Metaxas Papillon

[Foxbat]

W&F measures are meaningless unless you know if weighing was applied and what the tape speed is.
Papillon W/F is 0.15% without weighting, but with weighting, is 0.09%. [not sure about tape speed]

The point is that chasing lower W/F is not going to lead to better sound. Something I believe, because you see it with other measures, like THD or SNR.

The curmudgeons here will argue anything to preserve the apparent benefits of the vintage machines, so I'm not going to entertain this further.
Tape speed accuracy: .001%, FYI.

So what about your earlier statement that: "The Metaxas machines measure as well as the vintage machines."

Somehow it doesn't ring very true... I am afraid. I told you earlier that 4mm capstans were bad... but you kept saying something about some "superior speed control".

Where is it?

 

[Zeotrope]

What brand and type of heads are being used on this machine? Heads like these vintage ones from PhotoVox which are on two of my machines aren't being made anymore as far as I know.

View attachment 127162

Both Metaxas machines use Photovox heads, as Kostas prefers them to AMB; but AMB heads can be used. I don't know what model of head is used.

 

[adrianywu]

W&F measures are meaningless unless you know if weighing was applied and what the tape speed is.
Papillon W/F is 0.15% without weighting, but with weighting, is 0.09%. [not sure about tape speed]

The point is that chasing lower W/F is not going to lead to better sound. Something I believe, because you see it with other measures, like THD or SNR.

The curmudgeons here will argue anything to preserve the apparent benefits of the vintage machines, so I'm not going to entertain this further.
Tape speed accuracy: .001%, FYI.

The quoted figures from the Nagra and Revox are at 15 ips. At 30 ips, the figures are lower. Typical figure with the Nagra T is 0.022%, with 0.032% as the upper limit of acceptability.
Not sure what the weighting you are referring to means. Please explain.
And how does the W&F relate to THD and SNR ? I believe W&F affects the time domaine, not the frequency or the amplitude domaine.

 

[Zeotrope]

The amps with the lower THD and SNR are usually not the best sounding.
If you chase the specs, you are often doing so at the expense of sound quality. Usually, it's because you have feedback loops (like global negative feedback) that end up doing more harm than good. Look at DarTZeel's specs, they are terrible - comparatively. You can argue specs all you want over at Audio Science Review .

Wow and flutter measurement - Wikipedia

en.wikipedia.org

"This fact forms the basis for the weighting curve shown here. The weighting curve is misleading, inasmuch as it presumes inaudibility of flutters above 200 Hz, when actually faster flutters are quite damaging to the sound. A flutter of 200 Hz at a level of -50db will create 0.3% intermodulation distortion, which would be considered unacceptable in a preamp or amplifier."

"Ideally, flutter should be measured using a pre-recorded tone free from flutter. Record-replay flutter will then be around twice as high as pre-recorded, because worst case variations will add during recording and playback. When a recording is played back on the same machine it was made on, a very slow change from low to high flutter will often be observed, because any cyclic flutter caused by capstan rotation may go from adding to cancelling as the tape slips slightly out of synchronism. A good technique is to stop the tape from time to time and start it again. This will often result in different readings as the correlation between record and playback flutter shifts. On well maintained, precise machines, it may be difficult to procure a reference tape with higher tolerances."

So the measurement is essentially meaningless if you try to compare from one machine to another.

 

[adrianywu]

The amps with the lower THD and SNR are usually not the best sounding.
If you chase the specs, you are often doing so at the expense of sound quality. Usually, it's because you have feedback loops (like global negative feedback) that end up doing more harm than good. Look at DarTZeel's specs, they are terrible - comparatively. You can argue specs all you want over at Audio Science Review .

Wow and flutter measurement - Wikipedia

en.wikipedia.org

"This fact forms the basis for the weighting curve shown here. The weighting curve is misleading, inasmuch as it presumes inaudibility of flutters above 200 Hz, when actually faster flutters are quite damaging to the sound. A flutter of 200 Hz at a level of -50db will create 0.3% intermodulation distortion, which would be considered unacceptable in a preamp or amplifier."

"Ideally, flutter should be measured using a pre-recorded tone free from flutter. Record-replay flutter will then be around twice as high as pre-recorded, because worst case variations will add during recording and playback. When a recording is played back on the same machine it was made on, a very slow change from low to high flutter will often be observed, because any cyclic flutter caused by capstan rotation may go from adding to cancelling as the tape slips slightly out of synchronism. A good technique is to stop the tape from time to time and start it again. This will often result in different readings as the correlation between record and playback flutter shifts. On well maintained, precise machines, it may be difficult to procure a reference tape with higher tolerances."

So the measurement is essentially meaningless if you try to compare from one machine to another.

Are you now saying that intermodulation distortion also does not matter to sound quality as well ?
"So the measurement is essentially meaningless if you try to compare from one machine to another." How do you arrive at this conclusion ? W&F given by the manufacturers are measured by using standard reference tapes, not signals recorded by the machine itself. These figures are comparable between machines.
And I still don't see the logic of extending the THD and SNR argument to W&F. If these figures are meaningless, what accounts for the differences heard between different turntable drive systems ?

 

[Zeotrope]

Read the wikipedia link and it should be clear why W&F measurements are essentially meaningless when comparing across machines. Measuring using the same weighing on the same machine with the same tape is useful, as you can adjust and track changes over time.

I am not comparing THD and SNR to W&F. Forget about W&F for a moment. I am saying that chasing the best/lowest THD or highest SNR for amplifiers usually does not yield the best sound.
Applied to W&F - you have a guy who has recorded hundreds of tapes professionally who has built a cost no object machine say the same thing. You can choose to not believe him, of course.

 

[adrianywu]

Read the wikipedia link and it should be clear why W&F measurements are essentially meaningless when comparing across machines. Measuring using the same weighing on the same machine with the same tape is useful, as you can adjust and track changes over time.

I am not comparing THD and SNR to W&F. Forget about W&F for a moment. I am saying that chasing the best/lowest THD or highest SNR for amplifiers usually does not yield the best sound.
Applied to W&F - you have a guy who has recorded hundreds of tapes professionally who has built a cost no object machine say the same thing. You can choose to not believe him, of course.

The reason why THD is a poor measurement is because it fails to distinguish between consonant (harmless) and dissonant (harmful) harmonics. This is equivalent to measuring total cholesterol for cardiovascular disease risk. That's why we now measure LDL (bad) and HDL (good) cholesterol separately. This problem is specific to THD as a measurement and not applicable to anything else. If you strip out the consonant harmonic component and only measure the dissonant harmonics, the figure will correlate very well with perceived sound quality problems. This has been shown over and over again with panels of blinded listeners. And to say that W&F measurements are useless because TDH is useless, is like saying measuring blood pressure is useless because measuring total cholesterol is useless. This is poor logic if there is even any logic in it.
You might have one guy who has recorded a lot of tapes and who is trying to sell you his machine that does not measure so well telling you this. Versus the hundreds of engineers who have designed the professional machines used for making all the commercial recordings telling you otherwise. W&F measurement is an accepted standard to compare (one aspect of) the performance of tape recorders and an important parameter for design engineers. Whether you accept it or not is moot.

 

[Zeotrope]

What is the weighing curve used on the W&F measures you quoted from Nagra? Was the tape started and stopped with a series of measures taken? You don’t know because it was not disclosed. You obviously have not read the details of how W&F is measured from the link I sent. You don’t know what you don’t know and are unwilling to learn, so I am done trying to help.

Valin wrote that the Tourbillon is the best source he’s ever heard, and he’s heard all the vintage machines. No ulterior motives and no, Metaxas is not pushing his machine on anyone.
Perhaps you just cannot accept that a machine with 50 year old electronics and motors cannot possibly be better at moving tape than a well designed modern machine.

I honestly don’t understand why you feel the need to post in this thread. Go and push the superiority of 50 year old AC motors and controllers in the vintage thread to your heart’s content. You’re so myopic and narrow minded, it’s incredible.
[+1 to ignore list]

 

[Foxbat]

What is myopic is claiming that .15% W&F is unimportant.

I am trying to be fair here, I hope this is just a typo.

 

[Ampexed]

The best mastering machines of the 50s/60s had weighted wow and flutter of 0.1%. This was the spec for the Ampex model 300 which used a rim-drive flywheel with relatively large diameter capstan, and the actual measured day-to-day wow and flutter on a well maintained machine was around 0.06% - 0.08%. My direct drive Ampex 354 measures around 0.07% today.

Wow and flutter at this level is mostly inaudible, but anything more is going to become audible on instruments like piano. I'm very sensitive to flutter and can hear it well below 0.1% in some instances.

Anything like 0.15% is definitely sub-par, regardless of the vintage of the machine. With today's precision motors and constant tension spooling systems, figures of 0.07% should be a worst-case result.

 

[Zeotrope]

The best mastering machines of the 50s/60s had weighted wow and flutter of 0.1%. This was the spec for the Ampex model 300 which used a rim-drive flywheel with relatively large diameter capstan, and the actual measured day-to-day wow and flutter on a well maintained machine was around 0.6% - 0.8%. My direct drive Ampex 354 measures around 0.7% today.

Wow and flutter at this level is mostly inaudible, but anything more is going to become audible on instruments like piano. I'm very sensitive to flutter and can hear it well below 0.1% in some instances.

Anything like 0.15% is definitely sub-par, regardless of the vintage of the machine. With today's precision motors and constant tension spooling systems, figures of 0.7% should be a worst-case result.

Interesting, thanks.
Again, weighing curves make a big difference, so it's difficult to compare just the % numbers. When you say anything like 0.15% is sub par, but your Ampex measures 0.7%, are you saying it's sub-par? Or did you mean 0.07%?

And again, the Papillon is 0.09%. So it's the same as your Ampex, if you meant 0.07% -- with the caveat that unless the same tape was used and the same weighing curve was used, at the same tape speed, you really cannot compare numbers among machines.

 

[Ampexed]

Interesting, thanks.
Again, weighing curves make a big difference, so it's difficult to compare just the % numbers. When you say anything like 0.15% is sub par, but your Ampex measures 0.7%, are you saying it's sub-par? Or did you mean 0.07%?

And again, the Papillon is 0.09%. So it's the same as your Ampex, if you meant 0.07% -- with the caveat that unless the same tape was used and the same weighing curve was used, at the same tape speed, you really cannot compare numbers among machines.

I meant 0.07% - add an additional zero to my numbers! I measure weighted RMS and DIN. Ampex used RMS back in the day, but like I mentioned, the actual numbers for a well maintained machine could be better than spec. The 3M mastering machines (M56/M79) had an even larger flywheel and a capstan well over an inch in diameter with their closed loop drive system. The resulting wow and flutter numbers were extremely good. The Technics consumer machines also used a closed loop system.

Sounds like this machine is in the ballpark of what the usual numbers should be. Getting really good wow and flutter numbers is much harder with tape than it is with a turntable, regardless of the precision of the motors.

 

[Foxbat]

.09% presumably at 30ips is indeed VERY sub-par.

So, what happened to the statement that it measures just "as well as the vintage machines."?

.09% would be unacceptable even for good consumer machines.

You never answer the question about "weighting" and you don't even provide the proper test condition for W&F, especially the speed, without which all this is totally meaningless.

Where's the beef?

 

[Ampexed]

.09% presumably at 30ips is indeed VERY sub-par.

So, what happened to the statement that it measures just "as well as the vintage machines."?

.09% would be unacceptable even for good consumer machines.

You never answer the question about "weighting" and you don't even provide the proper test condition for W&F, especially the speed, without which all this is totally meaningless.

Where's the beef?

I think we need to separate the 'spec' from actual measurements. Unless we have actual measurements, we just don't know. I agree though that a measured 0.09% is not good enough, especially at 30ips, and with modern motor control no less. My 30ips machine, which is far from a Studer, actually measures at 0.06% DIN. We also don't know what proportion is wow verses flutter. Flutter is far more offensive to *me* but measurements lump that together with wow, and wow doesn't bother me as much.

 

[Foxbat]

I have measured many different machines, many brands, the pro models, and they all, even being 40-50 year old, meet or exceed their specs, as long as they are not damaged... so when I see published specs from an established company I do take it at face value, based on my experience.

For instance, Ampex ATR-100 has the specs of .03% RMS Unweighted at 30ips, and .04% at 15ips. This is how the specs should be stated, unless someone is just hand-waving. They also have specs for peak values.

 

[Ampexed]

I have measured many different machines, many brands, the pro models, and they all, even being 40-50 year old, meet or exceed their specs, as long as they are not damaged... so when I see published specs from an established company I do take it at face value, based on my experience.

For instance, Ampex ATR-100 has the specs of .03% RMS Unweighted at 30ips, and .04% at 15ips. This is how the specs should be stated, unless someone is just hand-waving. They also have specs for peak values.

The older Ampex specs tended to be conservative, and the machines actually measured better. I have no idea how conservative or not the specs of the machine which is the subject of this thread are. My 354 is specified for 0.15% wow and flutter, but I routinely measure 0.07%. The only area where the old Ampex specs were 'optimistic' was frequency response at low frequencies.

 

[adrianywu]

What is the weighing curve used on the W&F measures you quoted from Nagra? Was the tape started and stopped with a series of measures taken? You don’t know because it was not disclosed. You obviously have not read the details of how W&F is measured from the link I sent. You don’t know what you don’t know and are unwilling to learn, so I am done trying to help.

Valin wrote that the Tourbillon is the best source he’s ever heard, and he’s heard all the vintage machines. No ulterior motives and no, Metaxas is not pushing his machine on anyone.
Perhaps you just cannot accept that a machine with 50 year old electronics and motors cannot possibly be better at moving tape than a well designed modern machine.

I honestly don’t understand why you feel the need to post in this thread. Go and push the superiority of 50 year old AC motors and controllers in the vintage thread to your heart’s content. You’re so myopic and narrow minded, it’s incredible.
[+1 to ignore list]

W&F figures published by European manufacturers are generally DIN unweighted. Other figures are specifically stated when published, and Ampex usually publish several standards, but they differ only slightly.
I did read the Wiki page. As it says "As with many audio standards, these are identical derivatives of a common specification." Even if the different standards are used, they should be very similar. It certainly will not result in a 0.25% figure, which is clearly an outlier.
I have no experience with the Metaxas machines, and I was only commenting on the 0.25% W&F figure. It might well be an error.
The Nagra T has dual capstans and four independent microprocessor controlled motors. The capstans are ceramic and they use ruby in the tape guides. It is a completely over the top, cost no object design and is probably an unrealistic goal for modern designers to achieve. That I agree with you. It is also probably unrealistic to ask a small manufacturer today to replicate, let alone improve upon professional machines such as the A80, A820 and ATR100, since these were large companies with big engineering departments that sold tens of thousands of machines.
I would love to have a brand new machine that outperforms my Nagras. I have been urging the folks at Nagra to introduce a new tape machine, but the economics is not favorable. When I started working with tape machines 25 years ago, the only machine available new was the Otari MX5050. I sold mine after a couple of years when I bought the Nagras. Still looking for a better machine.
All the techs I know are quite obsessed about W&F, and in making sure machines they work on are up to spec. It is very audible. Professional machines are expected to have less than 0.04%, and good consumer machines less than 0.1%. This is the first time I hear someone questioning the validity of published W&F figures, esp. from companies such as Nagra, Studer and Ampex. Pro users are not easy to deceive, and this is something anyone can measure. I am happy to learn from you if you know something I don't, so please do tell me what you find deficient in these pro machines.
I will wait to see if the professional mastering facilities start to buy these new machines. I think some are acquiring Ballfinger machines, which is a good sign.

 

[Foxbat]

Well put, Adrian. It is not like any one is rejecting the idea that a talented group of engineers, with many years of experience and successes behind them, could produce an even better machine with today's technology... the problem is - there is no such group anywhere today. Perhaps there is that collective expertise at Nagra, I don't know, but as you indicated, the economy is against them. Modern machines of the caliber of Studer A820 and Ampex ATR-100 would have astronomically high price tags, and in today's market where recording to tape is becoming an oddity I doubt anyone could expect a financial reward.

 

[adrianywu]

Well put, Adrian. It is not like any one is rejecting the idea that a talented group of engineers, with many years of experience and successes behind them, could produce an even better machine with today's technology... the problem is - there is no such group anywhere today. Perhaps there is that collective expertise at Nagra, I don't know, but as you indicated, the economy is against them. Modern machines of the caliber of Studer A820 and Ampex ATR-100 would have astronomically high price tags, and in today's market where recording to tape is becoming an oddity I doubt anyone could expect a financial reward.

There are very few people left in the tape department at Nagra, shocking as this may seem. Now that Hubert Bartels has fully retired, we Nagra T owners are on thin ice. These machines are definitely not for DIY types. I have heard that Nagra will start manufacturing the QGB adapter again, given the large number of Nagra IV-S out there. These machines are indestructible and easy to service. They are excellent recorders, but were not designed for high quality playback. I think eventually someone will come up with an upgraded repro card. I told them that they can simplify the Nagra T; get rid of the time code, sync and complex editing functions, and use the rest of the design for a new "audiophile" tape machine. However, they told me that some of the parts are no longer available, and will be too expensive to re-manufacture.

 

[srs148]

There are very few people left in the tape department at Nagra, shocking as this may seem. Now that Hubert Bartels has fully retired, we Nagra T owners are on thin ice. These machines are definitely not for DIY types. I have heard that Nagra will start manufacturing the QGB adapter again, given the large number of Nagra IV-S out there. These machines are indestructible and easy to service. They are excellent recorders, but were not designed for high quality playback. I think eventually someone will come up with an upgraded repro card. I told them that they can simplify the Nagra T; get rid of the time code, sync and complex editing functions, and use the rest of the design for a new "audiophile" tape machine. However, they told me that some of the parts are no longer available, and will be too expensive to re-manufacture.

I had a conversation with Jeff Polan @NextGen about a plug-in replacement upgraded Nagra IV-S repro circuit and its something that's on his backlog of projects. It's something we plan to revisit later this year. I'll let Jeff comment on more details about it, including potential limitations he's identified that may necessitate a custom power supply if done exactly how he would want to do it. With that said, I've already pledged a loaner / test unit for development of the repro card when he's ready.