IME, not only the choice of material, but how the material is processed has a significant effect on the sound.
Again IME, the descending order of sonic quality is: 1 machined from solid billet, 2 extruded into approximate shape then machined, 3 forged, 4 vacuum or pressure-cast, 5 sand cast.
I should also point out that the phosphor bronze alloys used in machining are different from those used for casting (higher tin and lead content).
hth, jonathan carr |
Hi Henry.
By building, listening and measuring, not only to my own designs and prototypes, but those of other designers also. Subsequent discussions with yet other audio designers and retired designers have suggested that we generally agree about the ranking.
Compared to machining, casting is cheap if large numbers of parts are to be produced, and therefore would be most attractive to a manufacturer such as myself. This is particularly true when the shapes get complex, which drives machining costs up, up, up. Unfortunately, so far I haven't been able to convince myself to use casting for anything more demanding than an active digital cable enclosure.
How many materials? Off the top of my head, aluminum(s), magnesium(s), brass(es), bronze(s), iron(s), copper(s), titanium(s), stainless steel(s). Probably more if I jog my memory.
BTW, none of the above necessarily means that you and I would come to the same conclusions. It very well could be that your audio system and listening habits are different enough from mine that we'd have to agree to disagree.
cheers, jonathan |
Lew, when it comes to choice of material rather than choice of processing, it is harder to say what is better, and what is less so.
While audio design is predominately about engineering (or should be, IMHO), there is also an element which is similar to cooking, or matching clothes.
You pick a design direction which you think is technically correct, decide on a building method (including materials) which you think is likely to bring you the benefits in a cost-effective manner, listen to the results, then assess what needs to be added, subtracted, or changed. If you make a wrong decision at any stage, chances are that the resulting product won't do particularly well in the market. Build it, and they will laugh (grin).
What the above also means is that, the design direction affects the choice of materials, and vice versa. My preferred material choices are affected by my design direcions, and undoubtedly the same is true for other designers. There are some materials which, when used as structural materials, don't particularly sound good for my ears and my designs or operating environments. But these same materials seem to work fine for other designers and how they operate these materials.
When it comes to subjective choices, there is no "right" or "wrong", in the same way that chocolate isn't "better" than tomato, nor the reverse. You may listen to a material or component and like it, I may disagree. But if it produces the sound that you are aspiring to, that is what should matter the most to you.
FWIW, I also agree fully with Daniel and Travis regarding outboard arm pods. When you play a record, what you are actually doing is measuring it against the platter and spindle. Mounting the tonearm on a separate pod allows relative movement to occur between the tonearm pivot and the platter / spindle, and this will interfere with the accuracy of measurements.
I acknowledge that in some situations the tonearm may be picking up environment vibration, which will affect the sound, and some listeners may be reacting to that. However, what this strongly suggests is that the plinth design offers inadequate environmental isolation. I suggest that a more elegant, and technically correct solution is to mount the tonearm pivot and platter / spindle onto a single rigid structure that allows everything to move together at the same rate and same distance (and phase), then isolate the complete system from the environment by means of an isolation platform (not footers). Even better would be to add an acoustic shield around the turntable so that it doesn't get affected by the sound pressure from the speakers.
Lastly, you may find it interesting to study grounding theory in amplifier designing. There are strong parallels to what is being discussed here.
hth, jonathan carr |
Dover: For whatever reason, cantilevered armboards appear to increase the bass volume and power, compared to non-cantilevered armboards. This is from my own experience, as well as from discussing these issues with other turntable designers.
Still, if I were to design an ultimate turntable, it would have a low-noise platter bearing, an ultra-rigid connection between platter bearing and tonearm pivot (ideally machined as one piece), a helluva lot of moment-inertia in the platter, and even greater moment-inertia in the plinth (which would be designed for low structural and cavity resonances).
The complete turntable would be integrated with a self-levelling air isolation platform, which would rest on a stone column that goes directly into the ground, without any contact with the floor of the listening room. Surrounding the turntable (but not contacting it) would be a double-wall acoustic shield, vacuum-evacuated between the walls to minimize energy transmission.
cheers, jonathan carr (using 60kg solid zinc plinth to connect platter to tonearm) |
In general, I try to avoid commenting on things that I have no hands-on experience with, or at the very least, have never discussed with another designer who has had hands-on experiences with the topic in question.
This thread is no exception to my policies. I have tried and listened to independent arm-pods on multiple occasions, spanning from the early 1980s to earlier this year.
Any dissent that I may have voiced for independent armpods or other design particulars espoused in this thread, is based on a combination of personal experience (including listening), engineering training, and study and analyses of other turntable manufacturer's design efforts.
Everything that I have learned and experienced about turntable design (particularly regarding DD) suggests that the plinth should have very high moment of inertia but with as few structural or cavity resonances as possible, and as small diaphragmatic area as possible, while the tonearm mount should be non-resonant and completely rigid in relation to the platter so that there is no possibility for relative movement between the LP and tonearm pivot. The reason is that if any relative movement occurs between the LP and tonearm pivot, the cartridge has no way of distinguishing whether the relative motion comes from noise or vibration in the environment, or is part of the LP groove.
This should be accompanied by full isolation from structure-borne noise and vibrations from the environment, and preferably full isolation from air-borne noise and disturbances from the environment.
Some of the posts in this thread very clearly suggest that the poster isn't hearing distortions that should be quite measurable and audible, or that the sound of their system is deemed to be preferable with those distortions present.
cheers, jonathan carr (hugging a pneumatic isolation platform - grin)
BTW, if you place equipment between the speakers, you create an acoustic problem for the speakers, not only a vibration problem for the turntable, CD transport or electronics. IME, if you must place equipment between your speakers, it should present as small of an acoustic profile to the speakers as possible, and should be placed as far away from the speaker's radiating pattern as possible. |
Dear Halcro:
Regarding what I think is the overall point of your post, I agree that everyone has and should have the freedom to listen to the sound that they like.
Regarding the Olympos, I should point out that the Titan-i is the more neutral, better-performing cartridge, but it is more demanding of setup, and it is more demanding of partnering equipment.
>If you've ever heard what room 'volume' can do for your sound, you'd select that over most other parameters I believe.
I have friends and business associates that I visit frequently, with big listening rooms that are acoustically shielded, structurally solid, and receive electricity from dedicated, 3-phase power lines. I agree that room volume is good, but past a certain point, I prefer proper mechanical, acoustic and electrical setup, and I prefer close listening proximity to the speakers (and a speaker that allows this). The air between your ears and the speakers is a great sound absorbent (filter), and you can tell a lot more about the faults of your system and components if you can listen from within, say, 1.5 meters from the speakers (although I try to stay closer).
>The greatest changes I've heard to my sound over the last 2 years is in fact in the reduction of distortions from the turntable.
If you use a DD motor and you don't have much moment-inertia in the plinth, you will be creating a form of noise which is somewhat similar to the background noise of an LP (but is a separate, distinct phenomena). FWIW, Sansui designed a couple of contra-rotating turntables specifically to combat this distortion without requiring so much moment-inertia in the plinth.
If you have a tonearm mount that allows relative movement between the LP and tonearm pivot, you are also creating distortions.
And if the turntable shares the same acoustic space as the speakers, without structural and air-borne isolation, you will again be creating measurable, audible distortions (although the magnitude of the problem depends on how much acoustic or structure-born energy the turntable receives).
You can quantify the difference by making a high-bit recording of your turntable without the speakers playing, and with speakers playing at your customary listening levels, and compare the two files. If you put the two files through a program such as DiffMaker by LIberty Instruments, it is possible to extract the difference component and listen to it as a distinct "distortion" track.
There are reasons why I said that some of the posts suggested that the poster wasn't hearing distortions that were almost certainly present, and should be quite measurable and audible.
>major reduction in analogue distortions to my ears, has been the switch to MM cartridges over LOMCs.
My experience is that MM vs. LOMC is largely a phono stage and tonearm issue. LOMCs need a good phono stage, they need as few electrical contacts between themselves and the phono stage as possible, and the low-compliance types need a suitable tonearm that can sink a lot of mechanical energy without becoming perturbed.
I have heard (or own) some MMs that I rate fairly highly, but they still leave me somewhat wanting. OTOH, I do believe that MMs or MIs have more performance potential than most previous efforts have been able to demonstrate, and in the future, I hope to be able to design an MM or MI cartridge that shows this to be true.
>Now you obviously do not hear these distortions so I'm not sure that a meaningful discussion between us on that topic is achievable :^(
It would be more accurate to say that I hear other distortions from MMs or MIs that annoy me even more (^o^).
>I find far greater differences in cartridges than in drive type and I admire those who claim to hear those differences.
Interesting, because I've designed and built various turntable power supplies, control systems and drive amps, and I assure you that the difference between topologies and components (semiconductors, capacitors, rectifiers etc.) is quite audible. And that is without changing the particular motor or drive system under test, let alone the drive type.
>I can't stand the distortions I hear in digital reproduction yet most here, can happily live with them?
I hear a different set of distortions from digital than I do analog, but both have audible distortions. Open-reel tape has audible distortions, and recording microphones do, too (smile). FWIW, my experience is that the transport, DAC and line preamp all have a significant effect on the reproduced sound quality from digital audio.
My present digital system is capable of playing back 384kHz 32-bit studio master-grade recordings, and the transport is a dedicated solid-state device that runs in synchronous clock mode with the DAC (effectively eliminating or at least drastically reducing jitter). At this level, digital doesn't sound so bad (^o^).
>We all are different and all our experiences are valid.
When it comes to subjective preferences, everyone is free to choose whatever they like (and for whatever reason). But let us also keep in mind that not everyone who dissents is an armchair critic, Sunday designer, or lacking in the experiences that make others go ga-ga.
>This is a 'discussion' Forum and the more we have.....the more we can possibly learn.
If the discussion presents dissent as well as assent, yes. Assent only, not so useful.
kind regards, jonathan |
Hi Nick:
20 feet (from preamp to poweramp?) should be OK for preamps that have good output drive capability and low output impedance. With preamps of higher output impedance, you may encounter some high-frequency roll-off. This effect can be minimized by making sure that you use as low-capacitance interconnects as you can find. I think that Blue Jean Cables offers some interconnects which prioritize low capacitance.
IME, the acoustic problem from having big, acoustically reflective objects between the speakers is a bigger problem than needing to use long interconnects. Having big objects between the speakers really does mess up the soundstage and imaging big-time, with lesser (but still significant) damage inflicted on instrumental timbres and dynamics. If you absolutely must have your equipment rack between the speakers, I would try to get the rack and equipment as far behind the speaker baffles as possible, and get the equipment or rack's highest edge lower than the speakers' tweeters, preferably the midrange also.
If you can't disassemble your rack and reassemble it to get it lower, perhaps you could keep a thick blanket handy to throw over the rack and gear when the speakers are playing. This won't be as effective as opening up the space between the speakers, but it will give better results than doing nothing.
One more simple setup technique that I habitually use is to experiment with the rake angle of the speakers front baffle. Changing the rake angle of the front baffle will modify the time-alignment between midrange and treble (unless you use full-ranges), and can be used to alter the perceived height of the soundstage center, and the tonal balance. I find that most people seem to find the sound most comfortable if I adjust the speaker rake angle to bring the vertical center of the soundstage to approximately ear level.
Note that if the angle of the left and right speakers is different, you will introduce a height skew to the left and right sides of the soundstage. Making sure that the left and right speakers have identical vertical rake will give better imaging focus and soundstage depth.
hth, jonathan carr |
Dear Halcro:
I have a pair of HD800s, and a pair of K1000s. And a hand-selected pair of Stax Lambda Signature Pros. However, I don't particularly enjoy the physical sensation of listening to headphones in general. I agree with you that headphones remove room and speaker artifacts, however they introduce other artifacts and sensations of their own.
>There are no theoretical arguments which can turn 'black' into 'white'.
At least my arguments haven't been merely theoretical. I have had a variety of experiences, and performed a variety of experiments with armpods, over a timespan of perhaps 30 years. But I will concur that when it comes to subjective preferences, there is no "right" nor "wrong". You are free to choose anything that you want to.
>I don't doubt the experiences of others.......I expect the same respect for mine. :^)
I may wonder aloud at how you conducted your experiments, or your controls, or your conclusions, but in no way does that mean that I don't give you a lot of credit for having performed hands-on experimentation. For that you have my full respect.
Ct0517: there is an aggressive, threatening undertone to your post that certainly doesn't encourage constructive replies. All that I can say is that, do feel free to listen to anything that you think sounds best. You don't need anyone's approval nor permission to listen to what you like best.
FWIW, I don't manufacture turntables. Nor do I distribute them (although in previous years I have been involved in distribution and setup for turntable manufacturers that included both integrated armboard and separate arm-pod models in their lineup).
I normally try and have tried in this thread to not hide the fact that I am an audio manufacturer - am I supposed to add "Manufacturer disclaimer" to each and every one of my posts?
My impression so far has been that most manufacturers are quite enthusiastic about audio on a personal level - we collect gear from other manufacturers and historical periods, experiment a lot with setup, have lots of albums, go to concerts frequently, and generally enjoy listening to music. And in my own case, when I hear a piece of gear or a type of design that I think is worthy (including sounding good), if presented the chance to give it credit in public, I will happily do so.
Over and out, jonathan |
Yes, from the former VP of Micro-Seiki (now CEO of Stellavox Japan). He showed up at the Tokyo International Audio Show with a turntable that looked like it completed what the SX's and SZ's started.
I believe that only one prototype (very nicely finished!) exists as of now; pricing has yet to be set.
kind regards, jonathan carr |
Although the TechDAS design breaks all of the prerequisites for this thread, who cares when the turntable design is so interesting and focused on performance.
Driven via a woven aramid belt, but with a quartz-referenced, optically sensed servo system. The numerical display on the front of the pinth is a tachometer, and the user can adjust the speed with a dial.
Rather than having separate armpods, there appears to be a solid beam (machined from metal billet) which is dedicated to locking the armboard to the platter bearing and thereby preventing any relative motion between the two. Some of the later Micro-Seiki turntables were made like this.
The plinth is massive and seems to be largely machined from solid aluminum. A pneumatic suspension system has been built directly into the legs of the plinth. The suspension is self-levelling, I believe.
Platter is of two-piece construction, and by changing the top section, the user can choose from a conventional clamp, or a vacuum clamp. The lower part of the platter has a cavity machined out of it, which serves as an accumulation chamber when vacuum clamp is activated. The vacuum seals appear to be made of silicon rubber, but their shape is much like what you would find on the Micro SX or SZ series turntables.
The platter is nominally stainless (in the finest Micro-Seiki tradition), but the top part could be of chrome-copper, brass, aluminum or other materials.
http://www.phileweb.com/news/audio/201111/03/11428.html
http://www.phileweb.com/news/audio/image.php?id=11428&row=1
I have taken more and better photos, but don't have them hosted anywhere. Feel free to email me if you want copies of the photos that I took.
From talking to Nishikawa (the designer and Stellavox Japan CEO), my guess is that the Japanese retail price will land in the vicinity of 5,000,000 JPY.
Pity that the price (which I don't consider to be expensive, given the engineering content of the design) puts it completely out of my reach, and makes me wish that being an audio designer weren't such a poorly-paying profession.
kind regards, jonathan carr |
