ok so here goes! I don’t claim to be an expert in the more technical aspects of electronics, engineering or materials science that may go towards the design and manufacture of hifi turntables, but these are a few of my findings. I shall fast forward over the last 40 years during which time I cut my teeth messing around with vinyl players and focus on more recent times and developments. I didn’t buy my first serious hifi turntable until my Manticore Mantra in 1989, but within months I already had the bug and ‘upgraded’ to a Xerxes Mk1. It was good, but as I upgraded amps, arms and cartridges, it didn’t take me long to discover that this deck was a somewhat resonant structure and that some of the design features were in fact combating the inherent noise floor within the deck. I found this to be interesting rather than a disappointment. To my mind there was simply more information and performance lurking inside the basic design. I bought into some of the factory upgrades and introduced a few of my own. Another interesting thing was that even when I talked to Touraj the decks designer at a Roksan event about my tweaks he was not dismissive, but gave me good advice on how not to impose restrictions to free movement on the decoupling suspension ‘blobs’. He seemed to be genuinely more interested in the theory behind his designs than the fact I was messing with them. My Roksan has evolved quite a way since those days and is becoming more TMS than Xerxes, but see how the design evolved into the Xerxes 10 and now the 20 plus. I still have long term plans for my old Xerxes, but my more recent interests lie with some of the old style spring suspended turntables I acquired in parallel to my Xerxes as I became a hifi hoarder. The other two decks I am currently modifying and continually tweaking are a Systemdek IIX and a Walker CJ55 (the all wooden turntable). Now there is one key component I have discovered for myself, which has probably occurred to a few big hitters in this game. Namely that the internal subchassis, skeletal framework, or substructure, call it what you will, that is suspended inside those wooden boxes IS effectively ‘the turntable’. That might seem obvious to many or some, and see the more modern stripped down skeletal designs from the likes of Rega, Kusma and Nottingham, but if you look inside earlier AR, Heybrook and Thorens designs and these sub structures appear to be secondary to the large wooden box they float inside, either hanging from coiled metal springs. Later Thorens did develop a trapezoidal steel plate sub which did introduce much more triangulation with turned down edges for vertical rigidity, if not quite able to remove all the resonant properties in pressed steel. Interestingly Heybrook upgraded their TT2 from the old pressed steel crucifix which separated spring from main bearing and arm board to a braced alloy structure, which looked like the kernel of an idea for Linns Keel. I don’t know who thought of it first. Linn’s coffin shaped steel subchassis evolved with a spot welded brace to a bonded brace, which they must have noticed made a big impact. Now see how Linn have three different subchassis designs which evolved from their original steel pressing; the Majik, Kore and Keel. Each have a demonstrative effect on the decks outright performance. Some people balk at the price of these components, but if you changed your thinking to the idea that you are possibly effectively buying a ‘new turntable’ the prices don’t look quite so silly. So how did I also reach the above conclusion? A few years ago I bought my Walker without arm as a test mule. What I’d read about the Walter with it’s Tufnol platter and all wood construction intreagued me. Some reports said it was a Linn beater! But I thought maybe only if you were deranged enough to bash a Linn deck with the Walkers wooden plinth......it’s quite a solid item. Unfortunately the all wood skeletal subchassis is not so solid, and to my ears the sound was quite a disappointment. Then I hit on the idea of making my own subchassis for the walker using more solid wood construction and utilising the same suspension points. As luck would have it a carpenter friend gave me a slab of inch thick top grade birch ply. After many hours I had fashioned a working sub plate which fitted perfectly within the outer plinth. The original conical (comical!) springs also carried the extra weight with simple adjustment. I used a Jelco arm from a Revolver fitted with a 2m Red. Even with this basic arm the sound had been transformed with much more bass, weight and depth. The arm did get a bit ‘spitty’, but Incured this by looping some pvc tape halfway along the arm tube. Also rigged my Roksan Tabriz unipovot counterweight onto the Jelco. But it was becoming clear to my ears that the original MDF armboard was a limiting factor. I had a large offcut from a kitchen worktop made from medium hardwood blockboard. This offcut is over 30 years old now and is ideal for fashioning turntable parts from. I made the new board 22mm thick with a Rega cutout so that I could upgrade from the Jelco. Instead of the triple bolt fixing of the original Walker arm board I used a single central point fixing with an alloy puck so that torque within the wood could be minimised. Infitted an old RB300 with an early Elys cartridge. The sound from this set up was a revelation to put it mildly. If you can recall the first time you heard a Totem Sky bookshelf speaker, such was the new air of clarity. My thoughts immediately turned to my Roksan Tabriz ZI fitted with a 2m Blue MM. If the Rega was good the Tabriz would be even better. I was not disappointed and the Walker as it stood was now matching my modified Xerxes for sound, if not the pitch stability of the Roksan’s XPS7 motor controller. With what I had learnt from my Walker I turned my attention to my Systemdek. This had never been a very good example of the breed to my ears, sounding a bit turgid and slow, even with my Rega arm. It was no where near the quality of a friends IIX 900 with RB250 and 1042. I looked at the extruded aluminium sub chassis, which is basically an alloy channel with some outrigger springs. Thinking about my slab of seasoned block board, I decided to make a wood/alloy sandwich (Images of Rega and Dr Freikert bonded structures forming in my head). The slab of wood didn’t take long to carve with cut outs for almost the standard fittings. I also made a new armboard out of my own wood with a cut out for the Jelco or Linn. The first attempted slab wasn’t fixed by a few small blobs of blue, but was mainly held by screws from above. As with the Walker the revised Systemdek was a big improvement even with the basic Jelco and Ann old AT110 MM. I then made some improvement since and fitted my Linn Ittok with my 2m Blue. The results? Wow! This deck was going places! I noticed that SQ was affected by tension in the screws fixing the wood slab into the subchassis and concluded that an all bonded design would work better. Similarly with the arm board I reasoned that the Linn arm base might work better if it wasn’t simply fixed by three blobs of contact adhesive. There is possibly a case for just gluing a cartridge to the head shell to remove all forms of stress, but I fear over stressing the arm when I want to lever the cartridge body off again. Another aspect of the Systemdek is the spring mounts. The spring at the opposite end to the arm is bolted to a weighty metal block. Maybe this was meant to counter the spring resonance? The two outrigger springs are fixed to a cross bar which actually sits below the subchassis mounted below two hard plastic sleeves. If you tap these sleeves they make a ‘clack’ sound, but when a loop of PVC tape is put around them they make more of a ‘clk’ sound. Less ‘ack’ means less resonance in my book! So what did the revised IIX sound like? I’ve witnessed how the performance of the humble 2m Blue has evolved with each tweak to this deck. Now it sounds more like my moving coils than a moving magnet. Such is the effect of removing the mechanical nature of the sound I had started with. I am convinced that the quality of the subchassis IS key to unlocking the performance in some of these decks. Admittedly much of the SQ enhancements are down to the particular lump of 30+ year old seasoned hardwood blockboard, I would predict that any similar hardwood such as Teak, Maple or Elm would have similar benefits. Unfortunately we didn’t get to compare my IIX/Ittok with my friends LP12 the other day when I visited him to borrowed his pillar drill. I had to dismantle my deck to use the Linn’s arm base in fitting out the next arm board I am making for my next Walker upgrade. Then what larks!
My apologies for the many typos in the above post. The iPad it was composed on has a weird predictive spell checker which seems to have a mind of it’s own in spite of my own proof reading and correcting. Obviously there was a lot more to my tweaks than just fixing bits of wood into existing turntable structures. There was a good deal of trial and error getting the shapes right as well as experiments with different methods of fixing and set up. The important thing with the wood used is that the block board consists of bonded blocks with alternating wood grain patterns. Like ply woods the alternating grain direction cancels out the negative effects of one large single grain block and the resonant energy paths this is likely to create. Birch ply was used in the Walker sub chassis only, but a ply arm board might have created equally impressive results. The IIX’s new arm board is 12mm thick instead of the standard MDF’s 8mm. The main bearing was also raised with a large copper washer to give the suspension more room. The standard bearing screws were used, but some suggest gluing the bearing housing with Araldite. Maybe next time. There are some other minor tweaks in there I’ll keep for a rainy day. It’s often a case of trying anything that comes to mind. After all ‘everything’ makes a difference. Both decks still have their original and basic UK 50hz mains unregulated motor supply. Not that this seems to be a big minus. Admittedly they sound better late in the evening and through my mains conditioner lead and 6 way block. I think that the musicality of a turntable often has as much to do with the ‘compliance’ of a turntable structure and components as much as the nth degree of motor speed control. You cannot measure this, but you can hear it and demonstrate it compared with decks that are or like these two were lacking musicality.
To some extent you're iterating well-known conclusions about (at least in part) the manner in which sub-chassis assemblies are engineered and why they're engineered in that way. But there is implicit in your posts the idea that all turntable designs (there are many that, again implicitly, seem to be unfamiliar to you) rely on a sub-chassis for magic. That is not the sum of your posts by any means, but the point of discussion that you have in mind to invite seems unclear. That leaves the question, what is it you wanted to discuss? Or maybe I'm just a bit dense and missed the point?
My apologies if my motives are not clear. I am not implying a need to discuss anything in particular, perhaps just a wish to share my joy of discovery! However, now that you ask; in sharing my experiences of DIY I am also reiterating a point that the combination of turntable materials and design can have a big impact on how cartridges perform (given a half decent cartridge to start with) rather than as some on here claim that turntable performance depends entirely on the cartridge to the exclusion of everything else, and particularly anything else with a drive belt. I am also trying to bring encouragement to others who may not be able to afford a ‘superdeck’ of their dreams, but who also harbour ideas of significantly improving an existing turntable for minimal cost. No I am not saying that a sub chassis deck is the only way to reach Audio nirvana. These just happen to be the type of deck I am currently experimenting with. My observation about the ‘core’ (ha!) of a sub chassis in suspended decks being the heart of the matter is something that appears to have been overlooked by some. Just how much gain can be had from lowering the ‘noise floor’ and how much that floor can be lowered has surprised me, and I’ve been doing this for quite a few years already. This is also an object lesson in how not to be taken in by the external aesthetics of a solid looking plinth or claims that any particular turntable design has all the bases covered. I plan to further develop my Roksan, which is not a suspended design, and to build a DIY plinth Lenco L75, which is a completely different idler design. Some of the knowledge gained in the use of wood materials will be useful in these next two projects. I’ll give the last word of this posting to my partner who can hear the differences in my current Systemdek from the other end of the house on a different floor and through a closed door; “I can hear everything you are playing, the sound is so clear now”.
EF7 B7 E7 C ABF4 4 ECD A477 A901 F9530105 — Postimages Hopefully the above link will show an image of my DIY subchassis for the Walker CJ55.
Hurrah! If you click on the link, the spindly wood frame at the rear is the standard Walker subframe. The lump of dark matter looking like a prop from StarWars in front is my DIY sub made from birch ply.
Wow. I actually just finished reading Tolstoy's War and Peace, but I couldn't make it through the second paragraph of your post. I hope others will have more fortitude!
F31 B173 B 6 E45 4 DCD 84 FC C70 B49 DD9 E21 — Postimages Same again, but different! The above link shows the modified Xerxes base. Original mounting points for the blobs were cut out to make 50mm holes through which TMS suspension towers mounted on a new base underneath now support the top board. The original top board and wood surround are then fitted as before on top of this set up.
Hi Edd2b As a Mk1 Xerxes user, just interested in what other after market upgrades you’ve done to the deck. I’m not into chopping up my Xerxes but I can see the appeal of the TMS blobs!. I’ve had the top plinth flattened so no sag, new motor fitted by Roksan (old one had issues after 10 years storage), the better blobs, new ball bearing. I’m using Origin Live’s belt (gnarly looking), and bearing oil. PSU is the XP7 also. Still have the original feet, but I use a wall shelf (target TT1). So anything I’m missing that you’ve tried? If you get to the end of the line with the plinth, you might want to investigate a different tonearm to the Tabriz. I originally had a Tabriz on the deck, but after demoing a Vertere MG1, tried their SG-1 tonearm on the Xerxes, and found it a quite stunning. Keep up the good work
Cheers Mr T. I started looking at converting my Xerxes to a three decker like the TMS 25 years ago. My dealer was offering the upgrade to a Xerxes 10, but at £850 I thought it was a bit steep so I hit on the idea of making my own improved Xerxes. My first tweak was to install some silicon dampers to the underside of the Xerxes top board. These are in the position of the upturned grey plastic lids you can see stuck to the motor base. I fitted short M6 cap bolts screwed into 5.5mm holes drilled into the underside of the armboard. Small washers are glued onto these bolt heads and these are immersed in the plastic lids below which are filled with silicon damping fluid. I arrived at a suitable position for these dampers by placing the dismantled top board on a test jig attached to a vibrating motor. I covered the top board with salt granules and watched the granules dance about so that I could see the nodes of highest vibration. This tweak was very effective as quieting down armboard resonance. The top board sag is something I never found to be an issue. Mine had 1mm of sag in 1989 and after 32 years the sag still measures only 1.31mm . I think this may be due to my deck being kept in cool dry conditions. I have an allergic asthmatic condition which is why I love fresh air. However Roksan did observe at one point that it is normal for the Xerxes Mk 1s sag about 1 MM in the first few years then sag very little afterwards. Maybe early boards sag less as the veneer and finish looks slightly better than later models. Whatever the truth, the sag does not appear to me to affect the horizontal alignment of the arm headshell relative to the platter as this axis is 90 degrees to the direction of sag. I have a spare top board with zero sag so that is likely to outlive my current earthly tour! That spare top board came from a complete surplus set of Xerxes woodwork I acquired in 1997. I wanted a spare chassis so that I wouldn’t have to butcher my original deck, which is a very early 1985 model. The modded base came from an 86 model. I had a new chassis base made from two thicknesses of MDF to mount the TMS isolators onto. I used the spare mk 1 blobs I had (after upgrading to my 2 blobs early in 1990) to support the motor board above the new base, so the motor is completely isolated from the armboard by ‘blobs’ of some kind. The current top board is resting on TMS 3 blobs with Xerxes xb3i top rubbers. I bought these before the prices got silly. The bigger domed isolators under the blobs can be found in industrial isolator catalogues. I had to experiment to find the right grade as they come in 3, 6 and 9kg loading. I forget now, but think the TMS ones are 9kg. If they are too soft they don’t work right and become energy storage devices rather than dissipators making the bass erratic and the upper blobs unstable if that makes sense. My plan is to try to replace as much of the MDF in my Xerxes with hard woods. I am making a complete new top board for mine (like ‘Inspire’ do in plywood), but hopefully mine will be even better). I keep looking online at the various mods Roksan has made over the years and try to mimic these changes. Roksan have made a set of solid brass ‘mass dampers’ which are a retro fit to TMS models. Roksan claim that these boost signal to noise ratio. I will try to copy these at some stage. I am trying some experimental ones made out of hollow door stops on my Walker, filled with small decorative rocks would you believe? These sit each side of the main bearing. I was toying with the idea of fitting my Xerxes platter parts onto my Walker. I also have a later 24 pole Roksan motor which I could also fit. A ‘Rockler’ or a Walksan’? I did fit a TMS ball into my Mk2 Xerxes bearing, but I’m not sure if it’s an improvement. I just refused to pay £771 for a whole reference bearing. I think there are better ways to spend my money. I like the look of the new Sara tone arm so that might be a future purchase. Sadly my XPS7 just died on me earlier this year so I am back on the old XPS1. Getting fed up with Roksan so I might try the Heed Orbit 2......oh wait a minute, I think that the XPS7 was actually made by Heed!? I was looking at Vertere speed controllers, but those are pricy! I do have a TMS 1 controller, but it needs some work to build it into my deck or into a stand alone box. I already have a DS4 power supply. The problem I have is that I need 3 controllers tailored to my Xerxes, Walker and Systemdek. Yikes! Hopefully I can post pictures of developments soon. Thanks for the comments.
For the sake of detail if you need to know; The bolts I used for dampers are actually M5 cap bolts 20mm long screwed into 4.5mm wide holes drilled 7.2mm deep into the underside of the top board. The washers glued to the bolt heads are M5 to allow a hex key to turn the bolts. The plastic cups for the silicon are old Kodak film bottle caps. The location I chose for these, looking at the underside of the top board, are 100mm from the centre of the arm socket and 20mm inboard from the edge of the leaf cut. The second is outboard of the leaf cut in the rear corner of the board 83mm from arm centre. I guess that these are approximately the two most remote and unsupported points of the board, which is why they resonate most. Of course I cannot guarantee that others will see or hear the same effect as on my deck, but two small holes you cannot see will not be a terminal mistake to make. Spilling the silicon fluid is messy though and you need to remember this every time you move the deck or lift off the top board.
79335 A36 633 B 4 ECE 8 BF1 3 A67 A1465 AD3 — Postimages Another tweak to my Xerxes, if not exactly to the deck itself was my DIY glass support plate. This is 10mm thick plate glass slightly larger than the footprint of the three feet of the turntable base. I matched the position of the original feet for my new base. The inner black triangle of PVC tape is to control resonance in the glass. The plate sits on 12 Michel sorbothane ‘Magic Feet’, which are distributed to support the asymmetric loading of the turntable on this support. I use this support for my Xerxes wherever it sits. There just happens to be a large stoneware tile underneath in this picture. This does seem to improve the sound on occasion, but it’s not essential. The glass plate was knocked out by a local glass supplier several years ago for £27, while the Magic feet were bought for £7 in a sale at a hifi show.
My original Xerxes, became unusable due to plinth sag within a couple of years of purchase, funny how in those pre internet days the retailer and I guess Roksan acted like mine was unique and nobody mentioned it was a very common problem, I still have it and occasionally think I should do something with it, I'd love it to sound like it did in '86. Although I have other excellent decks I missed the sound of my Xerxes and eventually gave in and bought a used Xerxes 10 with the high spec power supply, I added my Artemiz, upgraded with the Artemiz II kit and it's a really nice deck that is very close to my Michell Orbe/SME IV, but even though it's an obviously better sounding deck the Xerxes 10 doesn't have the more coloured Roksan sound of the original Xerxes which is something I miss at times. My Xerxes 10 does sit on an isolation platform with sorbothane feet and does seem to benefit from it, I'd like to try one of the extra layers Roksan used to sell and see if that adds even more benefit.
Interesting story Dubmart. My 86 model came from a guy who upgraded to the 10 in 1997. You can see Touraj’s initials on the test label of my motor board dated 28/04/86. Strange that the top board this came with had zero sag after 10 years. Maybe he kept it stored in a cold attic for most of that time? Or maybe he did cough up for a replacement board? Whatever, there do seem to have been some real problem decks out there with 2, 3 or more MM of sag and plinth dragging platters! It would be interesting to know if your old Mk1 had upgrades such as the Mk2 main bearing, which I think was £180 in 1989. The Mk2 Blobs were £28, and the XPS 2 conversion of the Mk 1 speed controller was £100. I was lucky in that the previous owner on my Xerxes had already paid for the Mk2 main bearing. I still have an older Mk 1 from my spare chassis on the shelf so I could retro fit that to see if I get a more ‘glowing’ sound? But if you are keen, you could try a 10mm plate glass triangle under the Xerxes 10, like mine. I was trying to get some of the ‘Mana’ sound frame effect on the cheap. I took a card template in and the glass company cut it out and polished the round edges in less than 10 minutes. A possible ten MM for your ten in ten! Boom boom!
Back in the mid-eighties I lusted after a Pink Triangle as to me it blew the LP12 away, but even the people I knew who used them warned me off due to reliabilty issues so when the Xerxes came out it was the answer to my prayers, a genuine high end deck, better than the Linn, (IMHO), cheaper than the Linn and more reliable than the Pink Triangle, (I thought), I probably had a demo soon after my local dealer got stock in, ordered one, with an Alphason Delta arm and started saving. My Xerxes is bone stock, even the original power supply still works, well it was working, other than having the plinth sag fixed, or rather not, (this must have been before the shim kit), I'd upraded the arm to the Artemiz and the cart went from an Ortofon MC10 to an MC30 Supreme, when it was working I absolutely loved that deck though I did have TMS envy. With my Xerxes unusable I bought an Ariston RD 90 Superieur as a stop gap, fitted the Alphson arm and a Linn K-9 and it actually did a pretty good job though it was no Xerxes, late nineties I got a Michell Gyro SE, then an Orbe, sold the Gyro partly to fund the Xerxes 10 and have also gone very much down the vintage idler route; 301, 401s, G-99, TD-124, but that's another story. Having spoken to Touraj I don't think he quite gets what a problem the sagging was, but I don't hold that against him and have bought the rather nice Vertere phono stage and would happily buy a Vertere deck if I could afford one.
87097488 DD9 A 4 A8 E 9 F0 F 932 AAF30914 C — Postimages Better late than never. The above link shows my silicon damped bolt heads and washers on the underside of the Mk 1 Xerxes arm board. The M5 bolts self tap into 4.5 MM drilled holes. Simple, cheap and effective. Although I was considering upping the size of the washers to make them more effective prior to switching to a less resonant type of wood board entirely.
Yes I’ll probably be 84 before the paint finally dries on my Walker plinth! 5 A83 A095 7 E35 4457 9 EBF 5 E5 BD5 DDC287 — Postimages Meanwhile above is the link to my new Linn cut arm board for the Walker finished in Tetrion Matt black. I should have done the complete deck in this paint! The alloy disc in the centre is my novel arm board clamping device. The centre bolt is tightened into the threaded clamp and tension is applied to the arm board by fine tuning to the sub chassis with a hex key or you can turn it with the o ring or both.
Cheers Mark! I decided to put another coat of paint on the Walker plinth so can’t show that yet. And I discovered that a Xerxes main bearing will fit my custom sub-chassis for the Walker using a stepped sleeve insert. Oh oh! What have I started? Meanwhile in a sort of Roksan retrospective the link below shows the third layer to my 3 tier Xerxes. 70 C5806 B 3 D3 C 4 E86 9 FF4 35585277 D281 — Postimages The TMS style towers are positioned as normal to fit the standard MKI Xerxes Top plate. These towers are simply glued to the top of the new base board. The shorter Mk 1 blobs support the original base board holding the motor, and look randomly placed, but did require some thought. The two blobs on the left are positioned equidistant from the motor to aid isolation, but provide stability, while the third small blob to the right is far enough away to complete the triangle and provide longitudinal support. These blobs are also countersunk into the new base to provide the correct height for the taller TMS ‘towers’ supporting the top board. One doesn’t need to go to such extremes to improve an old Xerxes. Once I had the template of the standard top plate/arm board, call it what you will, I could try a number of alternative materials to experiment with the sound. I’m even thinking of cutting out a larger stepped hole in my spare top board where the arm socket is to fit a Xerxes 20 style arm plate. I could use interchangeable plates of different wood, alloy or an acrylic material. There is also scope for raising the level of this plate to minimise the height of the arm base once VTA has been established. I’ve always wondered if and how lengthening the arm pillar might compromise the sound.......or not. Do taller arm pillars improve the sound of some decks?
42 D668 AD 1 A02 423 A A1 B7 49 A30 F285420 — Postimages The above link shows how the TMS style towers extend from the new base through the original Xerxes base board. One benefit of my three decker over the standard Xerxes or TMS is that the cut always next to the upper blobs allow easy finger adjustment of the top board level by removing the standard wood surround.
741770 E2 5 B4 B 4 FB2 B3 FC 08262 FE459 ED — Postimages And 3, the standard top board sitting comfortably, if a little exposed until the wood surround is fitted!
