After a phone conversation with Missouri writer Chip Madinger about his Beogram 8000, he decided to allow Beomuse the opportunity to refurbish his turntable. When the turntable arrived we began initial inspection of the circuitry. Although the power supply didn’t show usual problems with dried-out capacitors, we decided to replace these inexpensive items for good measure. One of the capacitors is located in the microprocessor’s shielded enclosure and can cause serious havoc at times.

Chip’s turntable is a later model 8000. It can be determined from the existence of two “piggyback” boards added to the primary circuit board. Most of the problems with the turntable were simply the result of connections that can go bad after many years. All connections were cleaned up and re-soldered with SN60 wire solder. SN60, which contains an amount of silver, can really help out on these old connections. The carriage belt required replacement as well. The original triangular version is a wise choice over a square version. The clearances between the suspended chassis and the pulley/interrupter are very tight and a triangular belt allows some room for the system to work properly.

The major problem was in the tacho-disc. Some B&O turntables used a tacho-disc similar to the one that Beomuse has developed. As far as Beomuse is aware, Bang and Olufsen had two versions of the disc available. One was a steel unit and the other manufactured with the name “Kemiform”. The Kemiform is quite similar to Beomuse’s part. Chip’s 8000 had a Kemiform unit originally fitted and the litho material was beginning to separate from the substrate. The result of a bad tacho disc can be heard as serious wow and occasional flutter while the microprocessor fights to find a proper turntable speed. Installing a Beomuse disc on the hub cured that problem wonderfully!

The muting relay was cleaned up to insure that needle-drops wouldn’t be heard until the stylus was seated in a groove. Beomuse also noticed that the Datalink connection at the output was beginning to give way. A bit of SN60 and the turntable began communicating with a Beomaster 8000.

Urethane adhesive was used to secure the loose turntable base into the original position. Beomuse won’t cut corners here… all old adhesive was removed before the base was refitted. A previous repair of the flip-lid (garage door) had been performed with 3M type double-sided foam tape. Although the flip-lid is attached at a slightly odd angle, Chip and Beomuse decided to leave it “as-is” until a future time when it weakens enough to need repair. It was fastened quite well so will probably last quite a few more years.

When the oscilloscope showed good signals all around the turntable’s circuitry, we began inspecting three cartridges which were sent along with the turntable. They needed just a bit of cleaning around the bases of the stylii as our stereomicroscope confirmed. Beomuse uses optical contact lens solution to clean stylii sent to us for inspection. It evaporates with hardly a trace of residue and won’t attack the microscopic adhesives which hold the stylii to the cantilevers.

Then on to the final testing of the turntable.

Every turntable refurbished by Beomuse undergoes serious tracking tests along with frequency response checks and good old-fashioned “ear” testing. Using modern PC assisted audio programs is an excellent way to see what the waveforms coming from the cartridge look like. As a matter of fact, Beomuse supplies a custom CD with every refurbishment so that the owner can hear how their turntable performed at Beomuse! This CD also contains a few musical selections as well as test signals.

Turntables are connected to a Beomaster 8000 and the Tape Output sample is fed to a Philips CD recorder and then on to a PC audio card. As always, the usual outstanding Beomuse warranty is included with the CD.

Chip Madinger is a writer from Missouri and his book co-written with Mark Easter “Eight Arms to Hold You” digs deeply into the solo works of John, Paul, George and Ringo.

© Copyright Anthony Garza, used with permission.

“I love to count! Ah, ah, ah, ah!”… The Count from Sesame Street

Truly, the Beogram 8000 loves to count. As opposed to the earlier brother, the Beogram 4000 series, the Beogram 8000 series turntable has a single switch to tell the microprocessor where the “park” position is. This switch is adjustable by about 25 mm in either direction.

The 4000 series units had a light sensor and a LONG clear plastic ruler with black paint at various places. Black paint would sense the point where LP touchdown was located, where the 45 single touchdown point was located, as well as some stripes at the end to tell the circuit that the arm had moved into the “time to pick up the arm and go back to park”.

The Beogram 8000 series doesn’t work this way. On the screw shaft which moves the carriage across the disc area is a pulley which is attached to the carriage motor. Also on the pulley are some slots which block light from a single infrared emitting diode to two infrared detectors. These detectors switch a 15 volt signal through a resistor and are amplified via an operational amplifier. These pulses then are fed to the microprocessor which can tell what direction the carriage is moving and exactly how many pulses have occurred. Since the detectors are positioned in such a way that they overlap each other, the microprocessor can determine which way the carriage is moving by sensing which pulse comes first. The microprocessor is continually storing the total number of pulses in memory for various reasons.

Here’s the first reason. When the arm is in park position, the count is “0″. When an LP is placed on the turntable and “play” is selected, the arm begins to move. The pulses, 4 pair to a single shaft revolution, begin to be stored in memory. As the first arm passes the LP vinyl, a signal is sent to the microcomputer telling it that a 33 RPM LP touchdown point is desired. The number of total pulses needed to get there is stored in the embedded memory of the microcontroller. When the detected number of pulses matches that which is stored in ROM, the arm stops and the cartridge lands. The same situation applies to 45 RPM singles… a certain number is stored in ROM and when there’s a match, touchdown occurs. As the record plays to the end, the microcontroller knows the standard point that most music on a disc ends. As soon as it passes that point and can see “fast pulses” from the detector the microcontroller assumes that the disc has ended and will go into Stop mode. It then goes to park and the count starts again at “0″.

If the owner wants to move the cartridge back and forth across the disc, the point is always stored in memory so that the computer knows EXACTLY where the arms are at any point on the disc. Everything is based on that single switch. If the switch is off, then the landing points are as well.

What are those ROM stored numbers? I don’t know. It wouldn’t be a difficult thing to place an electronic counter on the detectors to find out. One of these days I’ll have some time to experiment and take notes!

It is obvious that the detectors MUST work every single time. If your turntable goes to the final groove and won’t pick up, it is a sure bet that the detectors are missing a few pulses. This can happen.

Now, here’s something I always wondered about. If the microcontroller knows where the arm is at any time, why not put in a sequence of code in the ROM allowing the equivalent of a cassette machine’s index counter? All that is needed are some buttons on the front panel and a bit more memory. A “GOTO” button could have been depressed, a number entered and then “Go”. Voilà! The arm would have counted pulses until they matched those entered by the user. Perhaps the reason for not having that option has already been mentioned in this paragraph. Not much room for buttons and maybe the embedded ROM is almost full with the standard code.

Wouldn’t it have been COOL!

© Copyright Anthony Garza, used with permission.

Before Y2K there was a lot of talk of “embedded systems” and how difficult it would be to make them Year 2000 compliant. No worry for such machines as Beocenter 7000, 7700, Beocord 8000 and many other microcontrolled BeoUnits which contained timer functions. Just as my analog Timex wristwatch is Y2K compliant by nature, so are the early Bang and Olufsen units. Embedded technology hurts earlier model B&O gear in the components themselves. Simply put, there’s not enough of them out there.

In layman’s terms, an embedded microcontroller is a single integrated circuit with Microprocessor, RAM and ROM in the same package. Some of these devices are designated as “OTP” (one-time-programmable). Most of the microcontrollers used in early B&O gear are OTP… the operating system is loaded into the chip’s ROM and then tested to make sure it is correct. If it is a good transfer of data, then the chip is stamped with a B&O part number, wrapped in static-protective foam and shelved into inventory.

Remember Commodore Computers? The Beomaster 8000 came out around the same time that Commodore was a household word. The Rockwell company was responsible for some of the groundbreaking chips that Commodore was using. One of those chips, a very obscure 6500/1, was selected by B&O for use in the 8000. Actually, there are two of those chips in the 8000… one the Master and the other acting as Slave. The 8000 was a complex system and one chip wasn’t enough to do everything demanded by the system. Replacement chips are extremely hard to find but one will occasionally show up in some B&O inventory somewhere. Sometimes, it will be a used chip which was swapped for a part thought to be bad. No point in wasting time getting the original back in!

Surprisingly, electronic parts brokers show inventory of “blank” 6500/1 chips here and there. I was lucky enough to find a datasheet on the 6500/1 a few years ago and was happy to know that it is “possible” to gather the code from the ROM. The problem here is that devices which could do this quickly and easily are a thing of the past. Sure, there’s all kinds of EPROM and EEPROM programming machines on the market but none of them that I know of will READ and WRITE with the 6500/1 chip. One of these days I’ll spend some extra time building a custom programmer to possibly keep the inventory going. Of course, that’s a matter of being able to find bonafide blank chips. If no chips can be found then a case of Reverse-Engineering will have to be consulted… copy the code, rewrite into a modern language, install into a modern device and then find some easy way to get the pins to align electrically with the original printed circuit.

In the early 80s I spent some time with about a dozen B&O technicians in Dallas who were there to be introduced to the Beocenter 7700. Our BeoGuy was Keld Hansen who is (as of this writing) the store manager of B&O San Franscisco. Keld was a lot of fun to work with and really knew his 7700. I noticed that the 7700 used a microcontroller labelled as 3870. The 3870 was an offshoot of Fairchild Semiconductor’s F8 language group… a very popular system for the time. As an EE student at Texas Tech I spent most of my time with Fortran in a computer room the size of most high-school locker rooms. F8 was just beginning to show its value in the industry. I LOVED the 3870 used in the 7700. It was very simple and quite robust. The only bug that the 3870′s BeoROM had was minor and as far as I know was never corrected. Seems that the only way to turn off the cassette motor was to go into standby mode and then select another function other than cassette. Just imagine the brushes of the cassette motor wearing away for no reason at all!

The 3870 is a tough nut to crack. If you have datasheets on the 3870, please send them my way. I would like to investigate the possibility of keeping inventory on that chip as well. 3870 chips manufactured by MOSTEK are also shown on broker inventories. Maybe someday!

Then along comes the Beomaster 5500. Great machine! Good microprocessor design. The microprocessor costs only $5 to replace and the memory is stored in EPROM. Change out a bad EPROM chip with a new chip containing BeoCode and you’re in business. No embedded system there. Well, there IS an embedded chip in the Master Control Unit. Darn.

Here’s a story with a happy ending. A sweet lady from Seattle recently sent her 7700 into Beomuse for repair after a lightning storm. She absolutely LOVES her machine and wanted us to make certain that the “computer thingy” was at fault as she had been told by her local servicer. When we looked at the machine we were able to find that the 3870 wouldn’t boot-up at all. We checked every angle of the problem and it turned out that the obsolete microcontroller was not at fault. Turned out to be the 5 Volt supply to the 3870. If I were a 3870, I wouldn’t want to boot-up if I were only given 2.1 volts of juice. Easy problem to miss here, though… the logic circuits of the 7700 use TWO separate 5 Volt supplies. The faulty one was strictly for the 3870 to keep timer and clock functions working as the 7700 slept in Standby. After getting the 5 Volt supply back up to par all we had left to do was service the entire unit which suffered from dried grease here and there along with a turntable cover that had separated from the aluminum.

If the microcontroller was indeed bad, I’m sure that Beomuse would have begun an eBay watch for a 7700 to be used as a donor unit. I simply don’t know where to find a Beo3870. Hopefully Beomuse will come up with a solution someday. If you have experience in these matters, please contact us!

It’s not my intention to cause anyone worry over these issues. For a little Peace of Mind, may I recommend a nice product? Please insert a TrippLite Isotel Ultra in your AC lines of BeoGear. I use a few of these devices on my BeoGear since we have quite a few lightning strikes out here in the West Texas countryside. I’ve lost a few pieces of electronic gear to lightning but the Isotel respects my BeoGear! I have no problem at all with losing a Sony clock radio to lightning but I won’t take a chance with the Beomuse Collection.

Lastly, we are refurbishing a Beomaster 5500 for a gentleman in Livingston, Texas. Lightning problems here again. Because of the reasonably good architecture of the computer system in the 5500, we are slowly and surely getting his machine functional one circuit at a time. Parts are “cheap” for this machine. Here’s to better days for earlier BeoUnits!

© Copyright Anthony Garza, used with permission.

When Kelton Ogletree first contacted Beomuse about his 5500 system which had apparently been hit by lightning we were eager to look into the problem. Most shops shun such repairs due to the intense possibility that many parts may appear to be functional but in the end will show that they were “borderline”.

Being in the broadcasting business gives Beomuse an extra edge where difficult repairs are involved. Texas radio stations are pelted with lightning and serious static charges pretty much the entire year particularly during the thunderstorm season between February and June. Beomuse is no stranger to lightning damage… we have to get our stations back “on the air” and usually with a rabid fervor. Lost air time is money (and advertisers) down the drain.

Lightning problems with any B&O unit are serious considerations for the owner. The value of the machine must be taken into consideration… especially any perceived or “heartfelt” values. Kelton wasn’t sure at first about having his units repaired but after looking into his past enjoyment with the machines he told Beomuse that “it will be a great challenge for both of us.”

And what a challenge its been!

At the time of this writing the only thing left to do on his 5500 is strengthening of the RCA inputs and outputs on the back of his machine. This is a common problem with 5000 and 5500 units although most B&O owners never use them. So far, a total of just over 50 parts have been put into his machine and his unit will undergo an additional length of testing beyond the usual 48 hour reliability test that all machines repaired by Beomuse must face.

The nice part about repairing a 5500 is in the microcomputer’s architecture… its just plain easy and parts aren’t that expensive. The most difficult time in the repair involved finding 4 integrated circuits that are obsolete or very close to obsolete. Those parts were eventually found and voilà… a unit ready to get back into service!

Admittedly, such repairs are LABOR INTENSE and the repair bill will usually be quite respectable. Given the options of looking for a replacement unit on eBay or having the 5500 repaired at Beomuse is certainly something to think about. I’m sure a replacement unit would have been 50% of the cost of repair. Kelton probably used the “personal mechanic” approach in his decision. A good technician will have a certain intimacy in the repair of any unit and keep good records of any unit’s history. Buying a replacement unit is like buying a used car. No telling what one might be getting into. The energy that Beomuse puts into repairs of this type are taken with such an approach.

Beomuse learned much more about a 5500 unit than we knew before. We also learned much more about serious owners of B&O equipment.

Back to the radio station for a second… FM transmitters usually cost in excess of $55,000 to replace. Most repairs to lightning damage will cost under $5000 in the most serious situations with a minimal amount of down-time. Another option? Buying a used transmitter to replace one damaged by lightning frightens me… its probably been hit by lightning before!

Hats off to Kelton and his willingness to take on the challenge with Beomuse at his side!

© Copyright Anthony Garza, used with permission.

I call these machines “Dalek Daddies” since they look like they might come directly off of the set from a Doctor Who movie!

The Cincinnati Milacron series of milling machines are quite impressive. Recently we had need of an obsolete part for a TX 2 turntable. The part was smaller than a dime but the Milacron did the job with absolute perfection. I became involved with Lee’s Model and Machine in Lubbock after a service call to their facility last year. I had business with Lee’s in the past and since they were aware that I “knew electronics” they gave me a call. I don’t know a single thing about milling machines but I do know about automation since I am in the broadcasting business. After an hour of studying the manual for the Milacron I was able to repair the control system by installing four tiny resistors in the power section. Voilà! The machine started back up and the operator began tests. Shortly thereafter the operator got back to work on critical projects needed for his clients.

In the case of the TX 2 part I sat down with the Milacron operator in front of his CAD (Computer Aided Design) program and we measured all parameters of the part with micrometers and calipers. After 20 minutes a computer generated code was then transferred into the Milacron. A small block of aluminum was then inserted into the Milacron’s milling base. The huge door was closed, coolant pumps were started and the “GO” button was pressed. The process sounded like a washing machine going bad! After the initial step the half-finished part was then reversed and Phase 2 began. Another run of washing machine noises and the part was completed. A gentle brushing of the part by hand then allowed us to measure the final product. A perfect fit as soon as the part made it back to Beomuse!

It is incredible that such a huge machine can perform such delicate operations with perfect results for our clients. I should mention that when I called Lee’s for this project they were very willing to get the job done at the end of the day. The Milacron operator spent one hour preparing and finishing this part. Not too shabby! Beomuse has good friends at Lee’s.

I understand that Cincinnati Milacron now manufactures a milling machine which will produce parts no larger than 5 centimeters cubed. The cost is just under $50,000. Would someone from Cincinnati call me so that I can look into learning this fascinating and beneficial talent of automated milling?

© Copyright Anthony Garza, used with permission.

A Mexican-American in King Valdemar’s Court

The Seal of Kolding, Denmark (circa 1230s):

And, a tapestry of the Seal of Mexico (from a legend circa 1320s):

(Anyone trying to find any truth in this story will be shot with a Rubando Pistola, otherwise known as a “rubber band pistol”)

My name is Anthony Garza and I am a communications engineer from Lubbock, Texas. A few years ago I was traveling in Mexico City and introduced myself to a young Mejicano named Penjamo. Since my spanish was so bad and his english was so good we became good friends as he showed me the sites in the Mexican Capital. Unfortunately, near the old Lake Tenochtitlan, I injured my head from a falling scaffold where some workers were plastering the side of a new building. The next thing I knew I was in a very strange land with a strange man holding a spear to my chest.

The man tied my arms and took me to a fellow named Valdemar, apparently the King of Denmark from the best my mental history could remember. And if my memory served me right, I was somehow transported to the year 1235. The King spoke in a language which sounded German so using my best “lengua de los Alemanes” I was able to get at least a few words across to him.

I was wearing a western-cut shirt which had the Mexican flag embroidered on it and around my waist was a rattlesnake belt which the King found quite impressive. I got the feeling that I was considered some sort of a magician. The King, his guards and subjects treated me with such grand respect. They took me to the Royal Danish Court and placed a beautiful amulet around my neck. The amulet was lovely and portrayed an eagle sitting on a rock surrounded with water which fed a beautiful plant which looked like a lily. I can’t be absolutely sure because jewelry back in those days wasn’t exactly made with precision.

In my shirt pocket I had a Hershey’s chocolate bar which I hadn’t eaten. Since it was the only thing I could offer to the King as a gift, I bowed to him and gave him the Hershey’s. He took a sniff of it and smiled. I opened the wrapper and broke off a square for him to sample. As best as I could tell he wanted to know where he could get some more. I told him the only place I knew where to get chocolate was way beyond the sea in a country called Mejico. King Valdemar placed me in charge of a great mission along with 100 of his finest Danish soldiers and sailors. Since I wanted to go back home I was delighted to make the trip. I told the King that I would find some chocolate plants and have his sailors bring them back to him.

The trip to Mejico took many many months but finally I was able to locate Cuba and we continued until the coast of Mejico was within view. We set foot on the coast and 50 soldiers accompanied me on the journey to find chocolate. The other 50 sailors stayed on the coast awaiting our arrival. Many weeks passed until we finally found some chocolate plants near where Mexico City stands today. Unfortunately, we came across a few Aztec tribesmen who weren’t very happy about us taking the chocolate plants.

I ordered the Captain of our unit to hurry back to the coast with the chocolate plants while I tried to evade the Aztecs alone. Since I wanted to get back to Lubbock, no matter what it looked like in the 13th century, I “borrowed” a canoe and headed north bidding the Captain goodbye. As I turned to see if the Aztecs were gaining on me, one of their warrior’s arrows hit me square in the chest. I pulled the arrow from my body and painfully continued to paddle until I found a small island in the middle of the lake where I could rest and tend to my wound. At this moment an earthquake shook the entire area. I hung onto a small Nopal cactus praying that I wouldn’t be washed into the lake. I passed out and found myself in a Mejican hospital with Penjamo at my bedside.

When I look back upon my fantastic trip to Denmark I realize that it was my body which was found by the Aztecs in the year 1325. My skeleton still had the amulet around my neck and the rattlesnake belt around my waist. I also realized that if it weren’t for my daring adventure back to the Americas the Danish never would have been able to make some of the best desserts known to the world.

So, the next time you see a Mexican flag flying in the wind you’ll know that it is my shirt which was “Primera Bandera del Pais”.

Anthony Garza is an amateur researcher of Mark Twain, whose story “A Connecticut Yankee” is satirized on this website.

© Copyright Anthony Garza, used with permission.