Brinkmann Bardo

Let's not forget the pioneers of this technology, the Dual EDS1000 / EDS1000-2 magnetic dd motor that they first introduced in '73. With 4 hall sensors, even though it isn't quartz controlled, it's rock steady, strong, dead silent, and shielded. Dual came out with this concept well before the others and was certainly on their drawing boards in the late 60's. 30+yrs later, they're still running spot on in decks. Japanese just copied. I too have had interest in the bardos (and oasis).

Dual came out with the first and only EDS (electro-dynamic suspension) DD TT motor, for which they've never gotten any credit. Being an aerospace engineer, I can tell you this type is the only true magnetic direct drive motor. The Technics platter is nothing more than a magnet that sits in a rotor, is configured horizontally, which essentially becomes a standard motor stabilized by tach signals and OCD type electronics. The Technics motor suffers from pole jerking, magnetic drag, hysteresis, and requires a very large amount of power. The Dual EDS motor works like a modern magnetic railway. When the magnet is between 2 poles, the powers of the 2 poles are proportionate. In other words, if the magnet is dead center between the 2 poles, both poles will have 50% power, but if 80% of the magnet is over one pole and 20% of the other, the power is split 80/20 and so on in a linear fashion. It only requires 50 milliwatts of power to operate, since opposing magnets are the major force behind its propulsion. There is no need for quartz control. The hall sensors monitor the strength of the magnetic field within the system and hold stable regardless of fluctuating line voltage. A heavy platter is not required, and the technology of EDS actually allows the platter to (microscopically) levitate when it is operating, significantly reducing typical negative spindle and bearing contributions. This motor is dead silent. Unfortunately this EDS motor never received recognition and was very expensive for Dual to manufacture. At one time, Dual had 3000+ employees and completely made 100% of their own parts and motors in-house. To compete and save money, they "cheapened" newer motors and went along with the crowd of quartz control. BTW, the motor in the Dual CS5000 is an EDS type motor, although it provided belt drive. It seems that the Brinkmann DD motor is nothing more than a new type of Technics DD motor. The fact that the coils are not totally equidistant means it's "pushing" and "braking" in an un-uniform manner favoring one side. I beleive they bandaid and hide issues by the use of a heavy platter. I'm in no way discrediting other manufacturer’s contributions to DD TT technology. Technics may have been the first to the commercial market with DD, but Thorens developed and patented the first DD motor way back in 1929. With respect to the discussion of "magnetic direct drive", Dual was the pioneer and implementer of this type of DD motor. Technics and other manufacturers have nothing to do with this type of motor as their DD motors act more like stepper motors. So the correct timeline is Thorens invented the first DD motor, Technics was the first to market the DD TT, and Dual was the first, last, and only to invent and market the EDS magnetic DD motor for use in turntables.

Dear Lewm, There are 2 different motor designs for the K07D. The initial Kenwood motor that looks similar to the Brinkmann (and the Dual) but with 6 red coils was a patent infringement on the earlier Dual design. This is why Kenwood had to later change the design to the green star shaped coils, which you can see are not asymmetrical. Kenwood and other Japanese manufacturers thought they could get around the patent issue by using a different number of coils, placing them asymmetrical, compensating with electronics, and changing the specs. It was very common practice, and still is today, for manufacturers to purchase competitors products, completely disassemble them, study the design, and attempt to deviate enough in their own design to try and beat any patents. The Dual EDS motor had 8 double field coils in symmetry with a special conductor plate below it. The magnet was made of barium ferrite and had 8 pole symmetrical magnetization. The electronics in this system were so minimal compared to others that it fit on a round circuit board the same diameter as the bottom of the motor (5 inches). The motor was one complete assembly including the electronics. The platter just fit on top of it. In regards to the Brinkmann motor, I can't understand the reason for the odd placement of the coils. One would think there is a dead spot of power in its rotation which is why I believe its concept is to push and brake. The motor seems by design to only pulse power to the rotation as needed. Once the heavy platter is at speed, the energy within its mass is creating the needed centrifugal force for rotation. The tach feedback will sense speed deviation and only micro-pulse the "motor" as necessary to keep the platter steady at speed, like cruise control. Judging by the size of the motor, it's not meant to "direct drive", it is just too small and weak. It's really a "soft drive" system. Weak micro-pulses of "magnetic" power to the platter would certainly not create a large impact on such a heavy platter, thus eliminating any cogging effect. I do like it's simplicity, and it must obviously work, although they don't advertise any specific specs other than it takes 12 seconds for the platter to reach speed. The white pages on the Brinkmann motor suggest they are using a non-standard 22.5 degree angle on the coils with an 8 pole magnet, claiming that the overlapping magnetic fields reduce cogging. Isn't it strange that this Brinkman motor is very similar to the Dual EDS motor, which has 8 coils instead of 4, both use the coils at a 22.5 degree angle, both have hall sensors, and both have 8 pole magnets. I guess the Dual EDS motor patent has long expired. Essentially, one can get a Dual EDS motor, drop it in a plith, and have a Brinkmann for about $200 + tonearm. It might be ugly, but it won't cost 8 grand. Honestly, and with sarcasm aside, if I were looking for a new TT, I'd consider the Bardos, but only after having a demo.

Have a look at Dual EDS motor:
http://dual.pytalhost.eu/701/dual701-04.jpg
http://dual.pytalhost.eu/701/dual701-38.jpg

Brinkmann white pages:
http://www.brinkmann-audio.de/inhalt/en/whitepaper/oasis.pdf

Best Regards

I forgot to mention kudos to Brinkmann for making their own motor in-house and taking the initiative to incorporate this technology into their product.

Please follow me on a journey that explains the relevance of good TT and DD motor technology. Imagine if you will, there are 3 automobile drivers. All 3 drivers will drive through the most beautiful parts of the Swiss Alps, or the Smokey Mountains, or any other beautiful and breathtaking scene. Driver one is performance oriented and cares most about how his car will handle through this beautiful and challenging terrain. Driver 2 cares more about how beautiful the scenery is going to be. Driver 3 cares equally about the scenery and the drive, and expects quality from both. I fit well as driver 3. I want the quality of the drive to be so good that it virtually disappears so I can concentrate on and value the beauty of the landscape. The speed limit on this road is, for exaggerating purposes, 33.33 miles per hour. All 3 drivers first get to drive a car with a cruise control spec of 33.33 +/- 0.002 miles per hour. This car has a disc attached to one wheel with 4700 lines on it. A sensor reads these 4700 lines throughout every tire revolution to produce the advertised spec.

Driver 1 is so impressed by the technology and performance of the vehicle and finds it exhilarating. Driver 2 really has no opinion and is very happy to be an active participant. Driver 3 is very unhappy. He is experiencing a constant micro struggle of power from within the car; with its constant applying of power and brake, he feels the jitter in the car, it’s annoying, and therefore distracting him from enjoying the breathtaking scenery.

The drivers are now given a car that has a different technology. It only monitors speed once every wheel revolution to maintain speed. The sensor is mounted on the outer most part of the wheel for accuracy. The spec is 33.33 +/- 0.1 miles per hour. Driver 1 is very unhappy. He immediately notices less speed control on sharp turns, up, and down hills. Driver 2 is just happy to be there. Driver 3 is happier than before. For him, the drive is smoother and it’s letting him enjoy more of the picturesque landscape, but feels more like a roller coaster at times.

The drivers are lastly given a car with technology that measures engine load only. Its job is to keep the speed of the engine at a constant regardless of load. The cars computer was programmed to specific values that would maintain a speed of 33.33 miles per hour on a perfectly flat and level road. Having no sensors on the wheels, the engine has no idea what the wheels are doing, or how fast they are spinning.

Driver 1 is very unhappy. It seems the engine has no idea what it’s doing. It’s all over the place. The engine performs great on a flat open road where there is no load, but in the mountains, it struggles. Driver 1 at times feels that the speed just isn’t correct. Driver 2 is just happy to be there. Driver 3 is miserable. As he’s trying to enjoy the beautiful views, the images at times are blurry. As he passes trees, sometimes it looks like one big blob of trees, and at other times, he can pinpoint how many trees there are. He’s having trouble focusing on the picturesque landscape. He concludes that the speed of the car is deviating so much that it’s distorting the view.

The diamond tip on the stylus is the passenger in the car driving through the beautiful terrain and experiencing the landscape of the vinyl. The TT is the cars motor. Car 1 suffers from extreme micro management. It’s constant control of the motor fights with the natural forces of the landscape. This motor will suffer from what I call “negative speed”. Simply, the stylus wants to behave in a natural forward moving manner. A stylus traveling down hill does not want to brake several times, just as when it wants to travel up hill, it doesn’t want to brake several times. The stylus in this case, for an almost immeasurable instant, travels backwards on the vinyl. Some may call it cogging, some may call it pole jerking. This negative speed is actually a form of recoil. Many people will use words like lifeless, boring, unrealistic, smeared, dry, bass shy, and bright. The constant internal power struggle to keep the motor at a strict speed ruins the landscape for the stylus. The music never blooms and is stripped of its magic due to the motor electronics being a control freak. Specs are great though.

Car 3 allows the stylus a little more freedom to travel, however too much. The problem is that at times, the motor is pushing the stylus down the hill when it shouldn’t, and at other times holding it back. The motor really has no idea what’s going on at the road surface. Its job is to just hold the speed as steady as it can via a current feedback circuit. If more current is detected due to a load increase, more voltage is applied to the motor. This system also suffers from motor recoil, but on a smaller scale. The difference in this case is that the platter is being belt driven. The elasticity in the belt will absorb some of this, but the downfall is that there is then the recoil of energy caused by the belt itself. In the end, the stylus is really forced into situations of being out of control. It’s sort of bob sledding. Some will describe the sound as bouncy, jumpy, lively, boomy, smeared, and unfocused. In poorly designed belt drive system, you can also have the symptom of negative speed due to the microscopic rocking of the platter forth and aft.

Car 2 is the better of the 3 cars, but certainly not perfect. The motor will hold its speed for the one full revolution, take a reading, make any adjustment if necessary, and wait for the next reading 1 revolution away. The one revolution allows the stylus to glide more naturally. In other words, when the stylus is going down hill, it’s not being pushed, nor is it being pulled back, or forced to brake. It can travel at a velocity more natural to the landscape of the groove. It will tend to micro speed-up by itself, naturally. When traveling up hill, the stylus will micro slow-down, naturally. One may ask, well how can that happen if the platter is ideally at a constant speed for at least one revolution at a time. Isn’t there a contradiction? The answer is no. Without constantly micro managing the speed, the stylus and its suspension are allowed the opportunity to function properly. The cantilever will bow positively going down hill, and negatively up hill. The suspension of the cantilever is the shock absorber. The more rigid the cantilever (like beryllium), the less positive and negative bowing will occur. The problem now becomes that the quality of the sound deteriorates as the stylus moves towards the center of the vinyl record. Placement of the sensor is critical. Placing it at the outer most edge of the platter will yield less frequent speed correction per distance of stylus travel, and too much speed correction at the inner tracks. The only way to try and compensate for this would be to monitor the location of the tonearm on the record. For instance, if the tonarm is in the middle of the record, it skips a reading, and checks speed every 2 revolutions. Unfortunately this just isn’t workable. A TT like this can sound lively and natural, but not for the entire record.

The best DD motor would be one that is able to maintain constant speed, without any external feedback systems, accept a reasonable load, and not compensate for speed. The magnetic motor is really the only viable solution. Too many manufacturers decide on specs first, and sound later, then slap a few band-aids on at the end. A magnetic drive motor that is manufactured properly will yield the best results regardless of where the stylus is on the record. No amount of electronics can ever compensate for a badly designed or cheap motor. You can have 10 speed boxes connected and it won’t matter. In the self contained system of magnet drive, it only has to worry about maintaining the correct magnetic field. In theory, if the magnetic field is correct and constant, the speed will be correct. Any corrections made would be extremely “soft” and undetectable corrections, as the change is not direct and done through a magnetic field to micro manipulate the motion of magnets. This is where I believe the true magic in the sound of vinyl exists. We can control VTA and VTF, and yield amazing results when hitting the sweet spot. But unfortunately, we cannot control a miserable and faulty designed drive system. If the stylus and its suspension are allowed the privilege of un-interruption by giving it the opportunity to glide at a true steady speed in its natural state, that my friends is the icing on the cake. Like vacuum tubes are soft switchers, solid state are hard switchers. The ideal DD motor will make the TT disappear, and let you forget that you’re listening to vinyl, draw you in, and allow you the privilege of participating in the soul of the music. The most important part of the drive system besides being quiet, is to allow the stylus to be itself, only then it becomes transparent, and presents the magic within the vinyl.

Best Regards

I wonder if that 12 seconds to speed is a conservative number. I spun a few LP's tonight on a fully automatic Dual TT located in my den. I started it manually, moved the arm over, waited 12 seconds, then lowered the arm. The whole process took about 16 seconds by the time the TT started playing music, 20 seconds total to be seated with a drink in hand. It seems like a very long time if you aren't used to it. Spec for the Dual EDS to reach nominal speed is 2 to 2.5 seconds. I'm so used to pressing the auto start button and being seated with a drink in hand by the time the music starts playing, which is <5 seconds. A dealer near me in NYC now has a Bardos. I'll do a demo this weekend and bring a speed disk to see just how long it takes to cruise. The other TT he has of interest to me is the Artemis Labs SA-1 designed by Frank Schroder. I'm told it beats the Bardos in everything hands down, and is about $2K cheaper in price. It's not direct drive, but has an innovative tape drive system that uses 1/4" magnetic reel tape, instead of rubber or string, to drive the platter. Nice thing is that you can make your own "belts" from old reels. The tape drive system is kept taught by a tensioning lever bearing. You won't see this on any other TT, and I've become very interested in this technology.

http://www.soundscapehifi.com/artemis-labs-sa-1.htm

Best Regards and kudos to a good thread...

Lespier,

Many people have done DIY with the EDS motors. From a service standpoint, capacitors C5, C6, C7, C8, and C9 can be replaced. You can basically use 4 sheets of 3/4" birch plywood, make a 5" hole, mount the motor, measure your spindle to arm distance, put it together, and perform a full setup. The shape of the plinth is your immagination. Maybe a modern tear-drop shape? If you want it to be beautiful, when you're done, add 3/4" mahogany to the top, round the edges, and use marine varnish to seal it. Wet sand between coats. Your choice if you want glossy or satin finish. For an armboard, use a standard Canadian hockey puck. The properties and composition of it make for an excellent isolator. If you want to get it more beautiful, finish the sides in flamed maple veneer. I regret to say I'm not familiar with the Revox TT's, but know much more about their reel to reels.

Sorry for off topic, Regards

I had the opportunity to demo both the Bardos and the Artemis TT's. I'm very impressed with both. If I had to briefly describe them, I would say that the Bardos is detailed, wide-open, and quiet. The Artemis is too but adds some element of magic, being more romantic, rich, warm, and smooth. The Bardos is definately tranparent, and the Artemis seems to be voiced like a finely manufactured and tuned instrument. There were LP's I brought that sounded better on one than the other. Looks like I need both :)

Answer to Homosapien - I brought my own tonarm and cartridges to be completely fair. New Ortofon AS-212s with 3 Ortofon LH-9000 headshells, one with a very low hour Micro Acoustics 2002e, one with a low hour Clearaudio Maestro Wood, and one with a low hour Ortofon 2M Black. Both tables set up using a Freikert alignment protractor, VTF set to exactly 1.25g for Micro Acoustics, 2.2g for the Clearaudio, and 1.5g for the Ortofon 2M via digital scale, VTA and azimuth set at level by using 2 Millennium turntable cartridge alignment blocks (http://www.m-puck.de/interanlageblockseite.htm). Both TT's leveled (at separate times) on same platform connected to the same sound (tube) system. In general, the Brinkmann to me seemed to have more toe tapping, Artemis seemed to me to have that too but gave a more emotional and natural presentation.

To homosapien, forgot to mention both TT's speed was checked and adjusted using a KAB speed strobe.

Best Regards