Wow and flutter on recordings and TT's combined

[cocoabaroque]

The flutter with an LP12 most certainly IS audible! Those primative early Hurst motors were attached with only 2 flimsy screws and had considerable vibration and cogging. The belt absorbed a small amount of the vibration, and the platter smoothed out some of the problems, but not nearly enough when compared to an Oracle Delphi, or idler drive ROK. I do not dislike the Linn or Thorens approach-- quite the contrary-- I think they are excellent designs given the tools available in the 1970s and 80s. As a system, the sub-chassis suspension provided a good means of isolation, lowered mid and high frequency noise, improved dynamics, etc. Sub-chassis designs sound great, they obscure faults and are alot of fun, but if you are unable to discern subtle changes of pitch, something is amiss. A simple test record between turntables would be an easy comparison, or perhaps organ music, or a slow piano passage-- all without vibrato or tremolo. The added flutter distortion will be immediately obvious by direct comparison. This is one reason why AC regenerators are used for turntables today--even the subtle, careful reclocking of the 60 cycle mains makes a noticable difference in motor stability (flutter). Its also the reason why VPI TNT platters are so massive-- far more than the light-weight LP12. Stretchy rubber belts have also been upgraded to dental floss or mylar tape with good effect.

[pogo]

The flutter with an LP12 most certainly IS audible! Those primative early Hurst motors were attached with only 2 flimsy screws and had considerable vibration and cogging. The belt absorbed a small amount of the vibration, and the platter smoothed out some of the problems, but not nearly enough when compared to an Oracle Delphi, or idler drive ROK. I do not dislike the Linn or Thorens approach-- quite the contrary-- I think they are excellent designs given the tools available in the 1970s and 80s. As a system, the sub-chassis suspension provided a good means of isolation, lowered mid and high frequency noise, improved dynamics, etc. Sub-chassis designs sound great, they obscure faults and are alot of fun, but if you are unable to discern subtle changes of pitch, something is amiss. A simple test record between turntables would be an easy comparison, or perhaps organ music, or a slow piano passage-- all without vibrato or tremolo. The added flutter distortion will be immediately obvious by direct comparison. This is one reason why AC regenerators are used for turntables today--even the subtle, careful reclocking of the 60 cycle mains makes a noticable difference in motor stability (flutter). Its also the reason why VPI TNT platters are so massive-- far more than the light-weight LP12. Stretchy rubber belts have also been upgraded to dental floss or mylar tape with good effect.

if someone had claimed that wow and flutter are never audible this might be relevant. But as it is your post has nothing to do with the question asked by the OP. Your one response to the question that was asked was incorrect.

[steve195527]

The flutter with an LP12 most certainly IS audible! Those primative early Hurst motors were attached with only 2 flimsy screws and had considerable vibration and cogging. The belt absorbed a small amount of the vibration, and the platter smoothed out some of the problems, but not nearly enough when compared to an Oracle Delphi, or idler drive ROK. I do not dislike the Linn or Thorens approach-- quite the contrary-- I think they are excellent designs given the tools available in the 1970s and 80s. As a system, the sub-chassis suspension provided a good means of isolation, lowered mid and high frequency noise, improved dynamics, etc. Sub-chassis designs sound great, they obscure faults and are alot of fun, but if you are unable to discern subtle changes of pitch, something is amiss. A simple test record between turntables would be an easy comparison, or perhaps organ music, or a slow piano passage-- all without vibrato or tremolo. The added flutter distortion will be immediately obvious by direct comparison. This is one reason why AC regenerators are used for turntables today--even the subtle, careful reclocking of the 60 cycle mains makes a noticable difference in motor stability (flutter). Its also the reason why VPI TNT platters are so massive-- far more than the light-weight LP12. Stretchy rubber belts have also been upgraded to dental floss or mylar tape with good effect.

If you decide a piece of equipment produces a certain effect its pretty easy to convince yourself that you can and are hearing that effect!thing is with a Linn or any TT with a substantial platter the fly-wheel effect of the mass negates any problems the motor may cause,engineers have been using this mass effect long before electrics were used to control speed variations

[cafe latte]

I dont agree Steve as wow is really very audable if you are sensitive to it it is not a case of convincing your self you can hear it, if you can you can which is why I like Technics as they to me at least have inaudable wow.
Regards
CL

[Trackside]

I would suspect that the combination of tape master wow, record off center wow and turntable drive mechanics wow is so random as to never conicide, and therefore the worst example of wow would be limited to which of those three sources has the worst deviation.

Each of those sources of WOW will by cyclic and non random and thus it's a certainty that they will coincide in the way described.

Nonsense. I suggest you understand catsquirrel's post. There will be an rms value of wow in the output of the final playback system. It will include components from all sources, but will not be = to the sum of those components. The idea that because they are all cyclic (what I would call periodic) they will obviously coincide is, well, nonsense. do you think that 2hz wow can coincide with 2.3 hz wow? (I'm assuming by conincide you mean be directly additive) BTW, as sources go, wiki is my last go to followed closely by special interest forums -- naming no names. To be fair both sources contain a lot of good information, but if you don't already know enough to sort the good info from the nonsense, then they're worthless.

2 different low frequencies played together will 'beat' - a fairly well known and understood phenomenon that does not require a wikilink.

[Trackside]

The flutter with an LP12 most certainly IS audible! Those primative early Hurst motors were attached with only 2 flimsy screws and had considerable vibration and cogging. The belt absorbed a small amount of the vibration, and the platter smoothed out some of the problems, but not nearly enough when compared to an Oracle Delphi, or idler drive ROK. I do not dislike the Linn or Thorens approach-- quite the contrary-- I think they are excellent designs given the tools available in the 1970s and 80s. As a system, the sub-chassis suspension provided a good means of isolation, lowered mid and high frequency noise, improved dynamics, etc. Sub-chassis designs sound great, they obscure faults and are alot of fun, but if you are unable to discern subtle changes of pitch, something is amiss. A simple test record between turntables would be an easy comparison, or perhaps organ music, or a slow piano passage-- all without vibrato or tremolo. The added flutter distortion will be immediately obvious by direct comparison. This is one reason why AC regenerators are used for turntables today--even the subtle, careful reclocking of the 60 cycle mains makes a noticable difference in motor stability (flutter). Its also the reason why VPI TNT platters are so massive-- far more than the light-weight LP12. Stretchy rubber belts have also been upgraded to dental floss or mylar tape with good effect.

I'm not disputing the early LP12 and other suspended subchassis designs have pitch instability (wow not flutter), my post is to do with how pitch instability inherent in a recording and the vinyl itself interacts with that produced by the turntable.

[Trackside]

The flutter with an LP12 most certainly IS audible! Those primative early Hurst motors were attached with only 2 flimsy screws and had considerable vibration and cogging. The belt absorbed a small amount of the vibration, and the platter smoothed out some of the problems, but not nearly enough when compared to an Oracle Delphi, or idler drive ROK. I do not dislike the Linn or Thorens approach-- quite the contrary-- I think they are excellent designs given the tools available in the 1970s and 80s. As a system, the sub-chassis suspension provided a good means of isolation, lowered mid and high frequency noise, improved dynamics, etc. Sub-chassis designs sound great, they obscure faults and are alot of fun, but if you are unable to discern subtle changes of pitch, something is amiss. A simple test record between turntables would be an easy comparison, or perhaps organ music, or a slow piano passage-- all without vibrato or tremolo. The added flutter distortion will be immediately obvious by direct comparison. This is one reason why AC regenerators are used for turntables today--even the subtle, careful reclocking of the 60 cycle mains makes a noticable difference in motor stability (flutter). Its also the reason why VPI TNT platters are so massive-- far more than the light-weight LP12. Stretchy rubber belts have also been upgraded to dental floss or mylar tape with good effect.

If you decide a piece of equipment produces a certain effect its pretty easy to convince yourself that you can and are hearing that effect!thing is with a Linn or any TT with a substantial platter the fly-wheel effect of the mass negates any problems the motor may cause,engineers have been using this mass effect long before electrics were used to control speed variations

Mass certainly reduces the frequency of variation but can't entirely eliminate it. Particularly in the case of a suspended subchassis like the LP12 where the additional factor of the lower mass arm and subchassis which are free to rotate around the platter adding other pitch changes. Indeed it may well be true that the platter rotates very smoothly in relation to the plinth but subtle changes in the stylus speed in the groove are caused by the rotation or oscillation of the sub platter and arm pivot.

[duficity]

trackside,
Ok, so a cutting table has a wow of 2hz, the tape recorder a wow of 3hz and the turntable a wow of 4hz and the offcenter has a wow of 1.5hz you suggest that it is certain that they will coincide and be additive. I suppose the 2hz and 4 hz wows will match every second revolution if they start at the same time, but otherwise not if they are truly cyclic and non random. But I think motor wow is unlikely to be cyclic in the same way as off center wow would be. Sorry, dont buy it.

[Trackside]

Additive in the sense that where the different cycles or frequencies 'beat' with each other there is inevitably going to be an increase in amplitude or volume to the signal. Is it possible that our ears could not mistake this variation during a constant tone to be a variation in frequency? Some cyclic variations will be random but many are known to be regular, some may cancel each other out and some may 'beat' - I'm not saying it's fact but it is a possibility given the well understood phenomenon of low frequency tones of slightly different frequencies 'beating'. I was trying to open up a debate with the hope of some technical input but if you choose to dismiss it then fine

[steve195527]

I dont agree Steve as wow is really very audable if you are sensitive to it it is not a case of convincing your self you can hear it, if you can you can which is why I like Technics as they to me at least have inaudable wow.
Regards
CL

I was meaning flutter on the LP12 or similar type turntables as commented on by the post quoted,wow can be an issue with any turntable I agree and is def audible:-one thing you could guarantee about the early technics DD turntables before they started using a quartz lock system was that they never ran at the correct speed and hunted like someone on safari!

[cafe latte]

Mine is a mk2 .
Regards
CL

[steve195527]

The flutter with an LP12 most certainly IS audible! Those primative early Hurst motors were attached with only 2 flimsy screws and had considerable vibration and cogging. The belt absorbed a small amount of the vibration, and the platter smoothed out some of the problems, but not nearly enough when compared to an Oracle Delphi, or idler drive ROK. I do not dislike the Linn or Thorens approach-- quite the contrary-- I think they are excellent designs given the tools available in the 1970s and 80s. As a system, the sub-chassis suspension provided a good means of isolation, lowered mid and high frequency noise, improved dynamics, etc. Sub-chassis designs sound great, they obscure faults and are alot of fun, but if you are unable to discern subtle changes of pitch, something is amiss. A simple test record between turntables would be an easy comparison, or perhaps organ music, or a slow piano passage-- all without vibrato or tremolo. The added flutter distortion will be immediately obvious by direct comparison. This is one reason why AC regenerators are used for turntables today--even the subtle, careful reclocking of the 60 cycle mains makes a noticable difference in motor stability (flutter). Its also the reason why VPI TNT platters are so massive-- far more than the light-weight LP12. Stretchy rubber belts have also been upgraded to dental floss or mylar tape with good effect.

If you decide a piece of equipment produces a certain effect its pretty easy to convince yourself that you can and are hearing that effect!thing is with a Linn or any TT with a substantial platter the fly-wheel effect of the mass negates any problems the motor may cause,engineers have been using this mass effect long before electrics were used to control speed variations

Mass certainly reduces the frequency of variation but can't entirely eliminate it. Particularly in the case of a suspended subchassis like the LP12 where the additional factor of the lower mass arm and subchassis which are free to rotate around the platter adding other pitch changes. Indeed it may well be true that the platter rotates very smoothly in relation to the plinth but subtle changes in the stylus speed in the groove are caused by the rotation or oscillation of the sub platter and arm pivot.

If a suspended sub-chassis design is executed well the arm/platter and sub-chassis should behave as one item(ignoring machining tolerances)the motor attached to a different part unsuspended of the deck needs a compliant belt to let this type of design work:-it has to be compliant enough to absorb the cogging affect of the motor and the noise/vibrations in the audible band,if the motor is quiet enough AND speed stable enough and attached to the sub-chassis then a less compliant belt can be used
As for the wow in recording chain being compounded by wow in the playback system I can't say I have really ever thought it a problem in the time I have been listening to albums(40 odd yrs)

[Trackside]

'Executed well' being the crucial phrase - some are some are not.

[cocoabaroque]

We are discussing percieved variation in pitch here-- wow and flutter and its impact on the music. Most of us can hear a quarter-tone difference in pitch, fewer of us can detect an eighth-tone or smaller difference without musical training. New students of violin and guitar, for example may have great difficulty tuning the instrument, especially as the pitch-increments get smaller, but more advanced musicians can easily hear them. This is why trained musicians do not need auto-tuners, they just listen for the correct pitch. I agree with Cafe Latte, small amounts of wow and flutter are clearly audible to me, although may be not to everyone. So regarding the original question, perhaps the threshold of detection for additive amounts of wow and flutter has less to do with theoretical or measured speed fluctuations and more with the individuals ability to hear it.