ifi Zen Phono Review (phono stage)

[Thorsten Loesch]

Let's make it then more clear for you then. The tripple pendulum is a model of 3 links with masses connected together rotating just around one axis.

Which fails to describe a Tonarm, headshell, cartridge system adequately for absolute precision, but offers a workable model for intuitive and inductive understanding of the system and allows intentional mitigation of the worst problems.

So it is both useful and valuable.

A non rigid tonearm-cartridge system in reality has to be modelled as an infinite number of masses able to be rotating and bending around all axes, something that obviously cannot be done with simple analytical models but is usually approximated with numerical discretisation approaches like FEM.

Yes and no.

The system can be simplified to account only for first and second order effects and doing so will deliver a model that is usable to affect major improvements on those effects.

Might this cause unpredictable changes to third and further order effects. Absolutely.

Does it matter? Usually not. Matthew 7:5

See above, of course the vibrational behaviour of the tonearm system can be measured with modern techniques like laser interferometry but those are neither simple nor give automatically a deeper understanding or model of the system, so above stories aren't good analogies and show the problem that @Frank Dernie correctly described.

I am a qualified engineer, programmer, child math prodigy (using slip sticks), child soldier, trained sniper and communication specialist and part qualified (but not chartered under UK law) Accountant.

Most of these have the concept, when I practiced, of materiality. In other words, there is a limit below which you don't bother, because going there adds nothing MATERIAL to the situation.

In my view, we have long crossed the materiality boundary if we want basic understanding and problem mitigation as well as practical considerations.

That does not mean I do not appreciate that there is a lot more there, but to a multidisciplinary generalist (or a normal user) much of that falls below the noise floor (materiality boundary).

As German I'm prone to over think and over engineering, despite my decades in the UK and China giving me sense of perspective.

If you outdo me, you may have crossed the materiality boundary.

Crossing that boundary, does not make your contribution worthless, far from it. But it confines to Ivory Tower envoirns, instead of sweat, blood, guts and solid metal where I weave my "magik".

Again, NOMA applies.

Thor

 

[Thorsten Loesch]

Well, yes, it's a very complex problem... now I'm thinking if you can trust the compatibility tables in the internet. Even the counterweight position changes the math.

Worst with the famous Japanese cartridges compliance measurements at 100Hz.

The issue is not accuracy of model, but practical usability of the model to affect improved outcomes.

Almost of the models used in electronics are technically speaking wrong, but they still serve to attain desired outcomes.

A simple useful model is usually superior in the real world to a complex and complete model next to impossible to use.

Thor

 

[thewas]

Which fails to describe a Tonarm, headshell, cartridge system adequately for absolute precision, but offers a workable model for intuitive and inductive understanding of the system and allows intentional mitigation of the worst problems.

It could be used although personally I would used a better adapted one, nevertheless it is very complex for analytical solution and shows chaotic behaviour, meaning a small initial difference can lead to completely different trajectories.

The system can be simplified to account only for first and second order effects and doing so will deliver a model that is usable to affect major improvements on those effects.

Might this cause unpredictable changes to third and further order effects. Absolutely.

Does it matter? Usually not.

To simplify it first knowledge of the real behaviour must be obtained, for example how large the deviations are from the measured real system to the simulated of a 3 lumped masses one.

I am a qualified engineer, programmer, child math prodigy (using slip sticks), child soldier, trained sniper and communication specialist and part qualified (but not chartered under UK law) Accountant.

Most of these have the concept, when I practiced, of materiality. In other words, there is a limit below which you don't bother, because going there adds nothing MATERIAL to the situation.

In my view, we have long crossed the materiality boundary if we want basic understanding and problem mitigation as well as practical considerations.

That does not mean I do not appreciate that there is a lot more there, but to a multidisciplinary generalist (or a normal user) much of that falls below the noise floor (materiality boundary).

As German I'm prone to over think and over engineering, despite my decades in the UK and China giving me sense of perspective.

If you outdo me, you may have crossed the materiality boundary.

Crossing that boundary, does not make your contribution worthless, far from it. But it confines to Ivory Tower envoirns, instead of sweat, blood, guts and solid metal where I weave my "magik".

For a German engineer (which I also happen to be) I have to say I see too much "poetry" in your posts . I also know that the industry reality looks often very different and how important the understanding of the basic principles behind is, but on the other hand some complex systems unfortunately cannot be simplified without being strongly compromised in their descriptional quality.

 

[Thorsten Loesch]

It could be used although personally I would used a better adapted one, nevertheless it is very complex for analytical solution and shows chaotic behaviour, meaning a small initial difference can lead to completely different trajectories.

I completely agree, safe for the preference for simple immediately usable models that allow real world results.

To simplify it first knowledge of the real behaviour must be obtained, for example how large the deviations are from the measured real system to the simulated of a 3 lumped masses one.

Well, not really. A basic theory (Say Newton on optics) can describe real world phenomena sufficiently well to be highly usable.

A carpenter making a wooden barrel is well served by considering PI to be 3.14. his barrel will be round the swelling of wet wood will take up the slack, actually, 3.14 is likely too precise, 1/3 will probably make his barrel work in practice.

Another example, I trained on the RuSSian Dragunov "sniper" rifle. Actually a brain amputated spastic can be sniper with that, once the reticle is understood.

Correct aiming becomes rapidly instinctive of checking target hight against reticle graduation and picking the correct "post" to aim. No adjustment, no difficulty.

If you can see the enemy, chances are very high you can terminate the target within 500m in a 3 second timeframe or less.

Even now, with shaking hands (too much booze with too many years), after a recent denazification of my property of Nazi pigeons (Lavrov said Hitler had pigeon blood) using a nice scoped .22 LR rifle I think I can hit that frame with confidence with a Drag.

I also know high precision bolt action sniper rifles. If you have all the time in the world and can fettle and adjust like so, the same round used in a Dragunov will kill at 1,500m.

But I won't sit around for days in Gillie suit peeing in a bottle and holding in my #2.

Me, I take an acurised .57' Simonov rifle (I also trained on that for counter sniper duties) and make sure the collateral damage snuffs the target.

For a German engineer (which I also happen to be) I have to say I see too much "poetry" in your posts .

I grew up and did my first degree (EE) in East Germany (a Saxon to boot) as well as becoming certified"Tonmeister".

I left for greener turf in the very early 90's at still a young age and did another degree in London. Since I resided in the Anglosphere and Asia.

Being mostly "white" (actually pink) and culturally (not religiouly - I'm an esoteric syncretist) Protestant, I guess I'm one of the few certified White Anglo Saxon Protestants (WASP).

I also know that the industry reality looks often very different and how important the understanding of the basic principles behind is, but on the other hand some complex systems unfortunately cannot be simplified without being strongly compromised in their descriptional quality.

All complex systems can be reduced to first order issues and thus be made accessible to "lay" people. Anyone who claims different either lacks understanding or good will.

The truly useful models are the simple ones, that give normal people a handle on what happens and how to make it happen the way that is useful.

Thor

 

[Bob from Florida]

Let's make it then more clear for you then. The tripple pendulum is a model of 3 links with masses connected together rotating just around one axis. A non rigid tonearm-cartridge system in reality has to be modelled as an infinite number of masses able to be rotating and bending around all axes, something that obviously cannot be done with simple analytical models but is usually approximated with numerical discretisation approaches like FEM.



See above, of course the vibrational behaviour of the tonearm system can be measured with modern techniques like laser interferometry but those are neither simple nor give automatically a deeper understanding or model of the system, so above stories aren't good analogies and show the problem that @Frank Dernie correctly described.

Thanks for taking the time to reply.

The story illustrates the difference between solving something in a lengthy manner or using a practical solution. If you were designing a tonearm - from scratch - how would you approach the design. Would you use math to the nth degree or just enough math to get something built to measure and make corrections?

 

[Bob from Florida]

All complex systems can be reduced to first order issues and thus be made accessible to "lay" people. Anyone who claims different either lacks understanding or good will.

The truly useful models are the simple ones, that give normal people a handle on what happens and how to make it happen the way that is useful.

Thor

Agree completely.

 

[Bernard23]

Thanks for taking the time to reply.

The story illustrates the difference between solving something in a lengthy manner or using a practical solution. If you were designing a tonearm - from scratch - how would you approach the design. Would you use math to the nth degree or just enough math to get something built to measure and make corrections?

Surely the end application is the key consideration here. Consumer audio is a very different proposition to engineering parts for aerospace for example. The fact that this site exists at all is testament the lack of consistent (good) measurement practice in the industry, or at least a customer base that demands it. You can, literally, get away with almost anything in audio, if you choose to.

 

[mike70]

All complex systems can be reduced to first order issues and thus be made accessible to "lay" people. Anyone who claims different either lacks understanding or good will.

I will quote another german scientific to agree with you

"If you can't explain it simply, you don't understand it well enough". A. Einstein

 

[Thorsten Loesch]

The fact that this site exists at all is testament the lack of consistent (good) measurement practice in the industry

Allow me to take umbrage here.

For the last seven decades a culture of measurements based audio has been in existence.

At some point (likely though the ill offices of Harold J. Leak) a specific marketing "cult" that emphasised specific "objective" performance over less easily quantified "good sound" became first a thing and eventually a "thing" that is out of control.

Here I might call the "distinctly unancient cult of SINAD" but alternative variants exist.

I have Zero umbrage with anyone measuring anything.

Actually I like for other people to confirm independently my own results (which they commonly do once differences in approach are baselined).

or at least a customer base that demands it. You can, literally, get away with almost anything in audio, if you choose to.

Actually, for discerning customers it is not easy.

You can fool some of the pee-pull some of the time, more easily if they want to believe.

But you cannot fool all people all of the time.

Thor

 

[Bernard23]

Allow me to take umbrage here.

For the last seven decades a culture of measurements based audio has been in existence.

At some point (likely though the ill offices of Harold J. Leak) a specific marketing "cult" that emphasised specific "objective" performance over less easily quantified "good sound" became first a thing and eventually a "thing" that is out of control.

Here I might call the "distinctly unancient cult of SINAD" but alternative variants exist.

I have Zero umbrage with anyone measuring anything.

Actually I like for other people to confirm independently my own results (which they commonly do once differences in approach are baselined).



Actually, for discerning customers it is not easy.

You can fool some of the pee-pull some of the time, more easily if they want to believe.

But you cannot fool all people all of the time.

Thor

No need to take umbrage - consistent is the key word, as an industry there are those that use measurement properly, and many that don't. The point is, there is no process of certification for consumer audio, so I just have to take your word that you (and Amir FWIW) know what your are doing, and that your data is correct.

Meant to add before hitting the send button - and of course the interesting / important role for fora such as ASR is it permits some form of inter-lab comparison, and ultimately could provide uncertainty calculations that gives confidence in the data etc etc

 

[thewas]

I completely agree, safe for the preference for simple immediately usable models that allow real world results.

Yes, but only if they are good enough for the purpose needed, a model should be not unnecessary complex but complex enough to correctly recreate the examined issue.

Well, not really. A basic theory (Say Newton on optics) can describe real world phenomena sufficiently well to be highly usable.

See above, as you probably know Newton's mechanics work well for normal velocities but fail when getting closer to the light of speed.

All complex systems can be reduced to first order issues and thus be made accessible to "lay" people. Anyone who claims different either lacks understanding or good will.

The truly useful models are the simple ones, that give normal people a handle on what happens and how to make it happen the way that is useful.

In some fields such oversimplified models can give people a basic understanding of the general mechanisms behind, but still don't allow them for example to understand and determine the complex vibrational behaviour of a multibody vibration.

Surely the end application is the key consideration here. Consumer audio is a very different proposition to engineering parts for aerospace for example. The fact that this site exists at all is testament the lack of consistent (good) measurement practice in the industry, or at least a customer base that demands it. You can, literally, get away with almost anything in audio, if you choose to.

Exactly!

 

[Thorsten Loesch]

Yes, but only if they are good enough for the purpose needed, a model should be not unnecessary complex but complex enough to correctly recreate the examined issue.

There we agree.

See above, as you probably know Newton's mechanics work well for normal velocities but fail when getting closer to the light of speed.

For now the risk of incorrectly engineering a vehicle (even for space exploration) due to the limitations of Newtonian physics is rather small.

In some fields such oversimplified models can give people a basic understanding of the general mechanisms behind, but still don't allow them for example to understand and determine the complex vibrational behaviour of a multibody vibration.

True, but here is the issue. Are we (consumers and users of turntables, tonarms and cartridges in need of fully understanding the complex vibrational behaviour of a multibody vibration?

Or will a simplified model that allows an intuitive grasp of the different behavior of (say) rigid single piece tonarms and non-rigid alternatives serve us better?

Thor

 

[thewas]

True, but here is the issue. Are we (consumers and users of turntables, tonarms and cartridges in need of fully understanding the complex vibrational behaviour of a multibody vibration?

Or will a simplified model that allows an intuitive grasp of the different behavior of (say) rigid single piece tonarms and non-rigid alternatives serve us better?

It depends also about the frequency region we are interested in, for the bass resonance for example a rigid body model will be probably be good enough, for the higher eigenmodes not. Also to know that some decent research needs to be done which measures the behaviour and compares to different models.

 

[thewas]

Thanks for taking the time to reply.

The story illustrates the difference between solving something in a lengthy manner or using a practical solution. If you were designing a tonearm - from scratch - how would you approach the design. Would you use math to the nth degree or just enough math to get something built to measure and make corrections?

Like on every engineering task it depends on the predefined target list and will be different for example if the main target is "make something that plays records with the lowest possible budget" or "engineer a tonearm with a lower eigenmode amplitude spectrum in frequency region XY compared to references ABC".

 

[Bob from Florida]

There we agree.



For now the risk of incorrectly engineering a vehicle (even for space exploration) due to the limitations of Newtonian physics is rather small.



True, but here is the issue. Are we (consumers and users of turntables, tonarms and cartridges in need of fully understanding the complex vibrational behaviour of a multibody vibration?

Or will a simplified model that allows an intuitive grasp of the different behavior of (say) rigid single piece tonarms and non-rigid alternatives serve us better?

Thor

Back when I had the Graham Robin - straight aluminum wand with detachable head shell, I can see how that would fall in the non-rigid class.
Now with the Satisfy Carbon - perhaps slightly more rigid. The satisfy is not a single piece even though the head shell does not detach. See below.

The head shell is inserted into the carbon fiber tube instead of single piece. The underside at the insertion has a set screw that when loosened allows some azimuth adjustment. Perhaps Clearaudio was thinking along the "non-rigid" design advantages when they decided on this design.

 

[Thorsten Loesch]

Back when I had the Graham Robin - straight aluminum wand with detachable head shell, I can see how that would fall in the non-rigid class.
Now with the Satisfy Carbon - perhaps slightly more rigid. The satisfy is not a single piece even though the head shell does not detach. See below.

View attachment 268150

The head shell is inserted into the carbon fiber tube instead of single piece. The underside at the insertion has a set screw that when loosened allows some azimuth adjustment. Perhaps Clearaudio was thinking along the "non-rigid" design advantages when they decided on this design.

I think this one tends possibly more towards "rigid" than "non-rigid", but hard to say without detailed examination.

Incidentally, I tend to set overhang near the final groves, once you consider the whole involved physics you realise that the further you go to the outside of an LP, the longer the mechanical wavelength for a given frequency becomes, meaning the whole system is much more tolerant towards tracking angle error.

Thor

 

[Bob from Florida]

I think this one tends possibly more towards "rigid" than "non-rigid", but hard to say without detailed examination.

Incidentally, I tend to set overhang near the final groves, once you consider the whole involved physics you realise that the further you go to the outside of an LP, the longer the mechanical wavelength for a given frequency becomes, meaning the whole system is much more tolerant towards tracking angle error.

Thor

I will have to check my Clearaudio adjustment tool, it has a total of 4 overhangs. If memory serves, I think the rest are optimized for more outer tracks rather than inner tracks.

 

[Bob from Florida]

I will have to check my Clearaudio adjustment tool, it has a total of 4 overhangs. If memory serves, I think the rest are optimized for more outer tracks rather than inner tracks.

It seems their suggestion is opposite of yours.

 

[Thorsten Loesch]

It seems their suggestion is opposite of yours.


View attachment 268518

Way I read it, they optimised for inner groves as well, I'd go with "red".

Thor

 

[cgallery]

I think they're just saying "audiophile records" have a larger inner radius, or more ungrooved wax at the end of the side.