Lenco GL75 plinth?

[Deco-Doctor]

Hi All

I just aquired a Lenco GL75 in an old Goodmans sprung base plinth (ugh!!) I was wondering what those GL75 experts out there would recommend in the way of a plinth, solid, suspended or what?

I was thinking of making something like I have seen 401's in, built up layers of plywood to make a heavy solid plinth. I bought the deck to experiment with a home made air bearing parallel tracking arm I am making so I need a bit of room behind the turntable.

Any suggestions guys?

Thanks

Martin

[James D]

Definitly solid and either birch ply laminated into huge thickness or a CLD type design...

Having said that I like to use three layers of different hardwoods such as Maple top, mahogony middle and oak bottom.

With the idlers the more massive the plinth the deeper the bass response - up to a point!

With a heavy plinth you will need to decouple vlf and Philips steel balls are perfect for the job - 19mm steel balls to you.

Also the tonearm will need decoupling from the plinth and yes, you do need to do that with an air-bearing arm as well

ciao

James

[Deco-Doctor]

Originally Posted by James D

With a heavy plinth you will need to decouple vlf and Philips steel balls are perfect for the job - 19mm steel balls to you.

Also the tonearm will need decoupling from the plinth and yes, you do need to do that with an air-bearing arm as well

James. Please excuse my ignorance, but how should I use the steel balls?

Also what is the accepted method of removing the platter? The bearing spindle fits into a taper inside the bronze bush in the platter.

What would be a suitable method of decoupling the tone arm? As I intend to use an air bearing arm levelling the bearing tube will be important so any decoupling method will need to be adjustable and stable.

Thanks

Martin

[James D]

No excuses needed just questions

Here is a link to Jonathan Noble's explaination of his deck including the ball bearing decoupling

THe platter is a press fit - so even lifting from below with vibration will cause it to work free. If you cab invert the deck this can help but it can come free quite suddenly so care needs taking as its heavy!

Here's a place to start reading about Lencos and this is the most active Lenco forum

James

[k9vap]

Hi Martin

Perhaps we can help each other....I have loads of experience with the Ladegaard arm & recently fitted to a Lenco.
http://www.world-designs.co.uk/forum...6342#post26342

I sure could do with some help getting the best from my lathe...& I'm in Rushden!

All the best

Vic

[andrew ivimey]

Hello Vic, do you mean Rushden just up the road from Bedford? I'm about to hack into a GL75 chassis, so I can easily use any arm. If you have the skills and tools and experience (you should see the mess I make of high mass plinths!) then could you help me out, please ?

[Deco-Doctor]

Originally Posted by k9vap

Perhaps we can help each other....I have loads of experience with the Ladegaard arm & recently fitted to a Lenco.
http://www.world-designs.co.uk/forum...6342#post26342

I sure could do with some help getting the best from my lathe...& I'm in Rushden!
Vic

Hi Vic ! Nice to hear from you.

I have to admit I have been far too busy to get very far making a plinth for the Lenco. I have rebuilt the main spindle bearing as there was quite a bit of play in the bushes. I made some new bushes and reduced the tolerance between the spindle and the bushes by 40 microns, I also made a new tungsten carbide thrust plate from a scrap 0.5mm carbide slitting saw and I replaced the 5mm thrust ball with a synthetic sapphire ruby ball. The bearing runs much better now, takes ages to stop and is quite silent.

I have two air bearing tone arms on the go, one is a Ladegaard and the other is going to use a tube bearing.

What sort of help do you need with your lathe? I'm about 40 minutes drive from Rushden so maybe we could help each other out as you say, PM me.

Martin

[pre65]

Originally Posted by andrew ivimey

Hello Vic, do you mean Rushden just up the road from Bedford? I'm about to hack into a GL75 chassis, so I can easily use any arm. If you have the skills and tools and experience (you should see the mess I make of high mass plinths!) then could you help me out, please ?

Hi Andrew-i have e-mailed you re the GL75 chassis mods.

Philip

[François]

Hi Martin,

I may arrive after the battle, but as suggested earlier, the plinth must be solid, and I will add: massive and heavy. My last one is 4 stones 10 pounds and it works a wonder!
The choice of the material to use is yours, though I would absolutely avoid MDF.
Birch plywood is fine, but if you consider using massive wood, don't use woodsthat are reknown for their resonace (ie, used in instrument making).
I hope this can help, and a jump at Lenco Lovers can certainly help too. You will be very much welcome there!

[Deco-Doctor]

Originally Posted by François

My last one is 4 stones 10 pounds and it works a wonder!
The choice of the material to use is yours, though I would absolutely avoid MDF.
Birch plywood is fine

Hi Francois

What material did you use to make such a heavy plinth? I was considering getting two sheets of 18mm birch ply ripped into 450mm x 500mm pieces and laminating them with sheets of a thinner material between sheets, I have not decided what to use as the thinner sheet yet, maybe something denser than the ply wood, but certainly not MDF. I also need to consider how to decouple the arm board as well.

Martin