Why three motors?

I have done the upgrade from Raven AC 1, to Raven 3 to BN. I found the difference between the AC 1 to 3 motors to be very subtle. I found the upgrade to the new motor controller to be much more audible and for the better.

As far as the "science" behind the positioning of the 3 belts and 3 motors - you can follow it as such:

One motor pulls the belt that the other motor pushes. You are eliminating the slack from the belt of a single motor design. Synchronization issues aside this is the same concept used by people using 2 motors or extra pulleys etc.

TW did experiment with different motor positions and the 3 motor setup in the photos is one of many different possibilities. You do get less rolling resistance as such. Imagine the tire of a car being inflated to a higher PSI and you get better mileage. But... you do lose the friction that is needed to start up the platter and do have some slipping in this configuration.

Now on to the BN. The Motor is an improvement. Easy to compare. Just run the belt around one pully vs. all 3. The increase in Torque must account for most of it. But it was easily audible. The improvement / difference between the new battery PS vs the older PS. Very very slight (I had a hard time telling any difference).

But the difference between the BN & Raven AC as a system is significant. I personally like the look of the AC more, but the BN is just a step up. More extended highs, more defined bass without becoming lean. That is the easiest way to describe it. I did keep the same tonearms, cartridges during the change.

But as all things audio..........much of what we find sounds better has little sense at times.

That takes me back to my favorite story of my Material Science professor at Berkeley. His specialty was electrical properties or materials. He was a fairly big guy in his field and often called in to analyze catastrophes due to electrical failures etc.

So.... I go up to him and ask him what he thinks would make a difference between different speaker cables etc. His answer was simple, (in a Southern Drawl) " Ah heck, I don't know. I have those MIT cables and they just sound better."

Thanks Dgad, interesting post. Are the motors with the BN the same as the AC 1/3? I thought from pics they looked shorter/smaller and if so might have less torque. What I am wondering is; if the AC 1 motor is stout enough the addition of more doesn't add much. Where as if the BN may have been designed to use 3 smaller motors and thus the test with one compromises the set up.

I also wonder what parts of the BN give the most improvement over the ACs. Very different materials are used for platter and plinth. I also wonder if a BN platter on an AC would be the value upgrade if it can be done.

Thanks, Terry

Thanks Dgad, interesting post. Are the motors with the BN the same as the AC 1/3? I thought from pics they looked shorter/smaller and if so might have less torque. What I am wondering is; if the AC 1 motor is stout enough the addition of more doesn't add much. Where as if the BN may have been designed to use 3 smaller motors and thus the test with one compromises the set up.

I also wonder what parts of the BN give the most improvement over the ACs. Very different materials are used for platter and plinth. I also wonder if a BN platter on an AC would be the value upgrade if it can be done.

Thanks, Terry

Terry

They are all the same motors just a different external casing. Power supplies are different between the tables.

Paul

Because it sounds better done right like my TW RAVEN AC3.