Return to Part 1 of RECORD CHANGERS.

Advance to Part 3 of RECORD CHANGERS.


The advent of World War II in 1939 changed much of the record changer industry. Because of Roosevelt's embargo on trade to Japanese possessions, the record industry had to change the way they were making records. Shellac (used in 78-RPM records) was in short supply, so cheap binders were added to the material, and cardboard was sometimes embedded into the record. Also, the rims of the records, which had been rounded before, were now squared off. Most of the record changers produced before the war started breaking these records. The knives used to separate the records no longer fit between the (no longer rounded) rims, and instead chipped the edges of the records or broke them in half. The assembly line and Capehart changers also tended to break these records, and the RCA throwoff changers were the worst offenders, breaking most of the records they ejected.

The changer manufacturers had a sudden panic, and searched for more gentle ways of handling records. At first, they tried removing one knife shelf and substituting a plain shelf in slicer changers. This helped only slightly. But the overall result was the general development of what was then called the "push-type" record changer. The first of these was the Garrard RC-6 on the previous page. In this kind of changer, the record stack is held up by a ledge on the spindle, and by one side platform. To drop a record, a lever or cam in either the side platform (Garrard - UK, and Utah-Detrola and Admiral - US) or in the spindle (General Instrument, Westinghouse, and Motorola - all US) pushes the bottom record to one side and off of the ledge and platform. An offset in the spindle or a latch holds the rest of the records back, so they don't drop. This device handled the records gentler than the knives used earlier did. Variations appeared where the entire side shelf (Webster - US, and the original Garrard RC-6), or the entire spindle (Philco - US) moved to drop the record.

The Motorola, Silvertone, and later General Instruments (204 and 205) changers used a rotating cam in the spindle. The spindle cam changer is labeled "Spindle push and shelf" in the above diagram, except that the spindle had a rotating segment instead of a pusher blade (Diagram "Spindle B" shows a pusher blade). An example made by General Instruments appears below. But the earlier General Instruments 203 changer and the Galvin-Motorola B2RC had the first spindles with pusher blades.

An interesting sidenote is that many users of the rotating spindle-cam-type changers damaged their records by not understanding that they had to turn the top of the spindle between the changing and the unloading positions. They put the records on in the unload position and they fell, breaking out the shellac around the center holes. The rotating cams also wore the edges of the center holes, beveling them. Since the pusher blades did not do this, most changer manufacturers eventually changed to pusher blades.

  • Maguire developed a system with two pusher shelves on opposite sides of the record and a notched center spindle. One shelf pushed the record into the notch to separate it from the stack, and then the other shelf pushed it out of the notch to drop it. The second pusher had a feeler to detect the record when it came into the notch. If no record was felt, the changer shut itself off. The shelves had to be turned for record size by hand. This changer did not work with warped records.
  • Farnsworth came up with two variations on the push type changer. The first, P-2, had two pusher shelves and a notched spindle, similar to the Maguire. P-41 is similar, but has two sets of extra hooks that hold the record on both sides after the pushers act, then simultaneously release it so it falls flat. This unit also senses the pushed record, to check for the absence of records for automatic shutoff. A control knob sets both shelves for record size. This unit also worked very poorly with warped records.

    The later Farnsworth variation was its P-51. It had two rotating shelves and a fixed pusher shelf. During the cycle, the rotating shelves moved under the record. Then the fixed shelf pushed the record to separate it from the stack. After this, the rotating shelves and hooks on the fixed shelf dropped it, after the weight of the rest of the stack had been removed from it. The record clamp on the fixed shelf activated automatic shutoff.

  • Lincoln developed a 2-side assembly line changer that brought the label-sized carrier arm to a feed stack of records, and used vacuum to pick up the top record and put it on the turntable. Then it played one side, inverted the turntable to play the second side (holding the record up with vacuum), and then dropped the record onto a second stack of already played records. A one-side mode was also provided, where the turntable inverts just to drop the record. This unit played the drop-automatic and manual sequences, and shut itself off after the last record.

    This is the only record changer made during this time that had no change cycle cam. The change cycle was operated with a series of vacuum-operated valves and actuators. The end of each process in the change cycle started the next process. See page 3 for photos of a 3-speed version of this (which worked in a slightly different way, playing the slide-automatic sequence instead of the drop automatic sequence).

  • Thorens created a 2-side drop changer with a rotating spindle and balancing disc. The turntable rotates in one direction, while the top of the spindle and the balancing disc rotate in the other direction. The head of the tonearm turns upside down to play the bottom side of the bottom record on the spindle ledge. The spindle design works in a similar way to those on the Collaro changers made after 1967, but it was actuated from the top. The changer shut off after the last top side was played. It had a velocity trip.
  • Just a few months before the US entered World War II, RCA started making its 2-side "Magic Brain" record changer RP-151. This was a drop-throwoff changer that could play both sides of the records. It had one fixed shelf plus two knife shelves for the dropping mechanism, but with no center spindle through the stack. A guide centered the dropped record on the label-sized turntable that turned it, and a forked pickup arm played first one side, then the other (the turntable reversed rotation for the other side). Then the turntable tilted and dropped the record in a bin.

    The 2-side "Magic Brain" had to be adjusted by hand for record size. It could also be set to play only the top sides of the records. This "Magic Brain" stopped playing when the stack was over, not because it had an automatic shutoff device, but because there was no record there for the arm to play. The changer just sat there spinning its tiny turntable until you turned it off. The Magic Brain could use either the drop-automatic sequence or the manual sequence.

    Very few of these were ever made, for two reasons:

    1. Factory production was commandeered by government for World War II shortly after manufacture of this changer began.
    2. Knife-type changers were breaking the substandard records necessitated by the lack of shellac. It was not made after the war because people wanted push-type changers.

    Thus, World War II deprived us of the Garrard RC-100 (see page 1), the Capehart turnover changers (see page 1), and the RCA RP-151 two-side changers. The Capehart persisted a few years after the war, but people were warned not to change wartime records on them.

Pic of record dropping methods

Garrard RC-70

Garrard RC-70 shelf-push changer


Farnsworth-Panamuse P-2 double-push changer

Farnsworth P-51

Farnsworth P-51 shelf-push changer

Utah changer

Utah-Detrola shelf-push record changer

General Instruments 205

General Instruments spindle cam 205

Webster-Chicago Model 56

Webster-Chicago model 56 nodding-shelf changer

Thorens CD-50

Thorens CD-50 2-side changer

RCA Magic Brain

RCA Magic Brain 2-side changer
Note the forked arm

Mixer changers

One disadvantage of the rim-push-type of changer was that record sizes could not be intermixed, because the shelf had to be adjusted for the size of the records. Webster (US), Garrard (UK), Thorens (Switzerland) and Zenith (US) made push-type mixer changers, but they were ungainly, and were easily damaged because the spindle had a very pronounced S-bend in it. Another more rugged mixer changer was made by Dual (Germany), which used a balancing disk (a forerunner of the overarm). All of these mixer changers except the Thorens use the shelf to push off the record to be dropped, and all shut themselves off after the last record. The Thorens had a pusher in the spindle that was actuated through the strange overarm that did not touch the stack, and its spindle was removed to remove the records, and for single play.

V-M had a spindle cam changer with a shelf adjustable for 10" or 12", and a drop feeler. Sparton sold it under its own name. If the shelf was placed in the 12" position, and the first and last records were 12", it could intermix 10" and 12" records. But it then repeated that last 12" record as 10", spoiling an otherwise good design.

The Lear PC 206A worked about the same way as the Sparton, but it shut off after the last record.

The Collaro (UK) RC-1 push-type mixer changer also had a forerunner of the modern overarm. The entire crossarm hinges up to the rear for loading, taking with it the top half of the spindle. The records are loaded on the half of the spindle that goes up with the crossarm. This changer has the pusher in the spindle, actuated through the crossarm. It shut off after the last record.

The spindles also underwent some changes during this time. The Garrard and Dual changers required that the spindle be removed before the record stack could be removed. Other manufacturers had fixed spindles, and used a sliding or revolving latch to hold the second record back (so it didn't drop too). Notice the hinged (instead of sliding) record latch (or guide) on the Zenith spindle. It swings one way to hold the stacked records in place, and the other way so they can be removed from the turntable easily.

Another disadvantage of the drop-type changers (but not most mixer changers) that was not seen in earlier designs was that the last record repeated over and over, unless an extra mechanism was added to shut off the changer. So more research and development was needed. One item that was noticed early in development was that the shutoff had to be delayed from the time the spindle became empty, so that the last record would play. But all manufacture of this sort was commandeered by government for the war, so the designers went ahead and dreamed up new devices, and waited for the war to end so they could try them out on the public. After the war, the budget changers often repeated the last record, while the more expensive ones shut off after the last record.

The early automatic shutoff methods were often different from the method used on all changers since the mid 1950s. The Zenith units turned off the power when the velocity trip actuated on the last record, instead of starting a change cycle. So the arm was left at the end of the last record. V-M changers with auto shutoff returned the arm to the beginning of the last record (mixer changers returned it to the 10" position no matter which size was last) and just turned off the motor. Garrard stopped the cam in the middle of the cycle for shutoff, and some of the Webster units returned the arm to its rest, but did not shut off the power.

Zenith Cobra-Matic

Zenith Cobra-Matic mixer changer had a unique
chain-driven change cycle mechanism.

Dual mixer changer

Dual 1000, from the 1940s

Webster Chicago model 70

Webster-Chicago model 70 mixer changer with velocity trip

Collaro RC-1

Collaro mixer changer RC-1

Garrard RC-60

Garrard RC-60 mixer changer

Thorens CD-40

Thorens CD-40 mixer changer


For two years after the war ended, the record changer industry got back on its feet.

By now, the industry had discovered that a mixer changer generally has to feel each record while it is dropping from the stack. The sensor on the Zenith Cobra-Matic (above) is easy to find -- it's red. It moves toward the spindle at the beginning of the change cycle, and if a 12" record drops, it strikes the sensor and moves it away from the spindle. Near the end of the change cycle, the sensor moves away from the spindle, so the user can remove a 12" record from the turntable if needed. As record dropping methods improved, mixer changers became easier to make:

  • V-M (US) invented the modern overarm to replace the side shelf, and reintroduced the pusher blade in the spindle, but combined it with the latch. This allowed the push-type record changer to take intermixed record sizes easily. That pusher blade in the spindle pushes each record off of the spindle ledge to drop it. The latch keeps the rest of the records from dropping too. V-M used a simple drop feeler to tell the difference between a 12" (30 cm) record (a record struck the feeler) and a 10" (25 cm) record (no record struck the feeler) while the record dropped down the spindle. Look for it near the pivot of the pickup arm in the picture. The height of the overarm told the changer when to shut off after the last record (although on this changer, the overarm was actually used to block the travel of the record pusher blade, and the pusher then sensed that there were no records on the spindle by not being able to move. The arm was returned to the record, and only the power was turned off when the changer shut off. The V-M 400C shown had a velocity trip, but earlier 400 models had eccentric trip.
  • Universal Camera made a strange changer that used flaps that rested on top of the record stack from opposite sides instead of an overarm. It resembled the Collaro RC-1 except that there was no crossarm across the stack, and the spindle did not separate into two parts. It also had a pusher blade in the spindle and a feeler for record size, but instead of dropping the record, it lowered it slowly to the turntable by lowering the pusher blade. The record rested on an extra projection on the pusher blade. That was one gentle changing mechanism! When the balancing flaps fell below the height of the spindle ledge, it told the changer when to shut off after the last record. This had a velocity trip.
  • Perpetuum-Ebner (PE - Germany) came up with a magazine-type drop record changer with a long straight spindle and two spiral posts, one on each side of the turntable. Each record rested on one turn of each spiral. To drop a record, both spirals made one rotation in the direction that moved the records down, causing the bottom record to drop from the spiral to the turntable. A drop feeler sensed the size and presence of the falling record. The spindle had to be removed to remove the records.
  • Meanwhile, Farnsworth (US) produced the first practical umbrella-type spindle (Garrard had one earlier, but it damaged records). It wedged a rubber ring against the center holes of all but the bottom record, and then retracted three fingers to drop the bottom record. It had no side platforms or overarms at all. This also used a drop feeler to tell 12" and 10" records apart, and used the weight of the records on the spindle to shut itself off when the last record ended. This was also called the Farnsworth-Capehart Gravity Record Changer.
  • Milwaukee-Erwood developed a strange record changer. This unit was unique, with its spiral ridge on the underside of the turntable. The ridge moved studs with rollers on them sideways to power the change cycle. GE used these shelf-push changers for several years. They repeated the last record.
  • Collaro had an overarm changer shortly after V-M made theirs. But it did not intermix sizes at first, because a size-selector switch set the record size. For some strange reason, both V-M and Collaro used an overarm with a hole in it for the spindle to fit through. Later Collaro also added a drop feeler to intermix 10" and 12" record sizes.
  • Markel (US) introduced a 2-side push-type record changer that dropped the records but did not turn them over. Duo Playmaster first dropped each record onto a set of three wheels that were rolling on the turntable (or the records already on it). This rotated the record on the wheels in the opposite direction. The dual-stylus pickup arm moved under it and rose to play it. On the next change cycle, the wheels moved away, dropping the record onto the turntable, and the arm played the top side. Then the sequence repeated until it ran out of records, when the machine shut off, leaving the tonearm on the last record. (There was a reason for this. Can you find it? If not, look for the answer on page 4).

    The Markel also had a single-side mode for drop-automatic sequence albums and singles, in addition to the two-side mode for manual sequence albums. It could handle only one size record at a time, because the shelf had to be set for the record size.

Record size sensing methods

VM 400C mixer changer with overarm

VM 400C mixer changer with overarm

1949 Perpetuum-Ebner

1949 Perpetuum-Ebner spiral changer

Farnsworth gravity

Farnsworth-Capehart P72 Gravity Record Changer

Markel model 70

Markel Duo-Playmaster 70 playing bottom side of a record

Milwaukee Erwood

GE - Milwaukee-Erwood P6

Enter the LP

Then a bomb dropped on the industry! In 1948, Columbia (US) introduced a new Long-Playing Record (LP) that rotated at 33 1/3 RPM, and had a new groove size about 1/4 the size of the 78 groove. The tracking force had to be much lower too, or the record would be ruined. Suddenly the changer manufacturers had to scramble again. They had to get something on the market to take the LP record too, or lose sales to their competition. The first results were turntables that rotated at either speed, with an automatic changer for 78s, and a separate manual arm for playing LP records.

  • Columbia developed a manual player attachment turntable and arm that came with a switch, so it could be inserted between the 78-RPM record changer and the preamplifier of the audio system. The switch selected which turntable was connected to the preamp.
  • Philco, Milwaukee-Erwood, Zenith, and V-M (all US) all quickly rushed out record changers that played stacks of 78-RPM records, or could play single LPs using a separate pickup arm. General Electric (GE) still used the Milwaukee changers during this period. All of these changers but the Zenith repeated the last record of the 78 stack, and none of them controlled the 33 arm at all.
  • Later in the year, V-M and Webster developed 2-speed changers with dual-stylus pickups that could change stacks of either 78 or 33 records. V-M had both shelf and overarm versions of these. The shelf version repeated the last record, but the overarm version shut itself off (returning the pickup to the last record) and intermixed record sizes. Both had eccentric trip. Notice the nearly identical pickup arms on both changers, excepting that the overarm version has the size feeler sticking out near the arm pivot.
  • V-M also made a 33-RPM changer for Columbia. It looked a lot like their 78-RPM overarm changer (above), but ran at only the 33-RPM speed.
  • Most of the European brands did not rush to produce machines that could play the LP, because LP records were not yet available in Europe. So almost all European record changers that could take the LP were also designed late enough that the 45-RPM record was also incorporated into the design.


Milwaukee-Erwood 2-speed record changer

Zenith Twin Cobra

Zenith Twin Cobra 2-speed changer

VM 800 D

V-M 800 D changed either 78- or 33-RPM records

VM 403

V-M 403 changed 78- or 33-RPM records,
intermixed sizes, shut itself off

More fallout from the introduction of the LP came because the methods of tripping the record changer were found to be wanting at the lighter tracking forces needed for the smaller grooves. Here is some info on that:

  1. The position (or positive) trip (see diagram) was used in the earliest record changers. It tripped the changer when the arm reached a certain point on the record. The trouble was that the various record manufacturers could not agree on where that point was. Some labels deliberately made records to cause competing record changers to malfunction, but to work correctly on their own record changers. The early Columbia changers used position trip, and position trip continued to be used by some brands into the 1950s.
  2. Victor started using the eccentric trip to stop its wind-up players in the middle 1920s. In the early 1930s, jukebox manufacturers got all of the record companies to put eccentric finishing grooves at the ends of records, to tell the jukebox when the record was over. This eccentric groove caused the pickup arm to move back and forth when the record ended, and it was the wrong-way motion of the arm that tripped the change cycle. This caused trouble when it was used in home record changers, because it also tripped the change cycle if the listener wanted to move the arm back to repeat a portion of a record. Most changers with eccentric trip were provided with manual positions on their control knobs as a result.

    Eccentric trip was also used into the early 1950s, but then it caused trouble for early LP players, because it threw the lighter-tracking stylus out of the groove, possibly damaging both the stylus and the record. As a result, some makers of LPs stopped putting eccentric trip grooves on their records, replacing it with a simple lead-out groove. This caused some record changer manufacturers to retreat to the position trip again until it was all sorted out.

  3. Luxor, a Swedish company, came up with the "progress trip." It looked for the cessation of forward motion when the record was over. It worked with all kinds of finishing grooves, including none at all, but it took some time to trip the change cycle after the record ended. It also tripped a change cycle if the needle got stuck repeating the same groove, and it was left that way for about half a minute.
  4. Believe it or not, the answer was found in something old. The Capehart Turnover changer used a "velocity trip." This detected the increase in speed of the arm when the stylus entered the finishing groove. Webster had also used it in all of their push-type changers before and during the war. It became the dominant trip method in the industry, with almost no other tripping methods in use after 1952. It is still the most reliable trip known.

By the end of 1948, most US changer manufacturers had models that could change either 33 or 78 records. But most European companies, including Garrard, hadn't even added 33 yet when the next innovation was announced.

Record changer tripping methods


Just when it seemed that nothing could make things worse, RCA dropped another bomb (a big one) on the industry with the 45. This record had a new speed (45 RPM), a new size (7" or 17 cm), no eccentric groove at the end, and a different center-hole size (1.5" or 3.8 cm). (Well, at least the groove size was the same as the LP.) PANIC!

With this new record came a new changer with a fat center spindle and a spindle-slicer dropping mechanism (RCA just would not drop the knife-type changer - but did design the record so the knives wouldn't damage it). This changer is shown to the right. The changer repeated the last record until it was stopped manually. All of the little 45-RPM changers used position trip, except the Webster one with velocity trip. And all repeated the last record, except the Webster models and the V-M 1500.

RCA actually developed the "45" system in 1939, but had shelved it because of the war. RCA had used "Vitrolac" (vinyl) recordings before as radio transcriptions (1932 on), but they rarely lasted longer than 7 plays, because nobody had developed a pickup that could track the records without destroying them. But it seems likely that when Columbia solved the problem of the lighter tracking pickup, it opened the door for RCA to make the 45.

The 45 was designed to be thicker in the label area than it is in either the recorded area or the ring around the edge of the center hole. This kept the grooves of the records from touching each other, and provided a space for the record changing knives in the spindle to fit between the records without damaging them.

Not to be outdone, Columbia introduced the 7" 33 for singles. V-M made them a changer that took all 3 sizes, but ran at only 33 RPM (see below).

Webster-Chicago sold little coil springs that could be placed on the 33-RPM motor steps of their 2-speed changers so the platter could be made to rotate at 45 RPM. The user had to take the turntable off to add the spring for 45, or to take it off for 33. Manual play was needed for the 45s here, because the changer didn't have any automatic index for 7" records.

Now the industry had to completely redesign for these new records. Some of the wackiest record changers I ever saw came out of this period, most of them being sold in only the years 1949 and 1950. (Not to mention some of the wackiest albums too, with RCA releasing classical albums on 45 - irking when you consider that all early 45 changers repeated the last record again and again.)

RCA RP-168

A 45-RPM changer - RCA RP-168

WHY 45?

Les Paul actually gave us the 45 rpm speed by accident.

He ordered a record cutting lathe from a machinist. The specifications included 78 rpm, the 33 transcription record speed, and "another speed somewhere in the middle" The resulting design made it 45 rpm. Les Paul used it to record his sped-up guitar effects.

A record lathe company bought the rights to his lathe and manufactured it for studios - 45 speed and all.

RCA bought some.

The first 3-speed changer

Webster had the first changer that could change records at all 3 speeds and for all 3 sizes - but using only one kind of record at a time. It looked very much like the 2-speed model they came out with the previous year, with a small box of toys included. But you had to be an expert at mechanical devices to use it. You had to take the turntable off to change the "slow" position on the speed knob to be either 33 or 45 by putting the little spring on the motor shaft or taking it off (at least they provided a little stud to store it on). Then you turned the rest post to set the record size, either for 7", or for 10" and 12" records. In the 7" position, the pickup arm's rest position was closer to the spindle, so the auto shutoff didn't work and the changer repeated the last record (7" records were not heavy enough to work the spindle-weight auto shutoff anyway). If you were playing a 7" record, you had to clip an extension onto the nodding shelf (in the 10" position) so it could reach a 7" record. Otherwise, you rotated the shelf for 10" or 12" records. If a large-hole 45 was used, an adaptor ring (called a "spider") had to be snapped into the hole so the regular spindle could drop it. And the 7" shelf extension had to be adjusted for the different thicknesses of 7" 33 and 7" 45 records.

The second production run of 356 had a 3-speed drive for the turntable, so it was no longer necessary to take off the turntable to change speed. A second-run Webster 356 is shown to the right, set up for 7" 45.

Webster also made a conversion kit to make a 256 into a first-run 356. It included the motor shaft spring, a replacement rest post, the shelf extension, and a replacement arm raising disk.

Webster 356

First 3-speed changer
Webster-Chicago 356

More early 3-speed changers

  • Luxor (Sweden) produced a two-armed 78 changer - 33/45 player. It had a very interesting device on the 33/45 arm. They called it the "Rolling Pickup", and when it was placed on the record, it always sought the edge of the record and started playing it there. Their later changers used this feature to provide not only size intermix, but also the ability to play odd-sized records automatically.

    This changer changed 10" and 12" 78s, but played single 33s and 45s. The 78 changer shut off power after the last record, but returned the arm to the record again before turning off.

    Recordchangers has much more information on this brand. This index is listed under "feeler wheel" in the "Basic Size Sensing" diagram above.

  • V-M modified its 800 D to produce the 802 "Tri-O-Speed" changer. It could change 10" or 12" records, or be used manually to play 7" records, at all three speeds. It looks just like the 800 except for the third position on the speed control.
  • Admiral came out with a clumsy push-type 3-speed changer. It had to be adjusted twice for record size, once at the shelf, and once at a control knob with 7", 10", and 12" positions on it. It is shown set up for a 12" 78. Then they modified this, and made it even worse. This second version had the sizes and speeds on the same knob (and of course, it omitted some combinations). It also had to be set for size again at the shelf. These changers repeated the last record over and over, and spiders were needed for 45-RPM records. It is shown here set up for a 7" 33.
  • The RCA solution for 3 speeds in their consoles was to install a 2-speed V-M 403 record changer for small-hole records, and their own little 45 changer for large-hole records. Of course, neither played the competing Columbia single. This was amusing, because the V-M changer shut off after the last record, and the RCA changer repeated the last record. Giggle!

    Note: At first, RCA made the RCA 45 changers, but later RCA farmed out production to another firm. The first RCA design for 45-RPM records had the change cycle cam on the bottom of the turntable. The change-cycle on this completed in one turntable rotation - the fastest change cycle ever.

  • Markel modified its Duo Playmaster to play one or both sides of 10" or 12" records, or one side of 7" records. It shut off after large records, but repeated the last 7" record. The pickup head had to be changed to select the stylus size. Both heads had two needle points, for both sides of the records.
  • Zenith came out with its "Twin-7" record changer, with two turntables and one arm. Both turntables were small, and able to take only 7" records. Both turntables had raised centers, so they supported the records by only the labels. One turned at 33 1/3 RPM, and had a ledged spindle and a tiny pusher post. The other turned at 45 RPM, and had a fat slicer spindle. The user rotated the arm 90 degrees to play one speed or the other. The changer had a velocity trip, and repeated the last record.
  • Zenith also made a small turntable that fits on top of the 78 rpm turntable. Rollers use the rotation of the 78 turntable to turn the little one at 45. It has a little arm to play the 45.

Admiral 500

RC 500 - Admiral's first 3-speed, set to 12"

Admiral 550

RC 550 - Admiral's second 3-speed, set to 7"

Zenith Twin-7

Zenith's Twin-7

RCA Twins

RCA console with two changers

  • The first V-M 3-speed 3-size Tri-O-Speed changer was just a little better. V-M modified its single speed overarm changer for first 2 speeds (VM 402 and 403), and then 3 speeds (VM 405, VM 406, and VM 407). The 7" record forced VM to give up the shelf changer at this time. Although their changer design now had sizes and speeds on the same knob, it was an overarm changer, and so had no shelf to adjust for size. And it could intermix 10" and 12" records in the same stack. The 406 and 407 knob had 4 positions: 10-12" 78, 10-12" LP, 7" LP, and 7" 45. 405 lacked the 45 position, and had to be manually set for 45 by placing an expansion spring on the 33 step on the motor shaft.

    405 had eccentric trip, but 406 and 407 had velocity trip (necessitated by RCA's newer 45s without eccentric grooves). All three changers shut off after the last record. But spiders had to be inserted into large-hole records (notice how the overarm fit around the spindle, preventing use of a large-hole spindle). 406 is shown here to the right.

    One oddity of this changer was what happened if you tried to intermix 12" and 7" records in one of the 7" positions. The page author tried it once, reasoning that the 12" feeler could override the knob setting. But when the 12" record dropped, the arm set down in a position that would be correct for a 9" (23 cm) record. Another oddity was that, when it shut itself off, the arm returned to the record, and just the power switch shut off. The user had to manually return the arm to rest.

    The page author's first experience (as a kid) with the limitations of record changers was on a V-M 407 changer belonging to his grandfather. The grandfather had given the author a kid's 78 version of Perry Como's "Round and Round." The author's father and grandfather got into a small discussion while trying to play it on this record changer:

    "Turn the knob here! It's a 78!"

    "No, turn it here. It's a 7-inch record!"

    "But that's 33!"

    "We'll turn it there, then turn it to 78 once the arm sets down!"


    "Something's wrong, it missed the edge of the record!"

    "Try the 45 position."


    "It still missed. This record seems too small. Let me get a ruler
    Turn it to 78. This is a 6-inch record. We'll have to play it manually!"

    This caused the author to wonder (at age 5) why they don't make a record changer that is smart enough to be able to play all sizes and speeds of records automatically.

    (Note: 6 inches = 15 cm)

  • Webster came up with its "Duo-Seven" record changer with a single turntable. It had two interchangeable spindles, one for each hole size. The large-hole spindle rotated, but the small-hole spindle was stationary and worked with a fixed shelf to hold the edges of the records. This changer used a velocity trip, played 7" records (but not other sizes) at either 33 or 45 RPM, and shut itself off after the last record. The one shown here had Admiral's name on it.
  • Milwaukee-Erwood (US) modified its rim-push record changer (see brochure at right) to be adjusted to the various kinds of records through changing the spindle (note the three different spindles in the pictures). This easily wins a Rube Goldberg award. It could not intermix sizes, and repeated the last record. It still had their spiral on the bottom of the turntable to power the change cycle. GE continued to use these changers for quite a while into the LP era, and some RCA players had them too.

    Huh? What's an "all purpose" automatic record changer? Does it mend socks too?

  • Emerson had a 3-speed changer with a fixed 12" shelf and a spindle cam. Extra shelves folded up from below for 10" and 7" records. The shelves that were folded up told the changer what size to index for. It repeated the last record, had a position trip that moved the trip point for each speed, and did not take intermixed record sizes.
  • Webster came out with an umbrella spindle changer that took 7" 33s or 7" 45s.
  • Columbia contracted with V-M to produce a 3-size record changer that turned at only 33 RPM. It automatically indexed all 3 sizes, taking intermixed 10" and 12" records, or playing a separate stack of 7" records. The mechanism was part of the famous V-M Tri-O-Matic series (page 3), except that it repeated the last record. V-M also released 910, a 78 version of it, but it indexed only 10" and 12" records, intermixed, and repeated the last record. All of these had the velocity trip.
  • Thorens made 3-speed versions of the CD-40 and CD-50, labeled CD-43 and CD-53.


This chaotic state of affairs caused one hi-fi equipment reviewer to speculate that nobody would ever produce a satisfactory record changer that could handle all speeds and sizes. But little did he know how soon he would be proven wrong.

First 3-speed VM

V-M 406 Tri-O-Speed
First V-M 3-speed 3-size changer


Admiral version of
Webster's Duo-Seven

Milwaukee Erwood

Advance to Part 3 of RECORD CHANGERS.

Return to Part 1 of RECORD CHANGERS.

Special Record Changer Lists and Links


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