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In Reply to: RE: For non-DJ buyers... posted by Mr. Dick Hertz on January 02, 2017 at 09:33:15
Should have offered the DJ TT and a SP-12 (LOL) that is an update of the SP 10 for audiophiles that doesn't cog. It would have an SME mount, no arm, or one purpose-built from SME like Oracle. Just my opinion.
The "new" electronics are supposed to be good but who the heck are their marketing people?
Follow Ups:
For iron-core motors, like the ones Technics used back in the late 70s, it's all in the number of poles. The more poles, the less cogging would be detectable. Also, I suppose it depends upon the sensitivity of the instruments used to detect cogging. Anyway, I think that what some DD critics describe as "cogging" is actually due to the action of the servo to maintain exact speed. This is true of the SP10 Mk2. The SL1200G now uses a coreless motor, which IMO is a major upgrade over the old SL1200.
That is the exact configuration I would have liked to have seen too - make the arm optional for those who want or already own an arm of their own choice.
Incidentally, there is no measurable evidence of cogging with the SL1200. The silent groove spectral analysis from my recordings shows no evidence of cogging. The only notable frequency components that pop through are plinth and arm resonance related with arm/headshell related resonances around 230Hz - the effect of which is more or less pronounced depending on cartridge compliance.
In fact the vintage non-quartz locked SL-150 reviewed in HFNRR (Oct 2015) had an extremely clean W/F spectrum with a very sharp clearly defined peak with a peak wow of 0.02% and peak flutter of 0.03% and Paul Miller noted "....there are no cogging artefacts to sully the rumble or W&F spectra." I don't know about the SP-10, but it appears that the Technics engineers had solved the cogging issue back in the late 70s.
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
Hi Anthony. Would you be able to post any pics of the plinth and tonearm/headshell ressonances, if you have these in graphic form that is? Especially the plinth - what frequency does it ressonate at?
You are right on the money Anthony. The SL1200 didn't cog and the new version doesn't either. This bugabear has been around since the 1970s, but no proof of it exists. Not in measurements as you report and not in double blind testing. The biggest difference I hear with the new G is that the new arm is a BIG improvement over the original. Removable headshell and all. Another nuance is that a better headshell improves the sound too. I have been comparing the OEM Technics with KAB and LP Gear's Zupreme headshells and the latter sounds the best.
Does cogging really exist in a 3-phase motor?
(As the motor in the SL1200 used to be).
I got my deck in the mid 90s and started experimenting with the different headshells - back then the Sumiko HS12 was the name on that design and they were priced similarly to the Zupreme before gradually increasing in price to obsolescence. I standardised on that design because of the azimuth adjustment and also because the headshell slots are the longest I have found which enables alternative LP optimised geometries to be achieved.
The other reason I liked it was because the plug axis is set "lower" than the Technics design (for the cartridge mounting plane) so a tall cartridge like a Stanton (using the 1mm mounting plugs) drops down to the middle of the arm adjustment range (rather than pushing up to the 5.25 to 5.5 range). You've also probably noticed that the cartridge mounting plane is parallel to the plug, whereas the Technics headshell has a specific upward tilt - although manufacturing tolerances are so wide you'll find the tilt all over the place; I even have some with a downward tilt!! An upward tilt is actually correct and you will see the reference angle on the L-jig.
Incidentally, getting back to the New arm, is the arm base diameter the same as the old one? I was talking to Kevin about this as the new design is not (yet) compatible with his damping trough kit and he himself hadn't gotten hold of one last time we corresponded. I was asking if the mounting plate is the same in which case we could drop a new arm in an old 1200....or an old arm in the new deck...but given what you've suggested that probably isn't the best option!
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
Anthony,
I have sold my old SL1200Mk2 so can't answer your question about the base diameter of the two arm mounting board dimensions. I had offered to send my GAE to Kevin for his evaluation, but he declined the offer. Timestep in the UK have developed mods for the new turntable with factory sanction in the form of an external PSU and the fitment of an SME Series IV arm. This was tested and reported on by Noel Keywood at HiFi World several months ago. It won rave revues although he made disparaging comments about the new arm without actually having one for comparison. Like I said, the new arm in impressive. It is brighter and has better articulation than the old one, but preserves the ease of setup and use of the original. To me the new arm is the big news and the reason to consider the new TT. BTW, the arm on the "G" was changed to magnesium just like the one on the "GAE."
With regard to the Zupreme headshell, your additional comments parallel my own observations. I would add that they are beautifully machined and equipped with double pins for mounting, which provides for a tighter fit of the headshell to the tonearm. The net effect of this can be observed on an "O" scope when playing certain test records. I use the Shure Era IV test disc. Using the Zupreme headshell provides performance similar to a fixed tonearm such as the one on my Prime with 3D arm.
Just a thought...which evil do we prefer.... cogging that is not audible to some or perhaps many or incorrect speed that changes with belt use, temperature etc. and must be corrected by regulation (VPI etc.) and may or may not be audible to some or many... Please note that with speed changes so does pitch change, however minor.
I guess my point is that a general take away I've had recently is that neither is desireable but the thought of note pitch actually being varied by speed flaws is upsetting...
I have two 1200s, a VPI Scout and an AE2008 (w/ SME 309) among others. I am about to take two Denon 103Rs and place one on the 1200 to compare or attempt to perceive which is really the greater arbiter of sound the cart or the TT/Arm (the second is on the AE2008 already). It will be interesting to see how these sound w/ the same cartridge. I will tell you that if the 1200 stands up the sound of the 2008 which is quite good, I may be making up my mind to choose direct drive over belt...
I know this is controversial but I mean no ill intent to start flames... I've been hoping to figure this out for my own purposes...it just bugs me that the most fundamental purpose of a tt is to play at the right speed... It drives me crazy to read the BS excuses in some of the magazines justifying why a 10K+ tt runs slightly fast or slow....really?
I'm glad a refined 1200 is now available!
"Please note that with speed changes so does pitch change"
Exactly!
For the benefit of anyone not already familiar with the term, in a motor, the cog (or detent) is defined as:
the point at which the center of the magnets perfectly line up with the ideal magnetic path through the poles.
The effect this has on the motor rotation depends on the pole construction.
With this in mind, it should therefore be clear that cogging isn't restricted to DD turntables....it applies to ANY motor. Therefore a belt driven turntable is vulnerable to cogging. The belt and the pulley ratio are what ameliorate the effect. However, the torque transmission changes with the belt tension which will be influenced by motor cogging. So motor cogging would manifest itself in higher wow and flutter figures.
Wow and flutter figures would therefore be the best measure to determine which was the turntable likely to give the best pitch stability.
When it comes absolute pitch stability, the SL1200 is certainly "up there" with the better decks. Absolute pitch level depends on how well the centre position of the pitch control pot was set initially (and can easily be reset - which I have done with mine), but the motor control does an excellent job.
Unless there is a fault in the motor drive somewhere, rest assured there is no cogging with the 1200! It hasn't been "solved" with the new model - it didn't exist before, but due to the popular misconception that all DD decks suffers from cogging, Technics would naturally draw attention to that as an "improvement" to encourage new sales. Certainly the wow and flutter figures given in the HFNRR review I saw show a small improvement over the original, but the original was already considerably better than the majority of belt driven decks that didn't have proper motor control.
Anyone in the press or elsewhere making claims of cogging with the 1200 is basing it on personal bias and not the facts. The HFNRR of the SL-150 I mentioned already showed that even without a quartz-lock based control system, the simpler drive control still didn't exhibit cogging.
However, if you ARE hearing pitch changes then I would point the finger first at an eccentric disc OR if the disc is a remaster or original analogue recording, then the pitch shift existed in either the recording itself or the playback of said recording during cutting...or even inherent to the lathe itself!
As I have mentioned before, there is zero evidence of cogging related artefacts in the spectral analysis of my recordings.
For me, the priority is consistency in performance and pitch stability. Any deck that is sensitive to temperature changes in the belt material etc is hopeless from the get go and the fact that the materials used are sensitive to the environment of use should already indicate that you are not going to be getting consistency over time.
Getting back to your experiment, remember that the DL103 is a lowish compliance cartridge and that the effective mass of the Technics arm (12g)is higher than the SM309 (9.5g) so would in principle be a slightly better match. The LF arm resonance value modulates the recovered signal so depending on how well damped the resonance is, you are going to get differing levels of colouration. The resonance of the 103 with the SME309 will be higher so the sidebands will be wider spaced around the central frequency/frequencies of the recovered signal. This will affect your perception and therefore is telling you more about the arm/cartridge match than the motor drive principle on the deck.
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
I will bear that in mind...back to the 1200 in regard to this; maybe best bang for the buck in terms of an upgrade path would be to focus on a consistent and easy means of changing the arm or a service to do that at reasonable cost with differnt options. Maybe that's something that Kevin at KAB would consider.
Last time I talked with Kevin, we spoke about that. He hadn't gotten hold of a 1200G at that stage. However, he already knew that the arm itself requires him to redesign his damping trough to accommodate the new shape.
You may have seen my post to Bill in another thread regarding the arm base dimensions. I had said to Kevin it would be cool to have the option of putting the new arm on the original deck and also asked him about the possibility of the PCB/motor as an upgrade, but Kevin said the internal space required is totally different so the arm is likely the only option for original owners.
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
I haven't seem Kevin in a while but i guess I should touch base with him in the near future...KAB is a great resource to us for sure!
I haven't seem Kevin in a while but i guess I should touch base with him in the near future...KAB is a great resource to us for sure!
nt
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