Thank you so much Jonathan for this series of videos on your turntables. Would love you to do a similar series on your amps and speakers! All the best from Austria.
This is the first time I got a satisfactory explanation why Idler wheel TTs sound so good. I have a few Dual 1019s and though not flawless by any account they have an X factor that makes you enjoy them.
It's been an interesting series on turntable that I have caught so far. Some good historical perspective that could only be compiled by someone with the interest and ability/ access to accumulate such a collection. My guess is some of those would have been just tossed out and are still sitting in some basement or such if only they could be found. But your efforts to bring them all together is very valuable. Thanks. You bring up a point that was drilled into my head by AT when they first came out and I was doing some training for them. The actual forces a stylus encounters playing back a record when scaled up to our size! (If memory serves!) such as the stylus reaches the equivalent of 12.5 tons sq/in of pressure. Velocities up to 6G! Thousands of degrees in temp! But it is across an extremely small cross section. Imagine the physical impact at point of contact and the inertia and energy needed for that instantaneous impact. That's why all that energy and mass is needed on a larger scale to compensate for needs at a much smaller but higher energy scale.
This is an eddy current drive. Usually, when speaking of direct drive, one means a motor that uses coils and possibly permanent magnets. Eddy current drives where found in things like electric clocks, which were a novelty back in those days, among other things.
I've never seen this McCurdy before. Very impressive beast. But I don't see any Prestos in the collection, nor a Gates CB500 or an RCA 73B... Very impressive collection of RCAs though and the Fairchild is truly a rare piece. A lot of drooling is caused by this video. None of these can be strictly direct drives though since, if I'm not mistaken, all use the same gear-drive mechanism (seen at the bottom of the RCA interior) thus the motor, the spindle and the platter (assuming we forget the flexible couplings for a minute) are not one piece. The whole idea of direct drive is that there is no loss of energy occurring between the motor and the platter. This, of course, is a double-edged sword. One thing that isn't mentioned is that all these players were build for broadcasters back in the day when AM was the main method of radio transmission and AM only goes up to a few kilohertz (and certainly did not go down low enough to pick up any of the turntable rumble), so most of the noise was never transmitted. All these were called transcription turntables because they were designed with 16" or even 17" (and I think in one occasion, up to 18") platters in order to fit the the acetate discs (like the one shown here) that were used by radio stations as a cheap means of recording. The acetate discs were played at a low speed (e.g. 16 rpm) so as to contain a lot of low-fidelity program material, such as speech, and would mostly contain radio advertisements. They needed to be large so that they could cheaply record as much material as possible, so combined with the low playback speed they could be quite economical (as opposed to magnetic tape recorders which were hugely expensive machines, used very expensive tape and also came a lot later). The acetates were considered throw-away medium and certainly were as after being played over and over during the course of a day, with these heavy tone-arms, they soon wore out. But they provided a very easy and quick way to record a (non-archival material) program on.
Ah finally someone who knows what he's talking about... very refreshing! So many people nowadays are parroting that belt drive turntables are the best and that it's the reason most high-end turntables are belt drive. But putting a belt in between it actually is a workaround to be able to use a crappy motor.
Torque... The word you're looking for: "Torque is a measure of the force that can cause an object to rotate about an axis. Just as force is what causes an object to accelerate in linear kinematics, torque is what causes an object to acquire angular acceleration. Torque is a vector quantity."
Personally I see nothing wrong with a belt drive turntable. The measurements that matter are speed accuracy, wow and flutter, and rumble. Systems that isolate the turntable and arm from external vibrations help also. Depending on how well the design is executed will determine how well it performs. That is the turntable's only job, to spin the record at constant speed and without spurious vibrations. How noisy the mechanism itself is is important when the turntable is in the same room as you are listening in just like the fan or lack of one in a power amplifier. One of the best motors is a high torque hysteresis synchronous motor. These are locked in phase synchrony with the power line frequency. The power distribution grid is tied in synchrony with every generator on the grid. In the US the frequency is locked at exactly 60 hz and you can think of the grid and all of its generators as the electrical equivalent of one gigantic flywheel. The number of cycles per day became very critical when this type of motor was used for electric clocks. You might say that a quartz clock oscillator is also ha a very stable frequency and can be used as a reference to regulate speed. This is why the most accurate wristwatch in the world is a $400 Casio watch which will beat mechanical watches costing hundreds of thousands of dollars collectors prize and pay for. Ordinary shunt wound induction motors cannot be as highly relied on because speed will vary with voltage. When I bought my first serious turntable in the 1960s I considered Rek-O-Kut as one of three brands I looked at it but didn't buy it. IMO it was a very fine turntable and tonearm. There are some very expensive turntables on the market which in practical terms perform no better than far less expensive competitors and are so absurdly engineered that they remind me of Rube Goldberg.
there's actually quite a few companies that made direct drive turntables today, I'd say a good 20% of turntables made today still are made with direct drive and not belt driven.
i enjoy your videos , reaffirming , wide body speakers are good , belt drive is not so good I remember Dual turntables, Bejamin Elac Miracord turntables , Lenco, Garrard,Perpetuum Ebner, many others. The absolute winner was my Dual 2019, 2029, 2029q, and yes i also had a 1019 precision was awesome gimbal on gimbal for the very light low mass tone arm, and while those were rim drive , albeit a massive 7 1/2 pound platter , i regret not keeping also I remember Empire Trubador , regret not getting one of those. Dual also had dd. belt drive etc
The truth is all three drive systems have advantages & disadvantages. You should avoid making such definitive statements as there are many aspects that factor into a good turntable design.
Glad to have been informed that ´belt-drive turnables’ suck. Now I’d very much like to know why. By the way, there is no absolute obligation using the cheapest of the cheapest of motors to use on a belt drive.
Andrè, the real reason why he says belt drive turntables suck, is because the one he's making, and probably going to be selling, isn't belt drive. Another case of hifi marketing BS.
Hysteresis. The issue he mentions, but does not connect directly back to belt drives is about drag and hysteresis. When the record starts playing something with high dynamic range and high amplitude, the needle puts drag on the plater and slows it down. A belt will stretch trying to maintain speed while the platter slows, then overshoot the intended RPM when it relaxes back to it's normal state. This is physics, nothing controversial here. About the only way to overcome the above issue is to use a massive platter to get a flywheel affect. Using a light plater and electronic control just runs into feedback issues and "hunting," ( a common problem in all closed loop motion control systems).
Michael Fremmer has just done a glowing review of their new turntable on Stereophile and here on YT Steve Huff has done an equally glowing review of the more cost concious Fleetwood Audio Deville.
@@ianmedium There was a first impression note by MF in 2020 for the debut of the K3 . That was for the pre-production version. The review of the finalised version at a measly 363k (placed in the A+ stereophile class in 2021) was in 2021.
I will watch your videos until all this nonsense ends and I make my way stateside and pick up a pair of AC1’s all the way to Sri Lanka.. just wait and see.. 😊
This idea that tracing of grooves slows down or modulates the speed of belt drive TT to any audible extent is complete nonsense. The flywheel effect of a sufficiently massive platter will completely swamp out any "drag" effect of tracking one or two grams, even on heavily modulated grooves. The total effect of stylus drag on speed modulation dwindles to total insignificance to the point it's not measurable let alone audible no matter what the drive. Show me any measured speed fluctuations resulting from groove drag on a well made belt drive TT, Jonathan. if you think they are audible then they can certainly be measured. Test equipment is hundreds of times more sensitive to measuring speed fluctuations than the human ear. The reason why idler drive TTs seem to sound "better" in many cases is because they are usually found on older TTs that are built like tanks. Massive, inert platters, bases and beautifully machined main bearings provide high rigidity, mass damping and much reduced spurious resonances. These are the factors that hugely contribute to the sonic excellence of a turntable. It explains the popularity of the Garrard 301 and 401. Great sounding turntables, not because they employ idlers but because they were constructed with fabulous platters and bearings. Not like the later on mass produced direct drive and belt drive TTs with their flimsy resonant platters and cheap main bearings nailed to thin resonant bases. Another factor in the "sound" of idler drive is the measurably higher motor noise transmitted through an idler wheel contributes to a richer bass. This is demonstrable and measurable. This small but still significant motor noise (rumble) is picked up and modulated by the highly sensitive stylus/groove interface. This has a subjective effect of thickening the overall sound. Some folks hear this as an improvement however because people love bass . Yes bass sounds rich and deeper with an idler drive but for different reasons than they suspect.
Here is what you are up against with my favorite turntable. I like it so much that I'm thinking of buying another one used. I won't tell you what the make or model is but it is real. I bought the one I have used in mint condition decades ago for around $200. Today a used one in mint condition sells for several thousand dollars. I wouldn't trade mine for any other turntable. BTW, although I have over 3000 vinyl phonograph records I also have over 3000 compact discs which are what I listen to mostly on my own invented experimental sound system. arm moves effortlessly on 32 jewelled, sapphire bearings with bearing friction a mere 0.001g. The aluminium tubular arm, dramatically reduced in mass, responds to the slightest variation of a records movement. A self-cooling hysteresis synchronous motor drives the platter with enough torque to reach full speed in one third of a revolution. To prevent any variations of speed each belt is ground within one ten thousandth of an inch thickness. Every two piece, 7ib, 3" thick, die cast aluminium plater is dynamically balanced, and once in motion it acts as a massive flywheel to assure the specified wow and flutter value. The suspension system consists of piston damped, 16 gauge steel coil springs. The main bearing features a stainless steel shaft with a precision ground tip sitting in self lubricating bearings, reducing rumble to one of the lowest figures ever measured in a professional turntable. Specifications Motor: hysteresis synchronous Rumble: 68dB Wow and flutter: 0.04% Startup time: 1/3 rev Platter: 12", 7ib 3oz, aluminium Tonearm: aluminium Effective length: 9 inches Bias control: diminishing spring Tracking force range: 0 to 4g The tonearm is dynamically balanced meaning that the center of mass is at the pivot point. tracking force is applied by other means, not a mass imbalance like other tonearms. The manufacturer claimed the main journal bearing which is massive is machined in match pairs with a tolerance of +/- 1/100,000 inch. He claimed an unweighted rumble of -90 db. The arm tracks the most heavily modulated record passages without distortion at one gram or less using very high compliance low dynamic mass moving magnet cartridges. . I use the Shure V15 type V MR. Review summary a beautifully constructed and finished product, one of the few remaining truly manual record players. It should be able to extract the fullest measure of performance from any cartridge and record. It is certain, too, that no one will wish to hide it from view since it is one audio product that looks as good as it sounds. - Popular Electronics
