First Build: "The Lenco Has Landed"

[itskeith]

Here we go then: my first Lenco build (a GL78). Should be some ideas and lessons learnt along the way to help any fellow newbies, some questions for the 'old hands' and plenty of photo's for everyone else  

First thing that happened: placed 4 bids on GL75's on you know where and lost them all for £100+  
Never mind, managed to do lots of reading up on brilliant LH, and lots of DIY around the house. More in  four weeks in fact than the previous 4 months. 'Her indoors' was imprerssed to start with, then downright suspicious  

Then eventually a bid for a GL78 was successful   and then a second GL78 for a good deal couldn't be resisted, so now the proud owner of 2 x GL78's.

The plan was (goddam plans changed already): To build two lenco's, both big mass plinths, once simple affair to get me up and running, and then an all singing dancing affair. The latter will involve an angle grinder  

Then two things happened, the first GL78 arrived and looks immaculate, and I simultaneously read Flavio81's brilliant post how to get a L78/L75 up and runnning quickly (thanks Flavio - hugely inspirational and helpful).

So, the plan now (which this post will deal with) is to renovate the GL78 in standard form as quickly ish as possible, keeping stock arm, chasis and plinth (but internally adding extra mass).

The stock GL78 - Hurrah  





Good bits:
- really like the look of it
- some maintainence has already been carried out
- arm has new v blocks in it

Not so good:
- the arms wires have been cut  
- not sure about the bit of ply stuck on below, that will have to go at some point

[itskeith]

Bit more done:
- have removed the corner blocks from the plinth and sub-plinth - seems that it would be stronger to have the new layers all the way into the corners and less fiddly having to cut all the notches out !



TIP:
Tried cutting down the side of the blocks through the glue and it is seriously strong stuff. In the end it was quicker to use a sharp stanley and cut through the blocks in line with the grain.

Have now just layed some paper on top of the existing plywood and traced its outline (quick and easy). Will then compare against the 'GL75 layered plinth template' before assessing the next step  

[ropie]

Great start, Keith, and a nice private workshop too you lucky man!

[Jolyon]

Hello Keith,

Great deck and the start of another wonderful project; I like what you've done.  I agree with you about the piece of ply on the bottom.  I think of plinths like loudspeaker baffles; i.e. what do you do to a baffle with a drive unit in it to get more low frequency coming out of the front ?  You put an enclosure around the back.  So, what can you do to reduce the motor noise coming through the top plate ?  You take the enclosure off !  An over simplification, I know, but it makes sense to me, anyway.

Good luck and keep us posted.

Yrs,

Jolly

[Skott2772]

Very nice Keith and you are right the workshop won't stay that tidy. Wait till your other half looks in there and tells you to tidy your room! boys and their toys lol. 

[itskeith]

Many thanks Jolly, Ropie and Scott for the info and encouragement.

Really enjoying this

Ropie - totally agree about being a lucky man, and that was before the bandsaw, router table and pillar drill that have just been 'borrowed' from Dads garage 

More soon, cheers.
Keith

[itskeith]

Yeah: Next step done then:

Plinth Assessment:

The top layer of existing ply has delaminated in parts and flexes a couple of millimeters on the sides, so some PVA glue inbetween and clamped overnight has brought it up solid again  
Clingfilm allows one of the next ply layers to be used with some weight on it and it not stick  


Going for 18mm ply layers next. They dont match the L75 templates as:
-  its a GL78,
- and also because the top ply layer here is approximatly 12mm so everything is off a bit.

For the first new layer, it was quicker to trace of the top layer. Added a bit extra in where its shaded black.

Then two more layers below that, cut from the GL75 template, with armhole enlarged in width slightly for the GL78. The sizes of these ply slightly smaller to fit the black sub plinth which the plinth sits on. Very pleased with first test fit  


Next:
- have to work out where to route the power cable, phono and earth before glueing all together  

[decanterlime]

Hello Keith,
I compliment you on your innovative idea demonstration. Think it looks excellent, utilising what you have already got.
To think it is your first project and you have tackled the more difficult machine the GL78 is inspiring.
One foot note with the original plinth you have improved is that this type is the weaker original plinth and when this project is complete I would exercise caution when moving it in its entirety (ie with the platter on) because those laminated original sides were not destined for too much weight.
What you do have with this plinth is the compact size feel.
Well done
Mark

[icemanhank]

Nice work Keith, and nice work space.

[itskeith]

Morning All,

Many thanks for the feedback Mark and David and points noted. Now you tell me that the  GL78 is more difficult   Have already got another one for a custom build for a friends secret christmas present   More to follow on that later.

Very pleased with yesterdays progress. Having to do this blog from memory. It should make a lot more sense once the photo's are added added.

The following show the layers lined up for a test fit:

First; the bottom of the subplinth - its looked like it was hardboard pinned onto the subbase. It turns out to be ply that is also recessed and super glues into it. Was quickest to drill into the corned and jigsaw it out, then get the remaining bits out with a sharp chisel. Phew  

1. Original layer.
The clingfilm worked pretty well to stop the glue fixing to layer 2 whilst it was all weighted down. Has come up really solid.


Also, noticed that once the chasis is up tight against this, some of the cables, so will modify this.

2. First new layer.
Good fit now. Not much room at the sides still so going to screw and glue. Just had a thought - have a circular sanding disc for the drill so will rough up the surfaces before glueing to help them bond as good as possible. Or score the surface with a stanley knife.


There is a leaver here which is catching on the next layer, so will need to get hold of some french curves (no - not that type of french curves  ) to mark and then cut an extra hole for that.

3. Next layer.
These layers downwards cut slightly smaller to allow the sub plinth to slot over them.


Note: all the black marks especially on the corners of the cut out. That is the timber burning mmmm! Close inspection shows that the jigsaw has the whole support pillar that the blade rests against has been bent and twisted at some point. The burning smell was a give away   Decided it's not enough to stop this project, but will get a new (e.youknowwhere) one for the custom build.

4. Next layer:

Found that 18mm layers brings the plinth approx 8mm short of the base, so managed to find some spare 8mm ply lying around   Decided to put it at this level rather than the base, as its the same depth ish as the power cable - so have cut out a channel in this for the power cable (as i wanted to use the original hole cut for this in the sub plinth), and a new channel for the phono cables. Will cut a pair of holes in the sub plinth for this shortly (don't call me shortly )


5. Base plinth.

Yeah  

Will probably cut a few circular holes for some washers to fit flush! Then use these to fit the nuts against for the threaded rods that come from the chasis. Still holes to cut for these.
Note also the masking tape with 'base' written on - so i don't take an angle grinder to this face also and mess it all up  

6. Sub Plinth

Have also turned the sub plinth upside down so that the circular hole already cut in this lines up even better with the 8mm layer.


Must admit to really enjoying the playing with wood stage.

Too late to get the power sanding disc out, so over to the electrics next (ohh ohh)

[itskeith]

Electrics next then. Likewise, photo's to follow.

So we have two GL78's, Lets call them A & B. I have a strong desire to avoid any more soldering of small fidley wires than necessary.

Arm A has new v blocks in, but the arm wires have been cut.   So, have moved these v blocks already onto arm B (which have the leads still attached). Managed to do this whilst the arm was still attached, but it was chuffing fiddley. Forgot to take photo's and I needed 3 pairs of hands as it was. Tip: when moving the v blocks out of arm B, they had protrusions on the bottom and needed lifting up, they couldn't be slid out sideways.

There was a good earth lead to spade, and set of phono leads attached to Arm A. Also moved them onto Arm B. Yup - that was a bit more fiddley. So, Arm B looks ready, its attached to chasis B, but will now move this whole chasis into the original plinth (A) that all the work has been done on and fingers crossed.


It was now half past bedtime, so:   and definitely huge progress today:
 

[itskeith]

TIME TO GET TECHNICAL, QUESTION / HELP PLEASE  

If you look at the photo below, the chasis normally sits on 4 rubber washers, that sit on the 4 metal recessed washers on the top plinth. This means that the chasis itself sits (guessing 4mm) off the top of the plinth.

PHOTO'S STILL NOT LOADING,
HOPEFULLY THE ABOVE MAKES SENSE!

QUESTION / OPTIONS:

- Is is best to leave it as is, so the height of the standard arm i'll be using is correctly set up for it?

OR,

Is it best to remove the rubber and reccessed washers and clamp and screw the chasis directly to the top plate? Kind of think this from what I have read is the best option (as it seems to be one of the underlying philosophies of getting better sound from the lenco), but will the arm still be ok to use as standard. If not, what do i need to do?

OR,
Pack the 4mm ish with a new additional layer of plywood etc.

Any and all tips, advice, info, help and photo's appreciated.
Kind regards.
Keith

[decanterlime]

WhOe, overeasy Keith,
Why does one struggle to make a solid chair for the Lenco to sit on?
Well the theory goes like this:
A hollow chair (plinth) makes the deck behave like a microphone during use and as a result from the speakers makes the chair resonate and resemble the properties of an acoustic guitar which some think is detremental to sound quality?
Or to provide enough "mass" to soak up top plate and motor vibration which may effect the tonearm/cartridge singing during play?
Those 4 fixing points you mention are just that and with the rubber grommets used insitu cancel out the 2 above theories.
My suggestion? Go into Wilkos or WH Smiths and buy 4 rubber pencil lead erasers at least 12mm thick and palce each in a vacant corner space under the top plate.
You will have a solid chair for your Lenco to sit on and better ventilation too as there will now be clearence.
Mark

[wer]

A bit of ventilation is an interesting point to consider, thank you Mark for the suggestion 

[itskeith]

Many thanks for the suggestion Mark - like it, and the theory explanation also helps a lot.

QUESTION:
Does this mean that the GL78 Arm height will also now need increasing, as I'm guessing the top plate would then end up sitting approx 7mm higher than it was before?

.... and whilst I'm on a roll:

SECOND QUESTION:
How best to fix the top plate to the top plinth? Have read plenty about fixing top plate to custom plinths, but not much about how to do it when renovoting an old model.

Options as I see it are (others welcome):

- use existing 4 fixing points, but replace with longer threads to bolt to the underside of the new base?
- drill some extra holes in the pan (technical name? under the platter) and use some longer screws to reach down to plinth layer 3-4 underneath them?
- here's maybe a novel idea. Don't know what the two longer red anodised / look like motor transit screws do, but could also place a larger threaded stud it these and also bolt to the underside of the new base?
- some or all of the above etc?

Work just started on the earthing the top plate whilst waiting for some answers to arrive