TW Acustic three motor unit


Since two weeks I have on loan three motor pad from my friends Black Night turntable. Today I have to return it and just switched back to my stock single motor.

When I first runned three motor pad I felt advantages and disadvantages of this unit. The sound become better but not in each aspect.

With three motor pad the bas was deeper and better separated. The attack of large drums in final of Mahler first symphony was simply spectacular. Three motor unit rocks on complex passages. Overal the sound become more dense, better separated and defined but there is a big but...
With three motor pad the airness and openess of the sound decreased and some "music flow" has gone.
The sound become more audiophile correct but a bit less musical at the same time.

Can you share your experience with AC1 vs. AC3 vs. BN motor?
Does anybody preffered AC1 instead BN motor?

I am puzzled.
milimetr
Went from AC1 to 3 motor it improved bass,imaging,depth stage and gave a more open sound. Don't see any negative side.
I have an ac3 and updated to the bn motor last year. Major improvement on all areas. I just recieved the bn platter. That also has produced major improvements. I have the bn feet those are another good upgrade. Now i am finished with tt.
Keep the AC-1 if you prefer it over the BN motor.

I preferred the original TW Acustik power supply to the BN battery unit. I found the battery unit was too smooth and lost pace rhythm and timing compared to the stk AC-3 unit.

cheers
I shared your puzzlement , speaking for myself
It took me a little while to figure why my $17,000. 2 motor AC TW got beat out so easly by a 35 year old table using the exact same arm and cartridge on both ,
Now I know , and finally you can change the sound of that table 101 ways,..
I also moved from the AC 1 motor to the 3 motor BN unit. I hardly listen to the TW anymore as I am getting superior results with a Garrard 401 and a Lyra Atlas.
It seems taht spending a big $$$ is not the way to get analog nirvana.
I must say it to my friend who owns TW Black Night and now is considerng purchasing DaVinci Audio Gabriel turntable...

In_shore - can you tell as what TT is so good?

I just returned TW BN 3 motor unit and borrowed three separate AC motors. Will check the effect within few days.
11-25-14:Milimetr

In_shore - can you tell as what TT is so good?


Kenwoods LO7D I believe
11-24-14: Downunder
Keep the AC-1 if you prefer it over the BN motor.

I preferred the original TW Acustik power supply to the BN battery unit. I found the battery unit was too smooth and lost pace rhythm and timing compared to the stk AC-3 unit.

cheers

I agree with the above when I went from my AC3 to Black Knight table, I was fooled at first just because of my new purchase BLING "being the Black Knight" feeling it should be superior at more than double the price but quickly realized after sometime in usage wasn't and in the end sold it.
In my opinion BN mystery is hidden in copper platter but beside the copper platter four feets instead three, aluminium chassis with only 25 mm thick derlin plintch and three motor unit in one chousing are disputable changes to original AC-3.

I have in my AC battery power supply, BN feets and BN platter and I stuck when tried to add BN motor unit.
Funny, my 35 year old Exclusive P3 gets more use than my TW AC-3 due to the better sound.
Milimetr, how did you make sure that you had the same amount of belt tension when comparing the one vs three motors. After dusting or moving the motor the Feickert tool is used to place it back to the same distance with in one or two millimeters.

From playing around with other belt materials and motor distances with the original belt one can hear differences in these things alone. Its not hard to kill the airiness with too much tension. Dampening is different
I suppouse that belt tension with one motor is smaller than with three motors. The belt tension with three motors is greater, simply because geometry of three motors around the table. It can be changed to greater tension but not to smaller tension.
So when we compare AC1 vs. AC3 the change in belt tension is inherent with this experiment.
Milimetr, Two things here. One how much the belt is stretched and two how much horizontal force the belt puts on the platter. Too much horizontal force hurts the sound.

With a one motor AC these both change together as you move the motor farther from the platter. It is straight forward in finding the sweet spot of enough.

With three motors the belt has to stretch around the motors and the platter. With in reason I don't know if some extra belt stretching is an issue on its own or not but I would not want to go too far. But if the over all set up places too much horizontal force on the platter I think that would be a bad thing.
Thanks for clarification. However with AC-3 setup I have a motors as close to the plinch as possible to avoid touching motors to the plinth. So cannot reduce belt tension further using this given belt length.
Milimetr

The belt is a different length for the ac1 and ac3. Sometimes I swap to 1 motor and change the belt.

You do have separate belts?
Downunder. I was always told taht for AC1 and AC3 the belt is the same, however with AC1 we are positioning the motor far apart from plinth and for AC3 as close the plinth as possible, but still can use the same belt.

I have such setup at the moment and the belt is already a bit slippery at running with 20kg BN platter.
Of course we can use the longest belt from BN with AC3, but it is not a default solution. In such setup motors needs to be spaced apart from plinth and the belt would be even more slippery due to less contact area with platter.

According to TW web site, they offers four different belts lengths: 860 mm, 925 mm, 1050 mm and 1360 mm.

1. The belt 860 mm is for Raven GT only where motor pulley is very close to the platter,

2. 925 mm was for old and discontinued Raven One. This belt can be used also with AC1 with motos almost touching the plinth,

3. 1050 mm is default belt for AC1 and AC3 (this is my understanding).

4. 1360 mm is default BN belt. Can be used with AC3 but you need much more space on rack to place motor further apart from plint. I am affraid that this belt would be to slippery witn BN platter I have.
BTW - I can see on the picture of your system that you are using 1050 mm belt with AC3, so the same as mine.