Nude Turntable Project
@lewm -- agreed re eBay, if you have room for some industrial tech the AVI series could work well -- for example this is a nice one However whatโs great about the TS-150 (except its price) is how compact (18kg, 450mmx400mmx78mm) it is and hence how easy to slot onto an existing stand or in my case wall mount |
FWIW, You can find Herzan isolation tables for sale on eBay as industrial surplus items, and in that format they can be quite affordable. ย (They really ARE most often used for electron microscopes or to isolate sensitive industrial processors of one kind or another.) ย Problem is they are often so massive as to be unsuitable for our sort of use. But once in a while..... Seems to me also that I once figured out Herzan make the MinusK or the Vibraplane, or both. ย |
Thanks for the kind words Jim, Some think that the Herzan is an 'overkill' for our application......and at the prices for their 'active' bases, it is an option few would contemplate. I haven't tried any other bases although I wanted to try the Minus K many years ago. It simply wasn't suited to my isolated turntable/armpods arrangement and I concentrated on making my cantilevered supporting shelf more rigid in the meantime. I'm sure your Vibraplane gives you most of the same improvements I've described..... It's hard to describe all the subtle effects one can hear once ALL spurious vibrations are removed..... Most of the records I own where the high-frequencies at times became strident and even sometimes unbearable.....are now listenable. It doesn't mean one is not aware of 'hot' recording or mastering techniques.....it just clarifies exactly what is occurring. Glad you enjoyed the Thread Jim and thanks once again. Regards Henry |
halcro, No, I didn't try a stationary grove test. ย After moving the table away from the corner the increased clarity when playing moderately loud music (I probably never exceed 90 dB, unlike some) was proof enough I didn't feel the need to test any further. ย Noticeable feedback (howling) was never a problem although I assume the problem was low level feedback from the pickup being in a high pressure zone area. |
Halcro, Thanks for your very informative post. I had a similar experience with a Vibraplane, which I still use. I have heard the Herzan is effective far beyond the Vibraplane and Minus K. Did you happen to try either of those and if so could you compare to the Herzan? I have followed this thread and am very happy to see this great conclusion. Best Regards, Jim Perry |
halcro, "The fact is, the air-borne energy is not of a sufficiently low frequency (and amplitude) to be a direct consequence." My experience was different. ย My tt is placed on a shelf within an alcove along one wall and built into the walls. ย The alcove is 60" wide. ย Originally I had the tt at the far right end of the shelf which placed the arm/cartridge very close to a corner. ย One day I happened to lean over the tt while music was playing at a moderately loud level, I was amazed by the amount of low frequency build-up I heard in that corner. So after thinking about this I moved the tt closer to the left end of the shelf where the arm/cartridge would be near the mid-point of the length of the shelf. ย That was one of those "you notice the distortion once you remove it" experiences. ย The sonics were definitely cleaned up, at least noticeably in the bass range. ย And so I would always avoid placing a tt in a corner, just to minimize air-borne energy. Mechanical transmission is another story. |
Thanks totem, Herzan USA is the Distributor for Australia (go figure).....so all dealings were directly with Reid Whitney and Tim Rather who were most helpful. The unit was shipped via FedEx (when the custom top-plate was ready) and was here in three days....๐ As I understand it, if something untoward were to occur, it would most likely need to be shipped back to Switzerland where it was designed and built? |
Thanks Norm, Five years ago after Thuchan listened to my system, he suggested I look into an isolation stand and I investigated Minus K (I didn't know about Herzan). The trouble with the Minus K (as you would know) is that it requires the load to be more or less centralised and evenly spread. It can't cope with isolated individual loadings. It's large-scale wobble movement was also rather alarming....๐ฑ I'm sure it suits your turntable perfectly. Can you remind me what turntable you have mounted on it? The degree of effectiveness in using an active or passive isolation platform largely depends on the amount of air-borne energy in the room. That's a common assumption many make but I doubt its validity. Just think about it.......with the Minus K stand, you have not decreased the amount of 'air-borne' energy one iota and as you turn the volume up.....you are certainly increasing it. Yet isolation stands (of all types) cannot prevent the air-borne energy in the room from interacting with the turntable plinth, platter, tonearms and cartridges directly. The fact is, the air-borne energy is not of a sufficiently low frequency (and amplitude) to be a direct consequence. More likely that some of this air-borne energy is absorbed by the rooms structure (including supporting shelves and stands) and transferred via 'structure-borne' feedback. That's why the Minus K and Herzan stands were designed to combat 'structure-borne' vibrations of the lowest magnitude. The Herzan is certainly a 'plug & play' design as you say..... I just hope the electronic actuators and motor controllers have a long and durable life....๐๐ฝ |
Hi Halcro, ย Congras on the Herzan! An amazing piece of hardware we TT owners all wish for. ย I have the Minus K and I have noticed the biggest difference in using this passive isolation platform is when the volume is turned up. You summed it up perfectly โThere is absolutely no strain or stress to any music at any volume and as you turn up the volume...so you want to continue turning it upโ ย The degree of effectiveness in using an active or passive isolation platform largely depends on the amount of air-borne energy in the room. My TT sits fairly close behind my left speaker and sub. Prior to using the Minus K in my system, on one occasion, I was able to make my Talea/Titan jump off the record groove when playing ย โ1812 overtureโ. ย In using the Minus K, the playback sounds consistently beautiful regardless of the volume setting. The beauty with the Herzan platform is as simple as โplug & playโ. The Minus K is a passive system that requires careful set-up (centring the spring, and is load sensitive) to maximize performance. ย ย ย |
When I started this ย exercise over six years ago, I began rather crudely with the Victor TT-81 simply supported on cones. MODEL 2010ย Unsatisfied with the 'flexure' of the motor-unit about the cones, three years later I designed an independent stainless steel cradle to support the now 'fully nude' TT-101 motor unit... MODEL 2013ย Two years after that, still unsatisfied with the vibrational and torsional movement possible with the flimsy steel frame.....I designed a cradle cut from a solid block of black granite and then polished. MODEL 2015ย Despite the fact that my floor is a reinforced concrete slab cast on the ground and the turntable is supported on a thick laminated shelf cantilevered from a solid brick wall.....I know that there are low-frequency vibrations in all building structures and materials particularly materials under stress like suspended floors, shelves and equipment stands. When materials are in stress (particularly tensile stresses)....they actually emit low-frequency vibrations between 2-10Hz and these frequencies are easily transferred through turntable plinths, motor units, spindles, platters, tonearm mounts and thus into the tonearms, cartridges and vinyl records themselves. So for this year....I invested in a Herzan TS-140 Active Isolation for my turntable/armpods combination. MODEL 2017ย This stand is designed for electron microscopes and contains numerous electronic actuators which isolate to 0.5Hz in all six degrees of freedom. HERZANย So what is the difference.....? Exactly what I expected.....but still almost unbelievable ๐ฅ The improvements at first seem subtle but are all-encompassing.... Be aware.....this has NO effect on frequency response, But every frequency SEEMS affected by suddenly having a purity, transparency and 'body' that was somewhat 'cloudy' before the Herzan. There is absolutely no strain or stress to any music at any volume and as you turn up the volume...so you want to continue turning it up ๐ถ I thought perhaps the bass would be deeper or more solid but no.....the bass seems unaffected but all the clarity and delicacy is bestowed upon the midrange and the highs with a singular crystallinity emanating from every cymbal, string, flute and horn. The first casualties of unwanted vibrations in the analogue domain are the tiniest molecular-sized groove modulations which contain the most ephemeral informational DNA. Qualities like body, soundstage, spatial depth and positional indications are simply smeared when other unwanted vibrations are present. So it's been an illuminating and rewarding journey... I hope you all enjoyed it with me.... Am I finally done? I think so ๐ |
Henry, If you will recall some years back in my experimentation I was running three tables side by side. I had each set up well on the concrete slab. Making nice music in their own different and unique way. The test for structure feed back was to lower the needle on a still record un mute and crank the volume slowly. Then jump up and down beside each table searching out air pockets in the poured concrete. You're not a true audiophile until you have danced with your turntable. I then brought out the bad boy. The Acutex 420 str. As naked a cartridge as there ever was. And I teamed it up with wiring that was unshielded except for its own poly covering. What followed was interesting. The Jean Nantais Lenco exhibited a drone like noise. If I remember it was almost mechanical sounding. In talks with JN, I added an extra ground from the motor to the plate but to no avail. I was unwilling to make further mods to his table so that was the end of the road. The Technics SP10 II made noise and required an extra ground. It was added from where the bolts goes into the casing and then into the preamp. This cleaned things up and it was quiet. Almost. My former modded thread drive TNT/SDS drive with pneumatic suspension. An absolutely black silence, as black as the table itself. It revealed a veil in the music that the SP10 was making. As we say - You don't know what's there, until you hear "it" removed. So the 420str is a very good test cartridge - imo. If things pass with that cartridge they can only get better from there. Cheers Have you tried testing the resonance characteristics of the granite pipe? Granite pipe 8^0 |
Halcro Have you tried testing the resonance characteristics of the granite pipe? The material does have a tendancy to ring like a bell. Also by "identically situated" do you mean that you placed the Raven at the same place on the shelf as previously occupied by the Victor? Does the Raven have a suspension? |
Richardkrebs, Is there a secondary issue here?Could there be acoustic feedback following the initial EMR problem?I think you're right.... When I play music at loud volume containing 30-60Hz bass drum beats (like Cream's 2005 Royal Albert Hall Concert or Copland's 'Fanfare for the Common Man' Ref. Recordings)....this 50/60Hz feedback loop can take hold. At the same time I can feel the vibrations in the supporting shelf and in the granite cradle...๐ฑ As the shelf is directly over the Vandersteen subwoofers, this seems like air-borne sound converting into structure-born feedback. But why only recently...and why is the Raven not similarly affected as it is identically situated? |
The cover is grounded by three screws to the frame of the tt. Also, originally there was a ground cable attached to the cover. I have grounded my tt via a new 3 wire pc that replaced the original non-grounded 2 wire line. The new ground-wire is attached to the frame via the circuit-board stand-offs. Also, I highly recommend damping the cover well, including using a footer at the center to drain it. I get zero feedback even when it is too loud to be in the room, and my left speaker is about 2 feet away from the turntable. |
Halcro - if the cover is tight, then I would run an earth wire to the cover and then just push it into the cylinder leaving a gap at the top such that it doesn't touch the main TT. As long as the cover is grounded to discharge any electrical buildup it works. You could spray some damping compound on the inside of the cover if you want to get rid of any mechanical noise. It is also possible that the tonearm & tonearm cabling could be picking up rf from the motor. A small point on earthing - I usually find I get a lower nose floor if I run the TT earths ( i.e. chassis, motor etc ) to ground through the power cable to wall if possible and run only the tonearm earth to the phono/preamp. In a single ended system noise from grounding or shielding is effectively in the signal path. |
Halcro, the can on my tt-101 is heavily damped with bituminous automobile noise suppression sheets, it is also wrapped with a fat rubber band and as I said I use a cone (more like fat cylinders with sharp points) dead center to further drain it. So while it looks primitive compared to the granite clerical collar (but far less primitive than letting it all hang out) it is actually fairly sophisticated. I use a mu metal shield under the platter, covering the motor. |
Hi Chris, It may be the camera angle....? I think the Dyna is riding just fine...๐ I hate removing the word 'Nude' from any sentence......๐ฐ |
Dover wins the Kewpie Doll...๐๐ When I changed the support of my Victor to the steel cradle two years ago, I removed the flimsy perforated metal screen surrounding the 'guts'. Well it turns out that this metal screen was acting as a Faraday Cage for the electrical emissions from the motor power supply. Without the screen absorbing and neutralising this energy.....the cartridge apparently picks up the 50/60Hz emitted frequency at very loud amplification levels (I can't imagine that the platter is vibrating at this frequency?). This is why there is no feedback issue with my primitive (sorry Aigenga ๐) original support system. And yes.....when I place the Victor into the granite cradle with the screen attached.....no feedback ๐โผ๏ธ This however gives me a dilemma.....I would prefer not to have the screen attached as there are audible benefits without it. I also don't believe the screen is as effective (being tight up against the granite inner wall) as I believe a Faraday Cage should have both sides of the metal screen in free air? I have orderred Mu Metal sheet and wondered if this was a possible alternative to the Faraday Cage? Is it OK to wrap the power supply transformer in Mu Metal or will it get too hot? Would it be better to line the inside of the granite cradle with the Mu Metal instead (or also)....or am I doomed to using the metal cover forever? |
I went back to my original set-up from 2 years ago and guess what........ No feedback.....๐๐ Then it dawned on me...... Has it dawned on you.....๐โ |
Henry, I suspect the coupling - 3 rubber grommets are the root of this evil. It won't matter how much mass or how stable the base is, if the coupling is inadequate. Can't say I have a solution, but I'd try something like a thin bead of silicon caulk, or possibly the sealer they use to couple a speaker driver to a cabinet. I wonder what Mosin uses to couple Saskia to the slate plinth. Regards, |
It cannot be air-borne feedback Aigenga.... The stylus is in the groove with the turntable motionless and no music coming through the speakers. When I turn the volume up to a very high level...a low frequency drone begins and then increases in volume without further manual volume input. The feedback begins when the room is in silence...๐ |
Aaaaahhhh....๐ฑ The feedback problem is still there..... Even worse if anything..๐ฐ This wasn't supposed to be like this... In desperation I changed the spikes to more substantial ones and then to Stillpoints Ultra Minis. No difference...โผ๏ธ In desperation I went to the hardware store and stocked up on all possible FLEXIBLE supports. No difference with any of them. This simply makes no sense.... My Raven has none of this feedback at all and it sits on exactly the same shelf as the Victor. Any ideas guys...? I need help...๐ |
I received the granite cradle and have epoxy'd the three Helicoil inserts into the drilled bottom holes to take the M8 stainless steel levelling spikes. Looks quite nice..๐ Bit of a squeeze inside.... But is just as I imagined it...๐ Now for the listening tests..... |
Lew, I have learnt to respect the Victor engineers when it comes to all things analogue. From their DD turntables to their tonearms to their cartridges to their pigskin mats....every product appears to have the ineffable quality of analogue knowledge and ingenuity. I think Dover is correct in his assessment of the plinth construction they used for their quality drives. I have just spent the afternoon at my son's place listening to the QL-A7 (now with the Empire 1000ZE/X). There appears to be little masking or colouration to the sound compared with a 'nude' TT-81. I might add that the turntable/plinth combination is heavy...and I mean boat-anchor heavy. This seems to give to the sound an authority and low-frequency heft that eludes many other decks. My advice (and my Tech's advice) to you is......get a good tech to burn out ALL the old solder joints in the TT-101 circuits and carefully re-do them. If they have already been done.......do it again to those joints on the Power Board Circuit under all the control buttons. An intermittent fault (or one that starts as such) is indicative of a crack or discontinuity in a solder joint. |
MDF today is just timber dust that is glued together.The glue is very expensive so in the manufacturing process they put in just enough glue to stabilise the outside faces of the board. In the centre where there is very little glue there is no structural strength at all. The Victor plinths appear to be more like the chipboard used in speakers in the 70's.This is quite different to modern MDF. From what I can see on the net the CLP2D Victor plinth appears to use layers of chipboard, and from the dark lines I can see, it would appear that they may have used layers of chipboard with each layer being veneered on both sides. The QLA7 appears to be a simplified and lighter version. Fast foward to todays speakers - Dynaudio put forward that they can get a cleaner midrange out of MDF than plywood, but they veneer both sides of the MDF with hardwood veneer to strengthen the board. An interesting material for plinths is Engineered Quatrz stone used in kitchen bench tops. Corian is basically a polycarbonate compound ( includes aluminium nitrate ( salt ) that is a fire retardant ). Engineered stone by comparison is around 93% Quartz stone and 7% Epoxy. It does need special blades for cutting but is much easier and less expensive than slate. Most decent bench top manufacturers use big router beds and if you draw up what you want including holes for TT, tonearm, screws etc they can cut everything for you very accurately. |
I bought my TT101 as part of a "QL10", with plinth and tonearm. I usually find that I hate hate hate the sound of plinths made with MDF, and since the QL10 seems to have a layer of MDF, I took some steps to CLD it by (1) replacing the MDF-ish tonearm mount board with an alu one that is in turn bolted to another piece of alu that runs cross-wise under the plinth. Then (2) I bolted large pieces of alu to the underside of the plinth. I hoped to achieve neutrality via CLD and in the process I added lots of mass. (The weight of the plinth is about doubled.) Sadly, though, I have no idea whether this worked because of the continuing malady of my TT101. |
Thanks for all the feedback guys....๐ Corian unfortunately is a lightweight in the density scales (1.7g/cm vs 3.0g/cm for granite/slate). It seems many of you think the material of this 'cradle' will have an effect on the sound? I hope you're wrong...๐๐ฝ If I were to physically 'bond' the turntable to the granite, I'd be inclined to agree with this thought but I intend to simply 'rest' the table on three rubber pads just like those on the steel cradle. I have experimented greatly with differing methods and materials in the support of this turntable. I have also recently bought for my son, a Victor TT-71 factory mounted in a heavy wood plinth and compared the sound in detail to my 'nude' mounting. Whilst the superb drive and timing of the Victor decks is untouched by the coupling to the heavy wood, there is a very slight (but inoffensive) colouration to the overall palette which is absent from the 'nude' mounting. There is little doubt that there is truth to the theories of resonances in materials and the effects of combining dissimilar materials to mitigate these resonances. I have my theories regarding the pervasive evil of structure-borne feedback in the turntable loop of analogue audio and the methods for handling it.......and I'm putting my theories to the test...๐ I'm not a believer Pryso, in the relationship between the 'ringing' of a material when struck and its performance in resonance dissipation and absorption. Polystyrene beats most materials in the 'ringing' test but is not ideal as a plinth material. And yes....I've tried it ๐ This exercise is not about developing a plinth for my 'nude' DD Victors. The sound of the 'nude' Victors is unsurpassed in my listening experiences. This is about adding mass to my turntable support to prevent it sliding on its supporting shelf. If there are any detrimental sonic changes....including colourations....the 'cradle' will be back...๐ฅ |
09-14-15: HalcroHalcro in my view you should purchase another QLA7. Based on your comments above this would give you a benchmark to aspire to. If you could duplicate the arm/cartridge then you will have a "constant" against which to analyse any mods to your TT101. |
Corian might be ideal. What about the material used by Kenwood which people call faux marble. It's ARCB - Anti-Resonance Compression Base. It makes up the plinth of the KD500, 600, and is used in the L-07D. Contrary to popular belief, it's a mixture of ground limestone and polyester resin. I imagine you could add liquid acrylic pigment for the color of choice. I think this could be sculpted like clay or put in a mold. You might find the best solution is a combination of materials - resonances tend to cancel. |
