i own 2 vintage tt's with Dobbin's plinths; a Garrard idler drive 301, and an Technics SP-10 Mk3 DD. i did also have a Dobbins plinth'd SP-10 Mk2.
so why do these plinths improve performance over the basic stock tt or OEM plinths?
my opinion, already touched on by others here, is that 60's, 70's and 80's 'even SOTA' tt's had their strengths and their 'areas of potential improvement'. obviously the strengths were that much more R&D could be directed to building motors since these companies were much more able to spend that money than the typical tt builder of today. OTOH their weaknesses were that the case work was an afterthought in comparison. system performace (cartridges, arms, phono stgaes) did not necessarily reveal limitations of the build quality back then.
it's not simply adding mass, or adding isolation. it's more a matter of engineering the precise plinth construction that will optimize the drive system. what is the best combination of materials put together in a particular way to allow the tt to have maximum livelyness, low noise, and drive which sounds the best.
i know that Steve Dobbins built many dozens of plinths before he sold his first plinth for the SP-10 Mk2. he did the same for the Garrard 301, and then again for the SP-10 Mk3. i know he experimented with many materials and ended up with a constrained layer design. eventually on the Mk3 he discovered that (in his opinion) mounting the Mk3 with the casework still in place compromised the performance due to the high torque of the Mk3 motor. the original casework allowed 'flex' and a slight smearing of the sound. eliminating the case and mounting the Mk3 'nude' inside the plinth performed better.
not every plinth designer necessarily agreed with Dobbins on that issue.
in any case; it should not be surprising that 30+ year old casework could be improved upon. |
Raul, to be clear; my comment on the nude (original case-work removed) SP-10 Mk3 referred only in the context of installing the nude SP-10 Mk3 inside a custom plinth. possibly that was inferred by your comment; Nice to hear that I'm not totally wrong about my thoughts on a nude ( non casework. ) SP-10 as a improvement. but that was unclear. you could be referring to a nude SP-10 with no plinth. in that case, although i have not listened that way myself, i would be skeptical it would be optimal. |
Raul,
ok, i get it about what you were referring to.
OTOH it's clear we are not referring to the same thing at all.
you are mentioning about the stock SP-10 and removing the bottom-plate of the stock case-work in hopes of improving performance.
i am referring to completely removing the case-work and installing the motor and platter inside a custom plinth...and even that point is only related to the Mk3 due to it's considerable torque.
so my comment about a 'nude' SP-10 does not support your comments. they are related in a round about way but i don't share your viewpoint although it would not greatly surprise me if removing the bottom of the stock casework might be better. although i think it more likely that removing only the bottom plate would cause the remaining casework to resonate more.
i don't mean to be argurmentative; i'm simply trying to make sure that my intended meaning is clear. |
i think Jfrech has it about right on the GP Monaco. i had one for about a year in my room. it's a really nice tt, fit and finish about perfect, great speed, low noise and neutral sounding in a good way. i 'prefer' my Dobbins SP-10 Mk3 for it's dynamics and foundation (wetness?) and my Dobbin's Garrard 301 for it's 'swerve' or whatever term you'd use. i seem to like tt's with a bit of 'mass' (Rockport).
but i could more than happily live with the Monaco for sure. |
I can definitely see where a copper or metal mat in general could liven things up assuming the table drive can handle the weight! i like copper too. |
the copper-tops are platter surfaces, not mats. Steve sells a Garrard 301 copper-top platter that lowers the noise floor 4-5 db compared to a stock platter and sounds great. i don't think he makes any copper mats that i know of.
all three tt's do large scale music nicely; maybe the Rockport slightly more nicely as it can separate musical lines in a cresendo like no other tt's i've heard. low noise, amazingly stable soundstage, perfectly flat record. |
Violin wrote; I am not trying to hi-jack this wonderful thread but I have a question about wall voltage and it's effect on not only tt motors but amps, pre-amp etc. Logenn's comments above caused me to think about my situation.
I live appx. 4 miles from a large hydro-electric power generating plant and the wall voltage in my home typically runs from 122 volts to 124 volts. What affect ,if any,does this have on the above mentioned components, particularly the tt motor? i have the same Loricraft PSU 301 AR power supply for my Garrard 301 as Logenn that regenerates the 50hz power. it sounds wonderful. unfortunately i have not heard it any other way so i cannot say how much it improves things. i do have a hydro power about 8 miles from my home and my own transformer for my home in a newer subdivision of acreage lots. so my street power is pretty good (or at least i thought it was). last week i installed a 'whole system' 10kva Equi=tech balanced isolation transformer; the 10WQ wall cabinet system. this has made huge performace improvements on every component in my system including my tt's. my viewpoint on 'good power' will never be the same. |
Jonathan,
i'll do my best to answer your question.
Albert does not do the 'nude' SP-10 Mk3 plinth. his Mk3 plinth design keeps the case-work on the Mk3. Steve Dobbins Mk3 plinth, which i own one of, does at least remove the top case-work. however; i do not know myself whether he removes anything else from the Mk3 before installing it in the plinth. my impression from my conversations with him is that the motor is secured directly to the plinth; but exactly what that might mean relative to your question i'm not 100% sure of. |
Pryso,
my guess, knowing the likelyhood that Albert tried quite a few of the pretender/contender cartridges while he owned the Walker, is that Albert had a pretty good idea of what cartridges worked the best on the Walker. and in any case; the Walker does not allow for an alternate arm, so you are stuck with comparing the Walker with it's fine linear tracking arm.
so Albert would have been in as good a position as anyone to make the comparison with the cartridges he knew at that time. he had way more experience with cartridges on the Walker than the Technics.
i have a Rockport Sirius III and sitting next to it is a Dobbins Technics SP-10 Mk3 with a Reed and Talea arm. i have multiple cartridges which have been switched back and forth. i have my opinions about this and that which is as close to 'a truth' as you are likely to have.
i respect Albert's perspective. |
So what I'm trying to understand is how you and all others who accept only a "single variable comparison" think it is fair to mount the same arm and cartridge on two different tables and then judge which table is best? Yes this may tell you which table you preferred within that particular "system". But in my mind it will not necessarily tell you that your choice will be preferred in all systems, i.e. that it is the best of the two tables. If one size fitted all, this would be a far simpler hobby. after first acknowledging there is no real ultimate truth of 'what's best' when comparing tt's, i think one can form useful conclusions with reasonable efforts. particularly when you own 2 or 3 tt's over a period of time amd move arms and cartridges between them. characterisitics do emmerge. preferences get established. if that preference holds in multiple situations it gains in credibility. it helps to have 2 of the same cartridges, or two of the same arms, or even a phono stage with 2 inputs. this allows speedy 'single varible comparison'. but for me it's the months of listening to tt's side by side which allow a real sense of what is what. quick looks are useful but less valuable for me. as far as 'system' synergy; i suppose there are amp/speaker/room combinations which may favor one vinyl front end over another. maybe tubes and horns may invite idlers and Koetsu's, as an example......but at the top of the vinyl food chain i don't see much of that approach. vinyl gear that aspires to be SOTA are typically all around performers and not limited to one system character. at the end of the day colorations will always get in the way of the musical message. |
Jonathan, on 9-5-2010 i did answer your question 2 posts below your question. i'll quote it. Jonathan,
i'll do my best to answer your question.
Albert does not do the 'nude' SP-10 Mk3 plinth. his Mk3 plinth design keeps the case-work on the Mk3. Steve Dobbins Mk3 plinth, which i own one of, does at least remove the top case-work. however; i do not know myself whether he removes anything else from the Mk3 before installing it in the plinth. my impression from my conversations with him is that the motor is secured directly to the plinth; but exactly what that might mean relative to your question i'm not 100% sure of. |
also some arms like the dobbins plinth are at the back and i'm actually unsure if they are attached or not. i've owned three Dobbins plinth'd tt's; an SP-10 Mk2, SP-10 Mk3, and a Garrard 301. all these have dual armboards that swing (for overhang adjustment and arm length flexibility) but are extremely firmly attached. i know Steve has experimented with many many approaches to the whole arm board/plinth interface question and having this be very solid is a high priority. OTOH not over dampning it is also very significant if the sound is to be lively, which all his plinths certainly are. i've not personally spent time with a tt where the arm board is not solidly connected to the plinth; so i cannot say for sure whether it's a valid approach. but my guess is that while it might work; it is unlikely to be optimal. |
