The EK-10

The Days of EK-10’s and sleepless nights
by Paul Gagon

For me, reliving the memories of the Rhodes EK-10 is much like remembering my first tooth extraction without the benefits of novacane, or the first time I was hit in the family jewels by a softball. I was introduced to the EK-10 while holding the position of Test Engineer over the Fender/Rhodes electronic assembly department. My job was to design and build test fixtures for the testing and/or repairing of both sub assemblies and finished product. I also had two other assignments as part of my job position. First, I was responsible for writing the test procedures and drawing assembly wiring aids, and second, I was in charge of the flow solder machine and cleaner station.

When I received my first demonstration on the EK-10, and examined its circuitry, it was pretty obvious that we were going to be in for some real interesting problems. There were several things that bothered me, and I list them here in no particular order. #1.The cleaning section of our flow solder system used standard, out of the tap, water which is not conducive to high impedance circuitry. #2.We didn’t have any anti-static assembly stations and the EK-10 circuitry was very high impedance and quite susceptible to damage. #3.The electrolytic capacitors we were using were pretty cheap and didn’t always survive the temperature of the flow solder machine or the water of the cleaner station without leakage problems. #4.The people doing the component inserting on the circuit boards were not trained nor properly equipped to handling sensitive circuit boards.

The first EK-10 units to come off the production line were rather problematic, to say the least. Notes would turn on by themselves and then suddenly shut off. Sometimes notes could be activated by simply breathing on the circuit boards over the voltage detectors. There was a period of several weeks where all anybody could talk about was what a piece of crap the EK-10 was. I remember one afternoon when I, along with a several department heads, were summoned into the quality control department for a special presentation. We were there to be “CONVINCED” that there were no problems with the EK-10 and that we should be shipping product instead of complaining about all the “PROBLEMS” we were having. The demonstration only lasted a matter of moments before the EK-10 started doing it’s own, unassisted, demo. The oddest assortment of notes and chords began sputtering out of the unit and finally somebody in the room (not me) started laughing. The gentleman in charge of the meeting screamed “YOU THINK THIS IS FUNNY!” and stormed out of the room, leaving the EK-10 in epileptic seizure mode. Actually, I didn’t think it was funny at all. I thought it was kind of sad. I mean, did management really think we should be shipping these things?

It was obvious to me that the circuit boards were being triggered by small current flows along the P.C.B. traces. This was being caused by contamination on the actual circuit boards themselves. My next challenge was to find a way to fix this mess. It was clear to me that the first order of business was to clean up the water used in the circuit board cleaner. This could be done by installing a water Di-ionizer system for the cleaner. Unfortunately, by the time all of the cost analysis, purchase requests, and mountainous red tape were overcome the EK-10 was pretty much on its way out. There was a way to get a perfectly functioning board off the cleaner system but you still needed to have a way to keep the board protected so it would stay clean, which the EK-10 did not have. I figure I shaved several years off my life by spending hundreds and hundreds of hours at my bench hand washing and component replacing to get an EK-10 to play notes when I and I alone wanted them. Another meeting that I will never forget was in the presence of approximately 20 repair technicians from Yamano Music in Tokyo Japan. I had to stand in front of them and hear their complaints about all the problems they were having with the EK-10 units, and they were plenty. They were experiencing T.V. interference, random notes being played, units not working at all, bad cables, and on and on. I shared my horror stories with them and they shared theirs with me. I gave them a list of all the repair solutions we had up to that point and they were nice enough to share with me some of the ways they had been repairing their units. If I had been Japanese I’m sure they would have expected me to fall on my own sword. Interestingly enough, the basic concept of the EK-10 was pretty cool. The problem was that it was very poorly designed, not field tested enough, and manufactured in a facility that was not properly setup to execute it.


The EK-10
("Houston, we have a problem")
by Gary (T-O) Drake

My increasing age has given me an appreciation for some of the finer advances made in keyboard design throughout history. For example, Moog, The Mellotron, Rhodes Suitcase and Kurzweil, the Hammond B3, The DX-7 and Roland, The EK-10......

The EK-10?

Once upon a time in a place called CBS Musical Instruments, a marketing team put together a plan, which while looking really good on paper, turned out to be one of the greatest musical Instrument disasters of the modern era. Some things are better left as ideas. Allow me to explain.

As a line technician (soon to be lead tech.) for the amplifier line of the Fender branch of CBS Musical Instruments, I had the pleasure of working on a large number of the amplifiers, PA systems and keyboard electronics that shaped our musical world, and has made a substantial difference to that end. I worked with some of the greatest engineers in the industry, and was encouraged by the acquisition of ARP Synthesizers and the movement into the high tech arena. This had all the earmarks of a bright future ahead, yessir, we were on our way.

To abject chaos...

First it started with a Production manager saying that the new "EK-10 Keyboard would be the salvation of CBS Rhodes" Now usually, when you hear this type of remark it is a damn good idea to get your resume in order, and call in old favors, but as a young man full of hope I gave Jim Carrigher the benefit of the doubt.

Soon we had pallets full of Frequency Counters, New Oscilloscopes and other goodies for us Tech heads arriving daily and new flow soldering machines and GenRad test systems being installed in the Rhodes assembly area. The only thing missing was a "clean-room".  More about this later.

The technicians were hustled into a demonstration room to be shown the mock-up of the new device we were to be assigned to. A couple of new engineers were in the room, and a man was sitting behind the keyboard. It looked pretty much like a normal Rhodes style keyboard, with the exception of these really cool switches on the namerail that turned green when pressed. These were mechanical switches that were obviously designed by "Q" from James Bond, and were in hindsight the only thing that worked flawlessly on this pig.

The musician played approximately 12 seconds of a tune that appeared on a late 70's game show, and then we were told to leave and get back to work. In reflection, I believe that we were thrown out because the keyboard was in imminent danger of growing legs and throwing itself out of the nearest window. You see, these things rarely played more than 30 seconds without becoming possessed by the devil, and acting like a psychotic transistor radio.

The first set of rails tested fairly easy. They were designed well and had 20 turn pots that could micro manage the rail and give you all sorts of options never seen before. The next items to hit our benches were the six voice boards that comprised the bulk of the central nervous system of the keyboard. Now the real fun begins. First off, there was a little-bitty resistor with a great big resistance (10 Meg. to be exact) across the feedback loop on all the op-amps that were on each board. This has the wonderful effect of causing all sorts of wacky things to happen. If you have a board with any type of contamination (remember the no "Clean-Room" statement), or even breathing hard on these op-amps would make them "freak-out" and start communicating with mars. Also, it might have been a good idea to use grounding straps too, but that was overlooked.


Rarely did any of these boards test perfect on the first try. These passed back and forth between rework and test, and some boards never, ever worked right. On this note, a word about flow soldering. Once the components (Resistors, Caps, etc.) were stuffed into the bare circuit board, they were sent through a flow solder machine. This (again on paper) should have always worked, but it was very susceptible to contamination (no "Clean-Room" again) so it would sometimes solder every lead to each other and left something that looked like a pop-art statue. The cold solder joints were another nightmare. The ribbon cable that connected the boards together was very weak, poorly designed and frail. The real kicker to all this was the fact that they used aluminum screws to secure the voice boards to the frame. These, without fail, always stripped out. They spent tons of money on those really hip green switches, and about 1/10000 of a cent on screws.  Once again, never underestimate the "hidden-flaw" It never remains hidden.

As usual, Paul Gagon our resident Miracle working engineer was brought in to design test boxes and fix issues (which were many and varied) becoming a one man support crew. I am sure, like the people exposed at Chernobyl, he has lost a few years off his life while pulling out his hair attempting to make these "FrankenKeyboards" do something useful. We were exposed to a new term: "Domino Effect."

The Ultimate drag was yet to come. We worked multi-shifts, Saturdays and Sundays to make 150 of these units that were to be sent to Japan. Now, the Integrated Circuit chip that ran the clock pulse that was then sent through a divide-by-seven chipto provide the individual notes, had a unique suprise in store for the land of the rising sun. You see, That chip would interfere with TV reception.  There is a reason that owners manuals talk about their products NOT interfering with communication devices. We didn't even know that this was going to happen.

In effect, Godzilla was reincarnated in the EK-10.

Sometimes you might have these things play all by themselves, other times they might play one set of sounds or another set or both at the same time. Hit the board with a pencil and it would go berserk and make sounds like the inside of a tornado might be like. I can only imagine the look on the prime minister of Japan's face as his favorite TV show was interrupted by the musical equivalent of an attack by killer bees.

As you can see, This helped to ease international tensions a great deal. It is rumored that instead of sending these things back to the USA, they used them as part of an artificial reef. From pencil to seabed these were truly a well thought out instrument.

In all fairness, two years ago I was shown an EK-10 that worked for 3 whole songs! It wouldswitch sounds and make notes rather than the yelping squeals of a rabid howler monkey that I had come to expect from one of these. I believe that if a clear, cost effective and technically attainable goal been followed, this may have been a cool keyboard. Instead, it is relegated to the "don't talk about that" area in the few remaining witnesses to that greatly ill-fated project.

In a few months time, the amp line was closed down and moved to Hooperston, Illinois. Fender Rodgers & Rhodes were sold off, and the rest, they say is history....

More about the EK-10
by John R. McLaren

The EK-10 was most certainly one of the largest and most costly recall in the music business. Over 3000 of these pianos were made and shipped, but this new instrument turned out to be a total failure. To satisfy the Rhodes dealers and correct the issues raised, approximately 3000of these items were returned to the CBS Musical Instruments receiving dock in Fullerton, Calif. It was the determined by the group engineers that nothing of financial value could be salvaged from these items due to their design specific changes, so they were summarily reduced to rubble by a team of staff and temporary services people.

Having witnessed this pummeling of these units with sledgehammers on the receiving dock, the thing I remember most is the shiny pieces of glittering shrapnel that littered the ground. Once the carnage was completed for each group, the "remains" were sent to the 40 foot dumpsters for elimination.

The EK-10 was, by and large, not designed by the normal Rhodes R&D design team. The bulk of the unit was sub-engineered by an outside firm. In the pursuit of offsetting the cost of over-engineeringthis problem unit, was the introduction of plastic keys. The piano was no longer a modular unit.  The guide pins (actual piano key movement) for the keys were plastic and were mounted directly to  the piano cabinet. Other than massive electronic issues, many of these return units had broken keys and shattered guide pins. To add insult to injury, on the later versions of the Mark II which nomally came with wooden keybed began to incorporate the same plastic keys as well! Shipping damage was a common problem to both units, so it had lost its ability to withstand handling once it left the factory. Plastic keys imparted a playability handicap and produced a clacking noise when struck. Production on the EK-10 ended in late 1981, with the Mark II shutting down in late 1982, along with all other Rhodes units, due to quality and design issues, as well as shipping costs incurred from these returns.

Harold Rhodes was absolutely sickened by what he saw, and the direction things were heading. He came out of semi-retirement to oversee the beginnings of a better , new piano, the "Mark V".  A substantial amount of cash was outlaid for the design of this new unit.

The EK-10 was shown on a local TV station in Japan, which uses the PAL system under NHK Japan, for a small demonstration of this unusual new electric piano. No big deal right? Well the EK-10, when played, caused a frequency interference that was never anticipated. Having designed the unit to operate a certain way, the design team unleashed a torrent of signal jamming clock signals that acted like wayward CB radios and bled through Public Address, Television and Night Club Amplifiers. This electromagnetic Godzilla was discovered to be the cause. In facing large return shipping costs, it was decided that these might be better suited for a unusual government project, an artificial reef where most of the pianos now lie quietly in the Japanese sea. In Paul Gagon’s comments above, he made reference to Yamano music that was founded in 1892. They currenty have 39 stores and 14 music schools, and were the original Rhodes distributor for the Japanese market.

The EK-10 Gallery

Below: Circa 1980-81 brochure, front side

Below: Circa 1980-81 brochure, back side

Below: John C. McLaren, then President of CBS Musical Instruments Division, at "Black Rock" CBS Headquarters in New York City, playing an EK-10. Wonder why there's no harp cover on it? Probably because the techs were desperately trying to get it to work just before John walked in.

Below: EK-10 with harp cover removed. Notice the dots on the keys; they are labled according to what sounds are actually emitted. Some keys make Rhodes sounds, others make no sounds, others make synth sounds and no Rhodes, and others make both Rhodes and synth sounds (as they were supposed to).

Below: For servicability, the voice boards were hinged to easily access the tone bars.

Below: "Wave Form" mechanical buttons which showed a green slide through the window when activated. While the mechanical property of the buttons worked flawlessly; what they controlled didn't.

Below: Rear view of the EK-10

Below: The six "voice boards" installed in their assembly on the piano; each board controls one portion of the keyboard.

Below: The "voice board" assembly removed.

Below: Close up of one "voice board" with computer-type ribbon cable connecting each of them.

Below: Rightmost "voice board"; notice upward-pointing pins from the master connecting PC board.

Below: Close-up view of the master connecting PC board which contains the black "clock" chip and just below it, the highly-stressed resistor which caused many problems

Below: Notice colored wires which accept the signal individually from each magnetic pickup. On a conventional Rhodes, all of the pickups are wired basically like an electric guitar. Each pickup also had a shield so that the signal of one pickup would not bleed through to the adjoining pickups; however, they did bleed through, causing distortion, radio interference, and the synth to go crazy.

Below: The pickup rail removed from the harp assembly.

Below: Notice the shields extending between the ends of the pickups. The number "0781" is a date code meaning July, 1981.

Below: Upward-pointing plastic guide pins of the keyboard action. Unlike a conventional Rhodes which allows the entire piano assembly to be removed as a unit from the case, on the EK-10 the guide pins were screwed to the piano cabinet, making them much more susceptable to damage during transport of the piano. On a conventional Rhodes, action rail is just like an acoustic piano, with guide pins made of durable metal, the keys made of wood, and using traditional felt bushings. The EK-10, however, used plastic guide pins, keys, and had no felt bushings. The playability suffered and professional musicians complained of the "clacking" sound as the plastic parts flexed and bumped against one another. When Harold Rhodes learned of this poor design, he demanded the action be redesigned to use a traditional piano action. This cost-cutting measure, used on the EK-10 and the Mark II, was corrected with the Mark V, which returned to a wood-key action with modifications to make it even better than earlier Rhodes pianos.

Below: Plastic keys were made fiberous composite material and were very easy to break.


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