[An ACR-225 being unloaded from a truck.]

Ampex ACR-225 comes to Quadruplex Park!

In it's single largest acqusition, Quadruplex Park has come up with an Ampex ACR-225. A product only about 10 years old, it was obseleted by disk-based video servers. Even though most of these servers cannot match the picture quality of even composite D2, or hold as much material as this machine, they still have major advantages to the broadcaster. Disk-based servers are smaller, consume less power, in general are more reliable, have instant access, are easy to interface to the station's computer network, and can be automated to a much higher degree. Ironically these server/automation systems usually have software for operating machines like the ACR-225. In any case, tape-based servers of all kinds (Old quads like the ACR-25 and TCR-100, Betacarts and LMS systems (Sony does have a D2 LMS similar in many ways to the ACR-225), and of course the ACR-225) are very quickly finding new homes in scrapyards.

This machine came from WNDU TV, which is a station on the campus of Notre Dame in South Bend, Indiana. It was removed from working service just a few months ago, and is in superb condition. The machine weighs 2,600 pounds, and uses 5,500 watts of power when everything is running. Transportation services were provided by my ex-neighbor, Todd Bowman from Rochester, NY. (He bought my house in Rochester as well. While he was picking up the machine in Indiana, the closing was taking place on the house back in Rochester!)

Just what is an ACR-225? It's hard to describe in one sentence. It is basically an automated spot playback system. It consists of up to four D2 digital videotape transports, which share up to two sets of signal system electronics. These tape transports are loaded automatically from a bin containing up to 256 19 mm small cassettes. These cassettes have a playing time of 34 minutes at D2, and can hold more than one cut for automation purposes. The loading is accomplished by a robotic arm that travels on an X-Y frame. The machine also includes a fairly powerful computer system (By 1988 standards!) that manages the operation of the machine. An external PC boots the machine, and takes care of assembling playlists, managing the content of the loaded tapes, and keeping track of tapes not currently loaded in the bins.

Besides spot playback, ACR-225's were also used for some production situations where fast access to many tapes was desired. News might be a good example. Each of the transports has full editing capabilities, so a show could be built inside the machine.

The tape transport Ampex developed for the ACR-225 is legendary. (Transport xpt1.jpg">(Transport view from left) (Transport view from right) Originally, the digital tape format developed for the ACR-225 was to be proprietary. But, Sony took a look at it, and said, 'here is a potential standalone format'. So, Ampex and Sony worked together to develop the ACR-225 digital format into what today is known as SMPTE type D2. (D2 is the last professional tape format developed where original VTR designs were produced by more than one manufacturer.) In any case, Ampex put a lot of work into the tape transport design. First of all, the tape guides (all but 1) are air lubricated, just as in the VPR-3 and AVR-1. This makes for exceptionally smooth and gentle tape handling. The threading system is designed to load a tape in just under 3 seconds, faster than any other helical scan machine ever built. All moving guides are physically clamped into their final positions to assure repeatable interchange. The critical entrance and exit guides do not move. The scanner features individually replaceable heads, which dramatically reduces maintenance time. The capstan, although not a vaccuum capstan, does not employ a pinch roller. This cuts down dramatically on tape wear. (A vaccuum capstan was tried when the machine was being designed, but the pinch-rollerless capstan design worked just as well. So, the vaccum capstan was eliminated to reduce the machine' complexity.) All moving arms, etc. do not have end position sensors on them. The electronics actively learn where the arms are by measuring motor currents. A sophisticated monitoring system greatly reduces the likelihood of tape damage. (Some people have described the tape handling of this transport as 'too gentle'!) Although an option in the ACR-225, AST is available for the playback heads. (My machine does have AST heads, which I understand was not a commonly purchased option.) Last but not least, everything is built like a tank, which is typical of Ampex mechanics. In any case, this transport design is so good, that it was used in the later Ampex DCT format and again on the current-production DST data tape drives. Thanks in a large part to this transport, the DST is the highest performance data tape drive in the world.

Here is the ACR-225's signal systems. Up to two digital signal systems may be installed in the machine (This machine has 2). Each signal system is capable of independently recording and playing back simutaneously. It is also possible for one signal system to feed multiple transports for record. Both signal systems can also play back one transport for redundancy in critical situations. Maxed out, the ACR-225 can make two different recordings, and play back two different tapes, simutaneously. The electronics are somewhat easier to understand than most modern digital VTR's because the level of integration is not as high. ASIC's were just becoming economical at the time the machine was designed, so only a handful were used. (Oddly enough, most of these were made by Sony!) Another result of this is that the machine has a rather hefty 5 volt supply for each signal system.

The control panel of the ACR-225 is essentially a VPR-300 control panel with an extra section to deal with multiple tape transports. Many of the machine's functions are controlled by soft keys around the large electroluminescent display. A keyboard is also provided, on a slide-out tray, for cart titles, etc. However, most of this type of information is entered via the external PC.

The robotics system is located in the back of the machine, which I cannot easily get to at this time. The robot is on a sliding platform tha has two degrees of freedom (X-Y). Movement is facilitated by aircraft cables, driven by cable drums. The robot has a hook, driven by a leadscrew, for removing and inserting cassettes. There is also a bar code reader on the robot for identifying individual cassettes. The movement of the robot is lightning fast! In fact, with 4 transports, the ACR-225 can play back continuous 7 second back-to-back spots.

There is an internal air compressor system for the tape guide air. It consists of two carbon vane compressors. Although these compressors can easily supply the machine, it is recommended that a house air supply be available. Air consumption is much less than quad!

The big hole in the upper right of my machine is where the picture monitor, waveform monitor and vectorscope belong. These did not come with the machine!

I have been asked by many people what I plan to do with this monster. Of course, the main reason for acquiring it is the fact that it is a neat piece of broadcast technology that is rapidly disappearing. I have no plans to use it for anything productive in the normal sense of the term. What I do have in mind, though, is to use it for demonstration. When I do get a real 'Museum' going, I will set up the ACR-225 to play back informative tapes at visitor's request. It will be set up with two viewing stations so visitors can observe the machine in action. Luckily, Ampex put big windows in the back doors so you can see the robot in action. They even put an LED on the robot so one could watch it move around!

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