The RMS value the program display as a number is a computed average of all or a range of values measured. That is why the "analog" meter (software) is jumping around, it takes many samples per ms. That is why there is a needle to show you the fluctuations. The analog meter is too slow to react to those changes and doesn't have a computer that can read/sample so fast. A needle with a coil and a spring is pretty slow (especially on the lower side - falling back) when comparing to a computer. This can explains why the analog is higher comparing to the digital reading, it is simply not fast enough. That is why we nowadays use digital meters because they are faster and more precise. More precise doesn't mean it is bad, it is just more accurate and because of that can give you different/lower reads. Personally I think the software perform better.
There are at least 3 different standards for W&F measurements: Peak (IEC), Peak (DIN) and WRMS (NAB). Most service manuals for cassette decks specify figures for more than one of these standards, but for many Japanese made portable units, they specify only WRMS. The purpose of the tool of course, is to check that the unit is operating within the specifications. The Akai GX-75 is specified at 0.04% DIN and 0.025% WRMS, so you are certainly close and the level of performance you are achieveing is certainly acceptable. But given the number of units you are repairing, you should probably invest in a proper W&F test tape.
When dividing two equal uncorrelated noise figures you don't halve them, you multiply them by 0.707 instead. The W&F is effectively noise. For example when you have 0.035% from a record replay loop your best approach to estimate the base is 0.035% times 0.707 equals near 0.025%
The DIN specification for W&F includes a weighted filter on the actual frequency of the frequency fluctuation: if you plot the frequency variation vs time you get a signal which has ist own spectrum; the ear is more sensitive to frequency fluctuation in a specific range of "frequency" therefore a filter is applied to account for the ear sensitivity. E.g. frequency fluctuation at 10 Hz are more discernible than frequency fluctuation at 100 Hz (ball park number i do not remember the actual filter shape). That is the reason why DIM RMS mesurements are tipically better than peak W&F
The DIN specification is the DIN specification and comparable. I can make sure a machine is within its proper parameters according to the manufacturer. I deal with reel recorders daily and there are subtle things with larger mechanisms to help obtain that figure you just couldn’t do with cassette mechanisms. Specifications and metering. That’s what they are for. Don’t doubt yourself. The meter is correct. You are correct.
Assuming the W&F of the deck is obtained by divinding by 2 the measued W&F implicitely assumes the recording and playback W&F do actually sum in phase. Given the partial ramdom origin of W&F i think it would be a more conservative approach to assume the two W&F sum in power; that means to get the playbacl W&F you have to divide by square root of 2 (i.e. 1.41).
As I said in the video, I did observe the reading of the meter over some time and stopped and started the deck multiple times to eliminate the influence of phase relation.
DrCassette that further reinstates my previous comment: if you sum two uncorrelated signals of equal amplitude, the resulting amplitude is sqrt(2) of the signal amplitude
@@enricoself2256 @DrCassette I have to agree with Enrico Self. If you recorded and played the same 3150 Hz tone tape on the same cassette deck, then the 'WFfinal' should be SQRT[(WF^2)+(WF^2)] Where 'WF' is the real Wow & Flutter of the equipment. Therefore WF = WFfinal / SQRT(2) BTW, I think you did a fantastic job servicing your cassette decks, and I myself am happy with WF less than 0.15% (RMS) on my restored vintage cassette decks when measured with the same software you are using and played with a 3150 Hz test tape (recorded with a DD QL cassette deck of WF less than 0.02% RMS (DIN)). Please see link below the statistical calculation method. socratic.org/questions/if-you-add-two-independent-random-variables-what-is-the-standard-deviation-of-th
The W&F meter is a good tool for detecting if something is really off, bad belts etc but there is really only so much you can do to correct those problems. Not every cassette player was built to be super accurate in the first place.
@@DrCassette it's a tool to see were your at so why not use it? your wow and flutter looks really good! also the recorded test tape has wow and flutter on it which needs to that your subtract to your number *so it better than the software say it is?* . You can also look at the text box for the average and your is right on w the RMS number and mine is not and has more spikes increase the average RMS #
I've been enjoying these videos. I've been playing around here with an actual Teac flutter test cassette and the WFGUI software, a RS-BX707, a WM-D6C, and a Dragon. The D6C runs at 3148, the 707 and Dragon both run at 3155. As far as W&F, it only really bothers me if I can detect it while listening. Some tapes will only play in a stable manner with the Dragon. I honestly have no idea if any of the ways that I can play with the calculations in the software match up with the specs in the manuals...so far none of my decks are doing all that well...more to the point, I don't think anyone outside of a few hobbyists actually make calibration tapes anymore, the 'official' ones that are hanging around are all getting a bit old, may have been stored or transported improperly... Makes more sense to test W&F using your own tape recorded and played back in the same deck because then you're just testing *that machine* (and whatever blank tape that you're using).
There's 2 primary objectives for tape decks. Freq must be within 5Hz of 3150, and the less instances it fluctuates the better W&F reading is. Does anyone know what the wow & flutter equation/ algorithm is ? ?
The spectrum of the W&F is just as important as the level. I can tolerate quite high W&F if it occurs at very low frequency but get progressively more sensitive to it as frequency increases.
Endlich mal ein direkter Vergleich auf dem gleichen Gerät, damit wird einiges klarer was die Software angeht. Ich habe mich auch immer über die komischen Werte gewundert... Ich muss das mal mit meinem Direct Drive Technics Deck testen.
Ich hoffe, dass hier irgendwer in den Kommentaren etwas Klarheit bezüglich dieses RMS-Wertes schaffen kann, ob das tatsächlich etwas ist, das auch bessere "echte" W&F Meter anzeigen konnten, oder ob der Programmierer der Software sich dachte, der Wert ist einfach zu berechnen und reinzuprogrammieren, also warum nicht. Das ärgert mich wirklich etwas, denn so bekommen die Leute mit dem Software W&F Meter fantastisch niedrige Werte, während ich mich hier mit den viel höheren Peak-Werten von meinem "echten" W&F-Meter zum Trottel mache... Schau mal, ob dein Technics Deck einen besseren (stabileren) Direct Drive hat, nach dieser Enttäuschung mit dem Akai würde mich das wirklich interessieren.
@@DrCassette Also ich bin auch kein Audio Experte, aber vielleicht hilft es etwas. Erstmal findet man zur Software auch eine Anleitung, da wird noch ein bisschen genauer beschrieben was die eigentlich tut, findet man z.B. usermanual.wiki/Document/WFGUIUserDocumentation.2031798649 Wenn ich mir die Angaben von meinem Onkyo TA-2570 anschaue, steht dort "0,035% (effektiv, bewertet)" bzw. "0,04% WRMS" - offensichtlich beziehen sich die Angaben auf einen RMS bzw. Effektiv-Wert. Ich gehe also davon aus, das RMS hier (zumindest einer) der üblichen Werte zur Angabe ist und das es auch Messgeräte gab die das direkt anzeigen können - ist also wohl keine Erfindung des Software-Entwicklers. Weighted bzw. bewertet meint wohl einen Bandpass mit ein paar kHz Mittenfrequenz bei dem unser Gehör am empfindlichsten ist. Bei meinem Tape wäre dann in der Software wohl auf DIN einzustellen und der RMS Wert abzulesen -> WRMS. Dein Leader zeigt ja anscheinend Peak Werte an, die einiges höher als die RMS Werte sind, wäre also für mein Tape nicht so hilfreich da ich mit den niedrigeren RMS Werten aus den Manuals vergleichen müßte/wollte. Das die Anzeige von Leader und Software beim Peak recht gut übereinstimmen fand ich übrigens sehr interessant -> Danke dafür!
Calibration tapes, like any regular magnetic tape, suffers from stretching and deformation over time and use, even though they're usually very short (just a few minutes), and this reduces the stretching, an old test tape should be used considering the fact it may not be as precise as expected. Depending on what the deck will be used for, time, money and equipment would be worthy of not. For a home user, a test tape recorded on a good quality, known good working deck, with a clean sine wave at an appropriate level, would be fine (most of these machines are about 30 to 40 years old, miracles should not be expected).
wie in diesem Video (ruclips.net/video/y2S3p79oShU/видео.html) zu sehen, scheint es auch ein Leader Wow & Flutter Meter zu geben, welches speziell für diese Paramter ausgelegt ist. Dieses scheint auch WRMS (kommt übrigens aus Japan, währen DIN aus Deutschland kommt, wie an der Abkürzung ja auch deutlich zu erkennen) anzuzeigen (über die Einstellung JIS, die deinem Gerät fehlt).
Can poor azimuth affect the WOW/FLUTTER readings? If not, what else is the main culprit for w/f? Tape speed is fine, but i want to get it down from 0.07 on my Tascam studio decks, which are rated at 0.03 or so.
There are countless factors that play into the Wow/Flutter performance of a mechanism. All you can really do is experiment. The azimuth adjustment will strongly affect frequency response, the influence on W&F should be minimal. Bearings, belts, motors, tape tension all have a much bigger influence.
For W&F the software can be trusted, however level and RMS are not trustworthy since it goes thru the computer sound card, Unless the sound card has been calibrated to a good known source at 100% volume there is no guarantee, A beast machine like yours is a must.
Some decks seem more sensitive than others to inferior capstan belts. Not sure if you've found the same from any servicing you've done on previous decks? The results I'm getting in WFGUI seem to differ dramatically with the same deck (Nak RX-505) depending on the capstan belts I've tried in there. So when people say "the job you've done is no good", ignore them as its probably just differing quality in belts causing the swing. No doubt you'll already know this, and know way more than I do!
I found that the caption belt is the most import belt and than the other supply belt. unfortunately all belts are made in batch's and later you buy another batch's and the wow and flutter will be different. have you found a good sources?
@@musicstevecom in a word, no. I haven't found a reliable source for my deck. It's difficult to find a supplier these days. FRSP belts tend to work well on a lot of Nakamichi decks, but last time I looked I struggled to find any for sale.
@@64bakes That's what I thought. trying to get the wow and flutter is a can of worms the old original belts if they still work have lower W&F. (I will order some normal and weaker belts maybe some thinner width ones also) The software is a good tool to tell you were your at. I been experimenting trying to get the W&F down since a have a bunch of the same decks, My New standard is if I can get the software under the lowest level .1% and like this video shows, I will be happy, I use the 10sec Din and Din RMS for my standard specification and if the numbers are similar than the the peak is not to bad since it appears that the peak goes into the 10sec Din. Its been a battel and the W&F changes from day to day , Very frustrating.
The AKAI 75/95s are fitted with a dual capstan direct drive, what you mean is: Quartz oscillator PPL-locked speed control. The bigger brother A&D 9100 of the AKAI has this, but the feature is totally overestimated in topics of „sound“.
I've read all of the comments. The devil is in the details.... The actual formulas used to calculate should clarify the differences. I don't know what the formulas are in fact. It all reminds me of installing aftermarket accessories on cars and trucks in the late 1980's. Particularly running boards on vans. You can measure whatever you like. You can use levels. These days you could use lasers. However, if it looks "straight" especially to the vehicle owner then it is straight. If it looks crooked then it's crooked. This discussion here is to a smaller degree a similar circumstance. If you know the fundamentals of the engineering specifications and tests then you generally know when and where and with what qualifications or restrictions these comparisons and discussions apply. The frustration may be somewhat internal. I know this personally. Once you fully explore and understand you become the expert. You then can try to educate and clarify others and their thinking. Some will not have the knowledge base, technical or mental competency or overall interest to follow you to that level of comprehension. We have to try to communicate with them, but once they reveal their inability to participate in the conversation you must stop at their first mistake and point them towards the information they need to master. After that talk about something else. Here on RUclips most readers in comment section will understand who has the mastery and who does not. Nice work. I'm new to your channel. I'll be watching your videos. Thanks for your time and effort and interest in sharing your knowledge and experience. God Bless
I do not understand perhaps, but if you have a machine with constant WF and it records the signal, then at the outputs won't this signal look clean? I mean I have tried it, but on a 2 heads one, and it looked almost tip top shape while the music was bad. Bought a test cassette from ebay, bad results. Bought a set from an UK seller, close to 200 euro (frequencies, dobly, etc) and I could calibrate the speed and also solved the WF issues after changing the roller.
@@rusuclaudiu1988this could only happen if the r&p heads were very close together. Impossible... But... of course, some low frequency components of the W&F, in case of 'direct R&P monitor', will be cancelled
I know what RMS stands for, and what it means, but the question is, was the addition of the RMS value an idea the creator of the Software W&F Meter had, or are there also "real" W&F meters that display both peak and RMS?
.707 x Peak = RMS It seems that all the program is doing is taking the Peak reading at the bottom of the screen x .707 and putting the result in the RMS box.
Програма работает только в ДИН стандарте. Там только пиковый детектор. Истинное значение указывается в верхнем окне над окном вэйвформ (за 10с). Окно РМС в данном случае - усреднение.
Regarding values and value differences between HW and SW you're showing, I am not sure whether you're familiar with this matter to the fullest or not but let me tell you what I meant to say. Your W&F meter (HW) is showing Peak values while SW is showing both Peak (red animated hand) and also RMS value in numbers only. RMS values WILL always show you lower values because they are averaged values in a bit longer time (not sure what does DIN standard for this says). For illustration purposes only, let's assume Peak is measured instant in (I'm guessing here) values of 50 ms (or less) while maybe RMS are measured in 300 or 400 ms. Difference in audio is always somewhat "hotter" when catching Peaks. RMS is more like avreaged value thru long(er) period of time. If you knew this or know this all I have to repeat once again, sorry, didn't mean to step on anyone's toes here. Simply was reacting on your statement how "if someone knows please tell me...", something like that is what you said. Hope this helps a bit to anyone interested in this topic. Nice of you to show these tools and this deck. Have one just like that and need to get it to someone better and smarter than me, and with all the tools and knowledge since it's been acting a bit strange with tape after belts replacements. Keep up the great videos.
Thanks for the info. I do know what peak and RMS values mean and what the difference between the two is. Maybe I should have more clearly explained, my question basically was if the RMS value is really used when measuring wow&flutter or if this was an 'invention' of the creator of the software. But as I said, any thoughts are welcome :)
@@DrCassette In WFGUI, the RMS% box always shows the RMS reading, while the drop-down box next to it chooses what the large meter and the numerical reading below it displays. The layout is a little confusing, but that's how it works.
@@vwestlife I do understand the layout and what those numbers mean, the question was if this RMS value is really a valid measurement method. Judging by other comments so far, apparently it is...
@@DrCassette Sure! And continuing on the same thought, I woulda say that initially RMS was indeed the desired and chosen method, then and now because Peak (my honest opinion) is not the value one would choose to look for because it's something super short and instant. So what better way to express value (and standard) then averaged value. That's my opinion anyway. Sadly, we are all loosing "old masters" of this technology and it is so nice seeing younger generation continuing legacy of analogue tape of any and all formats. I will be checking out your informative and interesting videos. Thank you!
@@DrCassette it reflect the fact that some deck manufacturer provide... RMS value!! RMS and Peak obviously are different (unless the W&F figure is a square wave... almost impossible) Value must also be 'weighted', i.e. a low frequency W&F is less annoyng than a higher one...
Jawoll, Windows 7, weil die im PC verbauten Video-Capture-Karten von Blackmagic Design wohl teilweise unter Windows 10 nicht richtig laufen. Das ist auch der einzige Grund, ich muss sagen, mit all den Updates ist Windows 7 über die Jahre entsetzlich langsam geworden. Tolles System unmittelbar nach Installation, aber sowie alle Updates durchgelaufen sind, ist es sehr schwerfällig.
Mein Lieblings Betriebssystem ist und bleibt Windows 95. Keine spielereien, keine unnötigen Funktionen, und es tut einfach das was es soll, ohne einem dabei auf die Nerven zu gehen! ;-)
@@leostechnikkanal Hast du mal Windows 2000 Professional ausprobiert? Ohne Spielereien, und anders als Windows 95 ist es extrem zuverlässig, ich glaube, ich hatte noch nie einen Bluescreen unter Windows 2000.
I've read all of the comments. The devil is in the details.... The actual formulas used to calculate should clarify the differences. I don't know what the formulas are in fact. It all reminds me of installing aftermarket accessories on cars and trucks in the late 1980's. Particularly running boards on vans. You can measure whatever you like. You can use levels. These days you could use lasers. However, if it looks "straight" especially to the vehicle owner then it is straight. If it looks crooked then it's crooked. This discussion here is to a smaller degree a similar circumstance. If you know the fundamentals of the engineering specifications and tests then you generally know when and where and with what qualifications or restrictions these comparisons and discussions apply. The frustration may be somewhat internal. I know this personally. Once you fully explore and understand you become the expert. You then can try to educate and clarify others and their thinking. Some will not have the knowledge base, technical or mental competency or overall interest to follow you to that level of comprehension. We have to try to communicate with them, but once they reveal their inability to participate in the conversation you must stop at their first mistake and point them towards the information they need to master. After that talk about something else. Here on RUclips most readers in comment section will understand who has the mastery and who does not. Nice work. I'm new to your channel. I'll be watching your videos. Thanks for your time and effort and interest in sharing your knowledge and experience. God Bless
Personally ive stopped measuring W/F after ive fixed a cassette deck. I just measure and adjust the speed with the help of my multimeter then i do a recording of a very nice album from a guy called Gøran Søllscher that consists only of classical guitar. If the deck has a W/F problem it will show up in that recording.. If i cant hear anything then its fine.. I found that measurements just made my life more miserable:D
That's exactly my opinion. If I can't hear any wow&flutter, the cassette deck is fine. Unfortunately after so many RUclipsrs have started using that damn Software W&F Meter, people keep complaining on my videos about me not measuring wow&flutter. Most of these people have no understanding of what those numbers mean, but if they are not shown in a cassette deck repair video that must mean it's a bad video :P
@@DrCassette I think it is more a case of your videos being more complete with a quick W&F test. I enjoy your videos with or without W&F measurements but I can see things from the point of view of a professional repair person. How can one claim to have properly repaired a deck if it is not tested against the specification. The listening test is OK for personal use of course because it is for one's own ears, but when repairing for others, I think a standard of some kind is rquired. There are different patterns of W&F depending on where the issues are in the machine and these patterns only manifest themselves when listening to certain kinds of music. The patterns can be seen in the WFGUI waveform display, slow undulation of around 1 per second is indicative of a pinch roller problem and a repeating pattern at 10 times per second is most likely to be related to the capstans for example. I am glad you showed the software in operation, it is a valuable tool in debugging W&F issues and I am sure you will find it useful in your future work.
@DrCassette, @@edradiofan7855 totally agree. If I'm repairing, or in my case, more often , "restoring"a piece of vintage gear, my goal is to return the device to its original condition. That means performance, specification and appearance. All cassette decks from day one listed the W&F specification as well as speed accuracy. It would be nuts not to check the values of my restored item against the manual's stated specs. Ok, so maybe my results are worse than new but also maybe they cannot be detected during playback, I don't stress over this. The point is, it's nice to know how close the restored deck measures as compared to when it was first taken out of the box.
@@edradiofan7855 Repair shop only fix the belts and maybe some grease and do a speed test , they don't have the time to recondition the deck and use Wow and flutter cuz is a can of worms and the customer would never pay for it. and they don't want to either and belts are a can of worms to when going to the next level.
I am not sure why you care about “public demand”. If people don’t like your channel or the way you do things, then let them go elsewhere. Whose channel is this anyway? People who do nor have constructive input have no input at all. I enjoy watching and usually learning something I didn’t know. If they know it all, why bother to deal with their egos or their showing your test methods to be less than they think they should be? Keep on!
Usually this is my approach, I do whatever I want. But sometimes I think it is good to look around and care for what people are interested in. Wow&flutter measurements are very common now that the Software W&F Meter has become so well known. I can ignore this trend, but eventually this would make me look stubborn and stupid...
Wow and Flutter suffer from the same issues as power output. With RMS power, peak, 1 or both channels working, etc etc. Ohh and don't forget, Chinese watts!!! They don't need ANY kind of meter, just magic up a number and double it, works every time.
Your comment reminds me of an old magazine article from the early 80s which criticized the method the Japanese manufacturers used on their equipment (WRMS) because the resulting numbers were much lower than the numbers measured according to DIN. They said that was a method of deceiving the consumer.
This shareware software is very inaccurate and unreliable. Furthermore a reference test tone cassette at best will have +/- 5Hz fluctuation. On 3 head machine - The only proper way to test tape speed or W & F is use a freq. generator into tape in's, and test the monitor signal on the machine's outputs. REC & Play on a deck use same capstan/ reel motors so this test is the absolute definitive test method !
Not true because recording and playback on three head machines are not simultaneous. Having said that, the machine will record the signa from a freq. generator on tape with some W&F and tape speed fluctuation then reproduces the recorded signal later on adding W&F and speed fluctuation again. This is because (I'm not a hundred percent sure) W&F and speed fluctuations are both stochastic processes rather than deterministic.
Using an ext sig gen to record, and a w&f meter on the output is the best method for test wow & flutter. If the speed is off it will show on the meter or counter. Using a test tape inherits the spd inaccuracy of the test tape's recorder, being +/- 5Hz per MRL tape's specification. All my decks sod accuracy are no more than 1Hz deviation on DIN 3150 test
I think you missed the significance of the fact that recordings and playback are both subjected to W&F and speed fluctuations. The signal from the generator is going to be contaminated during the recording process. The recorded signal is going to be contaminated again during the reproduction. As for the measured frequency during the reproduction, it will always be the frequency very close to that set on the generator regardless of the tape speed. That is why you need a test tape recorded on a reference equipment.@@dubdoodle7191
@@dubdoodle7191 Disagree, to measure absolute W&F ob the cassette deck - you have to use standard reference tape manufactured on best possible equipment, with known and lowest possible W&F. This is to get number for dick fight :D But on other hand, - if W&F is low or acceptable during REC then PB ( or monitor ) - good for you! Because REC/PB is an overlap of 2 W&Fs one during record and second during playback ! But you have to try it several times to get average, I think
The RMS value the program display as a number is a computed average of all or a range of values measured. That is why the "analog" meter (software) is jumping around, it takes many samples per ms. That is why there is a needle to show you the fluctuations. The analog meter is too slow to react to those changes and doesn't have a computer that can read/sample so fast. A needle with a coil and a spring is pretty slow (especially on the lower side - falling back) when comparing to a computer. This can explains why the analog is higher comparing to the digital reading, it is simply not fast enough. That is why we nowadays use digital meters because they are faster and more precise. More precise doesn't mean it is bad, it is just more accurate and because of that can give you different/lower reads. Personally I think the software perform better.
There are at least 3 different standards for W&F measurements: Peak (IEC), Peak (DIN) and WRMS (NAB). Most service manuals for cassette decks specify figures for more than one of these standards, but for many Japanese made portable units, they specify only WRMS. The purpose of the tool of course, is to check that the unit is operating within the specifications. The Akai GX-75 is specified at 0.04% DIN and 0.025% WRMS, so you are certainly close and the level of performance you are achieveing is certainly acceptable. But given the number of units you are repairing, you should probably invest in a proper W&F test tape.
When dividing two equal uncorrelated noise figures you don't halve them, you multiply them by 0.707 instead. The W&F is effectively noise. For example when you have 0.035% from a record replay loop your best approach to estimate the base is 0.035% times 0.707 equals near 0.025%
The DIN specification for W&F includes a weighted filter on the actual frequency of the frequency fluctuation: if you plot the frequency variation vs time you get a signal which has ist own spectrum; the ear is more sensitive to frequency fluctuation in a specific range of "frequency" therefore a filter is applied to account for the ear sensitivity. E.g. frequency fluctuation at 10 Hz are more discernible than frequency fluctuation at 100 Hz (ball park number i do not remember the actual filter shape). That is the reason why DIM RMS mesurements are tipically better than peak W&F
So there are hardware W&F meters that also show this RMS value, and this feature is just simply missing on the Leader Cassette Checker?
DrCassette yes, but din is not the only standard (as it happens with all standards...). The leader just displays the realtime amplitude of W&F
It is not DIN RMS, it is JIS RMS.
Thank you for the video. I agree with you
The DIN specification is the DIN specification and comparable. I can make sure a machine is within its proper parameters according to the manufacturer. I deal with reel recorders daily and there are subtle things with larger mechanisms to help obtain that figure you just couldn’t do with cassette mechanisms. Specifications and metering. That’s what they are for. Don’t doubt yourself. The meter is correct. You are correct.
Those AKAI decks are excellent, I had a few Nakamchi and Sony but I have to say the AKAI GX95 I used to own was superb..
Assuming the W&F of the deck is obtained by divinding by 2 the measued W&F implicitely assumes the recording and playback W&F do actually sum in phase. Given the partial ramdom origin of W&F i think it would be a more conservative approach to assume the two W&F sum in power; that means to get the playbacl W&F you have to divide by square root of 2 (i.e. 1.41).
As I said in the video, I did observe the reading of the meter over some time and stopped and started the deck multiple times to eliminate the influence of phase relation.
DrCassette that further reinstates my previous comment: if you sum two uncorrelated signals of equal amplitude, the resulting amplitude is sqrt(2) of the signal amplitude
@@enricoself2256 @DrCassette I have to agree with Enrico Self. If you recorded and played the same 3150 Hz tone tape on the same cassette deck, then the 'WFfinal' should be SQRT[(WF^2)+(WF^2)]
Where 'WF' is the real Wow & Flutter of the equipment.
Therefore WF = WFfinal / SQRT(2)
BTW, I think you did a fantastic job servicing your cassette decks, and I myself am happy with WF less than 0.15% (RMS) on my restored vintage cassette decks when measured with the same software you are using and played with a 3150 Hz test tape (recorded with a DD QL cassette deck of WF less than 0.02% RMS (DIN)).
Please see link below the statistical calculation method.
socratic.org/questions/if-you-add-two-independent-random-variables-what-is-the-standard-deviation-of-th
Correct!!!
The W&F meter is a good tool for detecting if something is really off, bad belts etc but there is really only so much you can do to correct those problems. Not every cassette player was built to be super accurate in the first place.
I know - this is why I refused to do any wow&flutter measurements for so long. I am doing all this only due to public damand...
@@DrCassette it's a tool to see were your at so why not use it? your wow and flutter looks really good! also the recorded test tape has wow and flutter on it which needs to that your subtract to your number *so it better than the software say it is?* . You can also look at the text box for the average and your is right on w the RMS number and mine is not and has more spikes increase the average RMS #
You can't divide by two... r&p doesn't sum in a linear manner...
I've been enjoying these videos.
I've been playing around here with an actual Teac flutter test cassette and the WFGUI software, a RS-BX707, a WM-D6C, and a Dragon. The D6C runs at 3148, the 707 and Dragon both run at 3155. As far as W&F, it only really bothers me if I can detect it while listening. Some tapes will only play in a stable manner with the Dragon.
I honestly have no idea if any of the ways that I can play with the calculations in the software match up with the specs in the manuals...so far none of my decks are doing all that well...more to the point, I don't think anyone outside of a few hobbyists actually make calibration tapes anymore, the 'official' ones that are hanging around are all getting a bit old, may have been stored or transported improperly...
Makes more sense to test W&F using your own tape recorded and played back in the same deck because then you're just testing *that machine* (and whatever blank tape that you're using).
There's 2 primary objectives for tape decks. Freq must be within 5Hz of 3150, and the less instances it fluctuates the better W&F reading is.
Does anyone know what the wow & flutter equation/ algorithm is ? ?
The Leader LCT-193D measures in Din WTD peak format with an accuracy of 10%
The spectrum of the W&F is just as important as the level. I can tolerate quite high W&F if it occurs at very low frequency but get progressively more sensitive to it as frequency increases.
Yes... in fact it must be 'weighted'...
Endlich mal ein direkter Vergleich auf dem gleichen Gerät, damit wird einiges klarer was die Software angeht. Ich habe mich auch immer über die komischen Werte gewundert... Ich muss das mal mit meinem Direct Drive Technics Deck testen.
Ich hoffe, dass hier irgendwer in den Kommentaren etwas Klarheit bezüglich dieses RMS-Wertes schaffen kann, ob das tatsächlich etwas ist, das auch bessere "echte" W&F Meter anzeigen konnten, oder ob der Programmierer der Software sich dachte, der Wert ist einfach zu berechnen und reinzuprogrammieren, also warum nicht. Das ärgert mich wirklich etwas, denn so bekommen die Leute mit dem Software W&F Meter fantastisch niedrige Werte, während ich mich hier mit den viel höheren Peak-Werten von meinem "echten" W&F-Meter zum Trottel mache...
Schau mal, ob dein Technics Deck einen besseren (stabileren) Direct Drive hat, nach dieser Enttäuschung mit dem Akai würde mich das wirklich interessieren.
@@DrCassette Also ich bin auch kein Audio Experte, aber vielleicht hilft es etwas. Erstmal findet man zur Software auch eine Anleitung, da wird noch ein bisschen genauer beschrieben was die eigentlich tut, findet man z.B. usermanual.wiki/Document/WFGUIUserDocumentation.2031798649 Wenn ich mir die Angaben von meinem Onkyo TA-2570 anschaue, steht dort "0,035% (effektiv, bewertet)" bzw. "0,04% WRMS" - offensichtlich beziehen sich die Angaben auf einen RMS bzw. Effektiv-Wert. Ich gehe also davon aus, das RMS hier (zumindest einer) der üblichen Werte zur Angabe ist und das es auch Messgeräte gab die das direkt anzeigen können - ist also wohl keine Erfindung des Software-Entwicklers. Weighted bzw. bewertet meint wohl einen Bandpass mit ein paar kHz Mittenfrequenz bei dem unser Gehör am empfindlichsten ist. Bei meinem Tape wäre dann in der Software wohl auf DIN einzustellen und der RMS Wert abzulesen -> WRMS. Dein Leader zeigt ja anscheinend Peak Werte an, die einiges höher als die RMS Werte sind, wäre also für mein Tape nicht so hilfreich da ich mit den niedrigeren RMS Werten aus den Manuals vergleichen müßte/wollte. Das die Anzeige von Leader und Software beim Peak recht gut übereinstimmen fand ich übrigens sehr interessant -> Danke dafür!
Link to download the "Software Wow & Flutter Meter" (top of the page, by useful utilities): www.ant-audio.co.uk/index.php?cat=post&qry=library
Calibration tapes, like any regular magnetic tape, suffers from stretching and deformation over time and use, even though they're usually very short (just a few minutes), and this reduces the stretching, an old test tape should be used considering the fact it may not be as precise as expected. Depending on what the deck will be used for, time, money and equipment would be worthy of not. For a home user, a test tape recorded on a good quality, known good working deck, with a clean sine wave at an appropriate level, would be fine (most of these machines are about 30 to 40 years old, miracles should not be expected).
I have a professional Konig W&F tape, but I don't trust it one bit. If only there was a way of making these things which was known accurate.
wie in diesem Video (ruclips.net/video/y2S3p79oShU/видео.html) zu sehen, scheint es auch ein Leader Wow & Flutter Meter zu geben, welches speziell für diese Paramter ausgelegt ist. Dieses scheint auch WRMS (kommt übrigens aus Japan, währen DIN aus Deutschland kommt, wie an der Abkürzung ja auch deutlich zu erkennen) anzuzeigen (über die Einstellung JIS, die deinem Gerät fehlt).
Can poor azimuth affect the WOW/FLUTTER readings? If not, what else is the main culprit for w/f? Tape speed is fine, but i want to get it down from 0.07 on my Tascam studio decks, which are rated at 0.03 or so.
There are countless factors that play into the Wow/Flutter performance of a mechanism. All you can really do is experiment. The azimuth adjustment will strongly affect frequency response, the influence on W&F should be minimal. Bearings, belts, motors, tape tension all have a much bigger influence.
no
For W&F the software can be trusted, however level and RMS are not trustworthy since it goes thru the computer sound card, Unless the sound card has been calibrated to a good known source at 100% volume there is no guarantee, A beast machine like yours is a must.
Some decks seem more sensitive than others to inferior capstan belts. Not sure if you've found the same from any servicing you've done on previous decks? The results I'm getting in WFGUI seem to differ dramatically with the same deck (Nak RX-505) depending on the capstan belts I've tried in there. So when people say "the job you've done is no good", ignore them as its probably just differing quality in belts causing the swing. No doubt you'll already know this, and know way more than I do!
I found that the caption belt is the most import belt and than the other supply belt. unfortunately all belts are made in batch's and later you buy another batch's and the wow and flutter will be different. have you found a good sources?
@@musicstevecom in a word, no. I haven't found a reliable source for my deck. It's difficult to find a supplier these days. FRSP belts tend to work well on a lot of Nakamichi decks, but last time I looked I struggled to find any for sale.
@@64bakes That's what I thought. trying to get the wow and flutter is a can of worms the old original belts if they still work have lower W&F. (I will order some normal and weaker belts maybe some thinner width ones also) The software is a good tool to tell you were your at. I been experimenting trying to get the W&F down since a have a bunch of the same decks, My New standard is if I can get the software under the lowest level .1% and like this video shows, I will be happy, I use the 10sec Din and Din RMS for my standard specification and if the numbers are similar than the the peak is not to bad since it appears that the peak goes into the 10sec Din.
Its been a battel and the W&F changes from day to day , Very frustrating.
I think you get better result when using a full direct drive deck like a technics for right speed , cool meter, 👍👍
I know there are plenty of Technics direct drive cassette decks, but most of them don't have dual capstan.
The AKAI 75/95s are fitted with a dual capstan direct drive, what you mean is: Quartz oscillator PPL-locked speed control. The bigger brother A&D 9100 of the AKAI has this, but the feature is totally overestimated in topics of „sound“.
I've read all of the comments. The devil is in the details.... The actual formulas used to calculate should clarify the differences. I don't know what the formulas are in fact.
It all reminds me of installing aftermarket accessories on cars and trucks in the late 1980's. Particularly running boards on vans. You can measure whatever you like. You can use levels. These days you could use lasers. However, if it looks "straight" especially to the vehicle owner then it is straight. If it looks crooked then it's crooked. This discussion here is to a smaller degree a similar circumstance.
If you know the fundamentals of the engineering specifications and tests then you generally know when and where and with what qualifications or restrictions these comparisons and discussions apply. The frustration may be somewhat internal. I know this personally. Once you fully explore and understand you become the expert. You then can try to educate and clarify others and their thinking. Some will not have the knowledge base, technical or mental competency or overall interest to follow you to that level of comprehension. We have to try to communicate with them, but once they reveal their inability to participate in the conversation you must stop at their first mistake and point them towards the information they need to master. After that talk about something else. Here on RUclips most readers in comment section will understand who has the mastery and who does not.
Nice work. I'm new to your channel. I'll be watching your videos. Thanks for your time and effort and interest in sharing your knowledge and experience. God Bless
What is the value difference between the instrument and the software? (Peak readings vs Peak readings) ?
Both the instrument and the software seem to read pretty much the same.
I do not understand perhaps, but if you have a machine with constant WF and it records the signal, then at the outputs won't this signal look clean? I mean I have tried it, but on a 2 heads one, and it looked almost tip top shape while the music was bad. Bought a test cassette from ebay, bad results. Bought a set from an UK seller, close to 200 euro (frequencies, dobly, etc) and I could calibrate the speed and also solved the WF issues after changing the roller.
@@rusuclaudiu1988this could only happen if the r&p heads were very close together. Impossible...
But... of course, some low frequency components of the W&F, in case of 'direct R&P monitor', will be cancelled
Afaik RMS is "root mean square", so it will always be way off any peak.
I know what RMS stands for, and what it means, but the question is, was the addition of the RMS value an idea the creator of the Software W&F Meter had, or are there also "real" W&F meters that display both peak and RMS?
I don't think analogue W&F meters will have it as they will have to sample and store all the values before calculating.
@@ColdSphinX There are ways to determine an RMS value with a carefully designed analog circuit, so it is possible...
Another unknown of the RMS value in this software is that it has no unit.. or is it a rms frequency deviation..
@@bwack 2nd...
.707 x Peak = RMS It seems that all the program is doing is taking the Peak reading at the bottom of the screen x .707 and putting the result in the RMS box.
i have different tape decks, some of them have low RMS and high Peak, some have same RMS and same Peak
Програма работает только в ДИН стандарте. Там только пиковый детектор. Истинное значение указывается в верхнем окне над окном вэйвформ (за 10с). Окно РМС в данном случае - усреднение.
Regarding values and value differences between HW and SW you're showing, I am not sure whether you're familiar with this matter to the fullest or not but let me tell you what I meant to say. Your W&F meter (HW) is showing Peak values while SW is showing both Peak (red animated hand) and also RMS value in numbers only. RMS values WILL always show you lower values because they are averaged values in a bit longer time (not sure what does DIN standard for this says). For illustration purposes only, let's assume Peak is measured instant in (I'm guessing here) values of 50 ms (or less) while maybe RMS are measured in 300 or 400 ms. Difference in audio is always somewhat "hotter" when catching Peaks. RMS is more like avreaged value thru long(er) period of time. If you knew this or know this all I have to repeat once again, sorry, didn't mean to step on anyone's toes here. Simply was reacting on your statement how "if someone knows please tell me...", something like that is what you said. Hope this helps a bit to anyone interested in this topic. Nice of you to show these tools and this deck. Have one just like that and need to get it to someone better and smarter than me, and with all the tools and knowledge since it's been acting a bit strange with tape after belts replacements. Keep up the great videos.
Thanks for the info. I do know what peak and RMS values mean and what the difference between the two is. Maybe I should have more clearly explained, my question basically was if the RMS value is really used when measuring wow&flutter or if this was an 'invention' of the creator of the software. But as I said, any thoughts are welcome :)
@@DrCassette In WFGUI, the RMS% box always shows the RMS reading, while the drop-down box next to it chooses what the large meter and the numerical reading below it displays. The layout is a little confusing, but that's how it works.
@@vwestlife I do understand the layout and what those numbers mean, the question was if this RMS value is really a valid measurement method. Judging by other comments so far, apparently it is...
@@DrCassette Sure! And continuing on the same thought, I woulda say that initially RMS was indeed the desired and chosen method, then and now because Peak (my honest opinion) is not the value one would choose to look for because it's something super short and instant. So what better way to express value (and standard) then averaged value. That's my opinion anyway. Sadly, we are all loosing "old masters" of this technology and it is so nice seeing younger generation continuing legacy of analogue tape of any and all formats. I will be checking out your informative and interesting videos. Thank you!
@@DrCassette it reflect the fact that some deck manufacturer provide... RMS value!!
RMS and Peak obviously are different (unless the W&F figure is a square wave... almost impossible)
Value must also be 'weighted', i.e. a low frequency W&F is less annoyng than a higher one...
user a freq generator, record on deck, and connect w&f meter to monitor out of deck.
The cassette checker has a modest reading than, the w&f software.
Sehe ich da Windows 7?
Bestes OS aller Zeiten!
Jawoll, Windows 7, weil die im PC verbauten Video-Capture-Karten von Blackmagic Design wohl teilweise unter Windows 10 nicht richtig laufen. Das ist auch der einzige Grund, ich muss sagen, mit all den Updates ist Windows 7 über die Jahre entsetzlich langsam geworden. Tolles System unmittelbar nach Installation, aber sowie alle Updates durchgelaufen sind, ist es sehr schwerfällig.
Mein Lieblings Betriebssystem ist und bleibt Windows 95. Keine spielereien, keine unnötigen Funktionen, und es tut einfach das was es soll, ohne einem dabei auf die Nerven zu gehen! ;-)
@@leostechnikkanal Hast du mal Windows 2000 Professional ausprobiert? Ohne Spielereien, und anders als Windows 95 ist es extrem zuverlässig, ich glaube, ich hatte noch nie einen Bluescreen unter Windows 2000.
I've read all of the comments. The devil is in the details.... The actual formulas used to calculate should clarify the differences. I don't know what the formulas are in fact.
It all reminds me of installing aftermarket accessories on cars and trucks in the late 1980's. Particularly running boards on vans. You can measure whatever you like. You can use levels. These days you could use lasers. However, if it looks "straight" especially to the vehicle owner then it is straight. If it looks crooked then it's crooked. This discussion here is to a smaller degree a similar circumstance.
If you know the fundamentals of the engineering specifications and tests then you generally know when and where and with what qualifications or restrictions these comparisons and discussions apply. The frustration may be somewhat internal. I know this personally. Once you fully explore and understand you become the expert. You then can try to educate and clarify others and their thinking. Some will not have the knowledge base, technical or mental competency or overall interest to follow you to that level of comprehension. We have to try to communicate with them, but once they reveal their inability to participate in the conversation you must stop at their first mistake and point them towards the information they need to master. After that talk about something else. Here on RUclips most readers in comment section will understand who has the mastery and who does not.
Nice work. I'm new to your channel. I'll be watching your videos. Thanks for your time and effort and interest in sharing your knowledge and experience. God Bless
Record a good quality tape and listen back to it on a known good deck. If u don't hear w/f its good in my book👍
That's what I used to do, but that's not good enough for some viewers. They want to see numbers.
Personally ive stopped measuring W/F after ive fixed a cassette deck. I just measure and adjust the speed with the help of my multimeter then i do a recording of a very nice album from a guy called Gøran Søllscher that consists only of classical guitar. If the deck has a W/F problem it will show up in that recording.. If i cant hear anything then its fine.. I found that measurements just made my life more miserable:D
That's exactly my opinion. If I can't hear any wow&flutter, the cassette deck is fine. Unfortunately after so many RUclipsrs have started using that damn Software W&F Meter, people keep complaining on my videos about me not measuring wow&flutter. Most of these people have no understanding of what those numbers mean, but if they are not shown in a cassette deck repair video that must mean it's a bad video :P
@@DrCassette I think it is more a case of your videos being more complete with a quick W&F test. I enjoy your videos with or without W&F measurements but I can see things from the point of view of a professional repair person. How can one claim to have properly repaired a deck if it is not tested against the specification. The listening test is OK for personal use of course because it is for one's own ears, but when repairing for others, I think a standard of some kind is rquired.
There are different patterns of W&F depending on where the issues are in the machine and these patterns only manifest themselves when listening to certain kinds of music. The patterns can be seen in the WFGUI waveform display, slow undulation of around 1 per second is indicative of a pinch roller problem and a repeating pattern at 10 times per second is most likely to be related to the capstans for example. I am glad you showed the software in operation, it is a valuable tool in debugging W&F issues and I am sure you will find it useful in your future work.
@DrCassette, @@edradiofan7855 totally agree. If I'm repairing, or in my case, more often , "restoring"a piece of vintage gear, my goal is to return the device to its original condition. That means performance, specification and appearance. All cassette decks from day one listed the W&F specification as well as speed accuracy. It would be nuts not to check the values of my restored item against the manual's stated specs. Ok, so maybe my results are worse than new but also maybe they cannot be detected during playback, I don't stress over this. The point is, it's nice to know how close the restored deck measures as compared to when it was first taken out of the box.
I would not accept a repair job without a report on frequency response, tape speed and wow & flutter.
@@edradiofan7855 Repair shop only fix the belts and maybe some grease and do a speed test , they don't have the time to recondition the deck and use Wow and flutter cuz is a can of worms and the customer would never pay for it.
and they don't want to either and belts are a can of worms to when going to the next level.
I am not sure why you care about “public demand”. If people don’t like your channel or the way you do things, then let them go elsewhere. Whose channel is this anyway? People who do nor have constructive input have no input at all. I enjoy watching and usually learning something I didn’t know. If they know it all, why bother to deal with their egos or their showing your test methods to be less than they think they should be? Keep on!
Usually this is my approach, I do whatever I want. But sometimes I think it is good to look around and care for what people are interested in. Wow&flutter measurements are very common now that the Software W&F Meter has become so well known. I can ignore this trend, but eventually this would make me look stubborn and stupid...
Wow and Flutter suffer from the same issues as power output. With RMS power, peak, 1 or both channels working, etc etc. Ohh and don't forget, Chinese watts!!! They don't need ANY kind of meter, just magic up a number and double it, works every time.
Your comment reminds me of an old magazine article from the early 80s which criticized the method the Japanese manufacturers used on their equipment (WRMS) because the resulting numbers were much lower than the numbers measured according to DIN. They said that was a method of deceiving the consumer.
This shareware software is very inaccurate and unreliable.
Furthermore a reference test tone cassette at best will have +/- 5Hz fluctuation. On 3 head machine - The only proper way to test tape speed or W & F is use a freq. generator into tape in's, and test the monitor signal on the machine's outputs. REC & Play on a deck use same capstan/ reel motors so this test is the absolute definitive test method !
I found the results of the WFGUI program correlate quite well with the results of the cassette checker.
Not true because recording and playback on three head machines are not simultaneous. Having said that, the machine will record the signa from a freq. generator on tape with some W&F and tape speed fluctuation then reproduces the recorded signal later on adding W&F and speed fluctuation again. This is because (I'm not a hundred percent sure) W&F and speed fluctuations are both stochastic processes rather than deterministic.
Using an ext sig gen to record, and a w&f meter on the output is the best method for test wow & flutter. If the speed is off it will show on the meter or counter. Using a test tape inherits the spd inaccuracy of the test tape's recorder, being +/- 5Hz per MRL tape's specification. All my decks sod accuracy are no more than 1Hz deviation on DIN 3150 test
I think you missed the significance of the fact that recordings and playback are both subjected to W&F and speed fluctuations. The signal from the generator is going to be contaminated during the recording process. The recorded signal is going to be contaminated again during the reproduction. As for the measured frequency during the reproduction, it will always be the frequency very close to that set on the generator regardless of the tape speed. That is why you need a test tape recorded on a reference equipment.@@dubdoodle7191
@@dubdoodle7191 Disagree, to measure absolute W&F ob the cassette deck - you have to use standard reference tape manufactured on best possible equipment, with known and lowest possible W&F. This is to get number for dick fight :D
But on other hand, - if W&F is low or acceptable during REC then PB ( or monitor ) - good for you!
Because REC/PB is an overlap of 2 W&Fs one during record and second during playback !
But you have to try it several times to get average, I think