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How Phono Cartridges Work

Frank Dernie

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Whatever arm you may prefer, IME, it really isn't all that complicated to decipher ... if you consistently hear a lot (or even a little) of needle-talk from the cartridge, your rig is either wasting precious energy or is overtly resonant.
I have seen you write this before. It is a gross oversimplification IMO. "wasting energy" is typical hifi speak and is meaningless in the world of accurate vibration transducers IME.
In a seismic vibration transducer the mode of working is simple and things like energy waste meaningless. Yes I know this sort of statement crops up all the time in hifi magazines but it means nowt.
 

TBone

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I have seen you write this before. It is a gross oversimplification IMO. "wasting energy" is typical hifi speak and is meaningless in the world of accurate vibration transducers IME.
In a seismic vibration transducer the mode of working is simple and things like energy waste meaningless. Yes I know this sort of statement crops up all the time in hifi magazines but it means nowt.

Yes, it certainly is a simplification, "over or under" is but your own opinion ... I stand by the statement, based on the fact it has certainly proved true in both measurable and sonic terms based on my many years of experience.

That bit is at the mounting end so will have pretty well zero influence on higher arm modes effect on the cartridge body.

mod wasn't intended to affect the cartridge body.
 

watchnerd

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IME the most rigid arms, particularly if there are no lossy joins, produce resonances big enough to be seen on the cartridge output. The more rigid the arm the higher in frequency will be the transmission band of vibration from plinth to cartridge body - which will also produce output from the cartridge.
I used to measure these things for a job but haven't for years. A cartridge is a seismic vibration transducer and once the input frequency to the stylus is ~2x the Fn of the effective mass on the cartridge compliance the only spurious rubbish appearing on the cartridge output has come either from the arm or along the arm to the cartridge body, which in an ideal transducer should be stationary relative to the groove.
There is an awful lot of static thinking and discussion goes on about record players, which is not sound (see what I did there?) science. Rigidity is one of them. Nothing is rigid over the whole audio frequency range.
IME there are very, very few record players which accurately pick up what is in the groove and transmit that, and only that, to the cartridge output.
It was often said back in the day all a turntable has to do is rotate at 33 ⅓ rpm. The engineering problem is getting anything which does just that and not lots of other undesirable things as well...
Not many do IME and I haven't seen many new ones, based on what I learned when doing it myself, which impress me.
Record players are mainly a fashion business nowadays (IMHO)

What do you think of the maglev turntables?


 

RayDunzl

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watchnerd

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Has gee-whiz factor, but looks kinda wobbly...

From our reference frame, it certainly looks wobbly.

But from the reference frame of the cartridge, I'm not so sure it's any worse than a regular turntable. If the tonearm/cart is able to keep the cartridge in the groove without mistracking, it may not matter what we see.

I'd actually be more concerned about its ability to keep a constant speed.
 

Frank Dernie

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There are 2 ways to get output from a cartridge over and above the wanted output of the groove. One is spurious vibration via the stylus, the other is vibration of the cartridge body (the bit that should be static) via the headshell.
Cartridge body design and material also influences how much, and the character of, the spurious vibration ending up at the "fixed" part of the transducer too, because it resonates over a range of higher frequencies.
The "standard" cartridge layout is far more influenced by having to be tolerant of poor records than by the requirements of an accurate vibration transducer :(

It used to be irritating to see so much misunderstanding of dynamics amongst hifi hobbyists and not a few manufacturers back when LP was the prime medium. It doesn't bother me much any more that I hardly use it.

BTW if I gave the impression I thought SME arms were poor it is only in one way. They are just about perfect in every static way. The bearings are in the right place (surprisingly rare) and the balance spot on (also rare). Apart from the high rigidity and low damping keeping the cartridge body less vibration free, which mods could probably fix, they would probably have been my choice of pivoted arm and I would probably have had fun fixing the dynamic shortcomings.
Turntables, arms and cartridges are all ridiculously and unjustifyably expensive to play with nowadays though IMO when modest digital is better in every way.
 

TBone

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Thoughts on Rega arms? They're quite rigid and have no VTA/Azimuth etc.

Used a RB300 for decades, and have had a few others Rega models grace my system over the years. While I liked all, they wouldn't be my first choice at their respected price ranges. Not a fan of dynamically balanced arms (or linear arms for that matter), or any arm using springs. Unless the spring(s) is damped, somehow, they can certainly introduce resonance. Put a stethoscope to a Rega, tap it even slightly, and you can hear the spring ring like a bell for quite some time. The old trick of setting the VTF gauge to 0 and using the counter weight for balance didn't work either, all that did was change the springs resonance characteristics. Minute magnetic anti-skate adjustment is finicky at best. Nor could I get any of 'em to measure as accurately as my Alpha does currently.
 

TBone

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It used to be irritating to see so much misunderstanding of dynamics amongst hifi hobbyists and not a few manufacturers back when LP was the prime medium. It doesn't bother me much any more that I hardly use it.

Do you have any rips to share which may provide a hint of your rigs capabilities?
 

TBone

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Indeed. Makes me wonder if Nagaoka is supplying AT with their special line contact styli....

I have read (forget where) that Nag have supplied other companies. IIRC, Nag is also just a small portion of a much larger diversified company.
 

Frank Dernie

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Do you have any rips to share which may provide a hint of your rigs capabilities?
No, I did a rip or two about 20 years ago but didn't think it was worth the agro, the cartridge is different now anyway.
I am not sure how anybody would judge how accurately a record player is working by listening to it though :).
I found when I was working on record players that improving the accuracy, particularly removing acoustic and mechanical vibration coupling to it, was less popular with listeners.
I had found myself that isolating the record player had a big positive effect on the accuracy of transduction but when I moved my TT at home out of the listening room it sounded more flat and uninteresting. It was a Technics SP10 in a "rigid" plinth, SME arm and Ortofon cartridge.
So having a nice sounding rip is, IME, not necessary evidence of the record player being accurate rather than euphonic.
Added resonance is a cause of PRaT for example.
 

TBone

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I am not sure how anybody would judge how accurately a record player is working by listening to it though :).

Well, there are ways to compare, and it certainly beats having to read fluff about someones choice of preferred setup/equipment.

I found when I was working on record players that improving the accuracy, particularly removing acoustic and mechanical vibration coupling to it, was less popular with listeners.

I've witnessed that also; but given my experience and peers, it really depends on which listeners, his/her experience & expectations, of what really-"accurate" analog rig should sound like (like a great digital source, w/very low noise floor, healthy dynamic ability, lack of obvious resonance & distortions, etc) ...

I had found myself that isolating the record player had a big positive effect on the accuracy of transduction ...

Certainly when playing a turntable at higher spl, lack of isolation potentially tilt sonics, but ripping via headphones bypasses all that and allows you the advantage of digital intervention.
 

deniall83

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Thanks for the replies. So do you guys have an opinion on which turntables perform best/are designed best at each price point?
 
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