Dwight Cavendish Videocassette Duplication Systems and Components

FAQ Frequently Asked Questions

01. How do I decide what I need in a duplicator?

02. What are the differences in the CM2500 and CM5000 Duplication systems?

03. What are the benefits of the CM2500 system?

04. What are the benefits of the CM5000 system?

05. What do you mean by a group?

06. What is involved in assembly of the duplicator?

07. Can we buy just the components we need and integrate them into our duplicator?

08. Can I supply my own picture or waveform monitors?

09. Why do you use DIN connectors instead of XLR’s?

10. The DA’s and interfaces are built backwards, i.e. the BNC and RCA feed connectors are on the rack mount side, why?

11. DC stacks VCRs 10 high in a rack. Can we stack our racks for 8 VCRs in height instead?

How do I decide what I need in a duplicator?

You need to know the format of the dub VCRs first of all. Dwight Cavendish builds duplication systems for VHS, 8mm, ¾” U-Matic, Betacam and SVHS. Either professional or consumer machines can be used. Then you need to answer some questions:

1. How many masters will feed the duplicator? What is their format? The answer to these questions tells us what size and type of router to recommend.

2. How many slave VCRs in the beginning system and what model/type are they? The answer to this will help us decide what rack size to provide.

3. How many dub programs will run at the same time? This tells us how many feed groups will be required. A feed group is one independent output for a signal. The output can come from a router or directly from a master VCR.

4. Do you require in-cassette monitoring or will this be a record only system? If record only, how do you plan to check quality of the tapes? This answer will help decide on the VCR control system and make decisions about QC processes.

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What are the differences in the CM2500 and CM5000 Duplication systems?

The CM2500 includes in-cassette monitoring. After a typical duplication session the operator stops the slave VCRs, rewinds for a period of time and then puts the slaves into the play mode. The monitoring control panel, VS-628-01, allows the operator to look at the output of any VCR, typically in a sequential mode. All of the monitor switching is done remotely in the rack so there is only one video and audio cable coming back to the control panel. The output of each slave is viewed on the right hand picture monitor (when using dual 8” monitors) and the waveform monitor and the picture is evaluated for quality. Audio is monitored simultaneously on the audio monitor. A “QC VCR” switch allows individual control of each VCR and a “QC Eject” switch allows the operator to eject a bad cassette. Slave VCRs in this system must be record/play models. CM2500 systems are expandable to 2,500 slave VCRs in 20 groups.

The CM5000 system is a record only duplicator. The QC function is done off-line in a manual QC station such as the Dwight Cavendish QC-2 or automatically in the QCM. The CM5000 is nominally expandable to 5000 slaves but it could, in fact, be expanded almost indefinitely. Group size is expandable to 20.

The CM2500 and CM5000 systems use different components and are not interchangeable. Some components are common between the two systems, specifically the VS-628-03/05 group controls and the VS-628-08 auxiliary function control.

A VS-900-01 auto control will work independently or as a satellite of either system. Up to 8 VS-900-01 control panels can be used with either system.

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What are the benefits of the CM2500 system?

The CM2500 system eliminates the need for a separate QC station because it uses the record VCRs for double duty as QC playback machines. This system is so popular it outsells the CM5000 components and system by about 10 to 1.

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What are the benefits of the CM5000 system?

The CM5000 system speeds up production by allowing use of the slave VCRs for recording only, not QC. If using professional VCRs, capital outlay is less because the record only VCRs may be used and they cost less than record/play machines. Finally, interchange will be identified in the QC process where it could be masked in the CM2500 system. Interchange is the ability of a poorly aligned VCR to play back its own recording but that recording may not play back in any other VCR. Interchange may be minimized with good VCR maintenance.

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What do you mean by a group?

Slave VCR grouping is the way you build versatility and flexibility into the duplicator. A group can relate to either video/audio feed or machine control. When talking about video/audio we mean the feed from a router or directly from a master VCR to a distribution amplifier (DA) or series of looped distribution amplifiers. This makes the group of DA’s independent of whatever else is being dubbed in the system and feeds that particular signal to only the slaves that are fed from the DA or DA’s in that group. If it is a machine control group the same principle applies except machine control gets assigned at the group control panel. Usually, to avoid confusion, feed groups match machine control groups. The smallest machine control panel is 10 groups but they do not all need to be used. A small system may use only 2 groups. Another 10 group panel can be added for a maximum 20 groups.

Typically the smallest group of slaves is 10 VCRs in the CM2500 system. This makes full utilization of the 1 x 10 DA. A 100 slave duplication system could have 10 groups of 10 VCRs. This would allow a maximum of 10 different signals to be recorded independently. Of course, 10 master VCRs and a minimum 10 x 10 router would be required as well. All 10 groups could be fed the same signal or the first 5 groups would get one signal and the last 5 groups could get another. Each group is normally assigned a number, 1 through 10. So you could have one signal fed to the groups 1 & 2 (20 VCRs) and another signal fed to groups 3 through 10 (80 VCRs) or any combination of groups.

Groups smaller than 10 VCRs require that some DA outputs and some interface inputs are not used.

QC groups are also possible. This means you set up your QC in a CM2500 system to cycle through, say groups 3, 4, and 5 and to skip all other groups.

Groups are the key to a flexible system and they are one of the features of Dwight Cavendish systems.

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What is involved in assembly of the duplicator?

Dwight Cavendish manufactures everything necessary for a system except picture and waveform monitors and VCRs. Assembly is a matter of identifying each part of the duplicator, bolting the racks together and installing the components and cables. It requires some experience with video systems assembly and is not recommended for those with little video experience.

At present, an assembly manual does not exist. We charge so little for assembly that very few customers decide to assemble their own system. An assembled system is tested at our facility and then shipped blanket wrapped on air ride vans to the site. Site assembly is very easy because all of the cables that require connection are labeled clearly. There is still a need for some experience with installing the master and slave VCRs. If there is any question, complete instructions can be provided. Dwight Cavendish sales will gladly quote the number of hours and the rates for both assembly and engineering and you can make your own decision about installation.

In some cases a Dwight Cavendish engineer can be sent to the site for either complete or final assembly. We highly recommend this with certain systems, such as the QCM, Quality Control Management systems but most of the duplication systems can be shipped assembled without the need for on site help.

Ask the sales team if you are at all unsure of your abilities.

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Can we buy just the components we need and integrate them into our duplicator?

Yes. We sell a lot of distribution amplifiers, machine controls, routers and audio switch mix components in boxes. Dwight Cavendish specializes in duplication components, so if you need only machine control or distribution then we have it!

The VS-628-01 and allied components make up a monitoring system that can be installed in existing duplicators that either lack on-line monitoring or in systems where current on-line monitoring is not functioning properly. This was developed as an add-on to existing systems. Of course, we use the same components when we build a duplicator, again proving the flexibility of the component products.

Some of our distribution amplifiers are built in the standard “broadcast” type configuration with the outputs on the back and the tweaking pots on the front. These are almost exclusively sold as components for non Cavendish system applications.

So mix and match as you need, we like to sell components.

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Can I supply my own picture or waveform monitors?

If you are building your own duplicator from scratch, picking some components from Dwight Cavendish and some from your own favorites, you will probably want to supply your own picture and waveform monitors.

If we build a system for you we normally provide Sony and Tektronix monitors. We can integrate your existing components, monitors, black burst generators or other components for a small fee. This must be quoted by the job.

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Why do you use DIN connectors instead of XLR’s?

The DIN provides both left and right audio channels in one connector. It saves space when designing the components and is less expensive than XLR connectors. When we build a system we use DIN connectors to send balanced audio around the system and it is very efficient.

Some of the components use both DIN and XLR. The VP-710-01 audio switch/mix for example uses XLR for input because the input is usually from a master VTR, Betacam or other balanced audio source which typically uses XLR connectors. The VP-710-01 then uses DIN for outputs because it will feed our router which uses DIN for inputs. A perfect match in our world.

If you buy a component that uses DIN connectors we will always provide a connector in case you want to make your own cable. Of course, we also sell DIN cables already made up in various lengths.

DIN connectors work well when you get used to them.

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The DA’s and interfaces are built backwards, i.e. the BNC and RCA feed connectors are on the rack mount side, why?

Dwight Cavendish racks use a unique rack mount for distribution amplifiers and interfaces that allows us to mount these components in the rear of the rack. Since all slave VCRs are fed from the back this is the most logical arrangement. It also saves space in the rack by placing the components up above and away from the VCR shelves.

The DC rack brackets are available for use with any rack or your rack may have rear rack mount rails that can be utilized. It is a matter of being inventive and resourceful. These brackets have dozens of uses. We have used them for mounting components on wood shelves for trade show displays. Try one and see the possibilities.

Not all of our DA’s are built in reverse. The VP-722-01 is a 1x10 DA that has all outputs and inputs on the rear of the unit. Likewise, the new 1x16 DA is built the same way.

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DC stacks VCRs 10 high in a rack. Can we stack our racks for 8 VCRs in height instead?

Of course. It just means you have to plan ahead for complete utilization of components that are made in ten output or input configuration. Most of our new distribution amplifiers provide extra monitor outputs that you can use for VCR feeds. For example, the 1x10 VP-702-04 has two extra outputs so it could be used as a 1x12. A pair of these DA’s could feed three racks of 8 slaves very efficiently.

The VS-628-24 interface can be programmed to skip any unused inputs. So, if you stack 8 high, you just do not use inputs 9 & 10 and the monitor will ignore them.