Of course they do. I have 6 Studer A80, all speeds from 9 to 76cm/sec including 2x QC, A820, CR7, and they all has playback azimuth adjustment knobs. Original or made by JRF. But it is nearly impossible to adjust mono 1 channel azimuth by ear if recorded frequencies are below 10khz. +- 3 bogen minutes are not audible in this case even on VCR speed. If you want to mess with VCR linear audio head azimuth, order correct knob from John French. With fine thread stud.

Wrong. It can be if you digitize full track mono tape in stereo and align head in accordance with phase spectral display. In all other cases you should return to nominal azimuth before.

Of course we cant align to frequencies higher than the recorded frequencies because there are none there to align to. What are you referring to? Aligning to bias tones? Not likely on a VHS linear audio track.


I find this unintelligible. Again when a tape such as VHS linear audio was - for whatever reason - obviously recorded off standard azimuth, what do you do when digitizing it?

I only want to say - if recorded frequencies are below 10khz (speech) it is nearly impossible to adjust azimuth by ear for mono recordings. Except for music recordings, but VHS tapes with music recorded with linear audio is rare. For stereo you can switch to mono and adjust by ear on headphones very simply.

If azimuth is off +- 3 minutes I do nothing. And 99% tapes are in this range. Because it will improve nothing for linear mono audio. My heads (vcr ;)) azimuth is always at 90° adjusted in accordance with original test cassettes (what all are close to each other). In those very rare cases when azimuth is really off because someone is messed with head at recording, it should be adjusted. But this is what you can hear well immediately, because those sound like from WC. But it is rare.

And for those tests I have Panasonic NV-FS1 what I commonly use for rewinding. I do not adjust azimuth on my JVC or FS-200 if I am not sure there is azimuth problem, not simply how it sounds. In 99% if sound is like from WC, it is recorded that way.

Radiocom, I find it hard to relate to your description in degrees and minutes to actual sounds. For me it's simple. Having an external azimuth adjuster as pictured, there is no setup time. I can quickly and easily listen to a sample of any tape playback while slowly turning the adjuster to find the peak point in the azimuth curve. It normally takes very little time.

You claim that 99% of tapes were recorded to the azimuth standard. I would never rely on mere listening sans adjustment to judge whether there is azimuth misalignment or not, or to what degree. For me that's too subjective and unreliable. We have no reference except this unknown recording made on whatever unknown VCR or camcorder. Adjusting azimuth on any given tape from misaligned to aligned then misaligned on the other side, then back to the peak tells me whether it is aligned or not. Maybe my deck was initially aligned to the tape. Maybe not. Adjusting azimuth in and out of alignment confirms that one way or the other.
Why use an indirect method of assessment, which includes an unnecessary assumption, when a direct method is possible?

Yes monitoring in linear stereo and alternating with mono summed monitoring is useful as again it provides some sort of reference point, but many people dont have access to a linear stereo VCR, and many amateur VHS and VHSC tapes were recorded in linear mono. With no linear stereo playback and no easy and safe way to adjust azimuth, many people dont know how much better their linear audio could sound.

I am just trying to say that with your method you are likely to play tapes with a much larger azimuth error than if the head was adjusted to a test tape. Because you can not hear what the hell you are adjusting. So - no to your method.

And keep in mind - original azimuth screw thread wears out. Adjusting azimuth N times even when it is not necessary simply damage your linear head assembly. This is why I advice to have separate VCR (it can be your sharp for example with that knob) what you can use only for test purpose if there are suspicions something wrong with azimuth. And right method is to adjust azimuth to 90 degree in accordance with test tape first and only then reproduce particular cassette and adjust azimuth and try to hear what changes. Not "on the fly" from one tape to another.

P.S. One more example - for speech recorded on audio cassettes digitization I use Nakamichi LX-3 and 480 (restored of course) with removed erase head. There is no need to use CR7 or Studer A80QC for any crap. But this is not because there are no other dual capstan decks but because of possibility to adjust playback head azimuth N times (and pressure pad lifter of course). Those nylon screws does not wear out. And speech is recorded commonly in half track mono. So when reproduce in stereo you should not hear nothing - simply look at phase spectral display and adjust azimuth "on the fly" and mix to mono after digitization. But if there is "stereo" recorded, you should return to nominal azimuth with test tape and then try to adjust something or decide to leave it as is, simply applying digital phase correction after recording.

It's your claim. Please explain yourself. Give examples.

Maybe my English is not good enough, but I think I have already mentioned enough examples. I will draw your attention again that for a mono track played as mono, the azimuth can be adjusted only according to the maximum level of the upper frequencies played. However, if these frequencies are absent, or they are episodically present, then all the adjustment is based on the principle of "I think this is correct, because I heard it that way". This is not a constant test tone from test cassette, according to which you can adjust the maximum (or minimum, if the sound track is divided into two, recorded in counterphase) level. So if you decide to mess with azimuth, the first you should be sure there is azimuth error enough it worth correction (using separate test vcr for that purpose). And then on main VCR be sure azimuth is at nominal position first (or calibrate nominal azimuth in accordance with test tape first) and then make azimuth adjustments. After playback return to nominal adjustment with test tape. But never "on the fly" from tape to tape. But it is up to you - that's your tapes and your VCRs so you can do all what you want.

Thankyou. I thought that might be where you were heading but it's your point so it's right that you explain it.

Of course in such a case we are in a sense flying blind re correct azimuth at points where there is not enough HF content for fine alignment to them. But if there is not the HF content in certain passages, such fine azimuth adjustment no longer matters, for now there are not the relevent HF's to be lost through azimuth misalignment! This is "the cat chasing its tail"!

After such a recording we can only say, "Well if those HF's had been still there, those HF's would have been captured." ! It becomes a pointless exercise aligning for frequencies no longer there.

We can only align to the content on the tape at time of digitization.
As you say using a stereo playback head helps in such a situation because it's more forgiving re azimuth misalignment. I sometimes capture a mono tape in stereo while monitoring in summed mono, including keeping an eye on an Azimuth Corrector tool's live meter.

Not because it is more forgiving but because you can exactly align correct azimuth on the fly and loose nothing. It is very simple - start Adobe audition phase spectral display, start 2 channel recording and adjust azimuth in seconds. After recording mix both tracks to mono.

In 80s most tape recorder manufacturers, including Studer and Otari stopped or limited full track head manufacturing. At least when I bought last new Otari MTR-15 fom Otari GmbH in early 2000s, they told me mono heads (I was interested in full track recording heads) are not produced long time ago, only old stock maybe is available in Japan. Instead of this for full track (6mm track width) mono was used stereo heads with each track width 2,75mm with mono/stereo switch (that 0,5mm gap between tracks affects nothing in real life).

For stereo azimuth adjustment switch to mono and you can adjust azimuth with ears very precise because of phase shift. + control on spectral display.

P.S. Some useful resources (however I am sure we hijacked this thread, it is no more related to OP Sony) :):

https://mrltapes.com/mcknight_azimuth-in-mtr.pdf

https://richardhess.com/notes/2006/0...hows-and-whys/

But the narrower tracks in a stereo linear audio head are more forgiving because the stereo pole pieces are narrower! This is no small thing. As Latreche stated earlier the standard linear audio track is 1mm wide. At only 0.35mm wide the linear stereo R/P heads are almost 3 times narrower. They are less sensitive to a given azimuth error because they sample a shorter wavelength. We can have a great playback head with sub micron gap length but unless azimuth is aligned to that same micron level of precision that head's fine resolving ability is wasted.

Especially for people without the skills/confidence to open up a deck and tweak the linear azimuth to a tape, this is an audio quality advantage. Played on a deck with a linear stereo head many tapes especially LP/SLP/EP which sound muffled on their linear mono head deck will sound considerably clearer. Many which sound only moderately muffled on a mono playback head will likely be reproduced with little or no HF loss on a linear stereo head.

Speaking of relevence to the original post, the Sony SLV-R1000 SVHS deck may have this linear stereo AC head. But this information isnt always made clear in owners' and service manuals.

If I was searching for a VHS VCR with good linear audio especially for LP/SLP/EP recordings but could not tweak the internal AC head azimuth I would be looking at a good quality deck with a stereo linear audio head. Unfortunately in video digitizing discussions this factor is rarely if ever mentioned. What would help people choose a suitable VCR for digitizing their tapes and who cared about audio quality is a list all the quality VHS machines which have the stereo linear AC head. Especially so for the LP/EP/SLP recordings. This factor could be incorporated into existing lists.

I much prefer these discussions to include sharing of actual audio and video examples. So trying to lead by example here.

I may have shared this audio before. LP mono linear original audio, captured with mono linear head, custom azimuth aligned by ear. Being a PAL recording this LP track runs at even slower tape speed than NTSC LP. Actually a quarter the speed of a standard compact audio cassette. This is from a roughly 6 hour long VHS E 180 tape.

No audio processing/ restoration used here. Straight off the tape.

Is azimuth alignment critical here? Is the Pope a Catholic?

Apologies for the late reply directly to your enquiry. I'm a service technician. I have no direct experience of this machine but here's a link to a video from an experienced technician familiar with servicing them. He has a high regard for this high end model while noting a few problems with a machine which he proceeds in the video to repair. Hope this helps.


https://youtu.be/0XMh7NKjzng?si=Q4kVEfZAmbO36A5z

radiocom, I've been puzzling over various things you've said about azimuth in this thread, and wondering if there is a simple solution here.
Is it possible your VCR has only mono linear audio, not stereo?

In your case, it is impossible to say this because there is no reference point (azimuth adjusted to 90 degrees according to the test tape) and then the particular tape was played with the nominal azimuth, then +1min+2min, -1m-2m, etc. In your file main high frequency is 4khz, at peaks 8khz so azimuth adjustment (for LP) is useful if error is more than about 1 minute.

radiokom, in your post #29 above you cited a Richard Hess article: "Azimuth: Hows and Whys." Thankyou. I reread it.

You might care to read Richard's first paragraph, which I have copied here.


"There is a recurring question as to what is the best way to set azimuth for playing a tape. Many people assume that using the test-tape alignment is best. Well, that makes another big assumption: The recorder used a proper test tape alignment. While that can be the case, it usually is not.

If the tape has tones on it (a big if in many collections), you align to that, right? Better, but consider this: When a 1963 album was being remastered, the mastering engineer aligned to the tones and after doing all his magic found that the tones were not recorded at the same azimuth as the program. Big redo!

Aligning to the track material itself is the only way to properly adjust azimuth in the absence of tones and it is still necessary to check the track material even if there are tones. The wider the track and the slower the speed, the more critical the azimuth adjustment is. Stereo makes it more critical and often times easier to adjust..." *

author Richard L. Hess, Audio tape restoration, Canada

*(My underlining).

You should read all article and understand what is written.
This for example:

If you have a mono tape, that’s all you have, but if you have a stereo or multi-track tape, you can sum channels that have similar program on them that should be in phase and get a wider baseline for tweaking the azimuth.

It seems that you simply consider your azimuth adjustment method to be correct and protest if anyone challenges it. ;)

He's talking about a stereo or multitrack tape. I assume he means using a matching multitrack head to read that tape, and then summing tracks with the same content for as he says a wider base for more accurate azimuth alignment. That makes sense to me. It allows better summing of the similar tracks to potentially reduce tape noise and dropouts. But again is your vcr linear head actually stereo or is it mono? Why not check this?

There is nothing to check, linear audio for all S-VHS decks we (I) use (Panasonic NV-FS200, HS1000 JVC HR-S77XX series etc.) is 1 track mono.

P.S. I have few professional Panasonic with stereo linear audio and Dolby B, but they "belongs to the museum" © :).

P.P.S. Although - one idea came to my mind as a result of this controversy. To use a professional Panasonic with a stereo head for accurate determination of azimuth error. If until now I did it "by ear" on the NV-FS1 and then decided it worth alignment or not, then by playing a mono track on a VCR with a stereo linear audio head, the azimuth error can be determined in a few seconds using the phase spectral display. And then decide there is a reason to mess with adjustment or better to leave it alone.

I suspected they might be mono. So you know you can't capture in stereo and compare time alignment of left and right tracks? I thought you might have seen the identical left and right waveforms and wrongly assumed azimuth was correct for that tape, and almost every other tape you played. Oh well I tried to help. Now I'm confused again as to what's going on.

Relax, I own a professional sound restoration studio and have some experience with azimuth for more than 35 years :) But as I wrote in edited comment above, it would be a good idea to use professional VCR I already have with stereo head to determine azimuth error in seconds.