Circular L75/SME Series III/Built-in VSPS Phono Stage

[Nick]

Edit, March 2020: Since Photobucket stopped working for me, I've re-uploaded the pictures, and also edited the text where necessary, so that the descriptive posts still more-or-less make sense. Since the photos appear to be hosted here, I've used fewer photos, but you should get the general idea!.

All the comments from others do of course relate to the original post.

Nick G, March 2020

This link takes you straight to the description of the built-in VSPS phono stage https://www.lencoheaven.net/forum/index.php?topic=5131.msg432188#msg432188


First a couple of pictures of the record player itself, taken in September 2015, when it had already been modified from its original 2011 form.






This record player (and indeed the whole set up) is an attempt to create a hi-fi system that both sounds good and fits in to a relatively small domestic setting. The room, about twelve by fifteen feet is in a flat somewhere in England. The aim here was that flat mates, visitors and latterly my wife could use it easily. In short, it had to have an obvious on-off switch and no record clamp.

The record player itself contains little more than the drive train and platter of the Lenco 75 that was left behind in a flat I rented about twenty years ago, and it's gone through various iterations, each more user-friendly than the last. It is mostly made from found parts, scraps and other bits and bobs: a chipboard TV table provided much of the raw material; sheet lead was cannibalised from previous iterations; duralumin strip, aluminium tube and dedshete damping material were bought new. My work area is a small space in the living room with a workmate and the dining table.

The annotated photo below (from 2011) explains in more detail. It's changed somewhat since, but it gives a fair overview.



It needed to be small, and a good visual and sonic match with the SME Series III arm. Besides the usual idler-wheel  plinths I also drew on the Simon Yorke, Wilson Benesch Circle and SME M10 turntables for ideas. Broadly, the general shape and notion of a small dense turntable on a dense slab come from the Simon Yorke designs; the notion of fixing the tonearm to separate outrigger comes from the W-B Circle, and the aesthetics (and stylus guard) are derived from SME's M10. I have also spent a good amount of time reading the messages on this invaluable site to get a general insight into the subtleties of making the most of these fine machines.

Now; to the  the sound. I've only heard one genuinely high end system, and that only for twenty minutes or so, earlier this year in a friendly hi fi shop in the USA. The system was an SME M10, VTL valve electronics and Wilson Sasha loudspeakers, all set up properly; the record was Bach's first Brandenberg Concerto. My memory of it is quite clear, because it did feel uncannily like sitting in a concert hall. Plenty of detail, but not overdone; realistic depth and scale of the orchestra; a sense of solidity in the instruments; a very neutral uncoloured sound; most importantly, the fact that it was terribly easy to suspend disbelief. This system happened to sound more or less exactly how I'd always imagined a really good system would and should sound, and so it now provides a baseline against which my own set up gets measured: a deeply unfair comparison, but there we are.

My system has a similar sonic signature, but is obviously not as good. The system is the record player plus Quad 33/FM3/303/ELS 57s, all heavily modified (bar the tuner). By comparison with the SME/VTL/Wilson system, it is reasonably detailed; has less depth, but no less height or width; lacks the same sense of scale and dynamics; possesses a slightly warmer sound; but overall it is very easy to listen to.

My own music preferences are classical, jazz, some folk, and rock, but not too loud!

The turntable itself weighs 10kg, and sits on a suspended ply/chipboard/lead base which weigh 12kg and is suspended at each corner on four compliant feet for a total suspended weight - 22kg.

[hatehifi]

Seriously just too much input to make any comment other than, "hi, Nick!," thanks for introdcuing yourself. That system is really imüpressive. Look forward to comments from other members but that TT (not only) is quite impressive with lots of IMO good ideas!

Which cartridge? AT OC9?

Cheers!

[Nick]

Thanks! It's a Goldring 2400. The arm came with the smallest damping paddle, but I enlarged it with epoxy carefully cut to shape, and it tamed the thing quite dramatically. It can handle all but the innermost tracking test on the HFN-RR test LP.

Nick

[reinderspeter]

Hi Nick,
That looks absolutely wonderful!

[jloveys]

Absolutely fantabulous ! 
Most welcome to Lenco Heaven, seems like the new members have lots of quick these days ! 

[Johan]

Welcome to LH. That is a really nice TT, with many great ideas! Congratulations!

I'd be interested in more details on how you reinforced the idler arm.

[Nick]

Thank you for the compliments, and the warm welcome.

The idler arm reinforcement went something like this.

Buy glass fibre PCB from local electronics shop (Maplin, in the UK). Drill holes through idler arm, maybe one every 5cm, 1.5mm diameter. Cut out reinforcing "spine" to fit idler arm from PCB (I probably just traced the profile of the idler arm onto the board with a pencil). Drill 10mm holes at 25mm centres to lighten the spine. Using the holes in the idler arm, mark through to the spine, and then drill fixing holes.

Bolt everything together (I think I used cartridge bolts, but they may be small bolts from a model shop) to make sure it fits. Correct anything that doesn't fit. Epoxy it all together, using the bolts to hold it all in place. Omit bolts where they may catch on anything, and grind down the spine with a dremel if it needs to clear anything; in this case, the end of the motor support beam, just behind the main bearing in the pictures.

The idler arm is, in effect, a horizontal beam, so the spine stops it flexing in the horizontal plane, which is the one that matters for our purposes. Fibre glass is light anyway, and the holes make  it lighter, so the drive train is not working too hard against the extra weight. I think the rubber band is slightly stronger than the original (and very tired) spring.

Hope that helps.

Nick

[hatehifi]

Right on! Good thinking. This place is a gas, er, fun...

[rfgumby]

WAY COOL BUILD.

That was similar to how I was going to make the next Lenco, so I guess I'll have to alter my plans a bit.

Great post!  Welcome by the way...

[jon]

Fabulous! For quite a few people this has been an objective - a true circular build.

Well done for achieving it!


 

[nic]

would changing the idler wheel to a metal one be on the cards? If so would like to hear your analysis of the differences.

Would also love to see more of your Quad 57s perhaps in the Quad 57 thread http://www.lencoheaven.net/forum/index.php?topic=202.0 

or members' systems http://www.lencoheaven.net/forum/index.php?board=23.0)

It reminds me a bit of this: http://hifiheroin.blogspot.com/2010/01/quads-and-plinths.html

[henkes]

Hi Nick welcome . Whow nice work . And nothing wrong with the photo,s It,s a specific identifiable project.

Great post.

Greetings Henkes

[rfgumby]

The Series III is a little lightweight, you'll want to stick with cartridges with a very high compliance rating.  I owned one a while back but sold it to a friend who had a lightly sprung table it was far better suited to.  On the other hand, you already have the SME mount pattern, you can swap various other arms in if you need to.

What's "dedsheet"?

[willbewill]

What's "dedsheet"?

http://www.soundservice.co.uk/dedsheet-sound-damping-sheet.html

[Nick]

Hi Scott

"Dedshete" is a bitumen-based self-adhesive damping sheet, with shiny film on the non-adhesive side. I bought mine from a long-established English company called Wilmslow Audio. They specialise in loudspeakers, and sell Dedshete for damping cabinet resonances.

Yes, the SME series iii is light, and I've been through a good number of cartridges: Shure VST V; the 97; a Grado; Goldring 1012 and the Goldring 2400. The best were/are the Shure VST v, which is long since defunct, and the Goldring 2400 (which has a compliance of 20 compliance units). That said, the arm is a little modified. The rear weight is completely filled with lead, and the damping paddle which technically is the smallest (black) one has been enlarged with the judicious use of carefully shaped epoxy resin. The Goldring 2400 also has a metal body and weight of 8 grammes, and so the overall set up is actually remarkably well behaved. It tracks the first three "torture tracks" on the HFN-RR test LP happily enough, but struggles a bit with the fourth one. In practice, that means that it tracks all of the LPs I've tried it on, including the awkward ones.

Oh; having looked at some of your scarily impressive projects, I don't doubt that you could knock up a circular Lenco in a jiffy! So please feel free to steal ideas as necessary! 

Nick