New Type Of Unipivot

[izzy wizzy]

Have always wondered how the Kuzma 4 point works and found this https://positive-feedback.com/reviews/h ... t-tonearm/. It too has a similar horizontal bearing locator thingy which offers stbility. Could be a good idea for a DIY effort.

[SUPATRAC]

Have always wondered how the Kuzma 4 point works and found this https://positive-feedback.com/reviews/h ... t-tonearm/. It too has a similar horizontal bearing locator thingy which offers stbility. Could be a good idea for a DIY effort.

Thanks for the very interesting link. The 4point was one of the arms I hankered after and whose unaffordability led me to develop my own arm. It is a very clever design, although my hunch is that, like a vertical uni-pivot it may allow a degree of scrubbing at the pivot points. This factor was one of the reasons why I decided to devise an arm with a single point which opposes the tug of the music.

Serial number 2 is now in use, and this is the recipient's assessment:

Of the former, similarly excellent results. On my first pressing of Pentangle’s debut — a disc I have listened to a million times — I have NEVER heard Jacqui's vocals sound so clean and present. A truly moving, spine-tingling experience.
Dave Holland’s Conference of Birds is brilliant, wide, clear, with superb textures on bowed instruments, an absolute audio thrill. Low’s C’mon sounds bigger and more dramatic than ever.

I’ve noticed that my system is also sounding better at all volume levels — I don’t feel like I need to get it as loud to get into the “thrill zone.” But this is probably just another way of saying “it sounds better".
Even with much experimentation to come, I can say with total confidence that my system has clearly never sounded better. This is a stunning arm!

His deck is a Sondek and he normally uses a Tiger Paw Javelin.

[SUPATRAC]

Yes, I read that, I wish him luck. Can’t say I like the look of it or the bit of string finger lift but it’s an interesting design.

[izzy wizzy]

Thanks for the very interesting link. The 4point was one of the arms I hankered after and whose unaffordability led me to develop my own arm. It is a very clever design, although my hunch is that, like a vertical uni-pivot it may allow a degree of scrubbing at the pivot points.

I'd be interested in what you mean by scrubbing at the pivot points? I have no horse in the race here BTW.

[SUPATRAC]

I'd be interested in what you mean by scrubbing at the pivot points?

This is wild speculation on my part, but the idea is that the curvature of the sharp pivot point is much higher than the cup curvature. The persistent increases and decreases of tension due to varying stylus drag might polish a tiny rut for the spike and reduce the arm's resistance to the tugging of the stylus on a tiny scale. it may be that this problem isn't real, but I designed my sideways uni-pivot bearing to be immune to this if it is real since the oscillating stylus drag force is opposed by a roughly perpendicular point contact. It seems to work very well, and I anticipate that any wear will not degenerate performance. It is interesting that the linked article about the 4point shows close-up images of the cups which seem to have signs of the scraping of the point on the cup surfaces around the pivot point if not at the point itself.

[SUPATRAC]

Review and video here:
https://www.hifiaf.com/supatrac-blackbird/

[SUPATRAC]

More complete manual here:
http://www.supasound.com/manual.pdf

I'm now offering a new style of thrust box designed to go well with a fluted Sondek. I'm calling it 'death star'.

[SUPATRAC]

Here is the Death Star thrust box Blackbird on my Sondek:

[SUPATRAC]

11 inch SUPATRAC Blackbird looking and sounding great on a Well Tempered Amadeus:

[izzy wizzy]

Is that, dare I say it, an almost trad finger lift?

[SUPATRAC]

Is that, dare I say it, an almost trad finger lift?

Just testing it to make sure it was a worthy second best, since one is included with every Blackbird. Normal service has now resumed - quite a relief:

[SUPATRAC]

The SUPATRAC string lifter has now been spotted on Schröder, Tiger Paw Javelin and Linn Ittok.

stringjavelin.jpg (63.53 KiB) Viewed 6765 times

ittokstring.jpg (255.31 KiB) Viewed 6765 times

[SUPATRAC]

The first VPI Blackbird has a happy new owner:

"First impressions are excellent, definitely leaves
the JMW Memorial Tonearm in the dust. More Bass
and tighter, separation is excellent and overall great
soundstage. Working through a load of albums as we
speak and loving what I am hearing."

vpi.jpg (201.1 KiB) Viewed 6765 times

[SUPATRAC]

Adam at hifiaf.com has reprised his Blackbird review now that he has a magnetic sideways pivot:

https://www.hifiaf.com/supatrac-blackbird-updated/

[SUPATRAC]

The SUPATRAC Blackbird has had a couple more reviews. This one compares the Blackbird quite favourably to a Kuzma 4Point:

https://gy8.eu/review/breaking-the-sound-barrier-again/

Meanwhile Chris Beeching at The Ear says his "record playing world will never be the same again":

https://the-ear.net/review-hardware/sup ... inyl-soar/