Objective ways to evaluate turntable performance

[virajsingh]

Hi

Was wondering if there are any objective ways to evaluate turntable performance other than the money you spend on acquiring them. The subjective appendages like sound was spot on, life like detailed, separation of instruments etc. are subjective and way from person to person.

How about this:

Play a blank LP (of highest quality but totally and absolutely without any sound) on various turntable setups which have the same downstream components like interconnects, phono stage, amplifier, speakers etc. and plot the frequency response charts. If the chart for an inexpensive turntable with its inexpensive cartridge is same as that of a so called reference table then I wonder if we can state that there is no difference between the two.

The exercise can be repeated with reference LPs of various genres and by comparing the chart we would come to know if the difference in frequency response (Chrat A- Chart B = Chart of difference in frequency response) is significant or not(and 'significant' can be defined scientifically say + - X% variation).

My hunch is that we would be surprised to find how 'close' a US$ 500-700 table comes to those costing in excess of US$ 10,000. What are your views on what might we find? Do share your views or any experiences you have in this area.

I know music appreciation is subjective but at the end of the day the a turntable is a machine and we should be able to evaluate it as one.

Viraj Singh

 

[Rajiv]

Hi,

Play a blank LP (of highest quality but totally and absolutely without any sound) on various turntable setups which have the same downstream components like interconnects, phono stage, amplifier, speakers etc. and plot the frequency response charts. If the chart for an inexpensive turntable with its inexpensive cartridge is same as that of a so called reference table then I wonder if we can state that there is no difference between the two.

Pardon my ignorance but how do you plot a frequency response chart/curve when there is no sound?

Regards
Rajiv

 

[virajsingh]

Hi,


Pardon my ignorance but how do you plot a frequency response chart/curve when there is no sound?

Regards
Rajiv

I was thinking that if the TT is indeed poorly made then the wow and flutter and the vibration around the spindle would cause the cartridge to pick them up and we would have it show up on the frequency response curve. For a good TT setup there should ideally be no frequency response curve. The idea behind the blank LP was that it should show no frequency response....if we do have frequency response curve then its variation from zero tell us how bad the TT is.

 

[reignofchaos]

What if a turntable aces this test completely but sounds pathetic when actual music is played? Say it has very uneven treble response when music is being played. Would you classify that as a good or poor turntable?

 

[Saket]

Sometimes I really feel that we, in a quest to get better & better and improved machines, tend to go too deeper that what is really required to..umm...what do I say....to enjoy the music. We tend to get obsessed with the technicals behind the machine so much at times & may be in turn forget the music itself.
Frankly speaking, I do not notice any rumble/noise in my listening sessions that I enjoy on my moderate Technics set-up. Also, I have 2 idler driven philips sets with ceramic cartridges. Of course there is difference in sound quality and I will not dare compare My Shure M44-7 on Technics with the 'hapless' philips GP204, but I dare to state that I never hear any noticeable wow or flutter on my philips too. My Technics has a great accuracy being a quartz lock with Wow rated at 0.025% WRMS or 0.035% peak weighted using a Test record (0.012% WRMS measuring directly from the motor frequency generator) that beats many mid-high end TTs (on these specs). Rumble rated @ -78db. Anybody including audiophiles would be severely impressed by these numbers. I don't have any specs for both of my Philips 633 or 832 . But I am sure that philips won't stand a chance against these tight figures of Technics if compared by just the numbers. But audibly there is hardly any noticeable difference in speeds.
I have older HMV players where rumble is very prominent, no doubt about that. These players could do exponentially well if given better motors, idler pulleys, gear mechanisms, platter, mats, nice suspension & tonearm coupled with nice base. These modifications will work wonders & improvement will be exponential. But how would you improve them further 'Exponentially'?? Whatever small and may be expensive mods that you apply to them, it will raise the bar in miniscule levels after a 'saturation point'.
The answer according to me is, after getting it to a level perfect, its too hard to tell any difference between a 500USD TT and a 1000USD TT in my opinion.
As it is famously said, its tough to improve perfection!

Just my 2 cents....I will take the criticism if anybody disagrees with the point that I am trying to make. No offence to anyone meant.

Regards,
Saket

 

[virajsingh]

What if a turntable aces this test completely but sounds pathetic when actual music is played? Say it has very uneven treble response when music is being played. Would you classify that as a good or poor turntable?

It was for this reason that I had suggested that the test be repeated with "reference LPs of various genres and by comparing the chart we would come to know if the difference in frequency response (Chrat A- Chart B = Chart of difference in frequency response) is significant or not(and 'significant' can be defined scientifically say + - X% variation)."

The uneven treble response should be apparent when we compare Chart A with B as mentioned above for a particular reference LP and we could try this over a variety of reference LPs to establish if a TT setup is indeed better another one. The idea is to have besides subjective assessment to have empirical evidence to convince people to spend considerably more on buying the so called reference TTs.

 

[Thad E Ginathom]

A member comes here, suggests objective testing of TT vinyl sound, and expects to get out alive? :lol:

I don't think a "silent" LP is going to reveal anything other than the noise floor of that particular LP added to the playing chain. Otherwise, are there not TT setup discs? Do our major TT freaks not do this kind of stuff?

The only way to measure correct speed, wow and flutter is to play a sound of known frequency and measure what comes out of your speakers. Probably, the accuracy with which those speed-test disks that look as if they are not moving when the speed is right is enough, but ...if you want to invest in some sentsitive test gear, then a PC, sound card, mic and mic pre-amp would be the starting point. Hours of endless fun watching oscilloscope-like displays!

What if a turntable aces this test completely but sounds pathetic when actual music is played?

If the test was done by an engineer who knew how to interpret the various squiggles on that screen, it almost certainly wouldn't fail the real-music test. But how could we measure like that?

Frequency response, also, is but one component --- and, as long as it exceeds the 20-20k parameter, more is not necessarily going to mean better. Didn't I read somewhere recently that, for instance, a speaker that does 50-16k really well is probably a better speaker than one that does 20-20k not so well?

I'm told that every cartridge has a unique sound signature. That is going to be a matter of personal choice, whatever the measurements say, and interpreting and applying the measurements would be a really specialist job.

 

[reubensm]

Sometimes I really feel that we, in a quest to get better & better and improved machines, tend to go too deeper that what is really required to..umm...what do I say....to enjoy the music. We tend to get obsessed with the technicals behind the machine so much at times & may be in turn forget the music itself.
Frankly speaking, I do not notice any rumble/noise in my listening sessions that I enjoy on my moderate Technics set-up. Also, I have 2 idler driven philips sets with ceramic cartridges. Of course there is difference in sound quality and I will not dare compare My Shure M44-7 on Technics with the 'hapless' philips GP204, but I dare to state that I never hear any noticeable wow or flutter on my philips too. My Technics has a great accuracy being a quartz lock with Wow rated at 0.025% WRMS or 0.035% peak weighted using a Test record (0.012% WRMS measuring directly from the motor frequency generator) that beats many mid-high end TTs (on these specs). I don't have any specs for both of my Philips 633 or 832 . But I am sure that philips won't stand a chance against these tight figures of Technics if compared by just the numbers. But audibly there is hardly any noticeable difference in speeds.
I have older HMV players where rumble is very prominent, no doubt about that. These players could do exponentially well if given better motors, idler pulleys, gear mechanisms, platter, mats, nice suspension & tonearm coupled with nice base. These modifications will work wonders & improvement will be exponential. But how would you improve them further 'Exponentially'?? Whatever small and may be expensive mods that you apply to them, it will raise the bar in miniscule levels after a 'saturation point'.
The answer according to me is, after getting it to a level perfect, its too hard to tell any difference between a 500USD TT and a 1000USD TT in my opinion.
As it is famously said, its tough to improve perfection!

Just my 2 cents....I will take the criticism if anybody disagrees with the point that I am trying to make. No offence to anyone meant.

Regards,
Saket

+1 to your statement, just put on a record, sit back and enjoy it.

Technics DD TTs are a marvel of engineering, without doubt. Near perfect. When I had done a comparison between my Dad's Garrard SP25 Mk1 with Shure M75-6 and my Technics SL3200 with Shure M44-7, the sound on the Garrard was a bit more rich and bassier. I would dare attribute the richness to the vintage Shure cart and the bass to the idler of the Garrard.

However, I am from the generation (as was my Dad) who believe that good amplification can make an ordinary turntable sound great. By experimenting with the equalization of the phonostage, we were able to achieve some credible results using an ordinary EEI Ceramic cartridge with sapphire stylus. However the purists would not agree with this approach and prefer to work towards accurate response at source.

Finally, from pure experience, getting accurate curves on an oscilloscope display or matching threshold standards is one thing and getting sound that pleases you, is a different thing. Sometimes, the most un-conventional of approaches, defying all conventional logic, produces the result of a lifetime.

 

[virajsingh]

Guys the short point of starting this discussion is that how do we know that one TT is 'better' than the other (or for that matter in case of a speaker "a speaker that does 50-16k really well is probably a better speaker than one that does 20-20k not so well"; how to be establish it other than by just relying auditory perception of a disparate group).

I am totally in agreement that my music is what it is to me and if i like what i am hearing the equipment does not matter. But we all like in this age where people compare one with the other and the discriminating point is the more it cost the better it is.....I have heard some high end gear here in Delhi and frankly i could not really find it 'way better' than some of comparatively modest setups I have heard (including mine)...so I am wondering if some guys are being taken to the cleaners when they are buying the hi-end stuff at fantastic prices.

......and finally the frequency response curves of different TTs ceteris paribus should tell us something about the TTs we are comparing.

...and not for a minute do I intent to sit infront of an oscilloscope or diy frequency testing rig ....neither do I have the time, money or the patience to do so.

 

[virajsingh]

Thought this might interest you guys

"Bob Carver caused a stir in the industry in the mid-1980s when he challenged two high-end audio magazines to give him any audio amplifier at any price, and hed duplicate its sound in one of his lower cost (and usually much more powerful) designs. Two magazines accepted the challenge.

First, The Audio Critic chose a Mark Levinson ML-2 which Bob acoustically copied (transfer function duplication) and sold as his M1.5t amplifier (the t stood for transfer function modified).

In 1985, Stereophile magazine challenged Bob to copy a Conrad-Johnson Premier Five (the make and model was not named then, but revealed later) amplifier at their offices in New Mexico within 48 hours. The Conrad Johnson amplifier was one of the most highly regarded amplifiers of its day, costing in excess of $12,000.

Of note that in both cases, the challenging amplifier could only be treated as a black box and could not even have its lid removed. Nevertheless, Carver, using null difference testing, successfully copied the sound of the target amplifier and won the challenge. The Stereophile employees failed to pass a single blind test with their own equipment in their own listening room. He marketed t versions of his amplifiers incorporating the sound of the Mark Levinson and Conrad Johnson designs which caused him some criticism by those who failed to understand the true nature of the challenge that it was possible to duplicate an audio amplifier's sound in two completely dissimilar designs. In light of this criticism, Carver went on to design the Silver Seven, the most expensive and esoteric conventional amplifier up to that time and duplicated its sound in his M 4.0t and later models which sold for some 1/40th the price (around $600$1500)"

Just wondering if it mean that the guys who were buying the mark levinson and conrad jhonson were in effect being taken to the cleaners....

 

[malvai]

On the whole, i agree that one does not need to spend multi million $$$ to get superb sound....

as far as TT's are concerned there are many ways to break an egg... which way works for you-- works!

i feel that the average Technics SL 1200/1210 is superb design... imagine if it were not!

DJ's use them on amplification that is in excess of 10,000 watts! if there were wow, flutter and rumble... that would show up wouldn't it???

At least that is what my brother says (he is a leading DJ of the country -- he just played at Big B's 70 B'day bash! and yes he carried his Technics 1200 mk2)...

add to this, the fact that just a few tweaks like a better tonearm, better cart (than Shure) a good phono and some tweaks to the plinth the 1200/1210 can take on TT's that are in the range of the $10,000 mark... but then, thats my 2 paisa... you can disagree!

 

[Thad E Ginathom]

Guys the short point of starting this discussion is that how do we know that one TT is 'better' than the other (or for that matter in case of a speaker ...

Or for that matter, any other hifi component.

Blind comparison. Blind testing is the key. There is no other way to get around human psychology, and it does not matter whether that psychology is a newbee, a die-hard audiophile, or an experienced engineer.

For some reason, the idea makes people scream; I don't understand why.

I recommend NwAVguy's and Sean Olive's writings for starters. Interestingly, the first is a non-commercial hobby engineer/designer and the second is a big man in the Harmon/JBL organisation. Two very different backgrounds.

 

[Saket]

I congratulate our Forum members.
In my opinion, they have really contributed some material thoughts coupled with their creativity & imagination to this thread. Also not to mention that most being true audiophiles, have based their replies on very practical experiences and most importantly practical approach.

Long Live Hifivision!

Regards,
Saket

 

[virajsingh]

At least that is what my brother says (he is a leading DJ of the country -- he just played at Big B's 70 B'day bash! and yes he carried his Technics 1200 mk2)...

add to this, the fact that just a few tweaks like a better tonearm, better cart (than Shure) a good phono and some tweaks to the plinth the 1200/1210 can take on TT's that are in the range of the $10,000 mark... but then, thats my 2 paisa... you can disagree!

Thanks Manav....I have know that my Technics is great but occasional confirmation and examples like the one about your brother above do keep my ego massaged....Maybe we need more Bob Carvers to clear the attitude we are being fed that 'more expensive is better...'

 

[Saket]

At least that is what my brother says (he is a leading DJ of the country -- he just played at Big B's 70 B'day bash!

That's great disclosure Malvai...Great to know.:clapping::clapping:

 

[jls001]

Thanks Manav....I have know that my Technics is great but occasional confirmation and examples like the one about your brother above do keep my ego massaged....Maybe we need more Bob Carvers to clear the attitude we are being fed that 'more expensive is better...'

Origin Live has Twelve Hundred specific mods that is claimed to take performance to a much higher level. In fact there are many other such firms too.

 

[kuruvilajacob]

I have played several of my turntables in my listening room. These include 2 Garrard 301s, Thorens TD 125, AR The Turntable,Lenco L 75,Denon DP-60L, Thorens Jubilee,Technics SL-1200,Thorens TD-150,Onkyo Integra CP 1057 ,Sony PS X 60 and a few other lesser known TTs. Of course, all of them fitted with either original arm or others and different carts etc. I have invited some of my friends also to compare these TTs. I have found that TTs with high torque like the Garrards, Lenco and Technics SL 1200 will easily outperform others in any parameter you take . The only player which has come to this elite group with a lower torque is AR. I am not saying that the other players are inferior in performance. In my opinion, and experience, torque plays a very important role in delivering the correct timing which makes these players sound more lively and natural . This is only my observation and could be subject to dispute among the fellow FMs
kuruvilajacob

 

[entsurgeon]

qouting from the murphy s law" the first 90% of any job requires 10%of efforts and resources. the last 10% of the job requires 90%." make that 95% and 5% respectively! but its that last 5% that makes all the difference. so if you are in search of perfect sound , please, before getting down to such finicky levels , work 5% for the following sub sets of audio realm:
1 components- these days, home audio systems are getting rarer due to portable/digital media players. if you are setting up a music system, you belong to an elitist group elite being defined more by your researches rather thn just the money you spend. research in advance on what to buy and what to match. read reviews and believe the general concensus. theres a reason experts are respected in every field.
2 set up- you can mess up the best of components by the way you place them. nuff said.
3. room treatment- if you know somebody who owns a multiplex, preferably with a small hall, take your system to its hall and set up. try replicating 95% or even 90% of the acoustic improvement at your home. may not really be achived in just 5% resources but it will give exponential result.
4- feed best quality source signal you can afford. rotten meat wont make a great mughlai.
5- for your mental satisfaction, keep fiddling with your tt cart et al. it wont noticaebly improve sound ( without fiddling with any of the above). but will give you enough to entertain your grandkids on how you were a genius audiophile who ,from his 2500$ system, got better sound than a 15000$ system.
ps1:
everyone here had different things to say and i agree with all.
ps2:
we already have 'blank ' lps at every rack. its the last groove of your lp. pray you dont have a self stopping tt.
ps3: apropos ps2^^- does this last groove of lps damages the needle in long term bros???

 

[jls001]

From http://www.kabusa.com/myth5.htm:

Quote:
Some important measurements:

Wow and Flutter (weighted and weighted peak)
Speed accuracy and drift
Rumble (weighted and unweighted)
Tonearm bearing friction
Plinth resonance testing
Phono cartridge stylus dimensions
Phono cartridge stylus effective tip mass
Phono cartridge tracking ability

....
Static and dynamic stylus drag

Unquote:

To the above, it would be real nice to have:
how much percentage of the vibration caused by the motor that travels to the plinth:

(a) is absorbed by the vibration damping mechanism employed (springs, some fancy plinth material, constrained layer damping plinth, rubber ball suspension, and no damping)?

(b) eventually reaches the tonearm and the cartridge to cause unwanted feedback on playback? How they differ for damped arms and undamped arms? How they differ from suspensionless cartridges and those with suspension.

 

[Saket]

these days, home audio systems are getting rarer due to portable/digital media players. if you are setting up a music system, you belong to an elitist group elite being defined more by your researches rather thn just the money you spend.

Couldn't agree more to it.