OK, here is another thing that I have been meaning to write about for a while but just haven't gotten to. .....
A while back I pick up a VPI SDS as an upgrade to my VPI PLC (my son had started to play 45s on his VPI and when I looked at what it would have cost to buy another PLC for him to use for speed control I figured it was worth the extra buck to upgrade my rig to an SDS rather than just buy a second PLC)
(https://encrypted-tbn3.google.com/images?q=tbn:ANd9GcQq39z71CKdfEekmWK3Ppxdr38MAiDlpF5Twu1E9kHztQ3W4o_j)
The main reason I wanted the SDS was the fact that the PLC emits a rather loud mechanical hum when used to play 45s, while the SDS is dead silent. For me, Getting rid of that hum was reason enough to buy the unit. What I was not prepared for was the significant amount of sound improvement I got when powering the TT with the SDS vs the PLC. Much lower noise floor much more solid imaging and a much clearer sense of space between the instruments. I was always taken back by the large difference in MSRP between the two units but after hearing them side by side I can honestly say that the difference in price is most definitively backed up by a significant difference (of course whether that SQ is worth the asking price is a personal decision that each of us must make for themselves, but the difference is definitely there.)
But after living with and enjoying the SDS for a while I did a little experiment with it that still blows my mind. The SDS sits in the rack right by the spot that I had the EE DAC plus when it was in my house on the recent tour. I was tidying up the other night and noticed that I had just unplugged the Triode Wire Labs Ten Plus power cord that I was using during the EE audition and left it sitting there. I figured this is probably silly, but let me plug the TWL cord into the SDS and see what happens. All I could say was HOLY CRAP! The addition of the TWL cord made as much of a SQ improvement to the SDS as the SDS did over the PLC. The bass tightened way up, and the soundstage move significantly more in the same direction as it did when I added the SDS. Vocals got lighter and smoother. Just more goosebumps all around. That cord just took the the whole TT system up to another level.
And of course this whole thing just completely blows the engineering side of my brain since the whole purpose of the SDS in the first place is to isolate the TT motor from any anomalies on the incoming AC current. So if the SDS isolates the voltage going to the TT from the commercial AC how can a PC, which is on the commercial AC side of the device have any effect on the ultimate SQ. Logically it makes no sense at all, but the difference is quite significant and not easy to miss. (And it is not just me because I have done the demo for other people without telling then what was being changed and everyone agreed the difference was not subtle at all.
Anyone who is running an SDS should definitely check this out. If you have already spent the money on an SDS (and a TT of significant enough quality to justify the purchase of that SDS) the additional cost of the TWL cord is small potatoes given the amount of SQ I got from upgrading the cord.
FWIW I have also hear reports of folks who got nice SQ improvements plugging a TWL cord directly into a VPI TT motor without even having an SDS in line with it.
As always YMMV, but this one is definitely worth looking into. :thumb:
Nice review Tom, thanks
What does SDS stand for? Is this essentially a brushless motor control?
Quote from: richidoo on May 24, 2012, 09:59:07 AM
Nice review Tom, thanks
What does SDS stand for? Is this essentially a brushless motor control?
SDS = Synchronous Drive System
Form a technology standpoint it is basically an AC regenerator similar to the PS Audio Power Plant line.
More details here:
http://www.vpiindustries.com/products_sds.htm (http://www.vpiindustries.com/products_sds.htm)
The SDS sufers from one small design flaw - it still uses the capacitor in the motor housing to simulate 90 degree phase angle on incoming AC. So it's not surprising that a power cord could help clean this up and make it better.
Bob Crump always said that the best place to put his upmarket power cords was the turntable motor. That over anywhere else in the system.
Congrats on the new acquisition Tom. Now I'm starting to know where you've been over the past month or so. Playing with vinyl (and the girlfriend).
Quote from: BobM on May 24, 2012, 10:42:25 AM
... Now I'm starting to know where you've been over the past month or so. Playing with vinyl (and the girlfriend).
And not necessarily in
that order! :rofl: :rofl: :rofl:
That's interesting, I also have the SDS, guess I'll have to try the 12 Plus in it.
God, I hope it doesn't sound much better, I've already sent Pete enough money. :duh
Quote from: BobM on May 24, 2012, 10:42:25 AM
The SDS sufers from one small design flaw - it still uses the capacitor in the motor housing to simulate 90 degree phase angle on incoming AC. So it's not surprising that a power cord could help clean this up and make it better.
Bob Crump always said that the best place to put his upmarket power cords was the turntable motor. That over anywhere else in the system.
"Congrats on the new acquisition Tom. Now I'm starting to know where you've been over the past month or so. Playing with vinyl (and the girlfriend)."
TMI, TMI, TMI, TMI, TMI :shock:
Quote from: BobM on May 24, 2012, 10:42:25 AM
........ Playing with vinyl (and the girlfriend).
........Who btw likes vinyl (and tubes!) :thumb:
Was there ever any discussion about putting a better cap in?
Quote from: BobM on May 24, 2012, 10:42:25 AM
The SDS sufers from one small design flaw - it still uses the capacitor in the motor housing to simulate 90 degree phase angle on incoming AC. So it's not surprising that a power cord could help clean this up and make it better.
Quote from: BobM on May 24, 2012, 10:42:25 AM
The SDS sufers from one small design flaw - it still uses the capacitor in the motor housing to simulate 90 degree phase angle on incoming AC. So it's not surprising that a power cord could help clean this up and make it better.
Bob,
Are you referring to the starting Cap on the motor itself, that is really not part of the SDS, but rather part of the TT. And I wonder if you could just take that out if you were willing to give the platter a hand boost and not try to start the motor spinning from a dead stop?
I beoieve it is a phase adjustment cap that allows the motor to run both legs 180° out of phase with one another. Unfortunately it is an approximation. So unless you can separately adjust for phase on your motor controller you are stuck with that. The only controller I know that allows for that is the Mark Kelly controller.