Lenco L70 - Help / Advice please

Hi,

Anil, the L70 tonearm is supposedly very good. Joseph Esmilla of JE Labs holds it in high esteem,and Joseph knows.:)

This is a true transcription quality arm that was sold separately in Europe and was used by the BBC mounted on a Thorens TD124. A handful of Lenco enthusiasts are already aware of its musical potential fitted with lower compliance cartridges sporting conical styli. I have seen vintage pictures of this arm partnered with Thorens TD124 or Garrard 301 in professional European installations.If you decide to fit a modern tonearm on your L70 or B60 series, send it to me I will pay shipping;)

JE Labs Arkiv: Retro Cool Tonearms and Cartridges

I too have been on the look out for the Shure M3D cartridge.

The Shure M3D uses Alnico magnets like the Denon DL103,Ortofon SPU's and the long body Koetsu cartridges.

The Shure M3D was the first stereo cartridge offered by Shure in the late 50s followed by the cheaper M7D. They were offered either with a low compliance spherical .7 mil stylus assembly [N3D] that will track between 3-6 grams or a medium compliance [N21D] tracking at 2.5 grams MAX! The only difference I hear between the two models is slightly better stereo separation with the M3D. To my ears these classics are the MM equivalent of the SPU. Original and replacement stylus assemblies are still widely available with the original giving wider frequency response, slightly better tracking and more refinement. The M3D/7D lineage survives in the Shure SC35C very popular in DJ applications. It does not posses the midrange warmth of its older brothers but I would highly recommend it to people who want to try out a high mass tonearm since they can be found for about $30 if you shop wisely. The spherical stylus tracks between 3-5 grams.

You should keep the L70 arm as is,(if you plan to use cartridges like the M3D etc) and use an externally mounted arm on the new plinth you will be making for more modern cartridges. The old Audio Technica(AT12T,1005 etc) arms are very good and at present are reasonably priced on Ebay.

audio technica tonearm| eBay

Regards
Rajiv
 
After reading up on the L70 , I do believe as well you should retain the arm as well... It is very different and better than the L75/78 variety
 
I didn't know the M3D is considered so highly. So does this mean I should get myself a replacement stylus from Jico ? It's cheap (<25 Dollars) too.
 
Hi,

I didn't know the M3D is considered so highly.So does this mean I should get myself a replacement stylus from Jico ? It's cheap (<25 Dollars) too.

The M3D is not your modern hyper detail cartridge. It is more akin to the Denon 103.

Regards
Rajiv
 
@anilva: thanks for pointing out about the mounting distance. It bothered me enough to act upon it by taking the easier route. I enlarged the mounting hole by about 7 mm away from the cartridge in the direction of the arm. Now the overhang is millimetric perfect!

And the sound has better focus about the center. Earlier the sound from the left channel used to be a wee bit higher.

Addendum: I revise what I said above - it has resulted in a major improvement in the sound. It is more like having a major upgrade to something critical in the chain. There is a huge improvement in the airiness, and details pop out. Should have done this long ago:) So all along, I had been listening behind that proverbial audio veil.
 
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@anilva: thanks for pointing out about the mounting distance. It bothered me enough to act upon it by taking the easier route. I enlarged the mounting hole by about 7 mm away from the cartridge in the direction of the arm. Now the overhang is millimetric perfect!

And the sound has better focus about the center. Earlier the sound from the left channel used to be a wee bit higher.

Addendum: I revise what I said above - it has resulted in a major improvement in the sound. It is more like having a major upgrade to something critical in the chain. There is a huge improvement in the airiness, and details pop out. Should have done this long ago:) So all along, I had been listening behind that proverbial audio veil.

Many phono enthusiasts do not give much attention to overhang adjustment or anti-skating. Those who don't give importance to these very critical points will certainly miss a lot of fun while playing back vinyls. Joshua, you have been a very obedient student in these matters and you are being rewarded for your hard work. I also realized late that alignment is one of the most critical factors in vinyl playback and paying attention to these are worth the trouble taken
 
Many phono enthusiasts do not give much attention to overhang adjustment or anti-skating. Those who don't give importance to these very critical points will certainly miss a lot of fun while playing back vinyls. Joshua, you have been a very obedient student in these matters and you are being rewarded for your hard work. I also realized late that alignment is one of the most critical factors in vinyl playback and paying attention to these are worth the trouble taken

spot on by Joshua and Mr. Kuruvilla, I would also add the tonearm height adjustment is also critical. Many users change carts but ignore this factor (only the tonearm balancing piece is usually done)
 
spot on by Joshua and Mr. Kuruvilla, I would also add the tonearm height adjustment is also critical. Many users change carts but ignore this factor (only the tonearm balancing piece is usually done)

Reuben,
Cartridge compliance is one thing I have not really understood properly but i know that some arms cannot tolerate some cartridges . Though there are many threads and formula for it, it is still not clear to me. i must apply my mind to it one of these days
 
Reuben,
Cartridge compliance is one thing I have not really understood properly but i know that some arms cannot tolerate some cartridges . Though there are many threads and formula for it, it is still not clear to me. i must apply my mind to it one of these days

same with me, I have to fully understand the compliance factor. What I was actually referring to was the physical aspect, some cartridges are taller than the others and hence, the tonearm heignt also would need calibration. The tonearm must be absolutely parallel to the surface of the record for the best possible stylus engagement
 
Reuben,
Cartridge compliance is one thing I have not really understood properly but i know that some arms cannot tolerate some cartridges . Though there are many threads and formula for it, it is still not clear to me. i must apply my mind to it one of these days

Here's an attempt to explain the concept of cartridge compliance:

Consider the cantilever of a cartridge - it is usually made of a tube of aluminium or boron (not necessarily round cross section), or a crystal of ruby or sapphire or diamond. One requirement for a good cantilever is it must be as rigid as possible and not flex. The visible tip of the cantilever has the diamond stylus. The invisible end inside the body of the cartridge is connected to a springing medium (like a rubber donut).

So when a cartridge is mounted on the tonearm and some amount of tracking force is exerted on the cartridge, the cantilever will act as a spring. If this "spring" is soft = compliant, you will need lower tracking weight. If the "spring" is hard = non-compliant, you need more tracking weight to keep the stylus tracking the groove of the record.

Heavy weight on light spring = spring over flexes

Light weight on strong spring = insufficient flex

The interaction between the "mass" of the arm and "springiness" of the cartridge will produce a resonant frequency. But why is the resonant frequency important? At the natural resonance, the output from the cartridge will get boosted by a good margin (say, 3 to 6 dB). The boost can cause a problem if it occurs above 20 Hertz. Or by more conservative estimates, even at or above 16 Hz (lowest note of pipe a organ is 16 Hz). The generally accepted wisdom (AFAIK) is that resonance must be confined to 8 to 12 Hz.

For the soft spring (which is nothing but a high compliance catridge), an arm with lower mass is to be used to maintain resonance within the above mentioned frequency window.

Similarly, a "hard spring" (which is nothing but a low compliance cartridge) needs a high mass arm for the resonant frequency to be within the desired window.

Recommended reading:
1) Cartridge / Arm Matching
2) PHONO Cartridge Compliance, Tonearm Mass, System Resonance, Loading of MC and MM Capacitance, RIAA Characteristic
3) Tonearm/Cartridge Capability

Also, for info are the generally accepted values:

Low mass arm: <= 10 grams
Moderate mass arm: 11 to 25 grams
High mass arm: > 25 grams

Low compliance cartridge: <= 12 x 10^-6 cm/dyne
High compliance: 13 to 25 x 10^-6 cm/dyne

Alternately,
Low compliance : 5 to 10 um/mN (meaning is moves by so many micrometers when one milli Newtons of force is applied)
Mid: 10 to 20
High: > 20


For the mathematically inclined,

resonant frequency, fr = 1000/[6.28 x sqrt(mass x compliance)]

Here, mass = effective mass of tonearm and includes the mass of the cartridge and headshell (measured in grams).
And compliance is measured in cm/dyne.

Hope this doesn't cause more confusion:lol:
 
Jls,

Very nice explanation of compliance and mass relationship. Very succinct and comprehensive.

Cheers.
 
Joshua,
Thank you so much for taking the trouble and time to give such a simple explanation. I am sure the post has been informative for many of us. I will make a note of the technical specs for future reference.
 
great post Joshua..i had lot of disjointed info which all seems very coherent now...in other words- A veil has been listed and the information is a lot more organic now :)
 
Couple of things to do on this TT:

Change the rubber mat - become brittle and hard

Get a suitable cartridge with low compliance and which can fit the headshell like Shure M3D

Do a complete overhaul including cleaning and relubing.

Get a new plinth.

Cheers.
 
Anil,
The arm is quite similar to a AR XA arm. Does it have fixed head shell? A friend of mine has a Lenco L 69 with a very special tone arm. Lencos are really special TTs and they can be considered as classics no doubt. Due to it's vertical idler wheel and heavy platter, they perform very well even without a heavy plinth unlike say a Garrard 301. This is my observation
 
Jean Nantais categorically says that all heavy duty motors (he says more torque is better), especially Lenco L75 and Garrard 301, both of which are 16W + motors, are best exploited by direct coupling instead of suspension and super heavy plinth (made of certain specific material, but i suppose that is his secret sauce, and even without that the heaviness and direct coupling principles will still hold). However the SP10 I believe is even heavier at 20W, but he says that does not come close to the L75 (which he claims can beat any source at any price).
 
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