Tag Archives: Ampex

ZinParts: Replacement belts and other parts for broadcast, professional and vintage VTRs and VCRs

Zin! VTR Works has parts available for a number of common VCRs, such as these high-quality replacements for Sony 3/4″ Umatic recorders:

A kit of all four belts seen below is only $43 plus quick shipping, INSURED! This one’s going to Canada! We’ve shipped kits to New Zealand, France, the UK, and quite a few customers here in the US of A.  Priority Mail get them to you in 1-3 days for less than the cost of FedEx Ground!


ZIN-ZinPart-Z-3-672-737-01-Sony BVU-VO Loading Ring Belt-Replaces Replaces Sony Part 3-672-737-01 on Sony BVU-950, VO-98xx, 96xx, 50XX, VP-7640, 7240 and others
ZIN-ZinPart-Z-3-672-737-01-Sony BVU-VO Loading Ring Belt-Replaces Sony Part 3-


Replaces Sony Part 3-672-737-01

For Sony BVU-950, 900, 920, VO-98xx, 96xx, 50XX, VP-7640, 7240 and others

$11.00 plus any applicable tax and shipping


ZIN-ZinPart-Z-3-653-387-00-Sony BVU-VO-Cassette Elevator Belt-IMG_9777
Replaces Sony Part 3-672-737-01 Sony BVU-950, VO-98xx, 96xx, 50XX, VP-7640, 7240 and others


Replaces Sony Part 3-653-387-00

For Sony BVU-950, 900, 920,  VO-98xx, 96xx, 50XX, VP-7640, 7240 and others

$11.00 plus any applicable tax and shipping


ZIN-ZinPart-VO-FF-REW-TIRE replaces Sony-VO-Series Fast forward / Rewind tre


For Sony VO-series and VP-series 3/4″ Umatic recorders and players.

$11.00 plus any applicable tax and shipping


ZIN-ZinPart-Z-3-668-785-00, ONE FF/REW BELT Replaces Sony Part 3-668-785-00
ZIN-ZinPart-Z-3-668-785-00, ONE FF/REW BELT Replaces Sony Part 3-668-785-00 for Sony VO Series inc. VO-98xx, 96xx, 50XX, VP-7640, 7240, others


Replaces Sony Part 3-668-785-00

For Sony VO Series including  VO-98xx, 96xx, 50XX, VP-7640, 7240, others

This ROUND belt avoids the twisting problem square belts have over time, becoming twisted, and stressed as a result, which leads to failure.

These round belts from Zin! VTR Works have been installed in heavy-use environments for more than a year with no replacements required.

$11.00 plus any applicable tax and shipping

ZIN-ZinPart-Z 3-718-758-01

ZIN-ZinPart-Z 3-718-758-01-ONE AIR DAMPER FOR Sony BVU-950, ALSO FITS VO-98xx, 96xx, 50XX, VP-7640, 7240 and others
ZIN-ZinPart-Z 3-718-758-01-ONE AIR DAMPER FOR Sony BVU-950, ALSO FITS VO-98xx, 96xx, 50XX, VP-7640, 7240 and others

ONE AIR DAMPER  FOR Sony BVU-950, ALSO FITS  VO-98xx, 96xx, 50XX, VP-7640, 7240 and others

ZIN-ZinPart-Z 3-718-758-01-Air Damper-010

The Air Damper improves flutter performance.  Replace missing Air Dampers on your BVU-900, 920 or 950, or add it to units that never had the air damper’s benefits like the Sony VO-98xx, 96xx, 50XX, VP-7640, 7240 and other Sony 3/4″ Umatic VCRs.

Slides on.

$18.00  plus any applicable tax and shipping.

We’ll be adding pictures and more items to this page and shortly, and will have items available for sale through the new Online Moving Image Tools and Technology Store! So, bookmark this page or contact us using the link below and ask to be notified when the MIT&T Store goes on-line.

Zin! VTR Works has recently supplied a brand-new replacement motor for original equipment on an Ampex AVR-3 Quad VTRs. It took some digging, but we were able to find a replacement, and mounted Ampex parts onto the motor before returning it to the customer.

Pinch Rollers:

We can supply other parts including Pinch Rollers for various machines.

We’re taking orders now for a new batch of replacement Ampex Quad pinch rollers, made to Ampex specifications including durometer (hardness/softness) of the rubber.

We  also supply replacements for Sony 3/4″ pinch rollers, which are becoming or have become unobtanium from Sony and other distributors.

These are fresh, new rollers and new bearings, not old rollers stripped of the rubber and recovered. They fit Sony BVU 950, BVU-920, BVU-900, VO-9850, VO-9800, VO-9600, VO-5850, VO-5800, VO-5600, VP-7640, VP-7240 and other Sony 3/4″ Umatic VTRs.

Replacement for Sony X-3668758-3 Pinch Roller
Replacement for Sony X-3668758-3 Pinch Roller

For more information or to order, click here ted@ZinVTRWorks.com and let us know how to reach you by phone and e-mail and what parts you’re specifically interested in. Make, model of deck, and manufacturer part numbers help ensure we provide the correct part!

 How are your Pinch Rollers doing?

Quick Roller Condition test:

If you take your thumbnail and push into the rubber of the roller, it should go in, but when you pull your thumbnail away the indentation should disappear.

If it doesn’t disappear, the rubber is too soft. If you can’t make an indentation, it’s too hard.

How will ZinRollers be different from what else you may find?  Ken advises:

These would be of the proper durometer so that the tape can make a slight depression in the rubber.

That allows the roller to contact the capstan shaft above and below the tape so that the tape is moved by the pinch roller contacting the back side of the tape… rather than the capstan shaft driving the recorded surface of the tape as happens when the roller is too hard.

Correct durometer as noted above helps avoid tape slippage and video errors, increased capstan roller pressure, additional wear on bearings, etc.

These replacement rollers would be ground to final specifications with new bearings installed, so that the results are concentric and the correct diameter so you won’t have issues with flutter or speed.

These rubber rollers stay cleaner longer than replacements made from materials such as polyurethane that may be available.  Ken tried polyurethane rollers in customers machines (in one case, a large duplication facility) and heard complaints that operators were having to stop work to clean the poly rollers about every fourth tape. Not good, especially on cassette-based units.

Ken supplied and installed rubber pinch rollers, which resolved the problem and gave significantly longer times between the need to clean the rollers.

fxsys Green 1.5" x 35mm PTRAs you may know, Polyurethane is used to make Particle Transfer Rollers (PTRs) used on film transfer equipment to do exactly that… transfer particulate matter like dust off the film and onto the roller. Our parent company sells those for use with film scanners.



New or refurbished video heads or assemblies may be available for some decks. Ask us for details!

We are an authorized representative for Videomagnetics, which is the world’s last rebuilder of 2″ Quad VTR head assemblies.

We have other resources and can supply refurbished upper drums and scanners for a range of broadcast 1″, 3/4″, Betacam/BetacamSP/Digital Betacam and Panasonic DVCPro recorders.

We also have several genuine, factory sealed new (old stock) Sony RV-12 replacement upper drums for Sony’s early editing recorders, including BVU-800, BVU-200A and BVU-200, Sony VO-5850, VO-5850P, VO-2860 and VO-2850A:

Sony RV-12 Replacement Upper Drum
Sony RV-12 replacement upper drums for Sony’s early editing recorders, including BVU-800, BVU-200A and BVU-200, Sony VO-5850, VO-5850P, VO-2860 and VO-2850A

And, we have boxes of new (old stock) Sony parts we haven’t yet cataloged.  These include small motors, reel tables, brake bands, and a plethora of other small items.

For more information or to order, click here ted@ZinVTRWorks.com and let us know how to reach you and what parts you’re specifically interested in.

Contact us for Service, Parts and Consultation on Videotape Recorder Modifications and Videotape Migration Systems.

(530) 301-2931  ted@ZinVTRWorks.com

Going to extra-ordinary lengths…

In mid-December, Chief Marketing Officer Ted Langdell drove 400 miles from Northern California to Los Angeles to pick up equipment for Zinspection that an Eastern US customer bought at an auction when a film and video company closed.

Ampex VR-7800
Ampex VR-7800 that Ken built a custom wooden top for when he refurbished this machine in the mid-2000s for a Los Angeles film and video restoration company

Among the five vintage video recorders was a late 1960s Ampex VR-7800 1″ VTR that Ken Zin had refurbished for the now-closed company ten or so years ago.

Colleague Al Sturm built an interface box to allow the VR-7800 to be used with a 1986-era digital time base corrector.

The Eastern customer needed the machine inspected, repaired to working condition if needed, and shipped to them ASAP.

VR-7800 Playback
Playback of a VR-7800 test recording after Zinspection and adjustments — with Textronix 1780R Test Set

Ken’s inspection revealed the machine to be working. He thoroughly cleaned, tested functions, made adjustments to improve the playback quality.

Once satisfied that the machine was ready to ship, Ken built a crate for safe shipping.

Ted and Ken crated the VTR, boxed up the associated TBC and interface.

VR-7800 ready to ship by FedEx Heavyweight Air

Here’s the ZinCrate with VR-7800, Ampex TBC-6 and custom interface box strapped on tope and ready to ship to our Eastern customer from the FedEx Heavyweight Air terminal in Sacramento

Ted worked with the customer’s logistics department to get the items shipped via FedEx Express Freight, and drove the items 90 miles from the Zin! VTRWorks lab in Magalia (near Paradise east of Chico) to Sacramento on Christmas Eve in time to make a plane for next day delivery.

The boxes were pallet-wrapped to the crate for safety and protection, and then strapped to the crate. “We wanted to make sure all three items arrived at the same time, so our customer could set up and go right to work,” Langdell says.

The customer got the machine the morning after Christmas, and was able to have a batch of tapes converted to files, QC’d and delivered to its customer before New Years Eve, which was the deadline for them to complete the job.

ZinFurbishing an Ampex AVR-2: What Ken found

Ken has been working on Ampex AVR-2 Serial #197, which began life as one of a pair of machines at KRBK-TV, Sacramento, California.

Seen here at time of pickup, this third-generation Ampex Quad is in need of some TLC, which it is getting now.

# 197 is undergoing a thorough ZinFurbishment.

Crazy waveforms from AVR-2 at first power-upThat’s designed to identify and correct problems that make “fun” vector and waveform paDSC_2303tterns like those seen here…

Leaky capacitor on AVR-2 board

The ZinFurbishment will replace quite a few capacitors, such as the one on this board that leaked, destroyed its lead and trace on the board,


Crispy connectors
Poorly crimped connectors heated up due to resistance, and got crispy.

It will also  fix “crispy” power connections such as on the rectifiers seen here, caused by poorly crimped connectors.

Ampex issued a field bulletin advising to solder directly to the lug on the rectifier or other part, such as transformers.

The system did power up, but there were quite a few power supply related issues to be addressed. 

Fuseholder added
A fuseholder was put in circuit with circuit breakers instead of fixing cause of breaker trips.

Apparently, previous owners or engineers chose to “band-aid” some faults rather than fix them… like put a fuse in circuit with a circuit breaker because what was found to be a poorly crimped connection wouldn’t support the current requirements of the circuit.

3M RF tap
3M RF tap for external TBC added to back of AVR-2. Will be removed

Rather than deal with a problem involving part of the TBC, a workaround involving a 3M dropout compensator RF tap was installed.


(Heads were being scratched while contemplating “Why’d they do THAT?”)

Broken wire on connector
Broken wire on connector caused transport problem dangerous to tape

A wire break found on one of the transport harness plugs was responsible for no rewind capability.





A lot of small and large things have been discovered and fixed as the process of problem finding, identification and elimination continues.


AVR-2 electronics cage
AVR-2 electronics cage needs a lot of air to keep things cool. Only three of the six muffin fans under the cage were installed. And only two worked.

Instead of the factory complement of six muffin fans under the machine blowing air up into the electronics chassis, only three were found, and one of those was frozen… didn’t move.

That means the heat generated by the electronics wasn’t being removed, and could be the cause of overheated components, malfunctions and shorter time between failures.

People wonder why the cost of bringing back VTRs and VCRs can be expensive. These things are why. It can be a very time-consuming process, and time is money.

The basic electronic and mechanical issues need to be addressed before any “fine tuning” and finishing work can be done.

Once those items are addressed, we can see what to do about cosmetics, like worn paint and button legends.

AVR-2 control panel

The good news includes two Ampex Extender Cards for the electronics chassis (needed to do adjustments where circuits on several cards interact) and an audio preamp extender.

The head spun up fine and has good life… as tested on another VTR.

All in all, we expect to see this AVR-2 transferring tape reliably very soon for new users.

Zinfurbishing an Ampex AVR-3–An ongoing saga

Principal Engineer Ken Zin has been Zinfurbishing this Ampex AVR-3 in recent weeks.


When first powered up, mechanical and electronic problems prevented the machine from operating properly.

Over time, Ken’s identified problems with power supplies, connections, small electronic parts, and the mechanical assemblies that are critical to safe and smooth operation.

Ken attributes many of the problems he has been finding to lack of maintenance or shortcuts taken by previous engineers or owners who wanted to run the machine without fixing problems.

After giving the power supply a good bath (yep, soap and water, a scrubbing, rinse and plenty of sunshine afterward), Ken discovered a bad solder joint on the +5 volt power connection:

AVR-3 Power supply connections with bad solder joint on +5 terminal.
AVR-3 Power supply connections with bad solder joint on +5 terminal.

Without the connections being clean, this bad connection might go unobserved, creating instability in systems connected to it.

More obvious is this rusting, leaky capacitor in the +5 volt power supply:

Rusty and leaky capacitor in AVR-3 +5 volt power supply
Rusty and leaky capacitor in AVR-3 +5 volt power supply

Large capacitors like this one are used in AC to DC conversion to reduce the ripple found on the DC lines.  When they leak, the chemicals can damage other parts of the equipment. There’s also an increasing potential for the capacitor to rupture or become a fire hazard.

Aside from the safety issues, the lack of clean and stable power can cause electronic instability or unwanted machine behavior, with poorer tape reproduction or tape safety.  Since 30-40 year old capacitors are often at end-of-life, its common practice to replace all of the power supply capacitors like this, instead of fix just one and wait for the others to cause problems tomorrow.

Ken discovered that air supply hoses to an important sub-system had been removed.  A new set of hoses was fitted and checked for leaks.

Tension arm rollers were found to be in bad condition.

AVR-3 Take up side tension arm
AVR-3 Take up side tension arm found to be worn and bent

They have bearings inside that were worn… to the point of being frozen. That caused wear on the surface that contacts that tape, resulting in drag that could have damaged tape, likely resulted in less than optimal picture quality, and ultimately wore down one part of the rollers.

When laid on a flat granite surface plate as a check, it is easy to spot the wear:  Light shines through where the roller’s not flat against the granite:

Worn end of tension arm roller revealed by flat granite surface and light shining under worn area
Light reveals excessive wear when this tension arm roller was placed on a flat granite surface

These tension arms are supposed to be aligned with the tape path—especially the tape guide rollers before and after each tension arm.  A check with a flat steel jig showed the arms were  significantly out of alignment.

See how the light shines through on the far side of this tension arm?

Bent AVR-3 tape tension arm revealed by light shining through where none should show.
Bent AVR-3 tape tension arm revealed by light shining through where none should show.

The flat steel plate is perfectly flat on both guide rollers to the right, however the tension arm is skewed (bent) to the right, allowing light to shine through the gap with the steel plate.

Here’s a video of the kind of damage that results from this type of mechanical problem.

Notice how the tape is wrinkling and is not flat when passing from the top roller to the tension arm, and then onto the bottom roller.

Damage to valuable videotapes from poorly maintained machines are  a potentially costly problem for users if tape owners demand compensation for harm and loss of content, or take business elsewhere.

Archives playing gems from their collections on such machines risk their most valuable assets.

Ken attributes the bending of the arms to continued use of the machine when there was something else wrong with the transport systems.  Possibly repeated jerking of the tape caused by an unstable servo system or other undiagnosed problem?

With the tension arms now back from being fixed at a machine shop (at some expense) Ken advises this AVR-3 is handling tape much smoother, especially when ramping down from a fast to a slow shuttle. He says the vector dots are smaller and more stable in Play mode.

Ken Zin tests an Ampex AVR-3 being Zinfurbished
Ken Zin tests an Ampex AVR-3 being Zinfurbished

Machines that haven’t been treated well over time can require sometimes significant amounts of time to track down the problems and fix them, especially when parts are not routinely available.  Time equals money, which adds to the cost of refurbishing equipment.

But the value in a Zinfurbishment like this is that the equipment can be brought up to a reference standard.  With continued routine maintenance, Zinfurbished VTRs will give years of smooth, safe and stable playback of high quality pictures and sound.

There’s more to be done on this AVR-3, and we’ll add to this post as the process progresses toward a clean-looking exterior, renewed systems providing safe tape handling with pictures and sound that meet or exceed factory specifications.