Tracking Issues: Repairing a U-Matic Deck

Editor’s Note (2021-04-06): The following post is the second in a series of three written by Savannah Campbell on the topic of analog video deck maintenance and repair. These posts were written by Savannah in the spring of 2017 as part of an Independent Study project with media conservator/audio engineer Bill Seery and video engineer Maurice Schecter, and published on NYU’s Web Publishing service under the blog title “Tracking Issues”. At an unspecified point sometime after Savannah graduated later that year, NYU cut off public access to the site. Though the content was recovered (with an assist from Ben Turkus) and the blog re-published, I’ve offered to also host the posts here on The Patch Bay. For the whole series, also check out  “Swab the Decks!” and “Repairing a VHS Deck”! Thanks, Savannah!

For my first video deck repair project, I examined a Sony BVU-950 U-Matic machine. This deck was purchased at an auction and had been untested at the time I first looked at it.

Since this machine was completely untested, the first step I took was to plug it in, hook it up to a monitor, pop in a test tape and see what happened. The deck powered on and images from the test tape (color bars in this case) soon could be seen on the monitor. However, the tape was squeaking terribly and drop out was appearing intermittently, but at regular intervals. Another issue I noticed fairly quickly was that one of the fans was not functioning at all.

The first order of business was troubleshooting the problem of the squeaking tape and determining what the cause was. As this may have been an issue with the test tape itself (possible sticky-shed syndrome, with the binder layer from the tape flaking off), I first got another test tape to use. I also unscrewed the lid from the machine and cleaned all parts of the tape path with PEC pads and isopropyl alcohol. For more pervasive messes where debris was stuck onto metal posts and even the video heads, I used acetone to clean them completely (acetone is a much stronger solvent than isopropyl alcohol). After cleaning the deck, I put in test tape #2 to see what happened. The squeaking issue persisted. With the lid of the deck removed, I watched the tape run through the machine. I noticed that when the deck squeaked, it was also putting creases in the tape at regular intervals. It was a good thing I was using a test tape and not a tape from an archival collection!

One method for diagnosing issues involves running the U-Matic deck in “emergency mode.” In emergency mode, the deck will thread up the tape path WITHOUT the presence of an actual tape in the machine. This feature is only available on some deck models (including the BVU-950), and it is one way to examine all of the moving parts of the machine, such as the capstan, to make sure they are functioning. To run the machine in emergency mode, it is necessary to disconnect the tape elevator (as pictured above).

Side note: When undergoing a repair project, it is highly recommended to have the service manual on hand! By following the instructions in the BVU-950 service manual, I was able to run the deck in emergency mode and assess the condition of the machine.

After running the deck in emergency mode, all of the parts seemed to be functioning properly. With guidance from video engineer Maurice Schechter, we determined the problem was likely with either the capstan or the pinchroller. As the capstan was spinning normally when we ran the machine in emergency mode, we decided to take a closed look at the pinchroller.

I removed the pinchroller and took a closer look at it. The material on it looked work out and glossy. As seen in the picture above, the pinchroller looked very smooth and slick, not rubbery like it should be. Even worse, the pinchroller had developed a beveled pit towards the bottom of it. This is the culprit of the tape creases! The worn out pinchroller was pushing the tape upwards, causing the creases in it. Luckily, there were spare pinchrollers on hand and I was able to simply swap out the part right away. With a new pinchroller in place, the deck was no longer creasing the tapes.

Though the primary issue with the BVU-950 was resolved, I still had more to learn, and more tests to run.

Though the test tape was no longer being creased, it still seemed to be moving fairly sluggishly throughout the deck. The part of the machine responsible for spooling the tape back onto its take-up reel was not moving very quickly (the left of the two black hubs in the picture above). I removed the take up hub from its metal post and greased up the post to make it smooth and slick. When I removed the hub, I was able to get a better view of the brake system, and noticed that the brake pads were very worn out and smearing black debris everywhere. I removed the worn out brake mechanism (also pictured above) and replaced it with a new one. After this, the tape ran smoothly through the U-Matic deck.

Next up, I took a closer look at the video heads themselves. To do this, I used a tool called a Tentel Head Protrusion and Eccentricity Gauge. This tool can be used for measuring how far the video heads protrude from the drum, which can tell you how worn out the heads are and if it is time to replace them. It can also be used to make sure the video heads are aligned and properly positioned in the drum.

First, I attached the tool to the drum and gently spun the drum around to measure the video heads. The guide book the tool comes with includes a chart with the recommended length of a healthy video head (which changes depending on which video format one is working with. It will be different for U-Matic, VHS, etc.). The heads on this particular machine were below the recommended length, so Maurice and I decided to change the heads.

Placing the new heads in the correct position was by far the most tedious part of this repair process. To ensure the heads were aligned correctly, I again had to use the Tentel gauge. To align the heads, I had to gently (GENTLY) and repeatedly tap the drum until the heads were resting in the correct position. The sensitive video heads must be within 5 micrometers of the ideal alignment point in order to pick up the signal correctly. It was very easy to tap the head just a little too much and move it off target. This process required lots of time and patience, but I eventually got the new heads aligned properly and screwed them into position. Once in position, I used the Tentel gauge to measure the protrusion of the new heads and wrote down their length.

To document this repair and leave notes for future engineers, I made a note of the drum itself with sharpie. I mentioned that the heads were replaced and noted the T/P (tip protrusion) of the V (video) and E (erase) heads, as well as the total number of hours on the drum. I also noted the date and left my initials.

To perform one last, thorough cleaning of the deck before I closed it up, I took an air hose and blew out all of the dust inside of it, leaving it as pristine as possible.

Throughout this process, I did not forget the issue of the malfunctioning fan I noticed when I first tested out the machine. When I plugged it back in again to test the new heads, one of the machine’s two fan units was not moving at all, and the other fan was moving very sluggishly.

To remedy this problem, I removed both of the fan units and replaced them with brand new ones. Fans for video decks can easily be found online (as similar fans are used in all sorts of electronics, including computers). To select the proper fan, one just needs to note the size and voltage of the fan already in a video deck, and purchase a replacement of the correct size and voltage.

With the new fans in place and the deck in otherwise good working order, I was finally able to screw the lid back on the BVU-950 and call my first major video deck repair project complete.

For the next post in the “Tracking Issues” series, continue to “Repairing a VHS Deck”.

Savannah Campbell (M.A. in Moving Image Archiving and Preservation from NYU, 2017), is now a Media Preservation Specialist, Video & Digital Media at the Whitney Museum of American Art in New York City. Prior to coming on board as part of the Whitney’s Media Preservation Initiative, she was a Fellow in Magnetic Media Preservation at The Standby Program and worked on audiovisual projects for the Dance Heritage Coalition, CUNY TV, and Crawford Media Services.

Tracking Issues: Swab the Decks!

Editor’s Note (2021-04-06): The following post is the first in a series of three written by Savannah Campbell on the topic of analog video deck maintenance and repair. These posts were written by Savannah in the spring of 2017 as part of an Independent Study project with media conservator/audio engineer Bill Seery and video engineer Maurice Schecter, and published on NYU’s Web Publishing service under the blog title “Tracking Issues”. At an unspecified point sometime after Savannah graduated later that year, NYU cut off public access to the site. Though the content was recovered (with an assist from Ben Turkus) and the blog re-published, I’ve offered to also host the posts here on The Patch Bay. For the whole series, also check out “Repairing a U-matic Deck” and “Repairing a VHS Deck”! Thanks, Savannah!

When encountering a video deck that is not playing back a signal properly, one of the first steps of troubleshooting problems is to examine the deck (especially the video heads) for signs of dirt and other debris. Running old tapes tapes through a deck can cause them to shed particulates onto the machine’s tape path, clog the heads, and prevent the deck from being able to read subsequent tapes. Additionally, some parts of a video deck are made of rubber, which can degrade over time. Old rubber can turn into black goo that can smear throughout the deck. In other areas of the machine, glue holding mechanical parts together can melt and also wreak havoc. All sorts of goop and debris can hinder how a VTR plays back tapes, impeding a tape’s journey throughout the deck or clogging the heads so the machine cannot interpret a tape’s video signal.

There are many cleaning solutions and materials available for cleaning video decks. In this post, I will discuss several different kinds of cleaning supplies and their effectiveness at scrubbing various deck components clean.

Cleaning Solvents:

Isopropyl Alcohol

The mildest, gentlest cleaning solution recommended for cleaning video heads is isopropyl alcohol. Isopropyl alcohol is safe to use on almost all parts of a video deck (metal, plastic, circuit boards, etc.), which is why many in the archival profession will recommend it as the best and safest option for cleaning VTRs, especially the sensitive playback heads. It is best suited for use on machines that will be regularly cleaned and are currently used for playback/digitization. Isopropyl alcohol is good for minor clean-up tasks, such as wiping dust particles and minor debris that was left behind from a tape with sticky-shed syndrome. If using isopropyl alcohol, one should purchase a solution with as little concentration as possible. 90% isopropyl or higher is recommended.



Moving from mildest to most severe cleaning solutions, xylene is the next-strongest solvent after isopropyl alcohol. Xylene is effective at cleaning up more pervasive remnants of gunk/debris, especially on the metal parts of the machine. Be careful about using xylene on plastic components, as it could melt them, and never use it on any rubber components at all as it will dry them out.



The strongest solvent recommended for cleaning VTRs is acetone. Acetone is absolutely the most effective solution for removing gunk, goop, glue, and debris. Though acetone is a very powerful solvent, it can still be safely used to clean anything metal, as well as circuit boards. It is even safe to use on the video heads themselves, especially if they are particularly clogged with goop. Acetone should never be used on plastic or rubber because it is strong enough that it will melt these materials. However, for the dirtiest of the dirty decks out there that have not been opened up or cleaned in years, acetone will get the job done.


Cleaning materials:


Q-Tips are great for cleaning any hard-to-reach nooks and crannies in the machine. For cleaning video decks, the Q-Tips with long handles are well-suited for the task. Though some cleaning swabs can leave fibers behind in the deck, the less-fluffy varieties of Q-Tips are a good option for deck cleaning and are less likely to shed in the machine. Q-Tips are best-suited for cleaning metal posts and hard-to-reach mechanical parts. Do not clean the video heads themselves with Q-Tips.


PEC Pads:

PEC Pad wipes are well-suited for cleaning decks, especially video heads and other easy-to-reach parts of the tape path. Anywhere the tape itself touches can be cleaned with a PEC Pad. PEC Pads are also recommended to use because the cloth does not leave any fibers/lint behind. If you use a cheaper, flimsier type of wipe (like KimTech wipes or tissues), they will shed all over the machine and create another mess to clean up. PEC pads are both sturdy and soft, and can be used safely on any part of the deck. To clean a video head, the best practice is to hold a PEC Pad doused with alcohol completely still against the drum/heads, and rotate the drum underneath it, making sure to apply sufficient pressure with the pad.


For audiovisual archivists or video engineers that finds themselves without PEC pads or Q-Tips, a page from the day’s newspaper is a surprisingly effective option for cleaning a video deck. Newspaper is completely safe to use on the deck with any type of solvent. Ink will not get on the deck, and the paper itself will not leave any fibers behind. Newspaper is sturdy, yet gentle enough to be a reliable and affordable option for cleaning a deck. Just tear off a piece, douse it in your favorite cleaning solution, and wipe the deck clean! If print newspaper is not available, sturdy paper like from a legal pad can work in a pinch, though printer paper is not stable enough for the task (it will leave fibers behind).

For the next post in the “Tracking Issues” series, continue to “Repairing a U-Matic Deck”.

Savannah Campbell (M.A. in Moving Image Archiving and Preservation from NYU, 2017), is now a Media Preservation Specialist, Video & Digital Media at the Whitney Museum of American Art in New York City. Prior to coming on board as part of the Whitney’s Media Preservation Initiative, she was a Fellow in Magnetic Media Preservation at The Standby Program and worked on audiovisual projects for the Dance Heritage Coalition, CUNY TV, and Crawford Media Services.

Upgrading Video Digitization Stations

In the primary MIAP lab we have four Mac Pro stations set up mainly for video digitization and capture. They get most heavily used during our two Video Preservation courses: Video Preservation I, which focuses on technical principles and practice of digitization from analog video sources, and Video Preservation II, which focuses more on vendor relations and guiding outsourced mass digitization projects, but by necessity involves a fair amount of digital video quality control/quality assurance as well. They get used for assorted projects in Collections Management, the “Talking Tech” workshops I’ve started leading myself, and the Cinema Studies department’s archive as well.

Over the course of 2016, the hardware on these four stations was really starting to show its age. These machines were originally bought and set up in 2012 – putting them in the last generation of the older “tower”-style silver Mac Pro desktops, before Apple radically shifted its hardware design to the “trash bin” style Mac Pros that you can buy today. The operating system hadn’t been updated in a while either, they were still running Mac OSX 10.10 (Yosemite), whose last full update came in August 2015 (with a few security updates still following, at least).

This guy isn’t allowed in anymore, for instance.

These stations were stable – at least, in the sense that all the software we needed definitely worked, and they would get the job done of digitizing/capturing analog video. But the limitations of how quickly and efficiently they could do this work was more and more apparent. The amount of time it took, to, say, create a bag out of 200 GB of uncompressed video, transcode derivative copies, run an rsync script to back video packages up to a local NAS unit, or move the files to/from external  drives (a frequent case, as both Video Preservation classes usually partner with other cultural organizations in New York City who come to pick up their newly-digitized material via hard drive) was getting excruciating relative to newer systems, wasting class time and requiring a lot of coordination/planning of resources as ffmpeg or rsync chugged along for hours, or even overnight.

So, I knew it was time to upgrade our stations. But how to go about it? There were two basic options:

1. Purchase brand-new “trash bin” Mac Pros to replace the older stations


2. Open up the innards of the old Mac Pros and swap in updated, more powerful components

Buying brand-new Windows stations was basically out, just given the way our classes have been taught, the software we work with, and my own personal knowledge/preference/ability to maintain hardware. And I was lucky that #1 was even an option at all – the considerable resources available at NYU allow for choices that I would not have many other places. But, MIAP also has a lot of equipment needs, and I’d generally rather stash larger portions of our budget towards harder-to-get analog video equipment and refurbishment, than jump for splashy new hardware that we don’t actually need. So I drew up some thoughts on what I actually wanted to accomplish:

  • improved data transfer rate between desktops and external drives (the fastest connection available, at best, was the mid-2012 Mac Pro’s native FireWire 800 ports; and many times we were limited to USB 2.0)
  • improved application multi-tasking (allow for, say, a Blackmagic Media Express capture to run at the same time as the ffmpeg transcode of a previous capture)
  • improved single-application processing power (speed up transcoding, bag creation and validation, rsync transfer if possible)
  • update operating system to OSX 10.11 (El Capitan, a more secure and up-to-date release than Yosemite and MUCH more stable than the new 10.12 Sierra)
  • maintain software functionality with a few older programs, especially Final Cut 7 or equivalent native-DV capture software

Consulting with adjunct faculty, a few friends, and the good old internet, it became clear that a quick upgrade by way of just purchasing new Mac Pros would pose several issues: first, that the Blackmagic Decklink Studio 2 capture cards we used for analog video digitization would not be compatible, requiring additional purchases of stand-alone Blackmagic analog-to-digital converter boxes on top of the new desktops to maintain current workflows. It is also more difficult to cheaply upgrade or replace the storage inside the newer Mac Pros, again likely requiring the eventual purchase of stand-alone RAID storage units to keep up with the amount of uncompressed video being pumped out; whereas the old Mac Pro towers have four internal drive slots that can be swapped in and out within minutes, with minimal expertise, and be easily arranged into various internal RAID configurations.

In other words, I decided it was much cheaper and more efficient to keep the existing Mac Pro stations, which are extremely flexible and easy to upgrade, and via new components bring them more or less up to speed with what completely new Mac Pros could offer anyway. In addition to the four swappable storage slots, the old Mac Pro towers feature easy-to-replace RAM modules, and PCI expansion slots on the back that offer the option to add extra data buses (i.e. more USB, eSATA, or Thunderbolt ports). You can also update the CPU itself – but while adding a processor with more cores would in theory (if I understand the theory, which is also far from a 100% proposition) be the single biggest boost to improving/speeding up processing, the Intel Quad-Core processors already in the old towers are no slouch (the default new models of the Mac Pro still have Quad-Cores), and would be more expensive and difficult to replace than those other pieces. Again, it seemed more efficient, and safer given my limited history with building computer hardware, to incrementally upgrade all the other parts, see what we’re working with, and someday in the future step up the CPU if we really, desperately need to breathe more life into these machines.

So, for each of the four stations, here were the upgrades made (separation made between the upgrade and specific model/pricing found; for any of these you could pursue other brands/models/sellers as well):

  • (1) 120 GB solid-state drive (for operating system and applications)

OWC Mercury Extreme Pro 6G SSD: $77/unit
OWC Mount Pro Drive Sled (necessary to mount SSDs in old Mac Pros): $17/unit

  • (1) 1 TB hard drive (for general data storage – more on this later)

Western Digital Caviar Blue 1 TB Internal HDD: $50/unit

  • (1) PCI Express Expansion Card, w/ eSATA, USB 3.0 and USB 3.1 capability

CalDigit FASTA-6GU3 Plus: $161/unit

  • (4) 8 GB RAM modules, for a total of 32 GB

OWC 32.0 GB Upgrade Kit: $139/unit


Summed up, that’s less than $500 per computer and less than $2000 for the whole lab, which is a pretty good price for (hopefully) speeding up our digitization workflow and keeping our Video Preservation courses functional for at least a couple more years.

The thinking: with all that RAM, multi-tasking applications shouldn’t be an issue, even with higher-resource applications like Final Cut 7, Blackmagic Media Express, ffmpeg, etc. With the OSX El Capitan operating system and all applications hosted on solid-state memory (the 120 GB SSD) rather than hard drive, single applications should run much faster (as the drives don’t need to literally spin around to find application or system data). By buying a new 1 TB hard drive for each computer, the three non-OS drive slots on each computer are now all filled with 1 TB hard drives. I could have two of those configured in a RAID 0 stripe arrangement, to increase the read and write speed of user data (i.e. video captures) – the third drive can serve as general backup or as storage for non-video digitization projects, as needed.

RAM for days
*Oh what fun it is to ride in a one-120-GB-solid-state-drive open sled*



The expansion cards will now allow eSATA or USB 3.0-speed transfers to compatible external drives. The USB 3.1 function on the specific CalDigit cards I got won’t work unless I upgrade the operating system to 10.12 Sierra, which I don’t want to do just yet. That’s basically the one downside compared to the all-new Mac Pros, which would’ve offered the Thunderbolt transfer speeds better than USB 3.0 – but for now, USB 3.0 is A) still a drastic improvement over what we had before, B) probably the most common connection on the consumer external drives we see anyway, and C) with an inevitable operating system upgrade we’ll “unlock” the USB 3.1 capability to keep up as USB 3.1 connections become more common on external drives.

…installed! Top row – followed by two slots for the Blackmagic Decklink Studio 2 input/output and the AMD Radeon graphics card input/output at the bottom.

Installing all these components was a breeze. Seriously! Even if you don’t know your way around the inside of a computer at all, the old Mac Pro towers were basically designed to be super customizable and easy to swap out parts, and there’s tons of clear, well-illustrated instructional videos available to follow.

[vimeo 139648427 w=640 h=360]

As I mentioned in a previous post about opening up computers, the main issue was grounding. Static discharge damaging the internal parts of your computer is always a risk when you go rooting around and touching components, and especially since the MIAP lab is carpeted I was a bit worried about accidentally frying a CPU with my shaky, novice hands. So I also picked up a $20 computer repair kit that included an anti-static wristband that I wore while removing the desktops from their station mounts, cleaning them out with compressed air, and swapping in the mounted SSDs, new HDDs, expansion cards, and RAM modules.


With the hardware upgrades completed, it was time to move on to software and RAID configuration. Using a free program called DiskMaker X6, I had created a bootable El Capitan install disk on a USB stick (to save the time of having to download the installer to each of the four stations separately). Booting straight into this installer program (by plugging in the USB stick and holding down the Option key when turning on a Mac), I was able to quickly go through the process of installing OSX El Capitan on to the SSDs. For now that meant I could theoretically start up the desktop from either El Capitan (on the SSD) or Yosemite (still hosted on one of the HDDs) – but I wanted to wipe all the storage and start from scratch here.

I accomplished this using Disk Utility, the built-in program for drive management included with OSX. Once I had backed up all important user data from all the hard drives, I completely reformatted all of them (sticking with the default Mac OS Extended (Journaled) formatting), including the brand-new 1 TB drives. So now each station had an operating system SSD running El Capitan and three blank 1 TB hard drives to play with. As mentioned earlier, I wanted to put two of those in a RAID 0 data stripe arrangement – a way of turning two separate drives into one logical “volume”. RAID 0 is a mildly dangerous arrangement in that failure of either one of those drives means total data loss; but, it means a significant performance boost in read/write speed (hopefully decreasing the likelihood of dropped frames during capture, improving time spent on fixity checks and bagging, etc.), while maintaining a total of 2 TB storage on the drives (most RAID arrangements focused more on data security and redundancy, rather than performance, will result in a total amount of storage on the volume less than the capacity of the physical disks), and files are not meant to be stored long-term on these stations. They are either returned to the original institution, backed up to the more secure, RAID 6-arranged NAS, or backed up to our department’s fleet of external drives – if not some combination of those options.

So it was at this point that I discovered that in the upgrade from Yosemite to El Capitan, Apple actually removed functionality from the Disk Utility application. The graphic interface for Disk Utility in Yosemite and earlier versions of OSX featured an option to easily customize RAID arrangements with your drives. In El Capitan (and, notably, El Capitan only – the feature has returned in Sierra), you’re only allowed to erase, reformat and partition drives.


Cool. Cool cool cool.

Which means to the Terminal we go. The command-line version of Disk Utility (invoked with the “diskutil” command) can still quickly create format a RAID volume. First, I have to run a quick

[cc lang=”Bash”]$ diskutil list[/cc]

…in order to see the file paths/names for the two physical disks that I wanted to combine to create one volume (previously named MIAP_Class_Projects and Station_X_Backup):


In this case, I was working with /dev/disk1 and /dev/disk3. Once I had the correct disks identified, I could use the following command:

[cc lang=”Bash”]$ diskutil appleRAID create stripe JHFS+ disk1 disk3[/cc]

Let’s break this down:

diskutil – command used to invoke the Disk Utility application

appleRAID – option to invoke the underlying function of Disk Utility that creates RAIDs – it’s still there, they just removed it from the graphical version of Disk Utility in El Capitan for some reason ¯\_(ツ)_/¯

create stripe – tells Disk Utility that I want to create a RAID 0 (striped) volume

JHFS+ – tells Disk Utility I want the striped volume to be formatted using the journaled HFS+ file system (the default Mac OS Extended (Journaled) formatting)

disk 1 disk 3 – lists the two drives, with the names taken from the previous command above, that I want to combine for this striped volume

Note: Be careful! When working with Disk Utility, especially in the command line, be sure you have all the data you want properly backed up. You can see how you could easily wipe/reformat disks by putting in the wrong disk number in the command.

End result: two physical disks combined to form a 2 TB volume, renamed to MIAP_Projects_RAID:

Screen Shot 2017-03-02 at 11.15.37 AM.png
The 2 TB RAID volume, visible in the GUI of Disk Utility – note the two physical drives are still listed in the “Internal” menu on the left, but without subset logical volumes, as with the SSD and El Capitan OS volume, or WDC hard drive with the “CS_Archive_Projects” volume.

Hooray! That’s about it. I did all of this with one station first, which allowed me the chance to reinstall all the software, both graphical and CLI, that we generally use in our courses, and test our usual video capture workflows. As mentioned before, my primary concern was older native-DV capture software like Final Cut 7 or Live Capture Plus would break, given that official OS support for those programs ended a long time ago, but near as I can tell they can still work in El Capitan. That’s no guarantee, but I’ll troubleshoot more when I get there (and keep around a bootable USB stick with OSX 10.9 Mavericks on it, just in case we have to go revert to using an older operating system to capture DV).

Screen Shot 2017-03-02 at 11.13.17 AM.png
In order to not eat up memory on the 120 GB SSD operating system drive, I figured this was advisable.

I wish that I had thought to actually run some timed tests before I made these upgrades, so that I would have some hard evidence of the improved processing power and time spent on transcoding, checksumming, etc. But I can say that having the operating system and applications hosted on solid-state memory, and the USB 3.0 transfer speeds to external drives, have certainly made a difference even to the unscientific eye. It’s basically like we’ve had brand-new desktops installed – for a fraction of the cost. So if you’re running a video digitization station, I highly recommend learning your way around the inside of a computer and the different components – whether you’re on PC or still working with the old Mac Pro towers, just swapping in some fresh innards could make a big difference and save the trouble and expense of all-new machines. I can’t speak to working with the new Mac Pros of course, but would be very interested to hear with anyone using those for digitization as to their flexibility – for instance, if I didn’t already have the old Mac Pros to work with, and had been completely starting from scratch, what would you recommend? Buying the new Pros, or hunting down some of the older desktop stations, for the greater ability to customize them?