2008 RMAF – – – all things analog.

i'll be there with my eyes and ears open.....paying particular attention to all things analog....tt's and RTR.

i certainly agree with Teres that stylus drag is real and audible, it varies based on the complete tt system, it's noise floor and how flat the Lp is.

i listen to an Lp on the top belt driven tt's and then on the Rockport and there is a difference in musical foundation, flow, continuousness, and ease on peaks. there is no escapeing from the benefit of (near) perfect speed and stability. it is only in the comparing that you hear this.

this is not to say that overall a belt-driven tt might not be preferred to a direct drive; but all other things being equal (which they almost never are) a properly executed direct drive has the advantage. 'properly executed' is the tough part.

i'm not qualified to argue theory but i know what i hear.

Teres would be in a great position to talk about this issue as he builds tt's both ways that are otherwise the same.

Raul,

i think we are going a bit in circles here (and i'm part of that problem) as we are back to the whole 'proof of cause/effect of stylus drag' issue......when the issue is not likely one to be proved other than by listening.

i wrote a long response here and then realized it was almost an identical response to your earlier 'almost identical' post.

so i'll let things go for now.

cheers,

Albert,

thanks. and i'm excited to read about the technical merits of the Mk3 drive system. it's all your fault i've dived into these vintage dd tt's.

i'll be shipping my Technics SP-10 Mk3 to Dobbins on Monday so he can work his magic with it. then we'll see how it compares to the Rockport and the Mk2.

are you listening to your Mk3 yet?

Albert,

that sounds exciting.....isn't it grand when something which seems to be soooo good.....becomes 'gooder' and 'for cheap'. i'm glad it's not some $2k power cord at least.

hopefully Dobbins will let me know what i need to do to cash in on your discovery.

it will be awhile before my budget recovers to where the Coral Stone and PC-1 Supreme are options.....but they were already in my gunsights. i'll have to settle for my vdH Colibri's for now. i'm sorta tt poor and RTR poor at the moment (according to the wife).

of course; i could always sell the Rockport to fund my adventures (like the Walker did yours). one must choose.....

but i'm not complaining.......

Dear Mike : I'm not saying that the stylus drag is not audible certainly is what I'm saying is that I can't say ( only in a subjective way with out scientific measures ) that due to stylus drag a TT platter change its speed, that's all.

Dear Raul; i would assume that top level belt driven tt's have similar performing arms, plinths and even suspensions to the Rockport. some have vacuum hold down and even an air bearing. but none have the Rockport motor, controller or servo. therefore i do relate much of the fundamental difference in the performance to the speed issue.

i used to have the Rockport Sirius II which was belt driven....as good as it was in many areas......the dd Sirius III is quite a bit better. better in ways i've not heard other tt's match. my Technics SP-10 Mk2 and Garrard 301 do have elements of the dd magic of the Rockport.

does stylus drag result in speed changes? something is happening which gives dd a big advantage. what other factor could do that?

Now, like I told to Chris if you tell me that your Rockport platter sometimes and due to stylus drag ( not because other kind of source like LP imperfections: LP not flat. ) " suffer " changes in its speed well I want to hear it!!!!!! if that really happen is fine with me and for that very first moment that " myth " disappear from my mind, easy.
Mike, that " fact " is happening in your Rockport? and if it is happening : how do you know is for the stylus drag?. Btw, Chris same questions for you.

it is hard to isolate individual design issues unless you are like Chris and are making design choices and isolating drive approaches.

in the last year i have invested in reel to reel tape decks. i have an EAR modified Technics RS-1700 which sounds very very good. it's the same one that Philip O'Hanlon was playing 'The Tape Project' tapes on at RMAF. i recently recieved my Studer A-820 RTR machine after considerable time and expense in reconditioning.

again; as good as the EAR Technics is (and the fact is it probably has better output electronics)....the Studer makes it sound broken due to it's amazing speed accuracy and stability.

i'm no expert; but it seems to me that getting the speed right, and i mean really, really right....... is the hard part and by far the most important part in music reproduction in the analog domain.

yet there is no drive system that will remove our drag problem that i am aware of.

hummmmmm.

as far as stylus drag/groove modulation.....i think that the Rockport Sirius III's drive system may solve this issue. you have an pure induction direct drive motor with zero torque ripple, a 55 pound platter, an air bearing, and a servo system (coaxially mounted optical encoder) which samples the speed every .000001 of a second.

the only support i have for my opinion besides the design description is the unique way that the Rockport handles musical peaks to my ears. until one hears it on a familiar Lp it's easy to dismiss the signficance of it.

a side note on the servo; when it is engaged a green LED flashes to red. the servo is never engaged unless the 'floating 250 pound plinth' is bumped or if someone jumps up and down on the floor in front of the tt. once the platter reaches speed it stays there. there is no hunting occuring. stylus drag does not cause the servo to engage on the Sirius III that i have observed. maybe the servo engages without the LED flashing, but i don't think it works that way.

i have a Technics SP-10 Mk2 sitting next to the Rockport which does a very good job on this issue.....but not at the Sirius III level of naturalness and continuousness. of course; there are more differences between the SP-10 and the Sirius besides stylus drag to cause these differences.

there may be other tt's which are able to do this same (stylus drag/continuousness) thing equal or better but i've not heard that.

anyway; stylus drag can be solved.....but it's not easy to do.