180 1970s 1/4" stereo tape masters to digitize....help!

[McLies]

hello folks,

I've taken on a task for a friend who ran a British record label in the 70s. He has a lot of master tapes ( 7 1/2 and 15 ) that have been lying around in quite damp conditions but the first few tapes I've checked seem to be holding together and not shedding much or any oxide to worry about.

The music is mainly folky and countryish and mostly recorded direct to stereo in the first place and has splices at the start of each song.

He's also lent me his old Akai GX400d Pro tape deck with a creaky belt or two. I think I've sourced a belt kit for it. I'm intending to use an m-audio delta 2496 sound card and hook up the tape machine direct to the card.

What I want to know is, can I do much to the sound frequency balance. The 3 tapes I've listened to so far seem to have acustic bass that sounds a bit muddy to me. The levels are very up and down with no noticable compression on anything. I'm sure it would be very wrong to try to err.. multiband compress it to sort out the bass.

I'm puzzled about where to go with this project. I'm hoping that readers here will have some experience to shed light on it for me. I have some basic 'low budget' outboard gear and a cheapish mixer but my instinct tells me to keep the signal path short and minimal.

Any advice is very welcome.

norman.

[Adam Dempsey]

First thing is to get as much info from the box labeling as possible. Stereo half-track or quarter track, no noise reduction, with splices in them is it possible they're second generation dubs?
I'd say your client's prerogative should be to have you digitize and preserve the tapes as-is (flat transfers) to high res digital, possibly cleaning the heads & tape path between each piece. Then any restoration/EQ'ing would be done after ascertaining the content and in addition to keeping the digital flat transfers of them backed up.
Depending on the tapes' condition you may need a machine with only roller tape guides, azimuth adjusted to the tapes, and yep, a minimal short signal path (as always, really).

[Thomas W. Bethe]

From the WWW

The GX-400D line consists of exactly one set, but boy it was the real high-end for the Akai line. I say that because it used the same chassis and motors as are found in the GX-400D-ss and the PRO-1000. Rumor has it that the GX-400D was limited to a production run consisting of just 200 units, I can't deny that, or confirm that. This series was definitely designed to appeal to studio's and radio stations, as well as high end home users, along with the GX-400D-ss version which was basically a Studio in a box, and the PRO-1000; a 2 Track version with more advanced microphone mixing which could be considered a "poor mans" Studer. Tipping the scales at nearly 69 lbs., within such esteemed lineage, the GX-400D shares the same 3 speed servo-controlled motor; 15 inches per second; and a closed loop dual flywheel assisted capstans within a belt drive system that rivals Studio Tape machines for low wow and flutter; also probably the biggest VU Meters ever seen in a tape deck; along with a set of audio controls that all tick off in minute increments. There are two cosmetic variations, the beige VU meters and the blue; the latter can be seen to match cosmetically some of the Akai Receivers and amplifiers of the period.

About the only thing the GX-400D lacks is internal Dolby "A" or even Dolby "B", or "C" noise reduction, well I guess they did have to build it to a price-point. It does feature a distortion reducing non-defeatable ADR Circuit that reportedly reduces distortion in the upper two or three octaves. As a benefit, it also has a record and playback frequency response that is flat almost to 30,000 Hz. at both 15 ips and 7.5 ips, which is no small feat! The only thing I fault it for, is the huge mechanical "Thunk" when it goes into Play, as both pinch rollers hit the capstans. Well just maybe that is elitist nit-picking :-). Still... some users will certainly jump for joy, at a machine that has such a frighteningly loud way of announcing... "I'm going into Play now "... THUNK... which then reverberates off the four walls of the room ( only if your room actually has four walls... ). On the slight down-side, its "logic" circuitry really isn't, its just eight of those costly 4 Pole Power Relays, which in reality can get a bit troublesome after a decade - or two, or three decades. Also the head changing switch is not sealed, and oxidation and can become rather troublesome, causing the wrong heads to be active, or losing the head interconnection completely - giving no sound in reverse, or forward play.

Both the Head Switch, and numerous Power Relays, are this design's weak points. That neither is quite environmentally sealed off does mean they are exposed to air pollution, sea salts, and other pollutants over the years; and then they become troublesome. The GX-400's feather touch operation switches which are all lighted ( except for Stop ) and the solenoid pause control, with the dual capstan mechanism - its a blast. Tape handling is both gentle and impressive as its keeps tight control of the tape between those precision balanced flywheel assisted capstans running between a 1/2 inch wide flat belt. It allows a more precise head to tape contact than can be engineered into a single capstan moving tape system. Also a tighter stop to start up nominal speed deviation compared to what one can find in lessor sets. Some interesting brochures and data can be found on the PRO-1000 Page about these functional aspects. The clear benefits of a dual capstan mechanism certainly defines these sets ( also the identical twin GX-400D-ss and PRO-1000 mechanism's - same capstans, same flywheels, same motors, same belt drive system ) as being in a higher class than even the rest of the set. So functionally, operationally, and audibly its pretty much the tops... While I can't get a peep out of mine in Reverse Play mode, I haven't yet wished to dismount and disassemble it, to clean those head switch contacts; it is a ton of weight, as well as, a ton of work.

AKAIs were never known for their mechanical stability or their "sound". Maybe you should think about renting a Studer or Ampex or Otari for the transfers. Also I am not sure of the head configuration of this machine but it seems it was 1/4 track and NOT 1/2 track Stereo especially since it had reverse play which pretty much rules out 1/2 track stereo.

Best of luck. If you do decide to do this transfer job with this machine do clean the relay contacts, as mentioned above. You should only do this if you know what you are doing inside a tape recorder, before transferring any tapes. Also it would be a good idea to run a test tape on this machine to check azimuth and frequency response.

Best of luck!

[wado1942]

It sounds to me like either the deck, the tapes or both need some physical restoration before moving forward. For a project this big, I think a 2496 won't do them justice either.

Your instincts are correct though, keep the sound as pure as possible to preserve the tapes as historical documents. If you want to do any adjustments later, you can do that non-destructively with separate copies.
No, multiband compression will not help. You'll have to fix whatever's causing the problem (bad mechanical behavior or bad amplifiers in the deck).

[Greg Reierson]

For a project like this it would be worth it to get a decent deck and put a 1/4 track head on it - preferable something will roller guides and decent electronics, etc. Just do flat transfers and deal with any issue later.

And have fun doing it!


GR

[Adam Dempsey]

Originally Posted by Thomas W. Bethe

Also it would be a good idea to run a test tape on this machine to check azimuth and frequency response.

To clarify.. while it's good to check how far it may be from spec, for playback you'll need to set azimuth to the tape being transferred, hence best matching it to that of the original record machine.

[dave-G]

Originally Posted by masterminder

you say the tapes are not shedding "much".

hmmm.

do you mean "not shedding much", as in "shedding more than not at all"?

you've probably already thought of it, but you might want to bake them before you transfer. i'm sure the directions are on the internets, or someone who's done a bunch of it will post.

Indeed .. seems like you should expect worse, and plan on gearing up with a Snackmaster, and budget for the time and process of baking tapes too.

-dave

[Thomas W. Bethe]

Originally Posted by McLies

hello folks,

I've taken on a task for a friend who ran a British record label in the 70s. He has a lot of master tapes ( 7 1/2 and 15 ) that have been lying around in quite damp conditions but the first few tapes I've checked seem to be holding together and not shedding much or any oxide to worry about.


Any advice is very welcome.

norman.

If this is important to the record company, and I assume it is, then I guess you should do the best job you can and if that means renting converters and tape decks and baking the tapes I guess you will have to do it all. You may also want to farm out this job to someone who has the proper equipment and expertise to do it correctly.

Best of luck!

[Bonati]

Honestly, the tape transfer part of this job is the kind of thing that Steve Puntollilo at Sonicraft specializes in:

Ultimate Multitrack Analog to Digital Transfers - Sonicraft A2DX Lab

It won't be the cheapest way to do it, but probably the best.

[wado1942]

all i know is if the tapes are shedding at all, its best not to ignore it, or to take chances with them. i think it also tends to screw up the playback machine.

No kidding on both accounts. It'll ruin the tape and gum up the deck. The heads can get scratched, which then scratches the tape, which then scratches the heads & so forth.

More on baking tapes...
Tape Baking

This must be done carefully so that you do not ruin the tapes and DO NOT EVER use a conventional oven.

[Time Tech]

Originally Posted by masterminder

you say the tapes are not shedding "much".

hmmm.

do you mean "not shedding much", as in "shedding more than not at all"?

you've probably already thought of it, but you might want to bake them before you transfer. i'm sure the directions are on the internets, or someone who's done a bunch of it will post.

First item to establish is what type of tapes you are working with. Formulations, acetate,Mylar or Poly. All were in use in the 70's. Acetate tapes should never be baked. quickest way to tell if a tape is acetate is hold the reel up to a light source. If you can see tranlucent light through the pack then it is acetate.
At the end of the reel hold on to a inch or so of the tape and give it a tug. If it breaks cleanly it is probably Mylar, if it streches it is poly.

If baking mylar or poly tapes they can be baked on thier plastic reels as the plastic reels should hold thier shape up to about 160 degree F.

Your playback machine should be fully calibrated and this means both audio and transport alignments.

I know you have a donor machine, but if there is a question about the recording format(s) 1/4 track or 2 track stereo, you may be better served by getting a machine such as a 1/4" Otari MX 5050. They have a selectable playback switch for 1/4 track or 2 track stereo playback.

The Richard Hess website is a treasure trove of archival information.
www.richardhess.com

DO NOT believe/Use any home brew information you read on the internet in regards to tape baking. Most of this information is myth,out of date or just plain incorrect. It is a sure road to disaster.

We prepare and transfer hundreds of analog tape reels a month, it is not a job to go into uninformed and not armed with the correct tools.

I do agree with the suggestions that you should invest/hire proper machines and convertors to work with. If these are record label assets it would be doing an injustice to both the tapes and the content contained upon them to work with the gear provided.

Please feel free to PM me with and questions you may have.

Cheers!

Bruce Maddocks
Cups 'n Strings LLC
www.cupsnstrings.com

[dcollins]

Originally Posted by Time Tech

DO NOT believe/Use any home brew information you read on the internet in regards to tape baking. Most of this information is myth,out of date or just plain incorrect. It is a sure road to disaster.

baking-old-master-tapes | b | quickfaq

Just in case someone reads his site and thinks Bob's 200F is good advice, because it's wrong and is likely to damage the master...............

140F has always worked for me in the past. The number one thing for restoration is to immediately stop and seek expert advice if you have any questions about what you are doing.

You'll never get the toothpaste back in the tube.


DC

[Huntley Miller]

Another good resource:
Analog Tape Restoration: If I knew you were coming I'd Have Baked a Tape

[Adam Dempsey]

Originally Posted by wado1942

No kidding on both accounts. It'll ruin the tape and gum up the deck. The heads can get scratched, which then scratches the tape, which then scratches the heads & so forth.

More on baking tapes...
Tape Baking

This must be done carefully so that you do not ruin the tapes and DO NOT EVER use a conventional oven.

... or bake acetate tapes.

[Greg Reierson]

Originally Posted by masterminder

you've probably already thought of it, but you might want to bake them before you transfer. i'm sure the directions are on the internets, or someone who's done a bunch of it will post.

IMO, baking has become a knee jerk reaction to overcome a common deck design flaw. For example, if you try to play 456 from 1980 on an Otari 5050 you'll probably have trouble. Just using that deck as an example, it has (IIRC) 7 static guides that the tape gets dragged across while trying to maintain a smooth motion at the heads. Each of those fixed surfaces adds friction and flutter. An A80 with the erase and records heads removed has only one. The difference has to be experienced to be understood.

Some tapes do need to be baked but most of them play just fine on a deck with minimal static friction surfaces. Once you go roller guides you never to back.


GR

[Waltz Mastering]

Here is a list of some of the tapes that may be prone to sticky shed:
Tapes with Sticky-Shed Syndrome

[McLies]

I thank you all very much for your interest and comments. Whaw!.... you've cetainly reved up my brain cells in a certain polarity with all this.

First off, all the tapes are stereo half track. The first 40 or 50 were recorded at a studio where a 'live' mix was recorded straight to stereo ( on a Ferrograph ) and only the err... good takes were kept. All the rest was poured onto the carpet. I know this because I was present at quite a few of the sessions as a youngster. Although the spools that those tapes are on now do not always match up, I also am pretty sure they used 3M tape throughout that period ( very early 70s - and well before SS syndrome becomes a factor )

Later tapes in the series are of more mysterious origin to me because I'm sure they were recorded at various studios around the country and most were mixes from multitracks. I've not got the full stock of tapes here with me yet so I've no idea yet if the later tapes have SSS problems.

As advised in a post on this thread I contacted a pro service in US for a rough estimate of a cost for passing the whole thing on to them. As a result, I'm gutted because it's almost certain that funds for that are not going to be available.

After reading all your posts I'm quite embarrassed by the kit I have here to attempt to do this myself. I've had a quick google for Otari 5050 B2 and it looks like, if I could drop lucky, I might be able to afford one and get it set up right, but I'll just have to hang-fire and wait for something to pop up on ebay or similar.

Converters: So what is a good enough converter?


Now here's a "silly" question that's going to make one or two of you flinch, I'm sure. I'm a bit new to higher definition digital audio and I'm confused about the difference between 24 bit and 32 bit (floating point ). I've set and locked the m-audio 2496 at 96/24 but my software ( the old cool edit pro2 ) only sees, or functions as, 32 bit. Is that a problem? or am I just being ignorant.

So, I'm sure all of you are by now thinking, "oh my god!, all those wonderful old masters in the hands of an idiot!". Errr.... I know I'm starting from a long way back, and funds are extreemly tight, but I'm a learner and just as much a perfectionist as the best of you, in my heart. In my head, I've got to work out how to do this on a pretty low budget.

Thank you all ( very much ). Illumination I wanted, and illumination I got.

Thank you,

norman.

[wado1942]

OK, think of 32-bit float as 24-bit but with 8 extra bits for setting overall level. So it doesn't matter if the level changes in the software through processing, the resolution doesn't change appreciably. It can even go above 0dBFS. Mind you, the converters are still 24-bit linear so if the level is too high or too low going through the sound card, it'll degrade the sound. Most software processes internally at 32-bit float. Syntrillium just took it one step farther and let you save the files in that format too. It does no harm. Just be sure to save in 24-bit linear when you're done with the project.

[jamesp]

Originally Posted by McLies

As advised in a post on this thread I contacted a pro service in US for a rough estimate of a cost for passing the whole thing on to them. As a result, I'm gutted because it's almost certain that funds for that are not going to be available.

There are plenty of people able to offer a similar service in the UK although I don't personally know of anyone in your area.

Personally I wouldn't try doing everything at once. If this is for future release then it may be better to transfer the tapes as they are needed. The record label can then fund future transfers from the proceeds of the first few releases.

Used tape machines are a bit of a lottery - a friend of mine used to spend hundreds of pounds on technician time to keep his old machines going whereas I do all the maintenance myself. I can deal with issues as they crop up rather than waiting for a technician to fix it.

James.

[Time Tech]

Hi Norman, I PM'd you.

Cheers!

Bruce

[neilwilkes]

Try giving Kevin a call at the FX CopyRoom in West London.
He is very good at this, will bake the tape (if it needs it - as dc has pointed out, not all tapes need - or even should - be baked) and transfer for you at the same time to resolution of choice.
This is the best way to go, believe me.

[DSPaudio]

I have to agree 24/96 on a low or mid-level converter is really not appropriate for archiving history.

You could get a DSD recorder running parallel for archival grade copies in addition to your immediate working PCM transfers. Then if something from the back catalog gets any interest or whatever, you can pull the higher quality DSD down to PCM and remaster.

Even Korg's portable DSD recorders are of good quality and pretty cost effective.

[McLies]

Originally Posted by McLies

Converters: So what is a good enough converter?......


............So, I'm sure all of you are by now thinking, "oh my god!, all those wonderful old masters in the hands of an idiot!"..........

After some heavy reality checking and some 'shrewd' counseling, I've decided to try to persuade the real owner of these tapes to shell out some capital on a temporary basis.

Now I know this isn't what various professionals here want to hear, but, I'm intending to go the route of buying an old Studer and an apogee or similar converter. The idea is a simple one really. When the job's done, they can both be resold and the capital recovered almost to the starting block. It's certainly well under the cost of hiring in pro services to do what isn't really that high-end to start with [ some of these tapes are utter crap - but don't tell the owner I said that ] ( others are pure magic! ).

I'm of the opinion that only the first 40 or so are the "valuable" ones. The later story was not unlike the Led Zep story in that the later part of the story was mainly about how ungracefully the plot was lost. There are real gems in the early collection and I feel very strongly that they should be treated with the highest of respect, even though the hardware used was only of mid level standard. Although the recorder/s was a Ferrograph the guy was constantly checking the azimuth etc and did his most pro best. I remember that the 'motto' at the time was " It's good enough for Folk Music".

The difference between the early recordings and the later stuff is massive. It's like comparing the early Elvis stuff with the pap he did later, and has a similar naffness to it too. I guess it's all about the management team's egos going over the top, in both cases.

I've noticed that vynyl pressings of the earlier stuff is changing hands on Ebay for several hundred pounds in many cases but the later stuff isn't even coming up in searches!!

So, I hate to dissapoint all you pros out there with studios all ready to do this kind of thing waiting to get the order, but, as I'm only just persuading the owner to move ahead with these tapes at all, it looks like I'll have to come up with a bomb proof financial case for doing it at all. The best case I could make to him was as described above. I havn't even had the nod to proceed yet though.

thanks for the wisdom guys,

norman.

[Thomas W. Bethe]

Just a caveat - having all the equipment does not really mean anything. It is knowing how to properly set it up, align the heads, check the frequency response of the heads and electronics and do a million and one other things that will make the transfers the best they can be. If you get an old Studer the heads maybe shot, the electronics may need all the electrolytic capacitors replaced and the unit may need other extensive repairs just to bring it up to spec.

I still maintain that transfers that are important should be done by someone with the proper equipment and knowledge to do them properly. FWIW and YMMV. It sounds to me that you already had your mind made up from the beginning of this tread and no one is going to change that - so have fun! I personally think you are doing a disservice to the client by not finding the best way to do what he needs done but that is only my view.

[Adam Dempsey]

Originally Posted by McLies

Although the recorder/s was a Ferrograph the guy was constantly checking the azimuth etc and did his most pro best.

Just to be clear, he really shouldn't have needed to do that, ie it's totally unnecessary, once the record deck is azimuth aligned using an MRL alignment tape.

Azimuth adjustment, from the digital transfer/mastering end of things, relates only to azimuth aligning the playback machine to that of the record machine (hence my post at #6).