Having actually seen Jean’s luscious Garrard 301, I have to stand by the original assessment that it is, in fact, “stunning” - no overstatement about it.
Our afternoon of listening at Jean’s digs, however, was taken up exclusively with Mr. Red which was quite a treat for me. (While Grant aka gjwAudio1 was there too, these impressions are solely mine and he should weigh in with his own take.)
Well, first the journalist in me was so much reduced by the subjective enjoyment of the session that I failed to objectively keep track of what combo was playing what – i.e. the Morch/Decca or the AS-R1/Denon DL-103“E”. But no matter – as this wasn’t a track by track comparison session to dig out the nuanced differences between the two (on which Jean has already reported) – but an audition where both armed combos were given free range to come “on song” by utilizing the Mr. Red based Lenco as a foundation and springboard.
My initial impression (and this will have to be for both arm combos as I was at a loss to discern the difference) was that this was a level of detail that defied the analog sourcing that I was listening to. This was a “digging out” that went beyond crisp/full frequency response and marched right into the field of quick paced timing and rhythm.
Non-analog descriptors came to mind like “attack & decay” – “tight envelopes” and digital “pace”. It was truly a listening experience that would have had many searching for a hidden SACD player. But if one listened carefully, the absence of truncation and clip allowed for a bloom that could only be analog.
For dessert, our amenable host outfitted the golden Morch Unipivot with the Grado Platinum woody. This produced a lush warmth that I was much more familiar with. Detail wasn’t lost, but was simply upstaged by the richness of what one might call a glorious “music hall” sound. The Grado promptly staked out its own turf in a field that would encompass all large ensemble recordings.
For me, there really wasn’t any issue of supercedence between the cartridge/arm combos. Each claimed its own laurel as an analog retriever. Before this session, my audition exposure to “detailed” retrievers was invariably linked to a “clinical” experience. Jean’s set-ups have changed all that. I love my Grados and someday soon, I’ll go Platinum. But I was so enthralled in what I heard from the D&D twins that I’m glad my Lenco plinth can host two arms.
We also were able to apply and test MuMetal on Grant’s Lenco platter in Jean’s system. This, I would call a qualified success. Success, in that it clearly provided a barrier to EMF induced hum on the Decca. Qualified, in that there was some slight hum in the first ¼” to ½” of play arc. This may have been attributed to:
1) That I had previously hammered out some slight ridging in this area. (Hammering, I would later learn, breaks down Mu shielding properties.)
2) The Canadian winter conspired to hamper a glue set-up temperature for an optimal meld to the platter.
3) Jean’s system was able to pick up a diminished “wrap-around” of EMF that I wasn’t able to pick up on my home system.
In the end, this was a wonderful and an all-around educational experience for me: Plumbing the depths of how this seemingly primordial means of recorded music can be retrieved in a magical way into something so full blown. I know there is a scientific explanation for each step along this analog trail – but somehow I can’t shake the notion that wizardry is somehow involved.
-Mario |
Hey Kim,
Looking Good! What's that beautiful gnarley wood on the sides? What are all the woods that you used? How's the Sumiko acting as a retriever? Do you have it set up with or without the dampning fluid? So many questions ....
|
My brother has been complaining of late about the harshness of his CDs (hard clipping). If ever the time was ripe for an analog intervention this was it. Since his music listening has been via one of those integrated Bose units, I had to assemble a complete, stand-alone system. The goal was to keep it around $200 - and with the help of the Salvation Army, we came in under.
Anteed up a rim-drive Garrard Zero-100 that I purchased nearly two years ago for $90 in my “waiting for Lenco” phase. It came with a Grado green cartridge. After pulling out about 2 to 3 lbs. of automation and a full servicing, this Garrard was still too terrain intense underneath to mount into a solid plinth. Instead, I left it on ¾” dowel stilts and put a black fabric skirt (more like bunting) around it. Made a couple of modifications. One was to place the neon stroboscope lamp on a micro-switch circuit, activated by new linkage added to the “auto” toggle, so that it stays off unless selected. The second was to hardwire directly to clips/cartridge and by-pass the contacts on the sliding cartridge tray. This allowed correcting the azimuth which was way out of whack.
For turntable sundries, I bought him a new AudioQuest anti-static cleaning brush ($20) and Silly Putty (original version) for a stylus cleaner ($1.99). For a dust cover, I used the thick clear vinyl that comes with comforters purchased at department stores. Just had to unstitch two of the reinforced seams; cut to fit depth; then restitched.
My good buddy, Stephen does the rounds at the thrifts, picking up various vintage receivers and he brought over three to audition before I left for New York. A hulking Kenwood KR-4600 ($20.00) won out for its excellent phono stage and bass response.
Speakers came by way of the Salvation Army – a pair of Pioneer CS-470 sealed 3-ways in excellent shape ($20.00/pair). The bass on these is commanding, if a little out of control. But the low-end distortion is pretty natural sounding and easy on the ears. My wife helped out with a little refinishing on the cabs and I bought some new grill cloth ($8.95) plus glue (2.95).
The big score at the Salvation Army was in August when somebody dropped off a nice LP jazz collection – Miles, The Duke, Zoot Sims etc. I culled about 20 of these – all scratchless ($20).
So for $183, a pretty sweet sounding analog system with a starter collection of LPs.
Next week, I’ll head down to Southern N.J. to deliver the goods. In the meantime, the gear came with me to New York for a three-week long visit with another brother. The traveling analog show seems to have wowed another – so I may be doing this again.
Sailing on the Analog Sea. |
Well, I decided to visit the good offices of AudioGon this morning which happen to be in my hometown, at least, the nuts and bolts part of the mission. After getting over the novelty of a virtual member dropping by the virtual mothership (a first, I was told), I had a pleasant chat with the moderator on duty.
Sadly, it appears, that despite gallant efforts, the old “Despot” thread has not been found and the likelihood of its recovery is growing doubtful. It also appears that the new thread will continue to fall under AudioGon’s now universal policy of moderator review on all postings.
It is my belief that AudioGon should not be second-guessed over exercising their prerogatives in this matter. We’ve had a long run and AudioGon has provided an excellent platform to allow us to have our unfettered discussions.
It is about how and whether this run should continue that we should now calmly reflect on.
My case for pressing on, is rooted in a meaning of continuum – to flow like an uninterrupted river with tributaries and distributaries. People get on or off at their pleasure – but this “old man river” needs to keep rolling along for many of us. The alternative, I fear, will be the occasional Lenco/Idler related post that will be short-lived and thin soup because of its fleeting nature and lack of full, round table discussions. The “Despot” thread has been a Kiosk and it is ours. We’ve known it would be there as surely as the rising sun, and it has allowed us to build a hobby into something a little more special. It has been the long term camaraderie, I believe, that has lent it that special luster – allowing people to check back in, catch up and be genuinely welcomed.
By the way, welcome back Bornin!
My selfish stake in this is only wanting that continuum. There is no stake for me as being “the leader of the pack” – because I’m not. I just happened to restart the thread because of desperation over its absence, an act that I’m beginning to regret. There are others far more knowledgeable than I.
But as Jlin has demonstrated, there are archives that can be called on, even if some of that knowledge base has elected to depart, for the time being, over the unfortunate, yet understandable row that has developed.
About that row, I will only say this. Jean’s control had its purpose in establishing the discipline over his innovations as he (and most of us) applied them to the Lenco. New innovations by new originators have, at times, been encouraged, cautioned or discouraged, under Jean’s close (too close - for some) tutelage. The results of these innovations have sometimes been applauded and sometimes ignored. The course of human dynamics of the whys and hows in all this is too great a minefield to warrant further treading. But I’ll only add this: Innovation is what the original thrust was about – and it should continue to have its day in its furtherance. |
Hi Widge,
At first blush, this sounds like a mono hook-up either bridged (grounds and hots married) or static. How many catridge clips are at the headshell? How many tonearm wires are at the phono to pre "junction"? A longways back someone posted pics of one these console jobs - but I don't remember seeing anything with the tonearm wiring.
- Mario |
Hi Goughary, and welcome to "Da Thread II",
Sure glad we have another archivist in our midst. A well done coup in capturing all that! I'm sure many of us will be calling on you for copies.
As for your Bogen Lenco, Mike Greene and I both use the Sonus Formula IV unipivots on our Bogens - his is a 70 (I think) and mine is a 61 (I think). This arm is the longer tube version of the Mayware and it matches up nicely for spindle to pivot mounting distance on these early top plates. The stock mounting armhole of the Bogens will be just a couple of mms larger than the Sonus stub. This was close enough not to bother with a subplate armboard (at least, for me). Two fender washers (one plastic/one neoprene) do a fine job in securing the arm once the overhang has been set.
The VTA is a close call with these low-slung Lencos even with the Sonus adjusted to its lowest limit. The armlift mechanism will just about bottom out on the top plate depending how tall the cartridge is. |
Just to fill everybody in … it is our hope that this “Despot II” is temporary, as we understand that the staff at AudioGon is hard at work trying to restore the original monster thread that was accidentally deleted two days ago. So this is a stop-gap for those of us who take this connection like our daily bread. That said … adversity truly is the mother of all inventions and Jlin what a service you have performed! Your putting together that digest is something that has been needed for a long time and should be reposted periodically on the old thread once it has been restored.
Just last night I received an e-mail from someone completely new to this who was bitten by the original lead in. I directed him to many of the sources that you used, but now I’ll contact him again and direct him to Jlin’s post #1.
And Mosin, like Grant, I’m thoroughly intrigued (and teased) by your hints of this innovational Lenco Idler modification.
Lastly, if AudioGon is willing, I will paste all postings to this thread to the tail of the original once it’s back up.
Sail on, oh fleets of Idlers!
Mario |
Up early today for the Labor Day weekend estate/garage sales. In the college town where I live, this is also move out/move in week where the total cast-offs in the garbage lanes would keep some third world countries afloat.
Those in the U.S. still in the Lenco hunt who are within driving distance of Canada should consider a little getaway to our great northern neighbor. Canadian imports of Lencos appear to have been ten-fold of what the U.S. took in under the Bogen badge. Bring pre-printed cards with the models that you’re after (L-75, L-78, GL-99 etc.) and your contact info to hand out at flea markets, antique stores and even thrifts. Have a good time and network!
Speaking of Bogen Lencos, I’ve finally broken down and sent off my L-70 plastic idler wheel for a retread while I ready the marble/birch-ply/mdf/ birch-ply/marble plinth.
The O-ring modification that Mike Greene and I have been dabbling in does seem to work fine – just thought I’d give the rebuild a try for comparison’s sake.
Enjoy the holiday weekend and remember Labor – the folks who brought us all the weekends. |
Hi Fishwinker,
It seems you are the point where you’ll need to adjust the block that surrounds the armature.
1- Remove the motor from the Lenco and place it on a resonant surface (I find Styrofoam shipping block to be excellent).
2- Hot-wire your motor’s AC, but don’t plug it in yet.
3- Remove the back plate so that you can remove the armature.
4- You’ll see four Philips head screws on the block – break them (the crack of loosening for the first time in a long time). Retighten to “to snug” all except the screw in the 4:30 position as you look at it head on. Leave this one a little looser since it’s hard to get at with the armature remounted spinning.
5- Remount the armature and back plate.
6- Plug in the motor.
7- With the armature hopefully spinning, back off on the three accessible screws until you can move the block orientation.
8- Adjust till you get smooth running.
9- Tighten up the three screws then unplug the motor.
10- Use a 90-degree Philips head driver or a tiny Philips screwdriver to tighten the last screw. You’re done. |
Jean,
Where are my manners? Thank you for the very kind words, and as I wrote you in an e-mail, it’s what any Lenco renegade would do – but, perhaps a bit too renegade – in that I’m not all too comfortable fielding the header responsibilities with all of this (e-mails and tech queries) – I’m still a novice in some ways and you’ve got the full grasp of the global picture here.
Let’s hope that the restoring of the old thread is in sight at the good offices of AudioGon and that the confusion being experienced by newcomers will end.
Sail on, Admiral Nantais!
|
|
Mosin, you may be speaking to a stage that, as I read it, is quickly clearing. So without further adieu …
Everybody on stage for the line number, please! Take your bows or take your best shots. Willbewill, Bornin, Freek? It seems apparent that the curtain on this long-playing show may be coming down shortly. So roses or tomatoes, come one, come all, while the getting’s good.
Ironically, the elements that have held this odyssey together for so long, may also be taking it asunder: conviction and passion.
- Mario |
Hi Justubes,
According to LencoLand this turntable is belt-driven with a lightweight, stamped platter and a good deal of automation - perhaps, not a good candidate for "the conversion".
That said, if this turntable is already in your possession, it might be worth a closer analytical look in seeing what can be done to improve on it.
Would the motor's flywheel be convertible to channel a nylon thread? Is there room underneath the platter for adding a bit of symmetrical weighting/dampning?
If so, and you're willing to work on it, this might turn out to be decent retriever.
If I'm not mistaken, the IC denotes a much improved tonearm - an S-shaped tube with an SME (non-detachable) headshell - a gimbled "modern" looking affair.
There are so many CD players in need of replacement out there, that any analog orphan can find a deserving home.
|
Hi Justubes,
That would be L-75, L-78, L(GL)-88, L-(GL)-99.
There are other earlier models with heavy platters, but plastic idler wheels which are prone to warping like the L-61, L-68 and L-70 which shouldn't be dismissed as out of hand. I've got an American badged Bogen/Presto L-61 that has sounded great in unplinthed, temporary duty.
Retread the idler tire with an O-ring and it was off and running. Currently getting this wheel re-built after finding a reasonably priced re-building service.
If you're in the hunt, make Blue-In-The-Face's site a "Favorite":
http://www.btinternet.com/~a.d.richarson/hifi/lenco/heavy_lenco.html |
Hi Fishwinker,
Been brooding about what could be causing your motor vibration ... and I'm still brooding ...
In the meantime, take a look at 4yanx's post from a while back and see if it applies.
04-27-05: 4yanx
"As a further aside, we've found that the proper "tension" placed on the nose end screw is such that it the cupped end just seats onto the end of the rotor spindle and allows free travel of the "springy" doo-dad (less than a millimeter). Too little tension causes slop and too much causes restriction. It is a very fine line and impossible to "see". It helps when you get it right to have one person hold the motor casing with one hand, and a small screwdriver set in the slotted end of the screw with the other, while a second person FIRMLY tightens the hold down nut. In our experience, tightening that nut otherwise almost always results in the screw tightening a bit along with it and mucking up the works. Too, if the nut is not secured tightly enough, it backs off - the screw along with it. On out first couple, the doo-dad was so frozen that we didn’t even know it was supposed to “give”. Getting the proper tension was a BEAR until we discovered that."
Is there a numeric designation on the GL Delta Lady? |
Hi Nigel,
Oregon’s post follows the most up-to-date recipe for the “sandwich”. These are two distinct areas of attachment: 1) perimeter bolting (4) of the top plate to the top layer of plinth – usually to mdf, and 2) coupling the platter well (pan) with wood screws to the 2nd plinth layer – usually birch-ply – sometimes with the addition of neoprene gasket material or hardwood shims to make up for any gap.
The first phase of the attachment was always part of the recipe. The 2nd phase – also known as “direct coupling” - came later in Jean’s development of this grand project. Because some (including myself) had difficulties in getting the torque just right on “direct coupling”, you might consider taking this as a two-step process: 4-Bolt the Lenco to the plinth and listen to it for a few weeks – then direct couple. This way you’ll be better able to discern any sonic improvements/degradations.
Since the bolting of the Lenco to the plinth is to draw the top plate perimeter edges into the top plinth layer, I see no reason to be locked into the bottom/up 4mm bolting. I drilled out the threads of the top plate lugs and bolted top to bottom using ¼” bolts with cone washer with black neoprene on the contact surface. This eliminated tricky alignments procedures. Initially, I drilled smaller holes to align a couple of plinth layers at a time using nails while I made internal cutouts. Once all glued up with top plate in place – I drilled down with a ¼” bit. Then recess the nut into the bottom layer by drilling partway through the bottom layer with a ½” bit. You can almost always find ¼” bolts for the correct depth.
Nothing is written in stone about how you get there as long as you adhere to the basic principles of the sandwich recipe.
Sail on!
|
Hi Mike & Peter,
Gotta wonder whether the idler arm speed channel would get burred up over time with aluminum - not that I have much need to change or fine tune speeds - but I do use Peter's Post for idler wheel disengadging all the time - even to swap records.
But whatever material or design, I'm interested.
- Mario |
Came back home last night after a month of travels to find a package (with postage stamps!) waiting for me on the hall table – the plastic idler rebuild for my Bogen/Presto Lenco-L-61. It was performed by a semi-retired gentleman in Mississippi named Ed Crockett to whom I have no affiliation other than being a very satisfied customer. The rubber rebuild is identical in both plane profiles as the original. (Note: Always save as much of the original rubber as possible to send into any rebuild service) The tire is supple, yet firm. It takes about three weeks and costs $25, which includes return shipping. Anybody interested in this service can e-mail me for details.
My next step is to rethink the material for dampening the wheel. Unlike Lenco metal wheels, the plastic ones have (4) 90-degree pie wedge recesses on one side that just beg for some kind of treatment. Initially, I applied a self-adhering rubber butyl called “Kool Patch”, but I think this may have added a little too much mass to the wheel. Lately I’ve been thinking of using the roofing product called “Ice Guard” (kind of a poor man’s Dynamat) – a thin matt that is rolled on roofs in place of felt over eaves (under shingles) to prevent ice damning. It has an adhesive on one side and can be cut with scissors. The big drawback with this product is that it has a tendency to spew out tiny bits of mica, asphalt and fiberglass – hardly the stuff you want dropping into a Lenco motor. So I’m thinking of sealing it once in place on the plastic idler wheel. Any suggestion for a sealant? An enamel lacquer?
After my older brother’s jaw was retrieved from the floor while listening to the humble little analog system that I set him up with a few days ago (headed by a Garrard Zero-100 rim drive), I could almost swear that there were tears welling up in his eyes as he grooved to his old beloved Stan Getz LP. Reaching around his back, I grasped his far shoulder and intoned, “I know… I know. It’s the long lost sound of analog that’s come back like an old friend”. |
Hey Mike & Fishwinker,
If this is for a Euro set-up, you might want to take a look at the photo in this thread:
http://www.lenco-lovers.com/forum/viewtopic.php?t=148&postdays=0&postorder=asc&start=0
Just realize that the wires labeled going to 220V will, in fact, be broken by the switch.
- Mario |
Hi Fishwinker,
The switch capacitor shunts the surge that sends a "pop" through the system speakers without it. Bridging the two switch leads at the terminal block with a replacement capacitor will not bypass the switch.
Hang in there.
Mario
|
Adding to the detective work on tracking down sources of rumble comes a poster over at Lenco Lovers who pierced my “stuck-on-stupid” consciousness like a lightning bolt – with the observation that rumbling cutters can be faithfully recorded in the grooves.
Had I been hauling my mass plinthed Lenco back and forth to the workbench these past months because it was actually an over-retriever?
To be sure, this area ushers in a host of new variables, many untrackable cold case files because nearly all of the witnesses are dead. What cutters? Scullys? At RCA? When did idler-driven lathes commence? End? Were some better plinthed or dampened? Does a phono cart’s VTA need to match the cutter’s to dig out recorded rumble?
Certainly, the “real world” signal to noise ratio makes this a phenomenon more pronounced in classical recordings because of distant mic placements and soft dynamics. But that seems to be the case regardless of the source of unwanted transmission.
This will be a difficult case crack. But over time and with continuing improvements to the Lenco, it is any area that greater light may be shed on.
A. Conan Doyle’s empiricism may be apt:
“When one rules out all the probable causes, whatever is left, however improbable, is correct.” |
|
Hi Oregon,
Having neither the cart nor the arm, I'm only going to parrot what I've heard others report and what I would try in your position for starters.
The humble Denon DL103.
That is, if you're low-output capable.
Maybe others will chime in...
|
Hi Peter,
What a wonderful and ambitious project! This should slay all competition once its set up in your system – provided, of course that you have proper structural support (i.e. jacks) to brace up your house. Certainly looks heavy! Exactly what are these surge tanks? Somehow I have visions of supply and drain plumbing being hooked up to this thing in some kind of massive dampening hydraulic Lenco project.
And speaking of dampening, you’ve done a very admirable job throughout – much better than my patchwork attempts. One thing I did notice was that you still have the original idler tension spring hooked up. Right from the get go, Jean fingered this spring as a potential route of resonant noise transmission and substituted an elastic infused fabric item (for sewing into waist hems) that can be found in most sewing supply sections/stores.
Thanks for sharing your work with us, Peter, and keep us posted on updates.
As for all my projects: (4) idler redesigns/plinth builds; hardwood lens horn design & fabrication; (4) Reel to Reel deck resurrections – I’ve decided to put them all on a short hiatus and address the dirty state of my growing LP collection. I’ve become tired of taking nice records that I’ve bought for .50 to 1.00 dollar down to my local audio store and paying $1.50 to get them cleaned on their VPI machine.
So I’m building an ARC machine using the previously trailblazed standards for this DIY project: Ice Cream Maker motor; Guts of a Dust Devil 3 hp (peak) Vacuum; 1984 VW Windshield Washer Pump w/120VAC to 12VDC Transformer. I’m relying heavily on Jimmy Neutron’s design – but plan to deviate on the critical double wand record contact area. Whether playing or cleaning vinyl, it always seems to come down to adjustable VTA. |
Johnnantais,
Allow me to intoduce you to Jimmy Neutron and his ARK.
http://www.jimmyneutron.org/ARK%20part%201.htm
- Mario |
Hi Jean,
Mr. Red indeed! Very nice job. We’re talking 7 or 8 stone here with this monster, aren’t we? Had no idea that Bogen continued its relationship with Lenco through the L-75 years.
Took the opportunity while browsing through “your system” to take a closer look at your tangential air-bearing arm. Would you hazard a guess over the cause of its falling short as a full bass retriever? Something endemic in its tangential design or set-up? This arms mass?
The reason I ask is that there’s a gentleman over at another audio site that I frequent who has caused quite a stir in posting results of his survey on stylus wear. He used a 200X Shure stylus microscope to examine every cartridge he has used or pulled from various equipment since 1962. His posted results: All used styli from pivoted arms show asymmetrical wear, while nearly all styli from tangential arms show symmetrical wear. He postulates that pivoted arms can never attain neutrality for long in the skate/anti-skate force battle because of groove modulation.
Well, if this is true, the implication for record wear is implicit.
However, if this boils down to giving up window thumping bass to extend record life, I’d probably elect to chomp the vinyl and go buy more. |
Hi All,
First, let me offer apologies for “My System” which resembles the untidiness of a flophouse. Instead of coherent exposition, there resides jumbled teasers. Someday soon, I must pursue some tutorial help in getting it order. Anyway, Chuck got hold of me and now has the MuMetal/Lenco application recipe and I believe he’s going to pursue the fix – a fix that will utterly banish motor generated EMF hum.
Work continues on my automated record-cleaning machine. Already there have been departures from Jimmy Neutron’s machine. The plastic gear drive interface between the ice cream maker motor and the cleaning platter had too much slop in my design which translated into wobble. This called for the introduction of a 12” “Lazy Susan” bearing assembly for the platter to ride on. With 80 balls this is quite the rumbler! A neoprene-lined chamber within “plinth” will house the 3 hp DustDevil vac motor and have a fabricated mini-furnace filter to keep cleaning fluid off the motor (fused – just in case).
Looking forward to visiting Ottawa in ten days or so to hook up with Grant for a CD release (mastered by our very own - gjwAudio1 – aka Grant) party featuring Terry Gillespie and The Granary Blues Band. Weather permitting, my wife and I hope to pay a visit to one of Jean’s old Archeo haunts, Bon Echo Park.
And maybe, just maybe… another Lenco.
Hey Mike,
You’ll have to split those royalties with Mr. Red Green.
- Mario |
Hi Mike,
“Who Dat?” Really Mike, you’ve been far too south for far too long. Red Green is the lead in a Canadian comedy troop carried on many of the PBS TV stations up here. The show always includes some outrageous Red Green DIY project where he invariably ignores the premise of “Why would anyone want to do something like that?” – as in the case of outfitting a hulking 70s Buick with Gull Wing doors after yanking the stock ones off their traditional hinges with his trusty van and chains. After massive amounts of duct tape and cumbersome home brew hydraulics, he gets it to work – after a fashion.
We know that the unseen spouses behind these and other all-male shenanigans often assert some clout over what they’ll tolerate. So that we have the commencement (at the end of the show) of their Possum Lodge meeting starting out with the head-lowering Credo: “I am a man, but I can change, if I have to … I guess.”
I’ll endeavor to tie in this wildly off-topic ramble by aligning myself with Red Green as a “practitioner” in the old sense of the word on my DIY MuMetal experiment and not a scientist with all that much knowledge of the behavior of EMF – especially as it applies to the direction it takes at the shield edges. It is, however, a scientific given that what comes off those edges is highly intensified EMF because of the unabsorbing nature of the MuMetal. This has the potential of worsening the situation that we are trying to correct with Lenco motor induced hum. From this premise, I decided that shielding areas of the motor and/or top plate was impractical and I never tried it.
The critical question of EMF’s directional behavior at the shield edge is one I cannot answer with certainty. My only gauss meter is a Grado cartridge mounted in its intended environment. Does MuMetal blocked EMF act like a fluid with a degree of “wrap around” at the edges? The more I think about, the more I’m inclined to think that it does. The literature accompanying my MuMetal, while not specifically addressing the edge intensification as a “wrap around”, nevertheless implies in its caution that it does. Otherwise, why a caution at all, if blocked EMF continued outward on its blocked plane?
But Mike, don’t let my guesswork discourage you, another practitioner over something that I have only the thinnest grasp of. I’ve got a 12” by 4” sample of MuMetal (Hi permeability - and more, if you need it) that I’ll be happy to send along to you for the furtherance of Red Green science.
- Mario
|
Oops! A simultaneous posting with Chuck's.
Hi Chuck,
The top application will be much easier. No flanged casting supports to contend with, nor that tricky area around the bearing hub interface. Also, there's the question of idler wheel getting proper purchase on the slick MuMetal.
The combined thickness of the two foils is .01" - no geometric threat to tracking, whatsoever.
|
Hi Mike,
Was trying to find information that related to secondary transmitters of EMF based on alloy ferrous content, but was unable to locate it again. Somewhere in researching this last year, I visited the whole question of whether unabsorbed redirected EMF off a MuShield would pose additional emitter difficulties as various metal alloys in the Lenco (platter, motor shaft, top plate) were permeated to the degree of iron in their respective mixes.
I do remember that it was of enough concern with the unknown (and unknowable?) alloy contents in various exposed Lenco parts to solidify a decision for going up top of the platter. Even then, I had concerns that the record spindle itself, might act as some RKO tower and omni emitter of interference. Thankfully, this is not the case, and one hears only a small amount of hum when the Gauss detecting Grado is directly over the spindle. Whether this is due to chrome plating of the spindle, or the brassy elements of the bearing sump, I haven’t a clue.
But I did come across a couple of notes today that should be highlighted as REVISIONS to the Lenco MuMetal recipe. (Grant & Chuck be advised)
1- It DOES matter which layer should be glued to the platter first. The thinner, low permeable foil should be closer to the EMF source and get pressed in first.
2- Hammering MuMetal reduces its effectiveness because it changes the crystalline structure of the alloy. Put your energies into cutting the MuMetal foils with a hard surface and many, many utility knife blades. Ridging of the cut edge is the bane of this project and must be avoided. It will not promote a smooth meld to the platter and its removal is problematic. Shearing often causes its own ridging.
In my application, I was able to get away with minimal shearing of edge burrs and some very light tapping with a hammer at the spindle hole.
|
Wow Jean, that certainly is a beauty! This is your best yet. Looks totally professional with an upscale bearing that screams “out of my way!” The red mat takes this ancient and plops it square in the 21st century. The tonearm looks like it can cut as well as retrieve. You, and this project have traveled quite a way upstream from the Home Despot store and faux marble, though lumberyards and finish are still our touchstones. In answering your own challenge made a while back, you’ve certainly honored our Garrard ancestors with that gorgeous and stately turntable.
|
Hi All,
The stunning arrival of Jean’s latest endeavor prompted some nostalgic waxings for me last night (never a good ingredient for empiricism). But his post today reminded me that this was not so much about “passing the torch”, as about lighting other torches.
Certainly, “For those who can’t afford the moon,” (Grease-bearing 301), the venerable Lenco continues to be the best value option in getting to the music.
New age Lenco tinkerers, practitioners and theorists have not been sitting idle by their idlers while Jean has been honoring UK ancestry. A score of Rheinderspeter’s redesigned Lenco top plates will soon be on their way to experimenters across Europe and North America (including one for our prime host) . These laser cut steel plates will advance on new design territory in motor isolation and speed linkage, as well as deal a deathblow to the inherent weakness of the Lenco’s stock top plate. And this may be just the first run. I know Mike and I plan to use Peter’s steel plate as a template for hand cutting aluminum ones.
Jean’s listening assessment about the Rek-O-Kut Rondine mirrors conclusions that I have come to face over this and Presto’s design: That their thrust plate bearing motors cannot be tamed enough to quiet transmissions for rumble-free stereo play. Maybe Herculean efforts in motor transplants and idler wheel rebuilds to a more supple composition might work, but I’m not sure.
But there is one mono era American idler still left – The Metzner Starlight – and it continues to show promise. It has a 4-pole inductor motor that is quieter and higher cranking than the Lenco’s. Its hybrid puck drive isolates transmission along the motor/spindle/platter path by the very nature of the puck’s composition – rubber. And we all know well how to isolate transmission in the other direction (motor/plate/tonearm).
After kibitzing with a couple of other DIY Metzner owners on another forum site, it became apparent that we all suffered from a stop-you-in-your-tracks design flaw. All our machines had gross platter wobble because the soft platter spindle sleeves had “egged out” over the years. I suggested that a high performance auto shop might offer a solution with pressing in a new sleeve, machined from a hardened valve guide in a line box. Well one of the guys took this baton and ran with it. He got a cooperate machine shop, run by an older gent who recognized the project for what it was and did the deed for $50. So we press out, press in and press on.
- Mario
|
|
It was remiss of me to neglect the comments of my wife, JoAnn, who had a chance to listen to Jean’s Mr. Red for about 15 minutes. She has asked me to post this in addendum:
“Everything was so clear. Each instrument stood both separately and in harmony - like a chord where each note can be distinguished. It was a wonderful sound.”
JoAnn, I should add, has become quite adept at spinning vinyl on both my manual Lencos as well as threading up tapes. She rarely plays a CD if there is an analog alternative and acknowledges the “Living Presence” has grown on her. When I prodded recently whether she might be another HoltyHelen in the making, she demurred. “You build it and I will listen.” |
Hi Mike,
We actually considered what you suggested. However, there were no closets in Jean's realm - only open architecture. Our only options for restraints were 24 ga solid core and duct tape.
- Mario
|
Hi Plinko,
You're correct. Many of us use rubber/latex infused waist band cloth in place of the spring. Can be purchased at most sewing supply sections in department stores.
Stops another resonant transmission path. Also, tension setting (where you tie the knot onto the post) is infinately variable.
More from me soon. Currently weighed down with massive redistribution of consumer goods.
- Mario |
Happy New Year All!
In the four months of this "Da Baby Thread" -
217 Posts - 21,701 Views.
May all your contributions be posted quickly in the coming year - a year shaping up to be filled with innovation and discovery.
Sail on, oh ships of Lenco, oh fleets of Idlers.
|
Hi Oregon,
Nice Nice Nice. You have a lucky friend indeed! What’s with the seam around the plinth about an inch down from the top? Is this top layer a separate – affixed after the rest was bolted together? Or are these cooling vents for the hot-blooded Lenco?
What wonderful reads on this thread for the past week. Great contributions, especially on the early formative experiences and wide-ranging, full-breadth examinations on the state of our physical art and science. Certainly seems that the momentum of old has taken hold.
With no wish to interrupt this great flow, I must proffer a more pedestrian, “mad scientist” question that’s been rumbling around my head like an idler with a flat spot at 78 rpm. Feel free to caution, put down or ridicule:
Will a 12” “Lazy Susan” (a crude turntable with several dozen balls and a 300 lb. load max), when sandwiched between two slabs of 7/8” marble have any sonic penalty under a Giant Lenco with acorn + isolation footings? We’re talking multi-arm ergonomics here.
|
Hi Mike,
Yes, that’s exactly what I’m thinking. Ideally, 18” to 22” diameter rounds – though this is a tougher cut than straight lines. “Lazy Susan” gets masonry screwed to one side then a light coat of mastic strategically brushed on the other “fixing” surface and plop the other marble round on top.
Having all these items on hand, I’ve already checked the rudiments out. Getting a level pedestal (base) is key, since we’re all accustomed to cheating (shimming or foot adjustments) to bring our tables level on off-level bases, stands or what-have-you - in their static positions. But the Lazy Susan mechanism doesn’t produce appreciable error to level in itself.
There’s about a ¼” gap between the marble in which two small rubber wedges can be inserted to secure “stops”. While a drifting, spinning Lenco might be a sight to behold, I’m not sure bringing any Coriolis effect, however slight, into play is a good thing.
Dressing phono cable for payout shouldn’t be too much of a hurdle. Traditional “corner” mounting demands a 90-degree swing for two arms and 180 for three. However, a plinth designed for this application (“thinking outside the box”, Jean once said) could well reduce this to 60/120 degrees depending on the arms and their swing arcs.
The crux question is what you elude to about rattling bearings ... with the huge sink of a Giant Plinth, footed with Acorns + isolators and that atop the first marble round, would vibration still be an issue? If so, what about infusing grease in the "Lazy Susan"?
|
Of course, one could also dispense with the Lazy Susan altogether and just plop this whole affair atop a VPI Scout and move to a new reality in crushing a belt drive.
|
Hi Mike,
Funny you should mention the middle of the room placement… Grant and I were just talking about such an idea the other night (he’s kind enough to humor me by listening to my wild schemes). He’s at the final design point for his plinth and is considering two or three arm mounts.
Well, in short order the brainstorming on the ergonomics of multi-arm use, got around to an “Island Altar” in the middle of the room (a phono pre by necessity in the pedestal base). Well, since neither one of us are bachelors, that ain’t going to happen. But it was nice to bask in the warm glow of that religious moment.
But seriously, the more I work with this marble, the more I find it to be an excellent isolator in upward transmissions (footfalls) and I suspect, in the other direction as well. If the double coriolis or free-range Lenco needs a third, decoupled marble round, so be it. However, I’m not sure whether I have a full handle on how coupling or decoupling in the footing realm effects “focus”. At what point does isolation become overdone and promote focus robbery? And if a degree of base coupling is needed for focus, isn’t there invariably some rattler down the line?
By the way, Mike, if you’re still in the marble hunt and 1- you still get back to the NYC area to visit family or friends: 2- have patience to wait out the next time I’m in the metro area doing the same, I can drop off a couple of slabs for you. (I find that marble as ballast helps focus my ’83 Rabbit on long distance cruises.) |
Hi Goughary,
My BPL-61 (forerunner of the L-70) has a spindle to pivot distance of 225mm. Your ATP-12T calls for a 242mm mounting distance. That extra 17mm would take you back to the corner of the plate. Depending how big of a mounting hole the AT needs, you might just be able squeeze it on.
- Mario |
Nice Post Turboglo. And having the courage to pursue this at all costs. Any chance of posting some of this in a "System" thread so that we can take a gander?
- Mario |
|
Hi Turboglo,
Here at AudiogoN they've got special "forum" called virtual systems. It allows you to upload pictures and descriptions of various components in your audio system. Once you complete the start-up of "My System", the little blue link that appears after your user name will have "System" added to "(Threads|Answers)".
- Mario |
This is so true about the stock Lenco’s ability to engrave its bold presence in our listening rooms. So much so, that early on in the original thread there were quite a few reports of procrastination because of it. Many of these Lenco pioneers were so smitten with the stock “iron fist in velvet glove” treatment to music retrieval, that some plinth builds languished for awhile. It was as if Ulysses Nantais had neglected to cover the ears of his crew to these seductive sirens songs. There were grumblings among the men - “Can it really get any better than this?”
Well, of course, time went on - plinth builds proceeded and the answer to those early grumblings was a resounding, “yes!”
My confession for today is that while I promptly sank a Lenco L-75 into a mass, constrained plinth - complete with direct coupling and two tonearms, I have another Lenco – a BP L-61 - that has been on stilts for nearly two years in my basement workshop system. It was sent to me as a trash unit for parts. I cleaned & lubed all the proscribed workings: Took an unruly, noisy motor and made it quiet: Got a wonderful the idler tire rebuild for $25: Reaffixed a broken idler arm anchor to the speed adjustment sled.
The tonearm was replaced with a Sonus Formula IV unipivot that was a perfect fit for the Bogen/Presto placed armhole. The Sonus, a longer tube version of the Mayware, sports a Shure V15Vxmr (of which the replacement styli buy-up and hording seems complete and criminal). A modest Marantz 2230 receiver drives a pair of Rectilinear speakers of unknown model designation. The music all this produces is so enthralling, that it seems vastly out-of-place for my humble basement.
There are plinth plans for this L-61. The marble for the outer shell that will envelope a traditional mdf/birch-ply sandwich, has already been dimensionally cut. Large, internal borings and epoxy fills to the inside of the 7/8” marble shell will be my attempt to break up any potential resonance from the marble.
Those are the plans anyway - which continue to languish amidst the siren songs of this stilted Lenco.
- Mario |
Hey Grant,
That was fun! And in two-track mono to boot. Your primal skepticism only lends credible weight to the chorus – a mass constrained sandwich in its on right. Not many months back, when the three of us were together, you continued to ask pointed, in-depth questions of Jean about many facets in audio. Of course, our savant host had an answer for just about everything. Lazily, after finding my ears agreeing with all Jean’s other audio recommendations that I’ve been able to try (Petra ICs, Athena budget speakers, V-FET solid state), I’ve found it very economical, just to sit back and reap the benefits on this road to stellar music listening.
But Grant, you’re an excellent and fun writer and this was a treat. Since you’ve made me privy to some pics of your Mighty plinth build, I can see that this is going to be one heck-of-a Lenco.
- Mario |
Hi Stephanl,
I can vouche for the entire Prestige Grado line short the Woody Platinum (which I haven't had the pleasure of trying). Even the lowly Grado Black is one powerfully lush and musical cartridge. Best bang for the buck - hands down.
However, my love affair with Grado has pressed me to MuMetal my Lenco platter because of induction generated EMF hum. This inadequate shielding was a conscious decision on Joe Grado's part when he chose not to copy Shure's cart grounding along the ground signal path because of "coloration". He was right, in my opinion, but some TT motors do produce a noticeable hum because of it, the venerable Lenco being one of them. Just so you know... (if you don't already).
While you're back checking in, I wanted to ask you a question regarding the innate anti-skate of the Rega 300 tonearm. You were the first person to draw this to my attention, which I confirmed by removing the magnet. Do you suppose this phenomenon is caused by the offset bearing placements?
Thanks,
Mario |
Hi Harry,
That McCurdy sure looks nice and at first blush, it seems to have a few things going for it that might lend itself to be a good candidate for “polishing the rock” to see if it has the potential as another dynamic idler in the rough. In fact, I was ogling one of these last year, but let it slip away.
What attracted me was that expansive flat top plate and how well it would afford vast real estate for attachment and direct coupling to a mass constrained plinth in one swoop. Now that I’ve seen your photos, I also like what I see in that highly polished steel motor spindle. This is almost certainly a leg up on the Rek-O-Kuts and Prestos rim-drives with their bakelite spindles which seem to be prone to a slightly fibrous surface upon wearing.
Nevertheless, you’ll need to be open to other potential difficulties like motor isolation, noisy bearing, etc.. In my search yesterday on this turntable I could not turn up anything definitive on it – other than some “idler” chatter from former studio DJs who referred to the McCurdy as “The Master Rumbler”. But we also know that similar digs were said about the Lenco, and those proved of little consequence to where we are today.
So Harry, you may have to pioneer this one on your own for the betterment of the idler community.
But since you have it up on stilts, you might consider testing with a quiet LP (string quartet?) and reaching under and manually disengaging the idler from the platter rim and listen for the difference in unwanted signal coming out of your speakers. A stethoscope may also be in order for this new patient.
- Mario
|
A Rek-O-Kut Rondine with a metal motor pulley/spindle? Jean, you certainly live a charmed life! The audio Gods atop Mount Idler certainly seem to take a shine to you. I won't be suprised if some day you crack open a newly arrived Lenco and discover a golden idler wheel.
I thought we had the same Rondines. Mine has no model designation - but has the huge chrome selector knob, faux faceted ruby run indicator and red script lettering. Is yours the B-12? |
Hi Kravi4ka,
Does your modified Rega 250 have any added VTA adjustments or is it stock & static?
If your Rega is in the original fixed version with only washers for height adjustments, then you’ll probably want your armboard about 1/8” below flush of the top plinth layer. I say “probably”, because I have a mounted Rega 300 and I’m assuming that the pillar/tube height mounting geometry is the same on the 250.
With mine mounted flush to the plinth without washer, the tube is horizontal with a generic height AT mm cartridge. But I don’t think this is optimal, because someone once wrote here many moons ago, (think it was Willbewill) that a Rega engineer said that these arms are optimal with their butts dragging a bit. But many things can throw minute variances into the VTA formula – cart height, platter mat thickness, the number of bearing thrust shims, MuMetal treatment, etc. Then there’s the question whether you’ll use something to isolate the armboard from the plinth or not. Some use plastic washers, others use rubber grommets and still others directly mount.
But my advise would be to plan for VTA and armboards, but don’t sweat it too much. By making multiple armboards of various thickness and flavors of wood (this stuff is freebie scrap at most lumber yards) you’ll give yourself room to experiment. The only hardwood I’ve heard spoken about negatively for this application is oak. Linn armboards are plywood – probably nicely laminated – but plywood nevertheless.
Maybe Stefanl who has helped me out with Rega issues will weigh in here.
All best,
Mario |
Hi Kravi4ka,
Not sure whether your question got answered. Make the armboard 1/8" to 3/16" thinner than your plinths top layer.
This will be about 3 - 5 mm. 5/8th should be fine if you'll be attaching the armboard directly to the second layer.
- Mario |
GP49,
Better late... I had Ed Crockett do a tire rebuild on my plastic idler from a Bogen-61 last year. Couldn't be happier. Firm, yet supple and at a very reasonable price. If you do decide to send it off to him, be sure to include as much of the old tire as you can so that he can hone the "V" for a matched profile.
- Mario |
Hi GP49,
It's possible that Ed Crockett held onto the old PVC tire that I sent along to him for reference with mine last year. If not, it's not super critical especially if you can trace the "V" profile. Diameter can be an "in the ballpark" matter - as the speed transfer from motor spindle to platter is linear.
- Mario |
