How does it sound running at the lower voltage? If it sounds good, personally I would leave it. In theory (and in practice in my case), the lower you can get the voltage without compromising speed stability the greater the reduction in motor noise and improvement in sound quality.
I don't own an SDS or a VPI product but did start to use a variac with my table (a Gyrodec) a few years ago after Harry posted about the benefits of doing so at Audio Asylum. I believe he has used variacs with Empires that he has and ramped the voltage down as low as 55V with them.
The Linn Lingo also drops voltage down to around 72V I think. Ultimately, it will be motor dependent. I find that with my Gyro speed stability might suffer once I drop in to the mid to high 50's. 62V seems to be the sweet spot for me with my table.
If it works well and sounds good at 72V I would probably not be increasing it. |
The 72 and 102V settings were originally for the TNT series motors for which the SDS was mainly intended. Maybe 72v was not enough for the more modern VPI turntable motors.
Lowering the voltage after startup reduces motor noise only, and does not affect speed unless it is too low and the motor does not turn.
I agree 72v for 45RPM is wrong. |
Adjust it to the VPI spec as explained and don't second guess. |
Stringreen,
As explained where? The manual is completely silent on the voltage selection as the unit is supposed to be calibrated before shipping. C'mon man. |
I run my SDS at 72V for 33 RPM and 90V for 45 RPM with my Aries 3. Everything sounds fine and dandy to me. On my motor startup, the voltage jumps to 115, but comes back down after a few seconds. |
Go to the VPI website and download the SDS calibration manual which will give you instructions on how to change the voltages settings. This way you can experiment with different settings and decide for yourself. |
Actusreus here are the instructions. SDS Calibration InstructionsIf I remember back I believe my SDS needed in the 90v range to work properly with my thread drive TNT otherwise 72 as the others have indicated with belts. Cheers |
Thanks everyone. I listened at the run voltage of 72 with both 33.3 and 45 records, but didn't get a chance to experiment with different voltage settings. Will do perhaps this coming weekend, but both worked ok as far as the speed stability. However, at 45 it did seem that the usual pace and dynamics were somewhat diminished, but I need to listen to more records to be sure.
Does anyone have any input or opinion on the torque issue with different voltages? |
Actusreus, the run default voltage for 45rpm should be set for 102v, not 72v, perhaps that is why your 45 listening impressions are less than stellar. |
If you're getting good results with 72v on 33 I'd be inclined to leave it there. 72v may be low (in terms of all electronic speed control with the SDS) for 45. Based on this:
http://db.audioasylum.com/mhtml/m.html?forum=vinyl&n=974466&highlight=variac+blake&search_url=%2Fcgi%2Fsearch.mpl%3Fsearchtext%3Dgarrard%2Bzero%2B100%26SelectForumvinyl%3Dvinyl%26SelectForumvinyl%3Dvinyl
I would try 72 and 92 respectively. |
Ok, so I tried to recalibrate the unit, and the voltages are set to 96 V and 102 V for 33.3 and 45 respectively. So why and how on earth does my run voltage drop to 72 V? |
If the SDS was correctly set to those run voltages, and they
still drop to 72V; the unit is obviously defective. That is
supposed to be the lowest voltage option, for 45RPM. The
45RPM default factory value is 90V for Software Version 1.1
and is 102V for Software Version 1.2, which the unit should
have dropped to, without having been reset, if operating
properly. |
With my VPI MK. IV, outboard motor, thread drive, TNT 3.5 platter/bearing, I find the 90v sounds/works best @ 33 rpm. |
