This page is a showcase of various quadruplex VTR's made by Ampex over the years. With each description is a picture you can download to get a good look at the machine. If you have any additional pictures to complete this catalog, or descriptions of machines not listed here, please email them to the address at the bottom of the page. I also need info on RCA quad!
See the new VTR history section, part of the VTR Theory section of this website.
For a brief history of Ampex audio and some video products, click Here. This document was carefully researched by Howard Sanner, and the dates given can be considered authoritave!
The Mark 1 is the original test bed for the early VTR project. Built in 1952, this machine employed arcuate scanning. (Note the vertical headwheel, parallel to the tape surface.) The arcuate system originally used three heads, but was later increased to four. The arcuate scan system was abandoned in 1954 in favor of transverse scan.
This machine was the primary test bed for most of the VTR development work. It was on this machine that transverse scan and FM modulation were first used. It featured a belt-driven headwheel. As you can surmise from the picture, changes were constantly being made to this interesting machine.
The Mark 3 was the update of the Mark 2, and this machine was close to being a real product. For the the 1956 NARTB show, this machine was repackaged into the cabinet shown here so it could be used for demonstrations in the Redwood City area. It featured a direct drive video head motor and electronics in 2 seperate racks.
The Mark 4 was the machine built for the 1956 NARTB convention in Chicago, Il. It's cabinet was designed by Charlie Anderson. One of the unique, and not commonly known features of this machine is that it was self-contained. All of the electronics were crammed inside the transport cabinet. Although this worked OK for the show (orders for some 60 machines were taken!), the addition of a processing amplifier forced the electronics into external racks for the VR1000 series of amchines.
The VRX-1000 was the first machine that was produced in any quantity. 16 of these machines were made by hand following the wildly sucessful 1956 NARTB show. These machines were for important customers, and helped get VTRs into their hands until Ampex was ready to mass-produce the machines. These machines were engineering models of sorts. Bugs worked out in the construction and subsequent use of these machines helped make the production VR1000 a very sucessful product.
The Ampex VR1000 is the original quadruplex VTR, and also the first VTR ever sold. The machine comes in two parts: the tape transport and the electronics rack unit. This machine is most definitely NOT solid state! It was only capable of recording and playing back black and white, and it contained no timebase corrector. (Color was so new that this wouldn't be a problem for a few years.) In the spirit of Ampex'es modular design concept, this machine could be updated piecemeal until it was nearly a VR1200!
There are several variants on this machine, such as the VR1000B, VR1002, etc. I do not what the differences are. The machine in the picture is a VR1000B.
A surprising number of these machines still exist, and some even work. All tube machines, however, are quite rare. Ampex has a restored, operational machine in their museum in Redwood City, Ca. This museum is a 'must see' for any broadcast or electronic equipment collector! (1-13-2000 The museum's contents are in Colorado Springs, looking for a new home!)
Click here for a picture of a VR1001
Photo courtesy of Hayne Davis
The VR1001 is a major mechanical variant on the VR 1000, in that the tape transport was vertical, but the reels were still side-by side. This configuration looked much more like machines to follow soon after. The electronics were still in a seperate rack.
Early Quad VTR's made extensive use of vaccuum tubes. After all, they were the best technology of the day. Early transistors could not handle significant amounts of power, and tended to perform poorly at high frequencies. Tubes, on the other hand, could do both. However, tubes used a lot of power, generated a lot of heat, took up a lot of space, and were subject to frequent failure. This didn't stop RCA from introducing an all solid-state machine, the TR22. Ampex responded with the VR1100, an all solid-state machine. It didn't perform as well as the VR1000 (At least at first), but it was smaller, lighter, used less power and was probably more reliable. It was also their first self-contained machine.
The VR1100 cabinet was also adopted to house an early helical machine that 'never made it', the VR8000.
The VR1100 was originally a stripped down machine, but could accept a host of upgrades. Many of these machinrs were upgraded almost to the point of becoming VR1200's. These conversions were sometimes called VR1195's!
I know of only one existing VR1100.
The Ampex VR2000 represented the next generation after the VR1000. Considered a top of the line machine, it had provisions for two different video standards. It also contained a dropout compensator. It was solid state except for four 7895's in the video head, and 12 6761's in the video record amp. (The VR1100 was introduced before the VR2000, but was not as high performance as either the VR1000 or VR2000 due to it's early transistorized preamps.) (The RCA TR-70, also introduced about this time, used vacuum tube preamps.) The video head was the new mark 10, which has interchangable preamp sections, and air bearings. (A ball bearing version was also available.) All earlier machines could be easily retrofit to use the mark 10.
Weighing in at 1300 pounds, and 3 rack units wide, it was self contained, but still a monster of a machine. It never was available with an overhead console. There is one significant variation on the basic VR2000, the VR2000B. The VR2000B featured a vastly improved audio section, and was prewired for a lot more options. It also used circuit breakers rather than fuses on the system power supply.
Few of these machines are still in service. There is a VR2000B in the Quadruplex Park collection.
The Ampex VR1200 was the workhorse of the late 60's and early 70's. I suspect more of these machines were built than any other quadruplex machine. They had most of the features of the VR2000, were smaller and lighter, had all the video standards built in, and were of course, completely solid state. Although they were still an option, most of these machines were supplied with the AMTEC and COLORTEC timebase correctors.
The VR1200 exists in three variants: the VR1200, VR1200B, and VR1200C. The machine in the picture is a VR1200B. The B differed from the original 1200 mainly in a updated power supply (Circuit breakers instead of fuses), and was prewired for several options. The 'C' variation included a greatly improved audio system, and an improved +/- 12 volt supply. It was also wired for more options than the VR1200B.
There are still a good number of these in service. They take a lot of skill (and patience) to operate and maintain, but parts are easy to find, and these workhorses will play just about anything. There is a VR1200 and a VR1200B in the Quadruplex Park collection.
The AVR-1 is perhaps the most interesting and unusual VTR ever built. A total departure from what had gone before, the AVR-1 was an attempt to create a 'goof-proof' VTR that anyone could operate. And this at a time when you had to have considerable training and experience to operate a VTR properly.
Just about everything that could be made automatic was. There was an auto guide servo, auto tracking servo, auto standards selection, a timebase corrector with an entire line of memory, and easy-to-use setup aids. The video head even had a retractable vacuum guide to facilitate tape threading.
This machine, weighing in at 2200 pounds, was overengineered and overbuilt. Vaccuum columns accepted tape from the reels, which guaranteed perfect tape handling under any circumstances. They also allowed for the industry's first search dial, and shuttle speeds of 300 in/sec. A vacuum capstan eliminated the troublesome pinch roller, and allowed full reel servo action at any tape speed. Most of the tape guides were air lubricated, so the tape never actually touched the guide. The video head motor was an eight phase motor! The servos used digital error measurement and correction. This provided for nearly instant lockup from 'ready' (under 200 msec), and you could almost 'take' the machine like a camera. The servos would also allow playback of a tape without a control track.
The timebase corrector used a series of glass delay lines for dropout compensation and error correction. The delay lines were switched in and out as needed to correct for timing errors, and a small electronically variable delay line took care of the residual error. The timebase error was measured using both digital and analog techniques. All of the electronics in the machine were designed to be as unconditionally stable and drift free as early '70s technology would provide for.
The built-in air compressor was in a 200 pound box that was so well isolated you can't even tell the compressor is running. Even the cabinet was overbuilt-- machined blocks of aluminum were used where a simple bracket would have worked just fine. This machine was a tribute to American engineering at it's very best.
The mechanical design of the AVR-1 and the ACR-25 was the work of Dale Dolby, brother of the quad pioneer (and noise reduction system inventor) Ray Dolby.
There are minor variations in the AVR-1 through it's production run. Early models had a small low pressure air pump that supplied guide air and guide vacuum. Later machines derive these items from the bearing air supply.
There were only 500 of these machines made, and most have gone to 'VTR heaven' because they were very difficult to maintain. There is an AVR-1 in the Quadruplex Park collection, and it is the centerpiece of the collection!
The Ampex AVR-2 was almost a reactionary throwback from the AVR-1. It was housed in three modules that were under 200 pounds each, and could be set up in a number of different configurations. The total weight of an AVR-2 in it's console was 635 pounds. You could also plug it into an ordinary wall outlet. (External compressed air was required. Just for a note, an AVR-1 requires 220 volts at 22 amps!)
The AVR-2 was stripped down compared to the AVR-1. The guide position was full manual adjust. The auto tracking servo was optional, and not frequently installed. However, a 1 line fully digital timebase corrector, velocity compensator, and dropout compensator were standard features. A stereo audio headstack was available-- the first quad machine to have stereo. The servos were quasi-digital, and not nearly as good as the AVR-1. The machine was genlockable, and would run on it's internal refrence. The signal system was high band only, with super high band an option.
Despite not having all of the AVR-1's bells and whistles, the AVR-2 was easy to operate and stable. It was also ideal for installations with little space, such as remote trucks.
No significant variations of this machine exist, except for the addition of proportional reel servos in later machines.
Today, there are more AVR-2's in serious use than any other Ampex quad machine. They also retain the most value-- about $1,200-- of any Ampex quad. (They were $60,000 new!) Quadruplex Park has three AVR-2's and a set of the very rare super high band modulators and demodulators.
The Ampex AVR-3 was supposedly an AVR-1 without the vaccuum columns, but it does employ a vaccuum capstan, like the AVR-1.
Note the unusual tape transport area. It looks like a cross between an AVR-1 and an AVR-2. The machine features a vaccuum capstan, like the AVR-1, but has mechanical compliance arms (under the cover) to control tape tension. Much of the machine's electronics are identical to the AVR-2, especially the TBC. The machine has definitely been 'minaturized' to a great degree, but still weighs in at a hefty 1100 pounds. It is also shown with an 'up-to-date' Tektronix color monitor (An available option at the time. This machine would probably be very common if it wasn't produced so close to the end of the quad era. Still, there are a fair number of them out there.
The Ampex VR3000 is a portable, record-only quadruplex VTR that was built for field acquisition. Despite it's Mark 11 ball-bearing head, the machine was quite capable of color. Power was supplied by silver oxide rechargable batteries. In use, the operator wore it on his back while handling a heavy, bulky camera. (It took great strength to be a videographer in those days! In fact, legend has it that the machine bent the dummy that was wearing it at the first NAB show where it was exhibited!) Despite being in production a fairly long time,relatively few were made, and there are only a handfull machines that I know of still in existence.
THere is one variant of this machine, a VR3000B. Most of the improvements in the B version apparently had to do with improved tape handling.
Quadruplex Park has a VR3000. It is in very good and complete condition, and I hope to soon have it running.
The Ampex ACR-25 is a quadruplex spot player built on AVR-1 technlolgy. It would hold 24 SMPTE quad carts, and could play ten second spots back-to-back. Like the RCA TCR-100, it had two complete tape transports and servo systems. There was one common video signal system and timebase corrector for both transports. These electronics were in a seperate unit. An AVR-1 could be used for the signal system/timebase corrector, as well.
These machines are pneumatic monsters. They contain an air system that would be at home in a factory! Air is used to move most of the non-motor moving parts of the machine. Just like the AVR-1, the ACR-25 had miniature vacuum columns and a vaccuum capstan. Puffs of air were used to get the tape into the right spots for threading.
Late model ACR-25's were equipped with the AVR-2's digital timebase corrector.
One variation of the ACR-25 exists, the ACR-25B. This machine features an AVR-2 Timebase corrector subsystem.
Sadly, all spot players like the ACR-25 (and the much more modern, all digital ACR-225) were obseleted almost overnight by computer-based video servers. Video servers have tremendous advantages over mechanical monsters like these, and were an overnight success.
It is said that the acronym 'ACR' was selected, because it is 'RCA' spelled backwards! :-)