Tape/digital hybrid recording and dbx noise reduction?

[Jeremy H]

Hi Guys,
I am currently incorporating a 1" 16 track into my mostly digital recording studio. I plan to record drums and other selected sources to tape and then transfer to hard disk.

The tape machine is equipped with dbx noise reduction...but I'm wondering what the latest thinking is regarding the need for it?

I would prefer not to use it for reliability, simplicity and to avoid calibration issues.

I think I read somewhere that guys using tape these days, tend not to use dolby or dbx....maybe because modern tape formulations are quieter, track bouncing is not required and digital tools can be used to remove any unacceptable hiss??

Any thoughts?

[Chris H]

You don't need it. What tape are you using? If you use a high output tape like 499 ir GP9 then thay can take a lot more level and its no prob getting above the noise floor. The GP9 can be better for older machines as the tape is thinner and sits better on the heads than the 499.

[mfdu]

yeah - what tape? and what 16track 1"?

i've been playing around with GP9, 499 and 456. but i don't use no noise-reduction, on either 2-track mixdown or the 8-track.

i very rarely remove hiss in the digital realm. if i track to tape, i keep some tape hiss in there. it pleases me.

i prefer 499. here's what i reckon :

GP9 seems to display less "tape" distortion characteristic right up to the point where it snaps into ugly distortion. i reckon you can HEAR the thinner tape - the sound (especially the transients) doesn't have as much oxide to control (compress) the signal. i consider GP9 the 'limiter' tape with -10db threashold, hard-knee 1:20 ratio. if you know what i mean.

499 seems (to me) to have a smoother distortion curve - there's more room to set the signal between minor saturation and intense slamming. i can sense the extra thickness. also, the distortion just seems more . . . pleasing (euphonic?). if GP9 is the 'limiter', then 499 is the low-ratio compressor, maybe -24db threashold, soft-knee 1:4.

i grabbed a pancake of 456 as well, just to play around with totally over-saturating it (both my machines are set to +6 for GP9 / 499).
so first off, i shoved the same amplitude to the poor 456 as i had to 499 and GP9 (yeah, mean bastard - i know)
i couldn't believe the levels came back off at unity! (i was expecting a 3db drop, i guess . . )
first thing i tried was drums.
now this is where it got fun. we're getting beyond "tape as a hard-drive replacement" (umm - isn't that the wrong way round?) and right into the territory of "tape as an effect".
think along the lines of drum o'h slammed ribbon mics. great low in the mix. i wouldn't track to 456 at the higher output (unless i had Bob Log III in the house!) but i would punch into it as a split in mixing or overdubbing.
if i'm still equating to compression, i'd call 456 overbias(?) a -30db soft-knee 1:4 guitar stomp-box.

sorry - i've been meaning to get that off my chest for a while. please forgive, but i do feel better now.

chris.

[mark rachelle]

i'm voting for dbx on

most semi pro machines with dbx relied heavily on the dbx system to get specs up to an acceptable s/n figure

if your machine is set up for it then by all means use it

it does have a sound thats for sure but much better than the sound of hiss from semi pro gear

my 2c worth anyway

[mfdu]

mark,

i trust what you say. i'll have to pull out my 2channel dBx unit and hook it up to the stereo deck again and scratch and sniff.

chris.

[Howard Jones]

If the tape machine in question is the 85-16 b to which you refer in your other thread, you can forget 499 and GP9 as that model will not pull enough bias to run those tape formulations.

It was generally accepted that you bypassed the dbx on drums and bass as the low frequency content could cause audible pumping. The dbx should be okay on everything else, but there's nothing like trying it for yourself.

There are no calibration issues to speak of in using dbx processing. Some models of dbx have gain control trimmers that you adjust to ensure the same input & output gain levels whether the unit is switched in or is in bypass. Apart from that, it's set and forget.

[Chris H]

It comes down to personal preference related to the type of work we do and the machines we have used. I have only used DBX noise reduction on my Otari MX 5050 1/2"8 trk, and a Ta@#$% 24 trk 1". The Otari was the earlier model and was still brand new ( new old stock) in 95 when i purchased it. The machine came with a rack of 8 of the better DBX units and i still hated what they did to the sound of my recordings. They were set up well as was the recorder. I found the dbx's sort of messed up the openness and ambience of the recording. After a few goes i sold the DBX rack. I don't get audible tape hiss when recording without noise reduction on the otari. With the Ta@#$% 1" 24 track we needed to record with dbx because of noise. I never liked that machine's sound anywhere near as much as the otari. Hard to get open sounding recordings and the bass lacked definition, etc. The other machine i worked a bit on was the MCI 24 trk 2" and never used DBX on it so couldn't compare with to without, but it sounded fine.
I agree with mfdu about the sound of GP9. I use it for acoustic and jazz recordings and 499 with bands. Funny though i haven't even tried 456 on the otari even though its favored by many for rock etc. Must give it a go. Can you still get it?
Another point worth making is that the price of tape recorders is cheap these days. So for anyone who wants to use tape it's worth getting one of the better machines for your dollar. Then you are really able to get the benefits of tape and not the compromises of an inferior machine.

[jkhuri44]

Another point worth making is that the price of tape recorders is cheap these days.

if thats the case, i would much rather do stereo acoustic and live recordings with tape...would be so much cooler than a portable PT rig (even though a portable PT rig is convenient)

how much can you score a GOOOOOOOD 2 track for??

[mfdu]

yeah ausrock - you pointed out the one thing i forgot.

i use GP9 when i want clean recording all the way to the 'flip' point into saturation (the 'flip' point is simply how the tape flips into distortion so quickly)
and i use 499 when i want tape compression/distortion as a mild characteristic.

sorry to all the people who had shivers when reading about my tests with 456. but i tried it on advice of the folks at prahran tape and cassette supplies, and they were right - it's good. as an effect.

and yes, you can still get 456. complete, or pancake.

jkhuri44 - have you checked the stereo decks at mixmasters (online)?
the Studer B67 is apparently a line in/line out, and may not have metering. $900. it's a model that seems to be copping a dissing on a few forums. better than my Ta@#$% 32? probably. who knows. who knows?
(after major trauma buying a tapedeck through evilbay, i don't recommend it!!!!!)

[Ausrock]

Hey Chris/mfdu,

It wasn't me, it was one of the other Chrisssssss :-)).


Back to the tape thing though, my ATR-60 1" is biased for 456 and to date I can't complain about it's performance and while I have a quantity of 456 on hand, I don't see any point in moving to anything else, especially with the need to re-bias the deck whenever I change tape type.

Also, I seem to recall seeing on another forum, comments along the lines of Howard's post with regard to some machines being less than suitable for some tapes (or vice versa).........must dig that discussion out.

[Jeremy H]

Well, thanks guys!!! (You mention tape and people get excited....I think there's a lesson in there for all of us!)

Howard.....Yes it is the Ta@#$% 85 - 16b and I appreciate the info about the biasing problems of this machine for modern tape. That was going to be my next question.

As far as I know the machine in question hasn't turned a reel in anger for well over 10 years and is currently set up for Ampex 456. (The machine originally came from Clive Shakespeare

[Ausrock]

Jeremy,

I last purchased new 456 about 18 months ago and from memory, it cost me approx., $140 -150, however, that may or may not be indicative of current prices.

If you'd said all this a month or so ago, I may have been able to help with a bit of s/hand tape as a mate has quite a quantity of 1" 456 which like mine, is regularly "spooled". Unfortunately, he is o/seas for a few months and there's no way I can follow this up.

ChrisO

[Howard Jones]

Getting the 85-16 to run 499 or GP9 isn't just a problem, it's impossible. The bias circuits in machines of that age were designed long, long before high-bias tapes were even thought of. Therefore, the bias drive circuits were not designed to be able to supply sufficient voltage to achieve 520nWb/m on tape. Set this machine up with 456 and be happy.

"Another point worth making is that the price of tape recorders is cheap these days."

Well, yes... That's because most tape machines on offer are clapped out or have been sitting in the back of the garage for 10 years and someone has decided to cash them in on eBay.

Tape is, for all intents and purposes, an obsolete format for which the primary recording medium is simply going to get more and more expensive.

It is our experience here at the machine hospital that most people just don't want to know when they find out how much it will cost to perform a thorough overhaul of an analogue tape machine*. Several things arise from these observations:-

Assuming that you won't have a heap of money to pay someone like me to repair your machine, then:

[1] Try very, very hard to buy a machine from a reputable source. A reputable source does not include your sister's boyfriend who has a mate who has a machine under his bed. Why do most people sell a tape machine? Because it's clapped out - buyer beware!

[2] Train yourself in how to identify good and bad points about a tape deck. The main areas to check are head wear, head wear and head wear. After that, check the pinch roller, capstan motor bearings (hello, Jeremy), tape travel, tension arm travel and general transport performance. Also, very important is to check for leaking electrolytic capacitors on the printed circuit boards.

If you do not know how to check these things, then you run the risk of buying a machine with faults that will be expensive (or impossible) to repair. For example, Fostex B-16s have now reached an age where they commonly exhibit capacitor trouble and this is costly to fix. If you feel that you are not confident to identify potential trouble, then at least consider paying for a service workshop to check the machine for you BEFORE you commit to buying it - could save you a heap of trouble.

[3] Maintaining a tape machine correctly, requires having the service manual, test tape and any special test jigs. If you truly want the machine running properly, you should factor these things into your budget (can you still get the service manual for the model you are thinking of buying?) and also be prepared to learn how to maintain the machine yourself.

Think of a tape machine as being like a car. If the car you are going to buy is 20 years old, then you know to expect to spend money on it. Sure, it might cost you only $xx to buy, but how much is it going to cost you to fix up? Do you know how to pull the head off an old engine, replace the valve guides, replace the piston rings etc etc?
Yes? Good! No - hmmm.

All that said, there are definitely some excellent machines coming up for sale from time to time. Just gotta be patient and know a good one when you see it.

* Clients aren't impressed by the cost of overhauling digital tape machines, either.

[Jeremy H]

Hi Howard,
Thanks for your comments - it all sounds like good advice to me!

Actually, I fully understand your "car" analogy - I am a mechanic by trade and spent many years specializing in restoring collectable cars. And I spent a lot of time explaining to customers that an engine overhaul and a paint job does not equate to "fully restored"!!

Years of use, abuse and even non use takes its toll on all machines - and usually the obvious wear and tear is just the tip of the iceberg.

I would agree that there is a lot of "romanticism" going around about old tape machines, as there is about old cars. And I am sure there are already, or soon to be, many tape machines (and old consoles) out there, that people took on as "a project", with all the best intentions. They are probably pulled apart, and in boxes - and that's as far as the "restorer" got... due to lack of resources, lack of know how or juct plain old lack of interest and motivation.

Like all those old cars, brought home by their excited new owner...and years later they are just taking up room in the garage, up on blocks with the engine pulled out and half the paint stripped off! (Sound familiar, anyone?)

But lets not knock 'em too much. All those half done projects are where the professional rebuilders get their bits and pieces (like the gasket set you bought for your engine rebuild and never used) from in years to come.

I'm happy to set my Ta@#$% up to original specs, including 456 tape. I'm a "restorer"...not a "hot-rodder"

[Howard Jones]

Hi Jeremy,

Thanks for the positive comments. There is nothing at all wrong with buying, owning & running a tape machine... people just need to have a realistic appreciation of what is involved.

I'm aware that my comments are sometimes seen as me being a bad-news bear. This is not the intention. Take the question of test tapes: these are required so that you set up your machine correctly and to ensure that tapes made on your machine will play back correctly on other machines. Being an engineering type, I personally can't imagine how anyone can run a tape machine for a long time never having run an alignment tape on it and, yet, many people clearly do.

So, is a test tape strictly necessary? Yes, of course. All those who have never run one on their machine are operating in ignorance.

There is only one manufacturer left in the world that I am aware of still making alignment tapes. As demand dwindles, it seems obvious that one day they, too, will go out of business and then we will all be stuffed. Running a full-service workshop as I do, we have alignment tapes for all formats from cassette to 2". However, as these tapes have started shedding or otherwise falling apart, we have not replaced them because there is insufficient demand to justify the cost (the exception is 1/4" - I reluctantly bought 2 x 1/4" test tapes late last year because we are still seeing some demand for work on this format).

Therefore, it will become increasingly incumbent upon owners to ensure that they are the ones who own test tapes so that they can have their machines aligned correctly. Given the cost of these test tapes, it would seem logical for groups of owners to pool resources and buy one tape to share amongst themselves. Perhaps owners of the same models could take this one step further and share a service manual, test tape, test jigs, spares etc. A bit like car clubs do. This forum might be one method for getting something like that off the ground.

' I'm happy to set my Ta@#$% up to original specs, including 456 tape. I'm a "restorer"...not a "hot-rodder" '

Very wise.

[Jeremy H]

Hi Howard,

"The Turtlerock Mastering Analogue Tape Recorder Owners Club". (What about it Rick? Will you sponsor us for some printed T shirts?)

Seriously though. that can't be such a bad idea . And I guess guys on forums such as this one, tend to interact in the way common interest "club" members do. But maybe formalising and encouraging that interaction a little more wouldn't be a bad thing?

"Perhaps owners of the same models could take this one step further and share a service manual, test tape, test jigs, spares etc. A bit like car clubs do."

Howard, I do appreciate that encouraging such a concept is a generous gesture on your part. (As is often the case with professionals that DO know what they are doing.)

Just for the "record" (Ha..I crack myself up sometimes.....sorry...) I have a "Ta@#$% 85-16B Operation Maintenance Manual" and a "TEAC Ta@#$% Series Model 15 Audio Mixer Instruction Manual" in my library. I intend to scan and PDF these documents soon for my own security. (If anyone is interested in the specific content of these documents...please feel free to PM me.)

Howard, at the risk of asking yet another dumb question: Is it not possible to compile a virtual test tape in the digital realm - to then be recorded to a tape machine of known accurate calibration?. I guess if it could be done, you would have done it? Or is the test tape itself a special formulation - and that is where the expense occurs?

Just wondering.

Cheers,
Jeremy

[Chris H]

Hi Jeremy,

Thanks for the positive comments. There is nothing at all wrong with buying, owning & running a tape machine... people just need to have a realistic appreciation of what is involved.

I'm aware that my comments are sometimes seen as me being a bad-news bear. This is not the intention......... '

.

One of the major benefits of a forum like this is the access to informed opinions and advice from people with your real world experiance. So i for one appreciate your input, Howard.
Sometimes i think there could be room for others expressing their opinions as candidly as you do.
Your comments following on from my "Tape recorders are cheap statement ore spot on and exactly what someone who is thinking of buying a tape machine needs to be aware of. The otari i mentioned cost me $3000 dollars in 1998 when the others i could purchase cost around $800. They were from radio stations and had a hard life. At $3000 it was cheap as it had only had 10 hours use. New when manufactured it was around $12,000 i think. Before i paid for it i had Serge at Audio Oz check it out as he used to work for Otari and it was as stated by the seller as brand new.
Often when buying vintage we tend to grab the bargain but the next bargain is just around the corner so its worth waiting / searching for the machine that has not got exessive head ware , has a better build quality. It's worth doing the research and not buying on compulsion and impulse. Sell the machine you have got when you find a better one for your purposes.

[Howard Jones]

"Is it not possible to compile a virtual test tape in the digital realm - to then be recorded to a tape machine of known accurate calibration?"

It's not a dumb question but, before answering, I would like to go back to the central question of why you (as in the plural sense, the industry at large) are using an analogue tape machine and what you expect to get from it.

Anyone reading my comments in this thread or elsewhere in this forum should be aware that I approach issues from a pretty hard-core purist engineering point of view and such an approach may need to be scaled down when applied to a home studio or prosumer application. Also, because I run a full-service workshop, I'm not in a position to cut any corners. If I am to set up azimuth on a tape deck then I need the appropriate test tape, end of story.

Now, to your original question... alignment tapes are generated on special tape recorders using full-track heads. This means that all tracks are, by definition, in physical alignment and are recorded at the same level. If you use, say, a machine with 16 individual heads in the headstack to record a 1" "test tape" then that tape will have azimuth and level errors on it due to the fact that 16 heads can't be stacked in perfect physical vertical alignment.

If you were using a tape machine a fair bit and had pretensions to serious pro standards - for example, a 2" machine in a high-end studio - then in my mind there is no question that you should be using a test tape and buying a new one when and as required. This is a serious commitment because my last 2" alignment tape cost well over $1,000 and heaven knows what they cost now.

This cost is justified on the basis that the machine is receiving a lot of use and that you must be producing recordings of high quality in a compatible format i.e. that the tape you record will play back correctly on a different machine. However, what of the situation where you are not operating at quite that level and cannot justify purchasing such an expensive alignment tape? Here is how I would approach such a situation...

Assuming that I don't have a test tape, I would get my machine aligned by someone who does. I would then immediately make a recording on the same tape stock for which the machine has been set up and I would then use that as my "test tape" for future checking of the machine. Yes, such a tape would have the imperfections I alluded to earlier but it would be a reasonable compromise between avoiding the high cost of buying a test tape and yet doing the best you could to ensure that you have a reasonable method of aligning the machine.

So, Jeremy, your suggestion is okay except that you would need to make a "test tape" using analogue tape rather than storing the recording digitally.

The alternative, as I have already suggested, would be for a group of owners to pool resources and share the cost of buying a test tape. I probably didn't spell out before the strength of the reasons for suggesting this. I haven't used my 2", 1" or 1/2" test tapes for some years now - due to zero demand for service work on these machines - and I doubt that any of them would run properly now because they will have started to shed. I had to buy the 1/4" test tapes I mentioned earlier in the thread precisely because my existing 1/4 test tapes were shedding so badly that they wouldn't run at all.

So, were anyone to contact me now regarding service work/alignment on a 2", 1" or 1/2" machine, I would say: "Sure, but you will have to go and buy yourself a test tape because I can't justify the cost of doing so to work on just one machine". We have a vast library of service manuals and still have all our test jigs and alignment tools but there is no way that I can spend $1,000 or $2,000 to service just one machine.

I think that analogue tape machine owners should seriously think about pooling resources to tackle this issue.

Some other matters:-

[1] For some reason, I seem to see Otaris with very low head wear come up for sale more than any other brand. Mostly, these are 1/4" machines because, towards the end of the heyday of tape, many radio and TV stations bought heaps of Otaris which then didn't get much use. I think that there should also be plenty of Studers and Revoxes in this category. If you are in the market for a 1/4" machine, these are the sort of machines to look out for.

[2] STL (Standard Tape Laboratories) are the only remaining manufacturer of test tapes that I know of. You can buy them through Musiclab in Brisbane http://www.musiclab.com.au

[Ausrock]

Howard,

Great post!

One potential problem I see with the "community resource pool" is the need to have complete confidence in everyone within that group, both in regard to an "honesty/trust" component as well as knowing that any shared resources aren't going to be abused, broken, "misplaced", etc.

I recall (over a year ago) Rick mentioning a Tentelometer which had not been returned, and from what I know of Rick, I can only presume that it was lent to someone he considered trustworthy.

I purchased my Ta@#$% ATR-60 1" 16 trk from a local radio station, with it came manauls, 9 spools of 456 and 2 MRL test tapes, one of which looks to have never been opened or used........all in good condition as prior to being decommissioned, the tech responsible for the gear had been somewhat fastidious in his maintenance. Also in the deal was an Otari 5050 1/4" plus a matching "parts" machine. The ATR has developed a "bug" which I may ask your advice on at a later time :-). Since buying the ATR, I have sourced most gear recommended in the manual necessary to maintain the machine......just got to learn how to do it now.

Now a question..........I have set a regime for myself to "spool" all tapes at least every 6 months as I was led to believe it can prolong the longevity of tapes and help the fight against "sticky shed". What is your opinion on this>

Cheers,

ChrisO

[Howard Jones]

I made an error in my last post... STL was the most recent test tape manufacturer to go belly up. Musiclab supply MRL test tapes, not STL.

[Chris H]

How is this for timing...A new forum specificaly about Tape machines has just been launched at analogue console. Will be interesting to see how it develops.
http://forum.analogtapedeck.com

[Howard Jones]

"Now a question..........I have set a regime for myself to "spool" all tapes at least every 6 months as I was led to believe it can prolong the longevity of tapes and help the fight against "sticky shed". What is your opinion on this?"

It won't stop a tape shedding but it is a good thing to do nonetheless. It helps diminish print-through (you do store your tapes tail-out, don't you?) and it breaks up stiction in the pack.

Tape shedding is related to the chemicals used in the tape formulation and how they react to airborne moisture over time - most formulations are hygroscopic.

There are EMItapes from the 50s and 60s that still play fine and don't shed - just a different tape formulation.

The best - and hardest - thing to do to prevent tape deterioration is to control your tape storage area for temperature and humidity. It's a lousy problem that we are all living with...

[otto ruiter]

Now a question..........I have set a regime for myself to "spool" all tapes at least every 6 months as I was led to believe it can prolong the longevity of tapes and help the fight against "sticky shed". What is your opinion on this>

I reckon yearly would be often enough, but don't just "spool" the tapes, you have to PLAY them through so that they are packed with even tension. If you spool them at high speed the tape pack will be unstable, and damage the tape if it is left in that condidtion.

regards,

Otto

[Ausrock]

Thanks for the feedback.

The "spool" function on my ATR is designed to run at 80 ips rather than the 240 ips fast forward speed and results in an evenly packed tape.

ChrisO

[mfdu]

yeah - my Ta@#$% 58 does a mid-speed spool which produces what appears to be a lovely consistent tape pack. you can see the density of it by the reflectivity of the pack, and it seemingly packs as well as 15IPS. . .

chris.

[Linear]

It won't stop a tape shedding but it is a good thing to do nonetheless. It helps diminish print-through (you do store your tapes tail-out, don't you?) and it breaks up stiction in the pack.

Tape shedding is related to the chemicals used in the tape formulation and how they react to airborne moisture over time - most formulations are hygroscopic.

There are EMItapes from the 50s and 60s that still play fine and don't shed - just a different tape formulation.

The best - and hardest - thing to do to prevent tape deterioration is to control your tape storage area for temperature and humidity. It's a lousy problem that we are all living with...

Tape shedding occurs to tapes manufactured from the early 70's to the mid-80's. It happened because tape manufacturers changed the formulation of the binder used to adhere iron oxide particles to the tape.

I've only ever encountered this with 456, never with 499 or GP9. It can be fixed with baking, however it's best to transfer immediately rather than think you can keep baking the tape for future use. I've done transfers from shedding tapes (that have been baked) and had to clean the iron oxide off the heads and guides after every song. it was a mess!

Ideally, if you want tapes like this to last, store them in a cold room with a dehumidifier. As howard said, the binder is hydroscopic meaning it absorbs water in the air, changing the adhesive properties.

As for test tapes, well I just purchased a 2" test tape direct from MRL. I tried the local distributor, but they didn't have any in stock and nobody there seemed to know anything about them. A few emails to Charlie and about $800 later, I had a short multi-speed test tape delivered within about a week.

And yes, if you're interested in a tape machine. Take the current cost of the machine, add 3x to get it functional and reliable, and 1/2 of the cost every year to keep it going. This formula has worked for most of my tape machines so far (in particular the ATR102).

Chris