Dear Captain,
I am not an expert audiophile, just a audiofool. Whatever little commonsense knowledge that I have gathered in 45 years of fiddling with record playing machines tells me this.
The tonearm
If this is pivoted at the top with the armtube hanging down, the weight of the tube itself can be utilized to achieve the radial balance. A heavy counterweight is required now for this, with the tube pointing up. When the tube is hanging down, a lighter counterweight can be used, reducing the moving mass. I am not convinced that a pivoted vertical tonearm shall be able to achieve uniform pressure on both sidewalls of the groove throughout its arc, irrespective of the pivot point being at the bottom or top. If it was possible to implement a vertical pivoted tonearm without any major compromises, then the Japanese would have done it thirty years ago. It is cheaper to make a pivoted arm than a linear tracker.
https://www.youtube.com/watch?v=6BCm4b0D4Pk
https://www.youtube.com/watch?v=4ZkV7vGvbYk
https://www.youtube.com/watch?v=_A9FlkbWDiE
The spindle bearing
This has not been discussed on their website so we do not know what sort of bearing design and materials are used. As the bearing is horizontal, the wear on the lower walls of the bearing shall be much more as the weight of the spindle and record, aided by the pull of the belt shall be on it. If the motor is repositioned at the top, near equal pressure on the bearing walls can be achieved, as the belt shall have an upward force on the spindle while the record weight shall try to pull it down.
The Motor
It is not mentioned whether the stepper motor that is used is AC or DC. Usually, AC synchronous, Shaded pole or brushless DC servo motors are preferred for turntables for their smooth and continuous motion. A stepper motor could be used if the step angle is extremely small and the controller does not chop current to one coil completely and then applies to the next one. Also, why cant we have speed change at the press of a button? Even the cheap plasticky belters made in the eighties and nineties had DC motors with electronic speed change. If this product is designed in the 21st century, do we have to manually shift the belt like a Rega?
The Speakers
Thank you for acknowledging the serious flows here. It would be better if the speakers are separates. They should be active units, two way TL with a 4 or 5 woofer. Possibility of a wireless Bluetooth connectivity should be explored.
My suggestion would be to redesign the vertical turntable with the tonearm pivoted at the top, or better still, a linear tracker, DC servo motor with electronic speed change, motor mounted above the spindle and off board speakers as suggested above. There should be a remote control. These changes shall make it most attractive to the market segment it is aimed at.
These are my two cents on this subject, IMO and YMMV strictly apply. While I would not be in the market for this, I wish Gramovox all the best with their project.
Regards,