Technics SL1000 MK3 (SP10 MK3) performance/value VS modern turntables?

@jpjones3318

Hi Dover,

The Technics "Quartz Locked" units utilize PLL motor control.

So you believe the frequency generator, speed and phase control circuits meet current state of the art performance do you, even though the SP10 uses 70’s chips and we now have chips capable of switching at a trillionth of a second, and computer power millions of times faster today ??

If indeed the SP10mk3 controller is as crude as described in their advertising - then basically it is correcting instantaneously any speed deviations calculated using data generated from those 70’s chips.

It is no different to digital jitter in my view. The advertising implies there is no smoothing of the error correction.

I note that Technics again claim in their advertising that the higher platter mass of the mk3 ( 10kg ) is key in generating a more stable FG used in the speed and phase control circuits.

By comparison the Victor 101 calculates the error over a period of time and feeds the correction in over a period of time to "smooth" the correction.

Also as you would know the L07D relies on platter mass for stability, the error correction only kicks in when the speed deviation is beyond quite a wide range.

It is clear that Technics, Victor and Kenwood, 3 of the supposed best direct drive TT’s from the 70’s, had 3 quite different views on how best to implement speed control of the platter.

They must have had 3 disparate views on how speed control circuits affect sound quality.

Since I believe you own all three decks - I would be curious to know if you believe they each have a sonic signature.

I have heard multiple SP10mk3’s and L07D’s and each motor has a signature sound to my ears that is readily identifiable irrespective of arm/cartridge. I have not heard the Victor, but I have heard the Thrax which I believe uses similar principles to the Victor 101 in the way the error correction is implemented.

Hi @dover - hope you've been well. 

So you believe the frequency generator, speed and phase control circuits meet current state of the art performance do you, even though the SP10 uses 70’s chips and we now have chips capable of switching at a trillionth of a second, and computer power millions of times faster today ?? 

If indeed the SP10mk3 controller is as crude as described in their advertising - then basically it is correcting instantaneously any speed deviations calculated using data generated from those 70’s chips.

It is no different to digital jitter in my view. The advertising implies there is no smoothing of the error correction.

This implies, as did your previous comment, algorithms, prediction, data, computational error, etc.  In other words, computing.

The SP-10MK3 uses analog PLL speed control.  Computing in the sense you conveyed is simply not relevant here, and as such your claimed deficiencies are also not relevant.  

I note that Technics again claim in their advertising that the higher platter mass of the mk3 ( 10kg ) is key in generating a more stable FG used in the speed and phase control circuits.

By comparison the Victor 101 calculates the error over a period of time and feeds the correction in over a period of time to "smooth" the correction.

FG is the speed proportional feedback from the motor, so I don't understand what you mean by 'more stable', as frequency stability of the FG is directly proportional to speed stability.  

The platter mass is a low pass filter, hence 'smoothing'.  Not to say that low mass platters are drastically inferior - it's a system where the components are designed to work with each other. 

The 101 is also analog PLL controlled. The lighter platter works well with the low torque of the coreless motor, and the PLL is tuned for such.  There's no 'calculating' error over time or applying correction over time, aside from the bandwidth, gain, and filtering of the system, as with any PLL implementation. 

Also as you would know the L07D relies on platter mass for stability, the error correction only kicks in when the speed deviation is beyond quite a wide range.

I know that's been claimed on L-07D.com, and I also know it's a false statement, or at least a very confused one:

"The PLL system plays backup, only being activated when platter speed varies by +/- 3.7% at 33.33 rpm or +/- 5.0% at 45 rpm. Within that range, PLL is maintained and the controller makes no speed corrections. Motor speed is regulated by a quartz crystal (vibrating at 5.5296 MHz) to precisely 33.33 or 45 rpm with zero tolerance."

The first sentence says PLL plays backup within the range yet the second sentence says PLL is maintained within the range.   Can't have it both ways. It's just another analog PLL motor control circuit, though with a couple of unique features. 

It is clear that Technics, Victor and Kenwood, 3 of the supposed best direct drive TT’s from the 70’s, had 3 quite different views on how best to implement speed control of the platter.

They must have had 3 disparate views on how speed control circuits affect sound quality.

They all put a different spin on analog PLL motor control, but they're not necessarily that different.  They clearly couldn't implement motor control the same way due to IP, and they'd presumably want to achieve real and/or marketable differentiation.

Since I believe you own all three decks - I would be curious to know if you believe they each have a sonic signature.

You tell me how to eliminate all variables such that only the motor control implementation is different and I'll tell you if I think there's a sonic signature between them. 

I own a Mk3, an L07D, and a TT101. I listen to each of these regularly. They do have a very subtle sonic signature I think, but the last thing I would do would be to try to describe it in words, for one thing because of the factors that JP mentions. Moreover, the differences that may apply are very subtle and certainly would not include a perceptible issue with speed stability. What I wonder, however, is why Dover is so intent upon discrediting these vintage turntables. It’s all very well to love and prefer whatever it is that you own over all other TTs, but why does that require that all other solutions to the problem of playing a record are wrong or sub par? If you want to say that direct drive turntable X is superior in speed stability to these vintage direct drive turntables and in the same price range, that would be very interesting, and I would like to hear about it.

I want to retract my criticism of Dover for his dumping on vintage direct drives.  He has a perfect right to say what he wants, and thanks to JP Jones for his informative responses to Dover's points. On the question of the L07D servo, I think it does say in some vintage factory literature that the servo is only activated when there is a fairly significant deviation from correct speed.  Having read that, I came to think of the L07D as an attempt to achieve constant speed partly through the use of a heavy platter, a la many belt drive turntables.  While the platter is not very heavy, as compared to some behemoths found on belt-drive turntables, it does have its weight concentrated at the periphery, so as to maximize any flywheel effect, and Kenwood did also supply an optional fairly heavy peripheral ring to add to platter mass where it does the most good.  When you use that ring, you also engage a switch on the power supply that changes the operation of the servo circuit.

@jpjones3318



I think you misunderstand the point I'm making - I'm not saying the Technics is "computing" - I'm saying the speed measurement and correction  system is built on old technology. Your own improved chip replacement circuit has already demonstrated measureable improvements are possible.

Even the reference quartz crystal can be producted to much higher tolerances today.

At the end of the day do you agree that in principle the FG servo is a negative feedback system that corrects speed anomalies - right ?

Quartz reference crytals have inherent jitter - right ?
The PLL circuit has filter out the jitter to deal with this - right ?

Re the Victor TT101 - the averaging of speed errors and correction system, I dont have time to trawl the net - this was based on comments by both an owner and a designer of a current production high end direct drive.

Sound of the TT's

With regards to the SP10mk3 and L07D - 
I have friends that own these and have listened to them for over 30 years with a myriad of arms/cartridges. Also had them in my own system.
If I were to summarise their sonic attributes - to my ears the SP10mk3 consistantly presents a leaner, cleaner more precise presentation. The L07D to my ears consistantly sounds slightly courser, slightly less precise.

I cant say this is due solely to the speed correction systems, because the mechanical structures, including platter, plinth and mounting are substantially different.

But I can say that the differences are consistant and audible to me across muiltiple systems - enough to blind test and identify each deck in a system that I know.