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Lenco L70 project

Tony L

Administrator
As some may have noticed from other threads I currently have two 1963 Lenco L70s as well as a Spacedeck / Hadcock. I’m starting a thread just to document where I’m up to – it may be a long, long while until this project is finished as I’m still not entirely sure where I’m going, but there has been some progress so it’s worth putting my thoughts in order / documenting progress.

L70 #1, from August 63, is entirely stock other than the fact I’ve stripped and polished the platter and replaced a few wires here and there:

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I use it as is in the TV room / office system (Marantz PM7200 / Quad 11L), the cart is a Pickering XV-15/625E. It is really useful for quickly assessing vinyl without going in the other room and firing up the tube amp and it sounds great. This one is done, I’m not doing anything else here.

L70 #2, from June 63, has recently been off to a pfm member for a blast and re-spray (Dave W, thanks again for doing this, much appreciated):

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The original eBay ad. The platter paint was flaked all the way round the top edge and there were a few pretty bad areas on the top plate. It just looked a bit tired and knackered all round. I stripped it right down, thankfully the name plate, serial number sticker and transit screw instruction sticker all came off intact with a heat gun. One advantage of being a record dealer is I have built up great sticker removal skills! I put the stickers onto a backing strip from some 'Airmail' stickers and kept them pressed flat in an encyclopaedia for a week or so it took for the re-spray. I spent the time really cleaning and polishing all the control linkage and stripping, cleaning and rebuilding the motor & main bearing etc and getting it all as close to factory fresh as possible.

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The top plate after bead blasting. Note Dave masked the area where the date stamp / SN sticker goes. A really nice touch as I didn’t want to loose that date as it’s my own month / year of birth – this deck is exactly my age!

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The platter after bead blasting.

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The deck re-sprayed and reassembled showing, amongst other things, both stickers back in their original position.

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With it’s beautiful white platter. Restoration phase done.

I’m not putting the arm back at this stage as I still haven’t reached a conclusion as to how I’m going to plinth it / what arm(s) it is going to get. I have several conflicting ideas floating around at this stage and may take months for me to really decide. Given that commissioning a plinth is the most expensive step in the project I really want to get the design right…

Tony.

PS better resolution pics here.
 
What's the spindle-to-pivot distance? That might inform on arm-choice a bit. (Assuming you re-use the original hole). If it's anywhere near 220mm, then a Nima might make for a hellfire combination!

Cheers!

Adrian
 
What's the spindle-to-pivot distance? That might inform on arm-choice a bit. (Assuming you re-use the original hole). If it's anywhere near 220mm, then a Nima might make for a hellfire combination!

A big problem with Lencos is that the platter, being recessed into the top plate, is very shallow, so the vast majority of arms that will fit can't be adjusted for correct VTA. This is especially true for unipivots which tend to have low-slung counterweights. I suspect the choice is between using a L70 arm on a two armed deck (it would do fine for 78s or a DL-102 for mono) or just using a single arm (e.g. my Hadcock 242) mounted off the top plate on the plinth.

Tony.
 
True enough, though I always think that with a little fiddling (shims under the cartridge, thick mat etc) the benefits may outweigh the compromises. Either way, looks like you've got a pair of fine decks there and it's nice to see someone retaining the 'original' look for once. I'm still waiting for the day you sell your spacedeck! ;)

Cheers!
Adrian
 
Very nice. How about a nice SME 3012 on it?

A 12" arm would be interesting, and I do like a detachable headshell, though they all seem to be so damn expensive - a really tidy 3012 is way more than I'd want to pay to be honest. More than it's worth too IMHO. Given the choice I'd love a 12" Ortofon arm, but again they are so expensive second hand if they are in decent condition. The 12" arm idea is one reason why I'm not planning to move fast on this - I'm just curious to see what comes up second hand over the next few months before committing to a plinth layout. I do fancy partnering it with a vintage arm - it would fit best aesthetically.

Tony.
 
Tony

Very nice - I have been looking at various Lenco based websites and I think I will be keeping the GL75. I have got it out of the horrid little plinth and taken the arm out so far. Now I just need to get my head round constrained layer damping and what it means in practical terms.

Guy
 
what did you polish the platter with?

with deck #1 I had a failed attempt at spraying the platter myself - I stripped the original paint from the outside with Nitromors, made a complete pig's arse of spraying it, stripped it again and polished the visible bits with Brasso wadding. There is a thread in DIY somewhere detailing this. It will no doubt need doing a couple of times a year the same way an LP12 platter does if one removes the protective clear-coat.

Tony.
 
I have been looking at various Lenco based websites and I think I will be keeping the GL75. I have got it out of the horrid little plinth and taken the arm out so far. Now I just need to get my head round constrained layer damping and what it means in practical terms.

Excellent news. Do you have the carpentry skills to do this yourself? There are some excellent AutoCad plans and a .pdf file for a multi-layer CLD / direct coupled plinth in the downloads section of www.lenco-lovers.com.

Tony.
 
Excellent news. Do you have the carpentry skills to do this yourself? There are some excellent AutoCad plans and a .pdf file for a multi-layer CLD / direct coupled plinth in the downloads section of www.lenco-lovers.com.

Tony.

Tony
I am sufficiently arrogant - Grade1 'O' level woodwork (my highest grade!) -to at least have a go. Thanks for the lead on the downloads - not sure why I haven't found those before.

Guy
 
Just watch out for those plans. They are spot on for a L75 but if you have a L78 they will need a little modifying as I discovered.

Anyway, Tony, if you are going to replinth the lenco, you could always set it up with the deck a little higher than the rest of the plinth so that you widen your choice of arms a bit. I am nearing the end (!) of my L78 build and have done this. I haven't put up any pics of the deck yet, but I'm almost finished the unipivot. Pics and thread on lenco-lovers. (which is a great site for DIY stuff)

Fran
 
Just watch out for those plans. They are spot on for a L75 but if you have a L78 they will need a little modifying as I discovered.

As far as I can tell there are a couple of differences around the arm cutout, but the rest is the same – the L70 arm is longer than the L75, plus the cuing linkage is different. I’m lucky in that I’ve got a spare very tatty L70 that I could send off to the plinth builder (yes, I’ve actually got three of the damn things – I bought one just to get the “lightweight” Bakelite headshell shown in the first pic!).

My initial plinth idea was along these lines:

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This was assuming I’d be keeping the Hadcock 242. Two possible positions shown, the leftmost one would allow for keeping an L70 arm in the standard position for 78s or whatever, the centre back position would be far easier to cue – I don’t like the idea of having the main arm on the back as it would be a nightmare ergonomically.

Since doing the above design I’ve been thinking more about 12” arms, i.e. just having one arm, but off the top plate to the right. I like this idea, but it is almost certainly additional expense. I just need to think long and hard plus investigate exactly what is available. I’d want a ‘classic’ / vintage arm for aesthetic reasons, but don’t really fancy dropping 600-800 quid or so for a decent 3012, which I strongly suspect wouldn’t sound anything like as good as the Hadcock (which is bloody good). The 12” Ortofon is more interesting, but possibly even more expensive, and it doesn’t seem to have any anti-skating function, and I care too much about my vinyl to want to play an LP I care about more than a couple of times without. There are some other options – I understand Denon made a couple of 12” arms and there must be others, hopefully even some that are vaguely affordable… I need to do some more research…

Tony.
 
nice project Tony, bravo. do these play tunes pretty well also?

L70 #1 looks very smart.
 
nice project Tony, bravo. do these play tunes pretty well also?

Very. Flat earth as they come – they have a huge high torque motor so pitch stability is remarkable. It has become blindingly obvious to me over the past few years that the belt drive movement led by Linn was largely marketing spin. The politics is easy to understand too, a belt drive deck is far, far easier to make using bought-in motors etc - no 70s UK start-up company could hope to compete with the tooling and manufacturing techniques demonstrated by either the Japanese direct drives or UK companies of the 60s (e.g. chassis castings on 301, 401 etc).

The idler decks everyone was instructed to abandon in the late 70s onwards actually appear to have better PRaT and leading edge definition. I always felt this at the time but was too easily led to stand by my feelings – I started with a GL75, read all the bollocks in the Haymarket press and went through several belt drive decks (Ariston RD80 etc) all of which lacked the ‘directness’ of the GL-75 despite it’s crappy arm. It makes sense when one thinks about it too, especially with belt drive decks where the motor and platter are allowed to move in relation to one another – this can never work as things are never still, and that’s before one starts to think about using a compliant drive method such as a rubber band. The idler drive decks are a very rigid closed loop when it comes to transmission – motor and platter connected by a hard rubber wheel. Where they fail is noise – as the motor is directly coupled to the platter via the idler wheel the potential for transmitting vibration is far higher, plus the motors tend to be so big and powerful, but this can largely be alleviated with clever plinth design. The torque is amazing, the L70 platter weighs about as much as a Linn’s (both parts) yet gets up to 33rpm in about 1.5 seconds. The decks will never be as quiet as a good belt drive, but they can be made quiet enough that it is not an issue.

Tony.
 
Hi Tony.

You didn't hang around getting the L70 back together and it's turned out very well.
That plinth on the Lenco site looks pretty interesting (and substantial), perhaps you could go for something like that a few alterations for the arm layout?

Dave.
 
Why not just rotate whole deck 90 deg clockwise, so that your 'back' arm position would become conventional?

The start/stop control would still be accessible, and the speed change (which you probably need least access too), is still within reach.

I think it would look great in a Loricraft style skeletal plinth.
 
I can't speak for Tony's decks, but the G88/99 and GL75/78 have an amazing drive system that is easy to quieten down, has high drive torque giving excellent pitch control and even the standard arm and plinth (sprung in my case) can sound truly captivating as long as you don't have huge cartridge aspirations. I'd like to try a DL110 in the L75 arm to see what it sounds like (I see occasionally on eBay some metal knife edge bearing blocks which should sort this weakness out) and I suspect an Ortofon Nightclub e would be interersting in the L70 arm as well.
 
I can't speak for Tony's decks, but the G88/99 and GL75/78 have an amazing drive system that is easy to quieten down, has high drive torque giving excellent pitch control and even the standard arm and plinth (sprung in my case) can sound truly captivating as long as you don't have huge cartridge aspirations. I'd like to try a DL110 in the L75 arm to see what it sounds like (I see occasionally on eBay some metal knife edge bearing blocks which should sort this weakness out) and I suspect an Ortofon Nightclub e would be interersting in the L70 arm as well.

The L70 motor, main bearing and drive is identical to the other heavy platter Lencos - whilst there are some very subtle differences in castings, i.e. the platters are very slightly different as is the external motor castings all parts are interchangable, e.g. you can stick a L75 rotor in a L70 motor etc. The idler wheels got better with time so later is better - both mine have the final spec five hole idlers, they would have come with the first plastic design which is far more prone to rumble.

Can you give details of what you have done to quieten the drive system? I'm curious as it would certainly be applicable to the L70.

When you come to replace the V blocks in the L75 arm there are quite a few choices: original final-spec (dark) rubber is still available from Technical & General, one of the guys over on lenco-lovers.com makes some lovely looking brass and quartz ones and there are hard plastic available on ebay. I'm not certain which is considered the best, though suspect the original are almost certainly the worst. I guess the ideal is rigidity without bearing chatter, though which achieves this the most successfully is anyone's guess. There are a couple of great step by step tutorials over on the LL forum detailing how to swap the v blocks out - it all looks very straightforward and can be done without desoldering the arm if you are lucky. You also want to try and lock out the floppy back section of the arm if you can, again there are suggestions as to how this can be done (dental floss and super-glue!). The general word is that with new V blocks and the back rigid it will see a Linn LVX off, it's very high mass though (about 23g) so stick to low compliance carts. It should be a great match with a 103.

Tony.
 


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