We’ve been a bit quiet since last year on our blog here primarily because we have been processing large, ongoing audio archiving digital migration job for Mood Media Ltd

In essence audio archiving, digital migration, transfer or digitisation, whatever term you prefer, is conceptually simple, one analogue or digital format is moved to another, usually digital, format.  It is in the details of this process that things can get complex requiring experience, specialised tools and often custom-built solutions.

This job has many factors not just attaining the best analogue transfers but also addressing the organisation of such a large amount of 10.5″ reels, their digital management once migrated and the creation and management of metadata.

The archive, dating from the 1950′s up the early 90′s, even though it had been stored in less than ideal conditions, is in generally good condition. An interesting and often fantastic sounding collection of recordings and music are evident all recorded at 15ips in mono, stereo and some encoded with Dolby A noise reduction.
There are specific issues with some tapes that are not uncommon with older audio tape:

• Binder hydrolysis or sticky shed syndrome (SSS) has affected a significant proportion of the archive in particular Ampex branded tapes from the 1980′s onwards.
• Some glue used in spices from the 1980′s spreads over time and tends to stick layers of tape adjacent to the splice together. This can be a very frustrating problem which rarely damages the tape but affects the tape tension on certain sections so that head to tape contact is momentarily lost and a very obvious audio glitch noticed.

The Analogue side is important to get correct initially but the management of the data is critical with such a large number of reels and individual artists and tracks. Each batch of tapes would be catalogued in a .csv file. The digital audio transfers were split into individual tracks which then had to be renamed based on the data in the .csv file. This was handled by some php coding which matched the metadata supplied with the files, checking for inconsistencies then renaming the .wav files on one of our servers.

This type of customised workflow can be tricky to setup initially and find the balance between accuracy and speed but once done a smooth workflow is possible maintaining high quality, accuracy and value.

We have recently worked on probably the worst looking tapes but with some of the best sounding music recordings we’ve seen for a while! A batch of 10.5″ NAB studio masters had bad tape mould growth.

Andy Leighton, owner of Bolex Brothers and music publisher of the Rocky Horror Show, found a batch of studio masters on quarter inch tape that had been growing mould for some of them over 30 years. All of these recordings had been made at the renowned Sound and Recording Mobile studios better known as SARM, later creative home of Trevor Horn.

Among these tapes was the first ever recording made at SARM in 1972 by Richard o’Brien, writer of the Rocky Horror Show, in addition to rare tracks by artists such as Kimi and Ritz.

When the tape mould was finally cleaned from the tapes and some of them baked for binder hydrolysis the quality of the recordings was very high and testament to the high quality available from analogue recording and even though tape can be vulnerable to physical problems it is also robust. If these had been tape based digital recordings, in the same condition, I doubt we’d have been able to achieve the same results.

We have Sonifex cart machines that while very well built do have rubber parts that will degrade over time and reduce the transport performance. Luckily we have some of the last remaining stock of new pinch rollers, motors and capstan drive belts.

The pinch roller in one of our machines had become quite hard and the rubber shiney over time. A pinch roller in this state may not hold the tape as securely and could also have flat spots both leading to increased wow and flutter and poor tape handling. These pinch rollers also have high quality cartridge bearings pressed into their shell. Over time these loose their lubrication, wear, become rough feeling and will also add to poor tape handling.

Older, fragile and valuable tape must be handled and used carefully. A ‘chewed’ tape caused by a poorly maintained tape transport in any tape machine, audio or video is a disaster and hard to recover from perfectly.

Both halves of the cart machine case need to be removed to easily change the pinch roller. While the access is good and the machine, in this case a Sonifex microHS, had been designed for easy servicing the pinch roller is still a little fiddly to get to so I removed the transport from the main chassis.

To remove the pinch roller a small slightly hidden C clip must be removed you can see in the image above the slot machined into the roller shaft where it sits and holds the roller. This is hard to remove as the plastic bush on top of the roller stops you getting a small screwdriver in. I managed to remove the C clip with some fine circlip pliers. Be careful not to loose the clip if you don’t have spares, they fly away very easily!

Now the new roller can be placed on the shaft. It’s a good idea once all the transport is out to give everything a good clean with IPA.

On this machine, the castan drive belt was quite slack so a new one was fitted, which is easy now the transport is removed. First though the capstan flywheel and motor pulley were cleaned of all the old rubber belt residue that tends to accumulate over time.

The last thing to do is check the pinch roller pressure. This is important to as to high or too low will increase wow and flutter, increase wear to the bearings and capstan surface and give poor tape handling. Due to the design of these NAB cart machines, the pinch pressure needs to be checked with a special cartridge. The pinch pressure is then adjusted from a screw pot on the top PCB seen outlined below in green.

That’s it, time to play carts again.

The capstan drive in the BR20 is belt driven by a wide belt. Both belts in our machines looked OK but we’ve replaced all roller bearings, belts and pinch rollers in both of our machines anyway as a matter of course. These parts are still available from Teac UK via Acoustic Services on 01-844-347600.

Below is a simple explanation of how to change the capstan belt.

1. Unplug machine from mains power and move to a strong stable base.
2. Remove cross head screws from the rear panel and lift plate off. Depending on the type of plug in your country you may not be able to remove it completely.
3. You’ll now be able to see the capstan motor and it’s control board attached to it.
4. Remove the 4 cross head screws and gently lift the analogue audio output board away from the machine as in the picture above.
5. We now need to remove the whole capstan motor assembly with the control board still attached. Remove the 4 cross head screws right at the front of the assembly, NOT the six nearest to you when looking at this image. 
6. Carefully unclip the 4 cable connectors from the motor control board. The other connector cannot be removed from the board and must be removed where it connects to the other board.
7. The whole assembly can now be lifted out from the machine. Be careful to not snag any cables and remember to unclip the black cable ties.
8. You’ll now be able to unclip the control board from the assembly by carefully compressing the black clips with some needle nose pliers.
   
9. Now remove the six cross head screws holding the capstan motor assembly together. This is the only way to remove and refit the capstan belt. There’s not enough room to do it any other way!
10. Now you can remove the old belt and capstan shaft. It’s a good idea to clean the capstan with IPA where the old belt has run and reapply a little grease to the bearing end of the capstan.
11. Fit your new belt and reassembly is the reverse of dissasembly! Be careful though to not drop the screws into regions you can’t get them out of – luckily there aren’t that many on this machine but a long magnetic screwdriver is very useful.. just don’t get it anywhere near the headblock and heads!
    

This is something you don’t see everyday! An almost unused and boxed 1/4″ 2 track reel to reel tape machine, a Tascam BR20 one of their highest quality machines sometimes installed with a Timecode head for broadcast and editing applications.

This machine somehow turned up at an IT Recycling centre in Essex but is now in much safer hands transferring tapes, in particular a very large archive of library music on 10.5″ NAB reels owned by Mood Media Ltd.

As you can see this machine is in it’s original box, with packaging and first look at the heads show almost no head wear but some nasty oxide that took a while to clean off.

This machine needed little work to bring it back to spec, a new capstan belt, pinch roller, tape tension and speed setting and a full calibration.
The capstan belt change is the subject of another blog post here..

A recent addition to our video arsenal is this rare 1976 vintage 1/2″ colour reel to reel machine.

This has needed some work to get it functioning well such as new belts, hardened grease cleaned off the mechanism, etc but is now able to transfer colour recordings made in this format of reel to reel video.

A more detailed article on the repair of this will appear soon as will information about our other reel to reel video machines, the Hitachi / Shibaden EIAJ machine, the Sony CV-2100 skip field VTR and the enormous Ampex VPR-2B 1″ video machine… and we’ve got two of these!

Thanks to Rich at www.labguysworld.com for the JVC service manuals.

While some of our machines are serviced by others we like to regularly check them and have gradually bought our regular servicing in house. Of course this needs specialised tools, test tapes and gauges, often totally unavailable new now.

On a lucky eBay day I happened to win one of these beauties, an Information Terminals M-300 gauge. This enables you to accurately set the tape guide height and also the head stroke. It is a universal gauge and can be used across many decks.

Nakamichi tape deck owners have had a hard time doing this part of their servicing as the original Nakamichi gauges are very very rare now as is this.

A member of the naktalk mailing list though recently borrowed our gauge and has had it measured and will soon have a small batch CNC machined and made available. These remanufactured gauges will have a few small modifications to improve the design.

Thanks to Willy at www.willyhermansnervices.com many more tape deck transports will be able to be aligned correctly.

We’ve been honored recently to have won a large contract to help in the digital migration of an extensive educational video archive by the transfer from U-matic archive copies to uncompressed video files.

While the archive had been stored in an suitable environment and rarely if at all played, they had not survived well. The Sony branded tapes from the 1970′s and 1980′s all exhibited binder hydrolysis or sticky shed syndrome. We were still able to get good transfers though using our range of umatic machines, particularly the Sony BVU-950P and For-A Time Base Corrector.

www.mowbraywoodwards.co.uk

We’ve recently been happy to be involved, with Mobray Woodwards Solicitors,  in the audio transfer of important evidence in a  local Crown Court case.

Even given the poor quality or the recordings, made on the slowest tape speed of 1.2 cm/s we were able to make transfers to CD which were clear and understandable with CD track markings for easy access to specific sections of the audio.

Microcassettes, until recently, were used regularly for voice recording in small, portable dictaphone type of machines. Their fidelity is not high but when used for voice it is usually acceptable.

Greatbear are able to transfer all formats and speed of microcassette in addition to 1/2 speed standard cassettes that were common for voice recording of interviews and meetings in the police service, inquests, etc.

For more information on high quality audio tape transfer and restoration please visit our transfer pages.

We are able to support a wide range analogue and digital, consumer and professional video formats from the late 1970′s onwards such as: Betamax, VHS, SVHS, VHS-C, Video 2000, 8mm, Hi8, uMatic, Betacam, miniDV, DVCAM, etc.

We offer straight video transfer to DVD and a higher quality transfer service to DV or  uncompressed AVI which can then be supplied on hard drive, edited, encoded to a very high quality DVD or supplied on digital tape.

We pride ourself on our positive, friendly service and are happy to give advice over the phone or by email. When you call us you won’t be stuck in a voicemail system or told we’re an internet company so don’t like speaking on the phone!

Feel free to contact us by phone or email.