Chris' construction site - two L78 from 1973 and 1975

[Christian Martens]

As written before I got my hands on two L78 from different sellers, different years and in different condition. I'll document my project in this thread and will use "some" photos. Image size will be reduced, don't know if that is important here on LH but there is no need to have another file of 5 MB showing some rotten parts that you've seen before a billion times.

My goal is to have one of the L78 up and running soon while parts from the other one will be used in a future (maybe PTP) project.

While comparing both L78 I will address them with their year of production.

Obvious difference: while the 73 has all sheet metal under the platter, the 75 has some plastic, are there any known technical differences between older and newer version? At the moment I'd like to keep the automatic power off of the L78.




V-blocks are shot as expected and are different over the years. 73 are black rubber that looks and feels quite similar to some new ones from Yekaterinburg, but are slightly collapsed. 75 are yellow / orange where the orange is hardened and shrinked and the yellow is still soft and a bit gooey, both are completely collapsed. Newer parts look worse than the older ones...

I have to admit that I ordered some additional V-blocks in white "special plastic", will report how these feel (and later: sound). After listenig to some brass V-blocks (on youtube only, please forgive me) I decided against brass but would like to try harder plastic ones.




Both main bearings look ok, both were slightly lubed (no grease) and have no noticeable play in the bushings. The thrust plate of 73 has a serious indentation while thrust plate of 75 only has a slighty indentation. New POM thrust plates and tungsten carbide balls are ordered, new bushings (because they are dirt cheap) arrived today ...





The bushings will be lubed using automotive engine oil and vacuum in a syringe, I found this respective instruction very helpful.

I'm very happy and thankful that you already did this enormous amount of reserch and development on these Lencos. Everything is discussed and documented, that's fabulous. Nice to be here!

That's it for today, comments are welcome 

[Kno]

I referred to this link when I was getting my 78 auto to work.  Worth bookmarking.
https://bornin50.webs.com/l78.htm

[Christian Martens]

Thanx David, that is looking very interesting. Will read that tomorrow. for now

[SteveM]

Good luck with your L78s Christian.
I still have 2 myself; one reconfigured and unrecognizable as a L78 - the other in pieces (someday...)
I recall some reports of loose fit with those bushings, maybe yours will be ok.

[Christian Martens]

This lasted one month - but '73 L78 is playing! 
and I only broke four items...

As said before I got some sinter bronze bushings 9x12x14 via ebay. These are available directly from the manufacturer as well. This seller is highly recommended, cheap, fast, reliable. Did I already tell you that I had to order twice? talking about broken items...

I started by lubricating the new bushings using a 5ml syringe (perfect fit for bushing's OD 12mm) and some 5-W40 engine oil following this procedure. These bushings come prelubed but I was curious how this works since I never did this before. When applying vacuum to the oil / bushing the oil foams up until most (relative to the vacuum applied) of the air in the sinter bushing is replaced with oil. Fun to watch.



Changing the bushings I mostly followed this great instruction from LH. Thanks a lot.

I used a 1/4" socket with an extension to remove the old bushings. Note to myself: completely remove the little screw on the side before applying force to the bushings.



Lenco used bushings 13mm long, now replaced with 14mm, can't harm. I took the large hammer as seen above in the lower right to push in the new bushings. This resulted in one bent bearing (not the bushing, I ruined the housing). The spindle can be inserted from each side and turned without problems but it's impossible to push the spindle through the second bushing.
Since I have two complete L78 (and luckily got a bunch of spare parts via ebay for cheap) I had a spare housing. Next time I used a smaller hammer and the socket I already used for removing and everything went well.



Since the bushings are oiled I only applied some additional drops under the spinde, no need to flood the housing with oil.
The bearing was completed with a new POM thrust plate and new ball from sph:




This resulted in a smooth bearing without any noticeable play that keeps the platter turning forever and ever and ever...

Next stop tonearm.
Cleaned the ball bearings, set them in dry as recommended and adjusted the play to a minimum. I did not like the feeling of the bearing and after reading in this fine forum I decided against it and used some very soft lithium grease for the ball bearings. Feels a lot better now, solid and smooth.

Using the V-blocks from Alexey as shown above I assembled the polished tonearm that was in better optical condition and managed to squash the left channel wire while mounting the plastic head. Don't ask me... No photos taken. 
Next day I cleaned the other tonearm, took the (hard, white) plastic V-blocks and assembled very carefully the second tonearm / bearing assembly. This time without any accident...

Motor:
Both motors have been cleaned and lubed according to this fine instruction. Everything went ok, my photos look the same as in the instruction. Nothing special. Oh. I managed to snap the nose setting screw of the second motor. 

Some adjustment to the idler arm according to this instruction using some pliers.

Mounted a new AT95E to the cartridge using standard 2.5mm screws from above through the enlarged holes of the carriage. No problems, must have done something wrong.
Adjusted the tonearm weights and the cartridge overhang - and played some vinyl. Finally! 

The Lenco is great, I love listening to vinyl again. I did not have a turn table for more than 25 years (even gave away all my records during another live) so now I am very happy!

The chassis currently is sitting in the Lenco plinth without springs.





1st record: That's the way it is, Elvis Presley, followed by Jazz, Bossa Nova, Soul and Jazz again. No hum, no rumble, no nothing, just a singing Lenco.

Summary: one running singing turntable.
broken so far: bearing housing, little screw at the side of the bearing, tonearm wires, motor nose screw.
That's ok for me 

Many thanks to all of you who contributed to this forum and made my job that easy.

Future plans:
- the other L78 will be converted, PTP5 in a plywood plinth, Supraphon P1101 tonearm (that I already got from a 'Lenco' Tesla 450) and an Ortofon OM10.
- will build a NSC and some kind of revmeter.
- listening.
- buying more records.
 

bis denn,
Christian

[Rotsch]

I use the same bushings from "Caspar Gleitlager"
in a couple of bearings....

Excellent !! 

[Christian Martens]

just an update:

I fastened the top plate to the lenco plinth without damping, went through some (cheap MM) cartridges and some aftermarket stylii, bought more records and enjoyed it.

Last week I got this beauty:


Early US-made version with the slim cantilever and a nude diamond.
Complete with all papers and box -  NOS.

Took me some time to adjust it to the lenco headshell (slightly out of parallelism at both the outer and the inner point, one inwards the other one outwards) and started listening to some records.

I got a knackererd M75 body with one of the lencos and bought an aftermarket stylus N 75 ED from thakker, sounded good -  but the Shure stylus is way above.



Started this morning with Friedrich Gulda, Das Wohltemperierte Klavier, after that some Frank Sinatra, now playing Hildegard Knef Concert (with Orchester Kurt Edelhagen).
loving it, can't say anything else.

The headshell is rather "used" but who cares if the lenco sings 

bis denn,
Christian

[wer]

Changing the bushings I mostly followed this great instruction from LH. Thanks a lot.

I used a 1/4" socket with an extension to remove the old bushings. Note to myself: completely remove the little screw on the side before applying force to the bushings.


Lenco used bushings 13mm long, now replaced with 14mm, can't harm. I took the large hammer as seen above in the lower right to push in the new bushings. This resulted in one bent bearing (not the bushing, I ruined the housing). The spindle can be inserted from each side and turned without problems but it's impossible to push the spindle through the second bushing.
Since I have two complete L78 (and luckily got a bunch of spare parts via ebay for cheap) I had a spare housing. Next time I used a smaller hammer and the socket I already used for removing and everything went well.

A bit late to comment on this, but it is terrible practice to use a hammer to either remove or insert bushings. Use a vise if you want to do it properly, even if you have to do it in a few installments.

[Christian Martens]

Use a vise if you want to do it properly, even if you have to do it in a few installments.

thanks Werner,

you are very right and I'll use a vice for my next bearing, parts are already laying around...

bis denn,
Christian

[analogadikt]

I'll use a vice
 bis denn,
Christian

Using a hammer is a vice, use a vise.

Enjoy your Lencos

[Christian Martens]

Using a hammer is a vice, use a vise.

AFAIK both spellings are possible / correct while using the "c" like in vice is the British variant.
Anyway, maybe I just use a screw clamp instead 

[wer]

AFAIK both spellings are possible / correct while using the "c" like in vice is the British variant.
Anyway, maybe I just use a screw clamp instead 

Anything will be better than a hammer 

[Wout]

[Christian Martens]

no news from the turntables (I'm awaiting a B52... ), managed to change the bushings in two platter bearings using a vice, all went smooth 

I had problems with my new to me amplifier, the speaker protection relais obviously needed some TLC. But cleaning the contacts did not cure it so I ordered a new relais. While at it I realised the power supply cap had become seriously incontinent:



Since this is a three-pin two-in-one cap I needed two separate caps, some wire and a "base" to fit it into the housing. I will not show this because it realy is tinkered.

after 10 long days the brick is playing again   



bis denn,
Christian

[DSJR]

The experts here may well disagree and put me right, but a 75 I have here came with dry main bearing and slight spindle play. Going on the HFN review of the 75 from 1969, I cleaned it all out, added some LM grease at the bottom (thrust pad wasn't bad at all but that may be changed later) and added a fair bit of Mobil Vactra ISO68 slideway oil to the spindle (apparently chainsaw oil is similar but I can't substantiate that), which apparently is safe on the bushings and a touch more viscous than a light machine oil so won't run away from the top sleeve so easily I'm told. Subjectively sight-wise, the spindle doesn't wobble at all now, the oil should stay put reducing the need for regular 'top-ups' and run-down is excellent. I come at this from Dual and Garrard changer bearings, where motor engine oil seems to run away as it's designed to be pumped under pressure, the slideway oil tens to stay more where it's needed...

As for the arm, for myself, I long ago abandoned the rubbery V blocks and went to (first) dezmo in one deck (the arm can slide side to side in these without slim nylon or Delrin washers added) and now to printed? types which seem really good (Thanks David H). My 75 which is still half done, has metal V blocks again with no lateral 'keepers' and I suspect these will be replaced at some point.