Using audio alignment cassettes
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- เผยแพร่เมื่อ 22 ก.ค. 2024
- Today we are using a set of alignment cassettes to check operation of a Marantz SD420 cassette deck.
We can test tape speed, wow & flutter, head azimuth and playback levels.
Tapes from:
www.ebay.co.uk/usr/we-love-an...
** UPDATE ** Adjusted playback level on preset control RJ44 to bring the right channel up by the less than 1dB which was required.
Audio and video transfers: www.video99.co.uk/
Please support us on Patreon / video99couk
or Paypal to colin@video99.co.uk
Music “Let It Run” with permission, copyright Cristie/MacFarlane.
Sorry I do not offer an audio or video equipment repair service.
00:00 Introduction
00:38 König wow & flutter tape
01:41 New wow & flutter tape
04:17 Azimuth tape
08:32 Lissajous pattern
09:13 Level measurements
10:21 Conclusion - วิทยาศาสตร์และเทคโนโลยี
More videos on calibration of cassette decks would be amazing
Thanks for keeping the old technology alive!
A note about the azimuth and level adjustments: The azimuth is usually adjusted so that you first find the maximum output level of a 10-15khz tone and only after that match the phase. That way you can make sure that you're not 360 degrees off. Sony service manuals also specify the azimuth at the mid point of left and right channel maximums (these are not always identical because of manufacturing tolerances).
The level should not be adjusted according to the decks' own meters but to a specified output level at the output jacks, after that you can adjust the decks' own meters to the correct value. This is important because there is no way of knowing whether the meters or the level is off if you adjust by the decks' own meters.
The fluctuation of the phase in the azimuth adjustment is completely normal for a cheap deck like that Marantz, it's caused by an unstable head- tape contact.
Cheers!
The Marantz isn't that cheap, I would say it's better than a lot of decks of the vintage. My main go-to deck now is the Aiwa XK-007 Excelia, which is a bit more expensive.
Thanks, man. I am currently at moment of repairing pioneer ct-s630s, and seems that other decks (yamaha, telefunken, another pioneer) all have different showing of level of the same tape....did you had such experience, is it possible? I was not sure how to correct that, which level is right. So, question: what voltage to expect if readings of level are 0 dB???
The azimuth and level tapes used in this video are not full track. They were recorded using an ordinary stereo head, as opposed to a special head that writes on the full width of the tape. This makes them fundamentally UNSUITED to precision alignment work. Fine for debugging a boom box, detrimental in a quality cassette deck. Even these days you can still purchase full track alignment tapes. There is some stock left of original TEAC, BASF, and ABEX cassettes (see e-bay), while new full track cassettes are manufactured by ANT Audio, Hanspeter Roth, and GennLab. Avoid all others if you don't want to end up disappoined or frustrated.
Yes alignment tapes are full track for good reason but nothing wrong with a stereo alignment tape designed for a stereo machine. In fact it allows alignment of head height better than a full track as the amplitude error is visible on both tracks. Also there is no need to compensate for the fringing effect (low frequency irregularity) which occurs when a full track tape is used. Note: all my test tapes are full track but I also understand their special limitations in measuring some parameters.
It would be interesting to see what the wow and flutter levels are like from the deck's own recording.
If I remember right the official Sony level test tapes were recorded across the entire width of the tape which meant Dolby levels could be set correctly even if the head height was slightly out of true, Nakamichi tracks were also slightly wider making them better machines for recording aftermarket level test tapes. I used to love working on this type of gear and I still have (up in the attic) a Sony TC-K75 and TC-K81 (both closed loop 3 head machines) along with my trusty Ferrograph RTS-2 and ATU-1 test set.
I use a Lissajous Y/X figure to adjust the azimuth. It's way easier than looking at the waveforms to me because the figure directly shows me where the phase is moving.
Yes, I do the same at 8:32
A level tape is used for setting the gain between the head and the Dolby decoder. This is an absolute necessity as Dolby encoding/decoding hinges around a fixed, standardised level. Any error leads to significant frequency response aberrations and audible pumping. The reference level is defined as 400Hz at 200 nWb/m measured according to ANSI, or 218 nWb/m according to DIN. Playing such a tape the internal playback level is adjusted so that a specific voltage is obtained at a specific test pin (see service manual). Alternatively, until a specific voltage is obtained as a specific pin on the Dolby chip (see chip datasheet). Setting level so that the 'Dolby' logo on the deck's meters is reached is NOT valid practice, as it should not be assumed that these meters are (still) properly calibrated.
Fair point.
That shifting variation of Azimuth is the tape waving on the PB head. The tape path should be clean and verified. Pinch rollers or worn heads may be a root cause.
This can be a problem on slow speed cassettes and especially mini and micro cassettes (Long Play) because even with equipment in good condition, azimuth can actually cycle in and out of alignment many times per minute . The tolerances are not tight enough to maintain steady azimuth tracking. Playback with a stereo rather than a mono head reduces this. Unfortunately most mini and microcassette machines were mono.
König electronic was a super brand. Greetings from germany
Do you know if (once someone has made a correct 10k tone tape etc) if you can also use that free Signalizer VST 0.3.2 oscillator program to get that circle/line adjustment curve on a screen or do you need a real oscilator for that funktion to show. If this windows program also works for that visual azymuth on screen funktion maybe you can show which steps to do in that program to get that curve on screen.
Once I use one of my "reference" deck to record 440hz with two tapes (no 3 head deck), and then I play right channel, and calibrate deck to left channel. I use only my ear to make speed right :D
Merci ... I have this TCC130 abex, how can I adjust the recording level on a 2 heads deck with this tape ? It's easy on a 3 heads with monitoring, but with a 2 heads ?
For check azimuth, i use my hears with my K702 akg....because there is no perfect azimuth between pre record tapes, it is obvious, I am often obliged to turn the screw to recover the sound on my Tascam 122mk3, it's subtle but i can hear it !
Could you do a video on computer cassette adjustments? Would been interesting to see comparison of tapes using standard load VS turbo loaders.
BNC 50 or 75 ohm for use in audio with an oscilloscope ?
Hi, I have a Pioneer CT-S420 and would like to calibrate it for Maxell UD XL II, adjust the bias and optimize Dolby B and C. I have a Nakamichi audio analyzer but since I am new to electronics I don't know how to adjust the calibration. Can anyone help me? I made pictures of the PCB that I can send, but which one is for what?
请使用矢量示波器 检查MII的 SCH波形
I also used the UK-made alignment tapes you have on my AIWA XK-S7000 and I am still not sure what to make of their quality. The first set I bought showed significantly different levels L/R when playing them. Matthew, the owner of the manufacturing shop, was very kind to check and replace my full set. The new ones didn't show the difference, but now my deck's L/R channels were significantly off after "aligning" them using the tape. I couldn't figure out if the tapes were 100% fine.
Yes, exactly the same here! I have to go back and re-align the audio levels of one of my decks for the same reason.
Great video Colin! I was setting azimuth on my Aiwa F660 by ear only and seems to work fine. But it would be great to do more precise job. Do you think some sort of PC scope via sound card input could work for this? I don't have a scope anymore and since we operate in audio frequencies this should be possible, right?
Yes that would work. Or even just use Audacity to line up the waveforms, would be a bit clunky but could work.
When you change the azimuth for the 15kHz tone, did it go out of phase for the lower frequencies? That's what I imagine happens as it was already in phase at the lower frequencies. So we should trust the higher frequency setting over the lower ones?
Adjusting azimuth with higher frequencies is way more precise. And if the signal is in phase, it's in phase. It has nothing to do with the frequency.
Aligning to standard azimuth is fine as far as it goes but it makes an assumption. There's no guarantee an unknown recording will play back with azimuth aligned correctly. Interestingly the only way to find out if a recorded cassette is "off azimuth" is to *adjust playback head azimuth* and note the changes in the sound. But most people including most transfer shops dont seem to bother. VHS and Beta cassettes are even more sensitive to audio azimuth errors, hence the common complaint that the linear audio is hissy and muffled. With azimuth adjusted *to the tape* the sound may be a lot less hissy and muffled.
With dictation cassettes (minicassete, microcassette), whose recorders were regularly knocked about, I do an Azimuth check with every tape that comes in. Generally VHS and Beta decks had well locked off audio/control heads so audio azimuth errors are not too common. N1500 and to a lesser extent N1700 tapes I do have to set up azimuth for audio or control track reasons.
@@video99couk My claim was that the only way to know objectively if record and play azimuths on any given tape are aligned is to test it by adjusting azimuth on the play deck and listening. Carefully rock the adjuster back and forth until we reach the peak. I'm not saying that any given recording is misaligned or not, but that we cant be sure either way unless we test it. As to the cause in each case, with the recorders long since gone we can only speculate.
Some consumer cassette decks such as some Nakamichi's have a playback azimuth control on the front panel. One model allows azimuth adjustment from the wireless remote (CR7). To twiddle the control knob or use the remote is child's play. It doesnt take much skill or intelligence. So I suspect the reason most dont adjust azimuth when transferring individual tapes is because on most decks, making the adjustment is too technical or inconvenient. Which it often is. But that's a different question.
6:10 could be tape skew perhaps due to a worn pinch roller.
thank you
Hello, thanks for the video: did you use RG59 BNC to RCA cables direct from tape output to the scope?
I think I did since I have those to hand.
Reason I asked, thought some 100k load had to be placed in between- in that case, I’ll order for me as I’m “playing” with my new scope and wanted to check my decks alignments
Thank you for your video, How do I shoes or find the right hz to calibrate the speed in my technics 175 ?
Any wow & flutter tape will have 3kHz and/or 3.15kHz, and either can be used to calibrate your machine speed if you have a modern oscilloscope which can measure frequency.
In a repair video for a REVOX B215, the KÖNIG 4907 wow and flutter Cassette says 6.3 KHz +/-2% and +/- 2dB @ -15dB. I prefer "Quartz" Direct Drive. What wow and flutter software was used here ?
I suspected that the König tape isn't great. It's likely then that at least half of the W&F reading I was getting was due to the tape itself. The software is wfgui and is widely available to download.
@@video99couk By +/-2% is meant the permanent speed deviation of the stroboscope cassette with measuring tone for frequency counter. But I dare to doubt that König recorded the cassettes with REVOX B215. Over the last few days I've been looking at what 0.025% WRMS wow and flutter Direct Drive dual capstan devices are out there. From the official data, neither REVOX nor Nackamichi can tell that these are supposed to be the “best” devices. I'm currently leaning towards SONY, but without NE5532 on the playback head and over 2k Ohm (total) output resistors for muting. This seems to me to be rather unnecessary for digitizing if you don't use normal speakers.😉
great vid! thanks for sharing :) had a quick question, could you maybe do a video on properly setting the REC head? I have a feeling this can be done relatively easy once the playback head is correctly set but would be very helpful. Cheers!!
Never thought too much about that. I'm not sure of the procedure for that but it may involve connecting the REC head to the PLAY circuit temporarily.
The standard procedure was always, on a 3 head deck, to align the play head to the standard, so the play head is now your standard. Then align the record head to the play head, adjusting the record head (very slowly to allow for the time delay) for maximum signal at say 10 kHz at the play head. The only time I know of when a record head needs to be azimuth aligned using it temporarily as a playback head is in a machine where there is no playback head, only a record head, such as many high speed tape duplicators back in the day.
I don't think I've ever seen an azimuth readout on an oscilloscope vary that much.
Old decks with worn-out mechanisms do that a lot. Also, pinch roller condition can make quite the difference.
@@mikec9112 there are people that produce full track test tapes. Alex Nikitin from A.N.T. Audio has some for sale.
Can you use a PC oscilloscope software in place of actual oscilloscope hardware? I assume yes since you used a wow and flutter software.
@Matt Quinn I would agree with all of that. Actually Lissajous figures can even be displayed on most single-beam 'scopes. I had an hold Heathkit from 1964 that would have been able do to this job just fine.
If I recorded a frequency onto a blank cassette via a you tube freq demo, would I be able to get an accurate wow flutter , azimuth reading with the wfgui ?? Instead of relying on a 3rd party cassette?
Well you roughly double the wow & flutter readings relative to a perfect (no such thing) alignment tape. But other than that, yes. Azimuth would require a known good recorder, and in the perfect world that would be a special recorder with a full width head, specially manufactured for this purpose. Very few such alignment tapes exist.
@@video99couk So, I have 3 tascams and a vintage Panasonic boombox. Tascams are 133 234 & 238. I would record a tone separately on each deck to run the w&f test? The azimuth screws all have loctite or red glue indicating they haven't been fiddled with so I'm assuming they are probably OK. They all sound great.
Hello, which audio interface are you using?
Not quite sure what question you are asking. What audio analogue to digital converter? Usually this one:
th-cam.com/video/8ffbf7jS62I/w-d-xo.html
do you have a link to the software you are using ?
It's here:
www.ant-audio.co.uk/index.php?cat=post&qry=library
@@video99couk Thanks :)
Thank you, tell me, please, where i can order these magic cassettes. Thanks.
Link to eBay sell is in the video description.
I imagine the quality of the pinch roller surface and capstan bearing fit would have produced the slight differences.
But who listens to tones anyway lol.
Your scope showed the playback to be low on one channel, the question is: is it the recording or the player.
Run away would be the best option :-D
I'm fairly sure that the right channel is about 2dB down, I could adjust it. Perhaps I should.
@@video99couk Only if you are sure the cassette has been recorded with both channels the same amplitude.
If so i would find the playback preset and tweak that only.
Any cassette recorded with test tone will have the inherent vice of the deck it was recorded on. Which is why new calibration cassettes are flawed. The desirable ones would come from the cassette era from respected manufacturers, like BASF calibration set.
That's right, there's no perfect alignment tape.
Old calibration tapes were flawed as well. There is no such thing as a perfect alignment.
@@svenschwingel8632 True. The only reliable result would be azimuth tape recorded by industrial duplicators to perfectly align to cassettes manfactured on said duplicator.
@@SFtheGreat even industrial duplicators can be off. At some point, you WILL have to settle for a reference. And having a reference with slight tolerance is better than having none at all. I buy my alignment tapes from Alex Nikitin over at A.N.T. Audio and use a Willy Hermann WHS300 gauge for mechanical alignments. They have worked out great for me thus far.
@@svenschwingel8632 Of course, everything has its own inherent vice.
If sombody like to have almost perfect wow aflater test cattet tape it shoul be order from high speed duplicators that copy the tape up to 100 time daster,. So any wow and flater is almost non exitance. The source of frequency is RF generator. That might be more inportant for speed ajustment. If you like to mesure just wow and flater take the casette tape and record the signal from computer and play and measure on the meter. The number that you get from the wow and flater meter just divide by two. This will be the most accurate measurement that you can make on your tape recorder no mater what profetionaly done tape you will obtain.
It may not be exactly divide by two for a self-generated tape, but in that order of things. If your cassette deck has a cyclical wow, then it could cancel itself out and imply that it's better than it is.
hello, I can ask, please, why does someone use 3khz and someone 440hz, somehow I do not understand 🤔🤔🤔🙏🙏🙏
3 or 3.15kHz are used for wow & flutter. The 440Hz is used for setting the channel gains.
You can use a guitar/instrument tuner for 440 Hz.
it s a great question what s the correct speed cassette for reading so far reach by ambitions poor by conditions i ve made my own in 2 steps this speed cassette is about 0.1 percentage from the nominal tape speed as mentioned ,4,75 cm per second not 4.76 oder 4.78.Firrst of all you ve got a new cassette one a basic typed is adequate.you measure with stop watch the time playing it ,its about 30 minuts plus minus 1 minuts,this will be the adjusting point. NOW YOU WILL RECORD 3 KHZ WITH A GOOD DECK IN MY CASE JVC DD5 WAS CLEANED, PROBALY YOU WILL GET 3 KHZ YOU WILL ADJUST IT IF IT NECESSARY.AFTER A GOOD QUART LOCKED TURNTABLE YOU WILL PLAY AND RECORD A PLATE ABOUT 20 25 MINUTES YOU WILL PLAYBACK AND SEE WHAT IS THE DIFFERENCE BETWEEN 2 ARES YOU WILL CORRECT THE POTENTIO METER IN TWO THREE STEPS WHEN THE DIFFERENCE WILL BE IN 2 SECONDS NOW YOU WILL RECORD NOW THE 3 KHZ IN FULL 30 MINUTES THAT IS IMPORTANT YOU CAN MONITORING THE TAPESPEES DEVIATION AT THE BEGINNING IN THE MIDDLE OR AT THE END.MY TURNTABLE WAS JVC QLA 2
Is that a floppy disk on your scope ? :'-)
Yes! Not very convenient.
hi have seen them before i bet they are loop bin cassette they are ok for the home
You didn't adjust anything. That right channel output was way off and if left like that it's hard to see what value the whole process really was. Azimuth, yes that's the easy one. Wow and flutter is often just inherent in the deck design unless the belts are naff quality. Right? If wow and flutter was way off manufacturer's spec what would be your next move?
I had changed the belts in a previous video. In this video I set up the speed. Today I adjusted preset control RJ44 to bring the right channel up by the less than 1dB which was all that was required.
You believe the old test tape, All tapes sold nowadays are made on consumer decks usually Nakamichi, Not factory made, So there is a compounding W&F added to the new cassette and the level can never be trusted due to aging electronics of those consumer decks
The new tape is made on some serious kit which is in tip-top shape. The tones of course are generated electronically, not copied from another tape. But I do see your point.
@@video99couk What company and what gear they use, Is there a video to back their claims?
As I expected they are using the Nakamichi deck, here is a snippet from their eBay listing:
"Recorded on Quartz Locked Ultra Stable Nakamichi Cassette Deck - 0.027% Wow & Flutter
The Recording Deck Is Checked & Recalibrated If Need Be Before Each Cassette Is Produced"
@Matt Quinn In the digitizing business the way it should be done is to tune the deck to each tape you're digitizing, There is really no need to any test tapes, At least that's the way I would do it for maximum quality. For people who playback or record tapes it's a different story.
@@Capturing-Memories Absolutely but it's rarely done. Most azimuth demonstration videos only go as far as aligning to a standard reference tape, as if all cassettes, recorded on who knows what decks back then, just happened to have been perfectly aligned. This is a blind spot especially from those claiming to have high audio transfer standards. When transferring, the tape recording we are transferring IS our azimuth standard. It should be obvious...
Nice video.. but those tapes are rubbish, good for a fast check but not good for as professional calibration... calibrating a deck with those "homemade" cassettes you risk to do more damage than benefit... I know, finding some new old stock calibration cassettes from the usual pro laboratories is a nightmare, but is a must to be sure to do a professional job.
I do understand the difference between these and tapes made with dedicated equipment for the purpose, but they are pretty much unobtainable.
These cassettes can not be trusted, they can immediately be thrown into the trash, bought tested, they are not even near the reference levels, but somewhere there ....and very wrongly you rebuilt the azimuth on them
I'm not sure reference levels will have any bearing on azimuth.
Have you had your vaccine(s) yet Colin?
All zapped up here.