Calibration tones on pre-recorded tapes?

[topoxforddoc]

"The importance of the dubbing engineers' job is very much overlooked and definitely underestimated within the recording industry; dubbing is sometimes considered to be on a par with tea making."

Fred, some might consider tea making an art form (like the Japanese). Many of the new releases have attention to detail, such as nice packaging, custom reels etc, but personally I couldn't care less about cosmetics. What I'm interested in is the best quality dupe, which I can align and play back at its very best. Some of us in the UK have a very ,ing apprenticeship in tea making - my wife considers it a mandatory skill for her husband i.e. me!

Actually I enjoyed reading the article in Studio Sound. The good thing is that I understood it, which is a real relief for a newbie in this field

Charlie

PS Bruce, I'm sure you're right. I can't see people putting tones on tapes - most of the purchasers wouldn't know how to line up the tape properly for repro, so why bother?

 

[Fred Thal]

I suspect that few "high end' tape suppliers will change practice and put tonnes on the tapes . . . the end consumer probably doesn't understand and just assumes that you thread the tape and press play . . . most of the purchasers wouldn't know how to line up the tape properly for repro, so why bother?

Hmmmn. You are ceding the argument for bringing the new generation of pre-recorded tapes out from being essentially only a novelty product, to something having an independently verifiable level of quality control?

(As an aside, remember that we already successfully did this for the cassette duplication industry. Back in the 1980s, a few of the most quality concerned pre-recorded cassette makers were putting short, but carefully thought-out tone sequences on their cassettes that enabled a panel of various quality control checks to be made on playback. It took up only a few seconds on the tapes. Customers did not seem to mind.)

Are you certain you want to now cede the argument for creating something that could allow knowledgeable users to achieve the highest quality analog tape playback?

If so, that's sad, because analog tape could indeed become the king of high-end analog playback today. (Not vinyl.)

We need just one person to step-up and commit to analog tape replication done technically right.

 

[topoxforddoc]

Are you certain you want to now cede the argument for creating something that could allow knowledgeable users to achieve the highest quality analog tape playback?

Fred,

Absolutely not conceding! I'm just reflecting on the market as it is today. For me, I absolutely want tapes with line up tones. I'm just explaining why some consumers might not be too bothered, as they may be ignorant of why tones are important.

Charlie

 

[Two-Track Analog]

...We need just one person to step-up and commit to analog tape replication done technically right.

It seems that one gentleman from China is setting out to do just that. He claims that none of the current tape producers are creating master dupes correctly and is setting out to (eventually) do it properly.

He's currently in the process of mass-acquisition of tape machines to set up his production facility. With an inventory approaching 200 high-end machines, he's an interesting guy to speak with for sure.

-Steve

 

[microstrip]

It seems that one gentleman from China is setting out to do just that. He claims that none of the current tape producers are creating master dupes correctly and is setting out to (eventually) do it properly.

He's currently in the process of mass-acquisition of tape machines to set up his production facility. With an inventory approaching 200 high-end machines, he's an interesting guy to speak with for sure.

-Steve

Fascinating news - we should ask where he will find people with expertise and technical knowledge to service and tune all these machines in a reasonable time schedule.

BTW, did you get an A80?

 

[topoxforddoc]

He's currently in the process of mass-acquisition of tape machines to set up his production facility. With an inventory approaching 200 high-end machines, he's an interesting guy to speak with for sure.

No wonder that the price of decent studio machines is going up. Does that mean that someone in China is going to start making raw tape as well? If this guy is buying 200 machines, he must be thinking about duplicating large numbers of tapes. Realistically it takes a good hour to duplicate one album of say 40 minutes music, as you need time to calibrate the record levels on the tape and to record tones to the head as well (plus change over time). With 200 machines and a number of staff, he could be doing 7-8 runs in a working day - that's circa 1500 albums a day - 500,000 tapes a year, assuming he has his staff working 7 days a week - 400,000 tapes a year if his plant works 5 days a week!

Charlie

 

[Fred Thal]

...He claims that none of the current tape producers are creating master dupes correctly

Hello Steve,

The statement sounds eerily familiar.

Does he explain why?

Does he identify what they're doing wrong?

 

[astrotoy]

I, for one, would like to have test tones at the heads of the prerecorded tapes. I have a bunch of safety masters and they all have test tones. Makes it a snap to set levels and fine tune the high frequencies. I do have calibration tapes from two of the tape companies where I have bought many of their tapes. If they have good QC then, having their calibration tapes given me reasonable confidence, though not as good as having the tones on each tape.

As far as gentleman in China with the 200 machines, it will be very interesting whether he can have a business model that makes sense. Elon Musk had over 400,000 orders for the Tesla 3 (each with a $1000 earnest money deposit) before the first car came off the assembly line. It is hard for me to imagine the demand for 500K tapes a year unless there is an iphone app that can play R2R tapes If they are going to issue their own tapes, a great difficulty is getting through the licensing and getting hold of the original master tapes to do the duplication, especially with the various mergers in the recording business. They may be thinking about just handling the duplication for companies, like Ampex did 50 or so years ago for many of the record companies selling prerecorded tapes. Manufacturing the tapes integrated the process for Ampex. I don't know whether Ampex actually made more from the production of the prerecorded tapes or from the tape manufacturing. QC is a major issue, since these are expensive products, and each tape should be defect free.

I'll be very interested in seeing how things work out.

Larry

 

[Two-Track Analog]

Fascinating news - we should ask where he will find people with expertise and technical knowledge to service and tune all these machines in a reasonable time schedule.

BTW, did you get an A80?

He has a staff of three techs who completely refurbish every machine he purchases, so along with completely refurb'd decks, he purchases as-is decks, parts machines, and essentially empty frames.

I have acquired several A80s. Like some other members of this site did many years back, I went a little nuts with it.

 

[Two-Track Analog]

Hello Steve,

The statement sounds eerily familiar.

Does he explain why?

Does he identify what they're doing wrong?

Not that I would remember them, but he didn't touch on technical details as we were covering many topics in the course of our conversation. Though one thing he cited that hampered quality are the choices of recording and playback decks used in the duping process by the current producers.

 

[Two-Track Analog]

I, for one, would like to have test tones at the heads of the prerecorded tapes. I have a bunch of safety masters and they all have test tones. Makes it a snap to set levels and fine tune the high frequencies. I do have calibration tapes from two of the tape companies where I have bought many of their tapes. If they have good QC then, having their calibration tapes given me reasonable confidence, though not as good as having the tones on each tape.

As far as gentleman in China with the 200 machines, it will be very interesting whether he can have a business model that makes sense. Elon Musk had over 400,000 orders for the Tesla 3 (each with a $1000 earnest money deposit) before the first car came off the assembly line. It is hard for me to imagine the demand for 500K tapes a year unless there is an iphone app that can play R2R tapes If they are going to issue their own tapes, a great difficulty is getting through the licensing and getting hold of the original master tapes to do the duplication, especially with the various mergers in the recording business. They may be thinking about just handling the duplication for companies, like Ampex did 50 or so years ago for many of the record companies selling prerecorded tapes. Manufacturing the tapes integrated the process for Ampex. I don't know whether Ampex actually made more from the production of the prerecorded tapes or from the tape manufacturing. QC is a major issue, since these are expensive products, and each tape should be defect free.

I'll be very interested in seeing how things work out.

Larry

That was my initial question as well - will there be enough demand globally to support a high-production duplication line?

You bring up an excellent hypothesis about providing duplication services for others, but even then the collective demand of all companies currently producing tape still wouldn't be enough to keep a large production facility busy - not these days. And as a 'boutique' tape producer selling relatively small quantities (after all, ours is a niche pursuit), if those companies are satisfied with the quality of their product and are not keeping their existing production decks continuously busy, what is the motivation to pay someone else to do it and add another cost layer to the equation?

Purely conjecture, but perhaps the plan is to also produce quarter track tapes on 7" reels to reach a broader market. We won't know truly what will come of it for some time, I'm sure.

As you mentioned, it all comes back to licensing and acquisition of the master tapes, which has always been the difficulty with broadening the market offerings for commercially available open reel titles. And limited rock and pop titles takes a large portion of the would-be market out of play.

 

[Skylab]

There was a point in time when I thought that 1/4 track 7" reels would mean a broader market for new reel tapes. Now I'm not so sure anymore. How many people who are interested in buying currently produced tapes have only 1/4-track machines? I actually think the state of reel to reel today is that the ONLY even close to substantial market there is currently is for 1/2-track, 15 ips tapes.

 

[Fred Thal]

I, for one, would like to have test tones at the heads of the prerecorded tapes.

I found this on another (apparently competing?) tape forum, posted just four days ago (on August 17):

"With the tape, once the heads are aligned (using an MRL calibration tape at the mastering and playback machine) it is push and play. Just keep the heads clean."

How could anyone with any technical background in analog tape be claiming that an azimuth adjustment tone on a pre-recorded tape is not necessary.

They couldn't. So we have to conclude that they lack an understanding of the subject.

Here are two introductory questions for those people to ponder. Perhaps with these questions we can get them interested in studying the subject more.

What is the "azimuth loss formula" and why does this matter?

How wide is quarter-inch tape and why does this matter?

The second question is the trick question. It's also a key insight into understanding the azimuth problem.

 

[c1ferrari]

I request tones printed at the head from labels, which vend directly to the end-user. Otherwise, one seldom encounters alignment tones.
Topoxforddoc mentioned spectrum analysis for possible use in alignment...I'm going to try applying this insturment
for yielding optimal results from 'master tape dubs', etc., particularly those (many) absent even basic tones: Tek 760A

 

[Fred Thal]

I'm going to try applying this insturment
for yielding optimal results from 'master tape dubs', etc., particularly those (many) absent even basic tones: Tek 760A

That is a stereo program channel correlation display.

It will be of no help to you in setting repro head azimuth if there is no azimuth tone on your tape.

 

[c1ferrari]

That is a stereo program channel correlation display.
It will be of no help to you in setting repro head azimuth if there is no azimuth tone on your tape.

Given tape with no tones, judicious -- read, very conservative -- adjustment of repro head azimuth may positively affect stereo image / phase.
My inference is that improved stereo image and phase (graphically corroborated with the 760A or another goniometer) are the result of better alignment to the tape.

 

[Fred Thal]

Given tape with no tones, judicious -- read, very conservative -- adjustment of repro head azimuth may positively affect stereo image / phase.

Please have a look at the azimuth loss formula to see that a repro head azimuth change of only one-half a degree (or thirty minutes of arc) can result in an attenuation of seven dB at 15kHz.

I can't see the wisdom in destroying the analog tape's high frequency playback response just so you can make experimental, subjective changes to the program's inter-channel phase relationships.

I suggest that you do your phase relationship investigations in the digital domain, after you have correctly played back the analog tape.

 

[c1ferrari]

The interest is to mimic the path of the tape as the tape transits the record head of the recorder with the path of the tape as the tape transits the repro head of the reproducing deck.

Naturally, more easily accomplished with azimuth tones.

Obviously, in most cases, not moot if tapes are in-house using maintained and known machines; however, as it's been asserted elsewhere...when tapes travel to another studio, for example,...

A goniometer may be a relevant tool for extracting information.

 

[Fred Thal]

. . . A goniometer may be a relevant tool for extracting information.

What kind of information? Measuring or using the phase angle between two independent channels of a stereo program would be a horrible way to try to adjust repro head azimuth.

Back to the topic of this thread please.

Did anyone reading look up the azimuth loss formula?

Did anyone wonder about question two, that asked about the actual width of quarter-inch tape, and why this is an important issue that necessitates putting azimuth alignment tones on tapes?

Or, do we drop all this, resigning ourselves to the fact that the tape copies being sold today are essentially only novelty products, made for people who don't really care about obtaining accurate playback?

 

[topoxforddoc]

What kind of information? Measuring or using the phase angle between two independent channels of a stereo program would be a horrible way to try to adjust repro head azimuth.

Back to the topic of this thread please.

Did anyone reading look up the azimuth loss formula?

Did anyone wonder about question two, that asked about the actual width of quarter-inch tape, and why this is an important issue that necessitates putting azimuth alignment tones on tapes?

Or, do we drop all this, resigning ourselves to the fact that the tape copies being sold today are essentially only novelty products, made for people who don't really care about obtaining accurate playback?

Fred,

I did look up the azimuth loss formula. I won't repost here, as it's easy enough to google.

The wider the track width and higher the tape speed, the greater the loss of HF when the repro azimuth is out of alignment. Cassette gets away with "acceptable" HF losses with poor azimuth, due to to very narrow track width and slow tape speed.

Charlie

Charlie