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The Eagle has landed, new tt ps kit has finally arrived!

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Posted on May 8, 2014 at 14:08:43
JKT
Audiophile

Posts: 461
Location: Midwest
Joined: November 26, 2002



Just got Kevin's new turntable power supply kit up and running and I have to say up front that if you have a Nott. tt or any other that uses a 115V AC motor and are not using a tt ps like this you are NOT getting the full potential out of it. What does it do? Think of it as a stereo power supply. An AC motor with two field coils needs the current supplied to one coil to be 90 degrees out of phase with the other. This is usually done with a capacitor connected in series with it. With this power supply, each field coil has its own power supply, with one shifted the needed 90 degrees. Unlike the capacitor, this arrangement allows for trimming the phase angle with a knob on the front panel so that optimum operation of the motor (think smooth) is possible. Even more important for the sonics is the level control which allows the output voltage to be adjusted. When the motor runs, it inputs energy to the spinning platter in pulses. This results in a small amount of frequency modulation. Frequency modulation can be seen as a form of analog jitter. As with digital jitter a little goes a long way. By reducing the output voltage to the point where the energy input from the motor balances the mechanical losses in the system (with my tt this was 60Vrms @33 1/3 and 110Vrms @45rpm), one can reap the rewards of a much more transparent sound stage. How much? I recently rebuilt my line stage (see post). This included replacing the Alps pot with a custom stepped attenuator and PS improvements. I got a nice jump in resolution and transparency from these changes. This new tt ps brought as big of change or greater than that. This is not one of those changes that you have to strain to hear. This is more of the 'holy shit' variety. I had an audiophile buddy over to listen the other night and he was pretty blown over by how much of a difference this makes. In trying to explain the changes, one can expect cleaner transients, a more organic overall sound, a more 3D sound stage and better separation of voices. When a vocalist adds overdubs each is heard clearly. Massed strings sound like individual instruments playing together. I'm really having a lot of fun playing all my favorite records and hearing new things. This new kit is great. If your tt has an AC motor you need to buy one.


"It is better to remain silent and thought a fool, then speak and remove all doubt." A. Lincoln

 

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Is this available?, posted on May 9, 2014 at 09:46:29
JLSmith
Audiophile

Posts: 110
Location: Northern VA
Joined: September 21, 2003
Kevin,
I don't see this on your website. Could you provide additional info on availability and cost? Thanks.
Joe

 

RE: Is this available?, posted on May 9, 2014 at 10:55:04
KevinC
Manufacturer

Posts: 2906
Location: NC
Joined: April 19, 2001



That's because the product is in beta trials now. John is one of my longtime beta testers and couldn't restrain himself once he finished it and listened...

This product originated several years ago as an idea (and a first prototype) when I was negotiating to bring Rauna/Opus3 turntables into the U.S. and sell them. Ultimately, that didn't work out, so the TT PS languished. One of the guys here in Audio Sunday School (Trent) helped me improve the design by building variants that we could test. The current design emerged from that effort. Several of the guys here built them in 2010 and nothing more happened due to my time constraints.

However, contacts who reacted to my webpage get trickling in and John pestered me for 3 years to get him one. So I relented and made minor PC board changes, and now plan on getting a small batch out there available to purchase. I haven't taken any pictures except the one attached. Due to the time necessary to support a kit, I'm strongly considering offering it assembled-only. The price will be determined in a couple of weeks, but it will be between $700-$1K. The features that my supply has are very similar to ones that high-end turntable manufacturers sell for $2K-$4K. Compare the features that John describes to the more modestly priced ones offered by, for example, the Music Hall Cruise Control (http://musichallaudio.com/cruise-control/) or the VPI SDS Synchronous Drive System (http://www.musicdirect.com/p-7709-vpi-sds-synchronous-drive-system.aspx). Both of these have impressive frequency displays that are really good only for noting the correct frequency for old off-pitch 78s! I've put the money behind features that LP players can use to improve their music listening.


Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: Is this available?, posted on May 10, 2014 at 13:23:19
AnandR
Audiophile

Posts: 738
Location: North Carolina
Joined: September 8, 2003
Count me in. Hopefully it will be compatible with VPI Traveler version 1, which has a regular IEC power cord in the rear; the version 2 has some 'switcher' looking supply. I may upgrade to a Classic which should be compatible.

Best,
Anand.

 

240V version?, posted on May 14, 2014 at 02:51:28
jusbe
Audiophile

Posts: 5012
Location: Ryedale
Joined: April 4, 2000
Contributor
  Since:
July 23, 2004
Any love for us here in New Zealand?


Big J

"... only a very few individuals understand as yet that personal salvation is a contradiction in terms."


 

RE: 240V version?, posted on May 14, 2014 at 04:59:21
KevinC
Manufacturer

Posts: 2906
Location: NC
Joined: April 19, 2001
There is always love for all of our former colonial brothers and sisters. ;+))

The center frequency can be supplied as 50Hz and there are built-in internal switches to select mains voltage (115/230) and motor supply voltage (115/230).

Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: The Eagle has landed, new tt ps kit has finally arrived!, posted on May 14, 2014 at 09:02:29
roscoeiii
Audiophile

Posts: 561
Joined: April 28, 2009
Ohhhh, very interesting. Been hoping that something like this might come along.

 

RE: The Eagle has landed, new tt ps kit has finally arrived!, posted on May 14, 2014 at 19:40:55
roscoeiii
Audiophile

Posts: 561
Joined: April 28, 2009
I saw elsewhere that someone commented that dual pole designs require rewiring your turntable motor. Is that the case with this unit? How involved is this rewiring, if it is in fact necessary?

 

RE: 240V version?, posted on May 15, 2014 at 04:42:19
Gnnett
Audiophile

Posts: 45
Location: N/L
Joined: September 7, 2002
Hi Kevin

Seeing Jusbe's turntables seem to be idlers, does this mean this will work with shaded pole motors and the like?

Cheers

Grant

 

RE: 240V version?, posted on May 15, 2014 at 07:23:06
KevinC
Manufacturer

Posts: 2906
Location: NC
Joined: April 19, 2001
I should make it clear that the only type of motor that this supply will work properly with is the hysteresis synchronous motor, the type most often present in "modern" audiophile turntables. It will not work with DC motors, three phase instrumentation motors, or shaded pole motors, nor will it work with the large motors in transcription/radio station type turntables. Commercial hysteresis synchronous motors typically have 4 or 5 wires (extra one being a case ground wire) and have a small capacitor between the "hot" AC mains lead and one of the motor wires. See the link below for a thorough discussion of synchronous motors, if you are unfamiliar.

Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: The Eagle has landed, new tt ps kit has finally arrived!, posted on May 15, 2014 at 07:31:09
KevinC
Manufacturer

Posts: 2906
Location: NC
Joined: April 19, 2001
The power supply I've design will allow you to plug directly into the back with your current line cord (for NA users, without an adapter) and use it. In this mode you will benefit from the ability to get the speed right and from the ability to optimize the voltage drive level. As the drive level is reduced the motor vibrates less, "communicating" less noise to the platter. This results in enhanced music resolution. However, to take full advantage of the capability of this supply to improve sonics, you will have to rewire the motor. Then you can drive each coil with a separate voltage supply, having then the capability of optimizing the phase shift between the drive voltages to minimize vibration further. The capacitor present in most turntable motor circuits does the phase shifting, but does so imprecisely, as each capacitor and motor is different with respect to manufacturing tolerances. So the capacitor must be removed and the motor rewired to accept to separate AC drive signals from the supply.

Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: Is this available?, posted on May 27, 2014 at 10:11:39
Ed Sawyer
Audiophile

Posts: 2532
Joined: November 3, 2000
I checked on my turntable (Wilson-benesch full circle), which uses a "250rpm Premotec AC-synchronous motor", hopefully this will work too!

Keep up the good work, Kevin!

-Ed

 

RE: Is this available?, posted on May 27, 2014 at 10:38:33
KevinC
Manufacturer

Posts: 2906
Location: NC
Joined: April 19, 2001
That will work.

Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: Is this available?, posted on July 25, 2014 at 07:22:11
indyhank
Audiophile

Posts: 5
Location: Texas
Joined: August 31, 2006
I bought a Wilson-Benesch Circle a couple of years ago and will put it into operation soon. I assume it has the same motor as the Full Circle, but don't know for sure and I will research. If it's a different motor I'll post here and ask if your controller will work with it.

 

RE: Is this available?, posted on July 30, 2014 at 07:28:19
Lakeshore Larry
Audiophile

Posts: 214
Joined: July 30, 2014
Pretty cool. When will it be available and do you have any specs you can release?

 

RE: Is this available?, posted on July 30, 2014 at 08:18:18
KevinC
Manufacturer

Posts: 2906
Location: NC
Joined: April 19, 2001
What specs do you need to see?

Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: Is this available?, posted on July 30, 2014 at 08:28:41
Lakeshore Larry
Audiophile

Posts: 214
Joined: July 30, 2014
I have several tables. I have a VPI classic with a 10W motor and a Gerrard 301 with a ~20W induction motor; will your supply work with these?

What is the frequency and phase adjustment range?

When do you expect to be shipping product?

 

RE: Is this available?, posted on July 30, 2014 at 10:34:11
Lakeshore Larry
Audiophile

Posts: 214
Joined: July 30, 2014
I'm guessing that with a knob for frequency control this isn't synthesized? Do you have a spec on frequency stability? What about FM? PSRR?

Do you have a price worked out yet? Kit or Assembled?

 

RE: Is this available?, posted on July 30, 2014 at 10:41:10
KevinC
Manufacturer

Posts: 2906
Location: NC
Joined: April 19, 2001
The power supply only works with synchronous motors, not induction motors.

Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: Is this available?, posted on July 30, 2014 at 10:58:09
Lakeshore Larry
Audiophile

Posts: 214
Joined: July 30, 2014
Got it. No go on the Gerrard. The VPI is an AC synch motor.

 

RE: The Eagle has landed, new tt ps kit has finally arrived!, posted on August 2, 2014 at 05:44:20
Lakeshore Larry
Audiophile

Posts: 214
Joined: July 30, 2014
JKT-

What about you? Can you provide anymore information?

 

RE: The Eagle has landed, new tt ps kit has finally arrived!, posted on August 2, 2014 at 08:28:21
KevinC
Manufacturer

Posts: 2906
Location: NC
Joined: April 19, 2001
No, he has no more of the info you asked for than I do. I generally design my products to meet functional and sonic needs, then make the measurements for those who need them to judge suitability to their needs.

As you surmise, the oscillator is analog. The THD is very low (<0.01%), but I have no equipment with which to make more sophisticated measurements. When I get onto making the manuals for these, I will also make the frequency adjust measurements, etc. The range is not suitable to accommodate 45rpm playback by running the motor on an 81Hz signal. I'm of the opinion after reading the motor literature that the motor was designed to run at 50 or 60Hz and should be run at that frequency for best performance. A dual pulley solves the speed change need in a simple, if not ultimately "pushbutton", way.

Kevin Carter
K&K Audio
www.kandkaudio.com

 

RE: Is this available?, posted on January 21, 2016 at 11:56:26
Ed Sawyer
Audiophile

Posts: 2532
Joined: November 3, 2000
The circle and full circle are the same table, so you should be all set. The full circle just comes with the arm and cart, vs. just the table for the circle.

When I get a chance to write up the process, I'll build a webpage or something on how to rewire the Circle turntable motor to take full advantage of the K&K motor controller kit. That should help some folks.

-Ed

 

RE: Is this available?, posted on November 9, 2016 at 06:44:11
indyhank
Audiophile

Posts: 5
Location: Texas
Joined: August 31, 2006
Ed, did you build that webpage or start a new forum topic?

 

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