SirSpeedy,
Glad to hear you're enjoying the EP units. Have you tried the EP-15a without the Ultra-Pure? I'd be curious to know how much additional benefit you hear from the balanced power.
BTW, upgrading the power cord from wall to EP-15 also makes a significant improvement. So does putting it on Rollerblocks. Strongly recommend you try both if you haven't.
Meanwhile, about the "Wobbly" Theorem:
I honestly don't know of "any" unipivot that relies on stylus/groovewall and cantilever/suspension pressure to help maintain steady azimuth,or balancing.That,alone,would be poor design,...
Well, I'm glad you said it first! ;-) But if there wasn't a problem (aka, opportunity for improvement), why did AJ Conti and Bob Graham go to such trouble and expense to give the Vector and Phantom additional stability? You've heard the benefits on the Phantom yourself: clearer, more resolving, less muddy, etc.
...and would surely put a "TON" of pressure on the stylus/suspension
Well, not quite that much. ;-) With a vacuum platter holding the record surface flat, the only impetus for an arm to roll comes from groove transients, which are pretty small events. The pressures being resisted are only significant to a mechanism as tiny and delicate as a phono cartridge. It might not matter to a low resolution cartridge, but to an Orpheus, UNIverse, XV-1S, etc., everything matters.
Who knows?
I admit my little theory is just a hypothesis. But consider the available evidence:
- a unipivot wobbles freely until the stylus touches down
- once the stylus is under full VTF, the arm becomes more stable
- nothing in the tonearm has changed to provide this stability
What other mechanism can we posit for the system's sudden increase in stability than assistance from stylus/groovewall and cantilever/suspension pressures? What else has changed?
Let's do what real scientists do with a hypothesis. Devise a test to prove/disprove it. (I'd do it but I don't have a unipivot lying about, so you're nominated if you're willing.)
1) With the armtube on the cueing support, nudge the finger lift upward with a given amount of force. "Measure" the arm's freedom to wobble by visually noting the amplitude of angular deflection and the length of time/number of cycles it takes to return to stability. Repeat a few times until you're confident you're applying the nudge consistently.
2) Cue the stylus down onto a blank (ungrooved) section of a non-spinning LP. Repeat the nudge test using the same upward force. Note the results.
3) Cue the stylus down into a groove on a non-spinning LP. Repeat as above.
Let us know how the arm's freedom to wobble in response to a given impetus changes under each condition. If my hypothesis has merit, the freedom to wobble will be greatest when the stylus is off the record, less when on the record and least when in a groove.
Doug
