over the AS pillar and is snug into the Lenco housing. I machined one up for my Jelco to make it fit an SME sliding base,

 

[Dowser]

Thanks Si - you maybe able to machine something, not me . However, I fail to believe I cannot badge it in the short term to get a listen, and can then invest in an aesthetic solution if I choose to progress.

Not even how sure how big a problem it is - will try and did out the 212 tonight to have a look.

Richard

 

[divedeepdog]

I know it may be frowned upon, but tightly wrapped electrical tape around the pillar, and the original Lenco collar WILL work.
The old Linn arm work around was 35mm film canister, but they're rare now-a-days.

I see too many Lenco's with double mats (or platters) with protrusions in the headshell causing more problems than they create.

KISS, Keep It Simple, Stupid


*Rant directed at internet rather than OP

 

[Dowser]

I know it may be frowned upon, but tightly wrapped electrical tape around the pillar, and the original Lenco collar WILL work.
The old Linn arm work around was 35mm film canister, but they're rare now-a-days.

I see too many Lenco's with double mats (or platters) with protrusions in the headshell causing more problems than they create.

KISS, Keep It Simple, Stupid


*Rant directed at internet rather than OP

He-he - I have a couple of spare film canisters too...I'm quite good at bodging, the old vblocks in original arm I replaced with filed screws

 

[paskinn]

I heard a Lenco 75 today in a homemade ply and lead plinth weighing 40 kilos. It sounded very good indeed, stable, rich and powerful.

 

[Chops54]

No worries Richard, just trying to give you some ideas. Believe me I'm no machinist, I'm just a selt taught bodger who gets a lot of enjoyment messing around.