Vintage DD turntables. Are we living dangerously?

Perfect Speed?
Perfect Speed?

Just a note from the peanut gallery:
Halcro, you and Richard are actually in agreement. The statement from Feickert (or whatever was the outside source) was that record eccentricity will produce a regular irregularity in the frequency, forming a sine wave around the center frequency. Since one is interested in wow and flutter due only to tt platter speed variations, that sine wave must be filtered out or subtracted from whatever is the actual wave form. The remainder would constitute w and f due to the tt only. Ideally, that would leave a straight line, if wow and flutter due to the tt were zero. I think we can all agree on that, including you and Richard.

Lewm -
No they are not in agreement. Halcro does not accept that the deviations in the sine wave are wow and flutter ( as explained by Feickert ). Richardkrebs argued that the spikes were speed corrections generated by the TT error correction, but they could be caused by many things, all we know is that they are speed deviations.

Other than eccentricity wow and flutter can be caused by imperfections in the record surface ( you must have heard of warp wow ) and tonearm/cartridge issues. So your statement that "The remainder would constitute w and f due to the tt only" is not correct.

Dover, No one can be absolutely correct, except you. I should have remembered that from past experience. Not that I would argue with your obvious point here, your condescending attitude notwithstanding. Instead of "due to the tt only", I obviously should have written "due to factors other than LP eccentricity" or words to that effect. The point was subtracting out the sinusiodal noise due to LP eccentricity. Serenity now!

Dover has comprehension problems (as well as others) with both my statements and those of Markus who designed the Feickert software.
The spikes in the generated sinewave are NOT "speed corrections generated by turntable error correction".
They are simply part of the software program to compensate for non-centricity of the test record and the effect it has on the steady-state 3150Hz test tone.
The previous software plot ( which I included) does not include these spikes.
How anyone can interpret it otherwise is beyond belief. Markus is amused....
Why don't you contact him yourself Dover to explain your interpretations...?

Halcro,
I don't know what test record you're using, but this software, app, or whatever, is giving an erroneous impression. The TT101 has W/F 0.02% WRMS, and speed deviation of zero w/up to 120g VTF.

That W/F is at the limit of conventional testing ability. With a DIN 45 465 test disc w/locked groove and centering, you can test to 0.06% unweighted wow, if you have the program.

Below is a link to Kevin (KAB) talking about positional updating tables vs. linear frequency generators. It's not what we're discussing, but might give some perspective:
http://www.kabusa.com/myth2.htm

Regards,

Fleib,

You bring up a good point. There is no piece of equipment that can measure W&F of true absolute '0'. So at some point in this discussion, it is going to have to be accepted that the TT-101 is probably at that threshold of being
non-existent in this regard of 'measurable' W&F

10-28-15: Halcro
Dover has comprehension problems (as well as others) with both my statements and those of Markus who designed the Feickert software.
The spikes in the generated sinewave are NOT "speed corrections generated by turntable error correction".

Halcro, read my post again - I wrote

Richardkrebs argued that the spikes were speed corrections generated by the TT error correction, but they could be caused by many things, all we know is that they are speed deviations.

The statement you ascribe to me was an argument put forward by by Richardkrebs. The second half of my sentence states clearly that my view does not agree with this notion. It is not I that has a comprehension problem.

10-28-15: Halcro
They are simply part of the software program to compensate for non-centricity of the test record and the effect it has on the steady-state 3150Hz test tone.

That statement is not correct. That is not what Markus says. Markus says quite clearly

That's what the spikes are coming from: it's a superposition of eccentricity and "real" WOW and flutter.

In engineering "superposition" is the overlapping of waves.
It is very simple - the raw data graphs are the sine wave generated by eccentricity (a) PLUS the wow and flutter ( speed deviations ) (b). The software uses a notch filter to remove the sine wave generated by eccentricity.
In a nutshell the deviations from a pure sine wave ( the spiky aberrations in the raw data graph ) are the wow and flutter as Markus says..

To verify this I went to the Adjust+ website and downloaded their manual. On page 37

Please note: most vinyl records are not perfectly centered. You will often see periodical fluctuations of speed at an interval of 1.8 seconds. This is exactly the time for one revolution at 331/3 RPM. In order to mask these effects, the recorded data is filtered using a steep 0.55Hz notch filter (results beneath "Filtered at 0.55Hz"). But please bear in mind that problems with the turntable bearing probably may also cause similar fluctuation patterns at 0.55Hz. These are also attenuated by the notch filter. Both values – filtered and unfiltered - are displayed.

This extract from the manual confirms that the unfiltered graphs are a summation of both the wow & flutter due to eccentricity and the wow and flutter to to the playback system ( TT/arm/cartridge ).

Guess what - in my previous post I stated if a TT had a fault that resulted in a regular speed deviation, like a faulty bearing, this would be assumed to be eccentricity and not reported in the filtered graph. The manual confirms this.

Lewm, I do not intend to be condescending, but where errors have been made they should be corrected.

A good point guys...
I recall on another Forum where someone used the Feikert Speed App to measure a CD player (a theoretically perfect 3150Hz sine wave) yet it produced a frequency response chart very much the same as the TT-101 albeit with slightly smaller ripples.

Whilst we are talking up the benefits of SOME vintage DD decks in relation to speed consistency and low wow and flutter.....it is not to say that surprisingly good results can't be obtained from certain belt-drive turntables.
Here is the Frequency Plot for my Raven AC-2 which is almost as good as that for the Victor and is better than that of even the VPI Direct...😱
Compared to other belt-drive models like the Wilson-Benesch and George Warren that I showed previously, it shows that 'smarts' and 'implementation' is everything in the world of analogue.
It also explains why I can happily listen to either of my turntables...😍
The main differences between a really good belt-drive and a really good direct drive is in the micro and macro handling-ability of 'stylus drag'.
With the Victors, the Frequency Charts (and Timeline tests) are the same whether an arm (or two or three) is tracking the record or not.
With the belt-drive however, the speed is different between tracking a record and not.
Now this may seem initially like no big deal...?
Just adjust the speed to be accurate when tracking a record....
But the 3150Hz test tone produces a steady state undemanding mid-frequency sine-wave.
The music embedded within vinyl grooves is an ever-changing torture test of low to high frequencies totally unlike the steady test tone.
If the belt-drive deck changes speed with the cartridge in the groove....it is also changing speed (at the micro level) with every change in frequency and amplitude within the groove.
The fact that most of us are not audibly aware (or bothered) by such an occurrence is highlighted by our abilities to be unperturbed by the Wilson Benesch.
But there is just something elusive to the experience of great speed-consistent analogue reproduction when you get used to it..😋

Sorry Dover,
I did mis-read your Post.

Halcro, you're a gentleman. Thanks.

Now that Dover and Halcro seem to have made up. Can we all agree that the spikes in the sine waves from the raw data are actually showing speed changes, W&F?
Secondly, as a family, TTs with tight speed correction tend to show greater aggressiveness in said speed changes?

And the winner is .....

Belt drive Onedof turntable.

Richard - one final correction.
Halcro keeps posting the VPI Direct Drive raw graph.

10-16-15: Halcro
Here is the real time analogue print-out of the actual sinewave produced by the VPI Direct whilst tracking the 3150 Hz Test Tone.

Unfortunately the raw graph Halcro posts is in fact the Onedof turntable.

Here is the link to the original graphs -
VPI Direct & Onedof raw data graphs
Figure 2 is the VPI Direct raw data graph.
Figure 3 is the Onedof raw data graph.

Interesting to note that the smoothest raw data graph by a substantial margin is the Onedof TT with stretchy rubber belt drive and high mass platter.

Fremers testing and listening notes that the Onedof and Caliburn turntables have similar absolute results, but different shaped graphs They sound substantially different in character, perhaps the raw data graphs go partly to explain it. This of course is conjecture only.

*since the availability of the Feikert Speed App I have regularly stated that the Data downloaded on its 'Chart Info' was imprecise and non-scientific as it was not possible to duplicate the results from test to test.*

Why do we give credence to this in a magazine? Stereophile is Amateur Hour, unprofessional and lacking expertise. Too much trouble for them to conduct a proper test?
Read the specs page on the VPI Direct and all it has is the price.

I propose (without any data to back me up) that the tonearm has a lot of influence on the shape of the Feickert App speed deviations. I believe that unipivots are more easily excited by the 3D eccentricities of the records and thus show a more ragged perhaps more exaggerated trace. This belief is easily attributed to my dislike of most if not all unipivots but at the very least I think it safe to state that the w&f measurements are influenced by the tonearm and are therefore even less comparable from one table to the next.

Non-sequitur: I was at VPI yesterday and Harry Weisfeld is experimenting with adding additional pivot points to his 3D arms. Good idea.

Aigenga.
re unipivot arms.
You raise an interesting point, different arm bearings may well show a difference in the graphs. (Arm geometry may also show difference, as BT argues.)
That said, have any of the rigs recently listed by Halcro had unipivot arms?
The W&F visible on the raw data for the TT-101 seems to be quite similar from arm to arm. This would imply that the speed changes are localised in the drive unit itself.

I believe that Halcro posted three gimballed arms - the only unipivots that I noticed was the VPI on the Classic Direct. It showed a rather ragged trace.

I lean towards the idea that the regular speed changes on the Feickert traces are the results of record eccentricity; the fact that they occur once per rotation (16 - 17 per 30 second measured period) tells me that they reflect an out-of-round condition and are not due to speed correction feedback which would probably occur far more frequently.

Continuing my last post, I believe that the out-of-round condition must be in the record not the table because records are imprecise and therefore very likely to have that problem and if both the table and the record were at fault the trace would show them either reinforcing or canceling each other depending on where the record was on the platter - so every time you measured the same record on the same platter but rotated the record relative to the platter you would get significantly different results. This is easily tested.

Good to see my Well Tempered provides superior results to both the Victor and the VPI direct drive:

http://i41.photobucket.com/albums/e297/06BucketT06/Sylv%205751%205963%20RCA%205963/90ae420cb59443179...

And...http://i41.photobucket.com/albums/e297/06BucketT06/Sylv%205751%205963%20RCA%205963/780e6fb13b38067a5...

Fleib, how would you know I have a better test record?  Maybe mine is worse?  Many components to sound and I didn't comment on this.  In retrospect, it's still very hard in some cases to determine from graphs what are better results and I cannot assume better results than the Victor but the other table results posted, likely.

Sorry, Dover. I was cranky that day.

For me, there's no perfect way to measure the phenomenon we are trying to understand, so I prefer listening tests.  Listening tests are inevitably subjective in nature.  However, lately I have been doing a lot of listening to my SP10 Mk3 as the Krebs mods "break in".  Richard originally suggested it would take some time, and I was skeptical.  However, now I must report that the Mk3 is "smoother", more "continuous" in sound by a noticeable amount, compared to pre-Krebsian era.  Furthermore, these virtues are attended by a new open-ness of the sound; the sound is freer of the turntable than before.  I would liken that difference to what I heard when I changed from a belt-drive with a conventional plinth to one with a plinth that resides only under the platter, a la Galibier or my old Notts Hyperspace or the plinths favored by Halcro.  Adding these new virtues to the rock solid timekeeping of the Mk3, and I cannot imagine anything much better. (Of course, the "timekeeping" should be better than OEM due to the effect of the Krebs mods to reduce the number of servo error corrections needed per unit of time.)

Lewm - there is no proof that the Krebs mods reduces the number of error corrections. Krebs provides no evidence that his "mods" reduce the number of error corrections. Krebs cannot provide any testing data to support the claim.
Although you say you cannot imagine anything better, it is worth noting that David Karmeli classes the SP10mk3 that he owns as a toy compared to his reference tables that include the Techdas, EMT 927, Goldmund Reference, American Sound & Thorens Reference. None of these are direct drives.
I share a similar view to DDK as I have heard both the Krebs SP10mk2 and mk3 and they simply do not have the resolution that my Final Audio VTT1 provides.  

 

Richard,
I have owned the Final for 25 years and in that time you have heard it once. I clearly recall your comment at the time which was "amazing".

During that 25 year period I have also had the pleasure of owning many other turntables - various Sotas including Star Vacuum, Well Tempered, Garrard 401and 301 idlers, Pink Triangle, Oracle Delphi’s, Roksan and others. I have just sold my Platine Verdier. I have personally set up many tables including various Goldmunds, VPI’s, Gyrodecks, Aura’s, Mapleknolls, Micro Seikis and others too numerous to list.

I regularly have listening sessions with audiophiles/music lovers, some of whom own Kenwood L07D’s and SP10’s and have no reason to replace the Final. I recently hosted a listening session which included the owner of a Micro Seiki SX5000 loaded with Graham Phantom’s who fully concurs on the relative merits of the above mentioned decks.

As regards "dynamic speed stability", there is a reason your SP10 and Halcros Victor have servos and speed correction - the SP10 and Victor cannot hold speed without the servos running. If you turn the servos and error correction off, neither of these Direct Drive TT’s will run let alone maintain speed.

The previous owner of the Final, Warwick Mickell was an opera lover, played harpsichord & wrote for The Absolute Sound magazine; pitch stability was a key requirement when he set out to select the best possible turntable, cost no object, in Japan, at that time. Warwick benchmarked the Final against the Denon DP100 Direct Drive and many other turntables prior to purchase - it was no contest. 
  
I’m sure there are other great turntables such as those I mentioned in my previous post - the EMT 927, American Sound, Micro Seki’s etc - that can give great musical pleasure.

Dover.
I heard the Final enough times at Warwick's to get a fix on what it did well and what it did not so well. Hearing it at your place only served to confirm this.
re the amazing comment. Under the right circumstances I find my car stereo to be "amazing" . We adjust our expectations based on where we are.

Re speed stability, Your comment re DD TTs needing servos to work is immaterial. It is just a different technology that's all.

I am on record during a conversation with Lewm stating that I could not live with a standard SP10 MK3. (To my ears they have a high frequency jitter speed problem that is just plain irritating, which took me 15 years to tame.) I will now expand that statement to say that I have not heard any standard DD TT that I could live with. So perhaps Warwick and I are almost on the same page.

Could I live  with the Final? 
While I admire what it does well the, to me, obvious dynamic speed problems disqualify it from my bucket list.

As I said, we each make our choices based on our particular biases. I have no beef with anyone preferring a different TT to what I would choose. This diversity alone makes our hobby fascinating.

richardkrebs
I am on record during a conversation with Lewm stating that I could not live with a standard SP10 MK3. (To my ears they have a high frequency jitter speed problem that is just plain irritating, which took me 15 years to tame.) I will now expand that statement to say that I have not heard any standard DD TT that I could live with.

It would appear then that you agree with me now.
It is surprising that you could live with DD turntables for 20 years prior to "taming the jitter". With regards to "taming the jitter" - thats what the digital guys claim each time they release some new algorithms or technology. As I said to Lewm there is no evidence that your lead and glue mods to the SP10 reduce the number of error corrections per unit of time which is what he claimed. You may have slugged the sound but the error correction is still going on.
Servos and error corrections are not irrelevant as you claim - these are micro adjustments to the speed of the motor and platter. This is why you hear "jitter" with all direct drive turntables ( other than yours of course ).

Dover, It has long been my observation that your major goal in participating in this discussion is to "prove" by the force of insistence that your particular Final Audio turntable is "the best".  Secondary goals are to prove that the finest direct drive turntables are inferior to the finest, most expensive belt drive turntables.  You've made these points over and over again, never with any sort of "science", except for the implication that what you hear and report is to be taken as gospel.  So, I hardly think it behooves you to come down on Richard for not offering "proof".  Actually, Bill Thalmann may have made some measurements of Krebs-modded SP10s that do support the claims.  I will inquire.

It is irrelevant to me that you place no value in my subjective judgement, so we are even, so far as that is concerned. What I wrote about the Krebs mod was meant for persons who use SP10s.  Direct drive has its issues, and so does belt drive.  Apparently you prefer belt creep and speed instability to issues related to servo mechanisms.  That's fine with me.  And by the way, if your Final Audio has a motor controller drive system of some kind, the chances are that it too has an error-sensing mechanism which has the potential to produce an effect not unlike that of a DD servo.  The only difference in the case of a belt drive is that the corrections are delivered via pulling on a compliant belt, which has its own pros and cons. Playing LPs is an exercise in inexactitude; each of us must find his own set of likes and dislikes which in the end must be based on listening.  What I don't understand is why you hang around here, if the subject of this thread is so odious to you.

Lewm -
Life is a constant learning exercise, that is why I read and participate in these forums. I regularly listen to and enjoy music on all types of drive ( other than digital ). You are quite wrong on the Final - I would be disappointed if there were not a better turntable out there - because I enjoy the constant upgrade process and the joy of rediscovering old records in a new light when one accomplishes gains in the playback system. I do not claim it is the best, I simply haven’t heard anything better yet. There are many TT’s I still have not heard. The comments I have made in this thread are only related to TT’s that I have heard in depth. Ditto with Rauls MM thread - I still prefer MC’s but have gleaned much knowledge and tried a few new MM’s in the past year or two. I continue to listen to other turntables in my system - it’s enjoyable and usually learn something.
A few corrections on the Final - it has a very powerful AC motor, no active speed correction. Speed is controlled by precision oscillators regenerating sine and cosine waves and a power amplifier to drive the motor. It has separate controllers for 33 & 45 and I can set the speed between 0 & 85 rpm on each as well as vary the level of torque applied. Speed relies on inertia (26kg platter), powerful motor and AC phase locking. As regards belt creep the Final uses silk thread - the stretch is negligible compared with rubber belts, otherwise I agree with your comments on belt drives (rubber) and so far the only decks that have approached the Final have been idlers.
Speed and power wise, the most astonishing TT I have heard in the past couple of years was a Denon RP52 Idler. The owner, a DJ, demonstrated side by side with a Technics DD in the same system that you could could start and stop the Denon with a low compliance MC sitting in the groove and hear virtually no slurring of the music on start up. Doing the same test on the Technics DD resulted in much slower start up such that you could hear the music coming up to speed. I wish I had made a video of it. I suspect the EMT 927 would be in that league - huge torque coupled with a 50lb flywheel.
The Technics DD motor used for driving lathes, the SP20, was designed specifically to operate in conjunction with the Neumann 60lb flywheel and has significantly more torque and poles than the SP10mk3 - this would be an interesting DD platform to listen to.    

Dover
I have listed the time line of my upgrade development on another thread. There I outlined why I persisted with the SP10. To repeat. It's "drive " is intoxicating. Halcro has used a different descriptor for his TT-101 but he and I agree on the point.

BTW a sine / cosine generator is necessary to create a rotating field in the two phases of your synchronous motor.
In its simplest form it can be approximated by a capacitor.
There have, for decades been more accurate devices available to generate the necessary phase shift, so what you have in the Final,  while being elegant, is not a big deal.

Many DDs have three phase motors. This requires a precision triple sine wave generator. Each wave shifted in phase by 120 degrees. These are then fed into a 3 channel power amplifier.
Since they are direct drive these three phase signals must be very accurate, if they were not the platters rotation would be very erratic.

Most quality DD TT manufacturers did this 4 decades ago.
Again it is not a big deal, but they at least provided the purchaser with the power amp.

Also a synchronous motor like yours has local feedback. The rotor lags slightly the rotating field.
With a varying load this phase angle changes and then corrects, hence incremental speed changes.

There is no free lunch when we try to drive something at a constant speed.

Richard -
Last time I looked under the bonnet of the oscillator preamplifier on the Final, there was a bit more than a capacitor. Time to move on and focus on direct drive.

A direct drive motor turns once per revolution of the record. By comparison the Final motor rotates 54 times for each revolution of the record. This means that the error correction and servos in a direct drive application are constantly error correcting over a larger time period per revolution between poles. To put it into perspective a typical direct drive with say 8 poles has only 8 pulses per revolution of the platter compared with 218 pulses per revolution ( motor speed 1800rpm x 4 poles /33.33rpm ) with the Final. This along with the high inertia generated by the Final 26kg platter results in an audibly superior sound.

This same principal applies to idler drive type turntables where the platter is typically driven from a high speed motor with small pulley driving a large platter. In engineering we call this gearing.

Cutting lathes also use this gearing principle, high torque motors and high mass flywheel to achieve stability.     

Dover.
yeah yeah we have all heard ( read ) the arguments extolling the virtues of BD,TD and ID over DD.
My point was that a synchronous motor in a thread drive has local error correction and under dynamic loads it is in play (correcting) all of the time, just like global error correction in a DD. Error correction, something that you seem to dislike with a passion, is clear and present in your own TT.
Different in nature yes, but it is feedback 

Further the fact is that the Final slows when you lower the tone arm. This you have published. You say that this can be adjusted out, but this adjustment must only be a best guess average. So there will be dynamic speed changes since modulation level and the radius read are not constant on an LP. IOW the retardation torque is far from constant.

This is the dynamic speed problem that I hear on the Final.

While one can debate the efficacy of the time line in showing what goes on within a single revolution, Halcro has quite clearly shown us all that a good DD TT maintains speed under load. The Final does not and high platter inertia isn't enough to resist this slowing 

Yes some cutting lathes use a gear principle and then many are DD.

Dover, that may have been a typo on your part.  The SP-20 was another in their series of studio and consumer motor units.  The mastering lathe model was the SP-02.

http://www.lathetrolls.com/viewtopic.php?f=1&t=1223

Huge difference. ;^)

Thanks Pryso - yes indeed typo. Thanks for the link. If you google around should find a picture of the SP02 set up with 60lb Neumann flywheel. Be great to have a set up like that for a domestic TT.

Lewm or Halcro


One of you mentioned a thin leather mat made in Japan, could you post a link to it please ?

Thanks in advance


Peter

Hi Peter,
Victor made a special pigskin mat for their Laboritory Series DD decks like the TT-101 
 http://imgur.com/UnMbyr3 
I was lucky to find one 3 or 4 years ago but they are really scarce.
The closest sounding alternative I have found is the thin Jico suede mat which was launched about 6 months ago.
Regards

Halcro
Is the colour of your mat black or is that just the way it appears in your pic?
The one that I have is tan.

Dear friends: I think that Dover have several reasons to be highly proudly as a Final Labs TT owner.
If I been an owner ( that unfortunatelly I'm not. ) I will be really proud of own it.

In those vintage/Golden BD TTs years the Final Labs TTs was " unbeatable " about its unique design characteristics and no TT ( I know ) like MELCO, American Sound or Micro Seikis were a real challenge for it.

Against the Final Labs any Micro Seiki ( I 'm an owner of it. ) is just a " child toy ".

IMHO Final Labs was many years ahead of any other BD TT. Other of what Dover posted here you can read something on that TT:

http://www.vinylengine.com/turntable_forum/viewtopic.php?t=6359

Normally BD TTs has an achilles heel against DD TTs: speed stability, W&F and SN ratio numbers. So what? nothing is perfect.

Tell me who of us can detect/aisle differences between 90db and 92db on SNratio? or between 0.020 and 0.015 on W&F? or between 0.001% and 0.0012% on speed stability or speed deviation?.
I'm sure I can't do it but the higher/better numbers gives me mind calm and " proud ".

Speed stability is always important but is only one parameter in the overall characteristic in a TT design and TT quality level performance and IMHO can't ( per se. ) define that overall TT quality performance.

So we have not to " cry " because " lower numbers " till you can detect it against quality performance levels.

I think that Final Labs can't compete ( in numbers ) against the best japanese DD TTs as Technics ( 10 MK3 ), Denon ( DP 100. ), Yamaha ( GT 2000 X ) and Pioneer/Exclusive ( PL 70L/ P3a. ). Not even the DD 801 by JVC.
 Btw, the JVC TT looking was a copy of the older Denon TTs, in the other side the double servo ( 1976 ) pioneered by JVC came in the Denon TTs ( not the 80/75 I own. ) too.

Probably the one that beats ( now defunct. ) all those DD TTs was the one  by Rockport.

Subjective " values " are always important. I made " amateur " mods in my MS control/power supply unit ( btw, the motor came from Panasonic/Technics members of the Matushita gigant japanese group. ), in my SP 10s and in mi Denons ( 80/75 ) and in all those mods I " heard/hear " improvements or I WANT that be in that way. 

When we are doing " something " , in any audio link on the audio system  chain,  to have a " sure " improvement our brain is just waiting for it and we can " hear " it when we finish that mods.

Now, the Krebs TT mods are not executed by an amateur like me  but for a professional  gentleman. I try to find in the Krebs's site the " numbers "  ( those numbers ) before and after the mods and there is nothing about even that ( for an audio professional. ) is really easy to take measure on W&F, SN ratio or speed stability.
For me is a must to have. Everybody that use those mods speaks many subjective " things " that no one can be sure why is that.

Things are that Richard himself is here and maybe he can be so gentle to give us light on that numbers that can corroborate those owner opinions.

Here I'm not asking for " rocket science " but if those mods are so " fabulous " must be reflñected on those " easy " numbers.

Lewm, just think this:

suppose that your unit, before the mods, was running on manufacturer specs. Example 92db on SN ratio: what if after the mods that " figure " gone down to 84db?

If that happened to me then I will rethink what really I'm listen to.

Why in vintage units as the SP 10s we have to wait for improvements? well 30+ years running the TT always degrade any unit, so a " refurbished " one can perform better.
If we re-oil the bearing/spindle on any vintage TT is almost sure we can have a better TT overall performance.

In the other side, when we made system mods what we are doing is changing the level and kind of distortions and if the mods were made by a professional I want to know those numbers.
Many of us are accustomed to listen high distortions in our system and we are " sure " that what we listen is more musical information  when it's not.

I know that many of you don't care about and if you like what you are listen then: that's all about and nothing wrong with that because each one of us are " unique " and as any audio product or any audio mods no one is PERFECT and individual audio/music priorities are different between people.

I hope that Richard can gives an answer that could gives some certainity foundation on its mods and what the people hear other that: " wow " or " I like it ". I'm sure that all the audio community will appreciate that.

Regards and enjoy the music,
R.

Raul, good to hear from you, thanks for echoing my sentiments & sharing your knowledge.

Totem,
AFAIK....Victor made black and brown pigskin mats.
Mine is jet black...🤓

Raul
Welcome back, we missed you!

Beyond core functional test numbers,  I do not put a lot of stock into equipment specifications. I prefer to use my ears. As above... We do not listen to specifications.
If we did, tube equipment for example, with its typically inferior measured performance, would be off our Christmas shopping list.
My view is that we can hear way deeper into the output of a product than measurements can articulate.

If you are interested in more detail on my upgrade, please feel free to PM me.

cheers