SDS or phono stage

Lew M, sometimes it is better to ask questions than to shout out answers, only to find out the world has moved on. All the variacs I have ever used or even seen have been of below par construction for audio use. I think most are used to control motors in certain kinds of factory production and OEM usaes in the same role, where critical adjustments are either not necessary or are supported with gauges or a servo mechanism. The speed precision needed to properly replay records far more important due to the sensitivity of our ears to even tiny speed inaccuracies. The KAB device used with VPI's SDS is capable of both setting and holding the speed steady, something else that the Variac likely does poorly in that it is set by mechanical means, whereas the SDS resolves in .01hz increments.

Arsh, if you are still looking for a tube phono stage in the $1500 range, you might want to check out the Eddie Current ECPA. This is the same Eddie Current that makes the Zana Deux (and a lot of other) outre-quality headphone amps. The build quality and design quality of their products is extraordinary, and the designer/owner is tube audio legend. I am happy with a 15 year-old Thor in my system, but if it ever needs replacing, I would put the ECPA at the top of my list to audition. Please note that I have no financial interest in that company, just a very happy Zana Deux ZDT owner who has a real appreciation for the work product of fanatics.

Variac works quite well in my experience with my Gyrodec. It's a fairly serious bang for the buck as far as I'm concerned. No ability to control speed (as far as switching from 33 to 45 RPM) and it lacks the elegance and automation of supplies like the SDS but certainly no drawbacks in terms of holding actual speed.

Granted, the SDS probably does more (and should at the price) but HW is actually on record as recommending the use of a variac with certain AC Synchronous motors and the fact is that the variac does accomplish some of what power supplies like the SDS and Lingo do, namely reducing the voltage and, as a result considerably reducing motor noise/vibration resulting in a cleaned up presentation and lower noise floor.

The VPI SDS also reduces the voltage once the platter is up to speed. The end user can program the final run voltage.