DCAudioDIY.com
http://dcaudiodiy.com/phpBB3/

Mark KelleyController
http://dcaudiodiy.com/phpBB3/viewtopic.php?f=4&t=843
Page 1 of 1

Author:  Stuart Polansky [ June 14th, 2017, 12:59 am ]
Post subject:  Mark KelleyController

Huge thanks to Guy Riffle for producing simplified Mark Kelley turntable motor controller boards. To the best of my knowledge, there haven't been any available for awhile.

My turntable was bought with a failed Pabst motor. Years ago,I had a machinist make an adapter and pulley to allow the use of a Maxxon 7-watt DC motor in its stead. Over the past two years, the power supply I built lost its marbles. Speed control went out of the window. It was a separate DC supply with an umbilical to the motor box/controller. The speed control was a constant current source fed, adjustable shunt regulator with 33-1/3 and 45 RPM pots. One of the pass elements was probably getting too hot, hard to measure because the motor box is sandwiched between the upper (floating) and lower plinths. To get to it requires complete disassembly.

After talking with Guy and finding that he had a board and some of the semiconductors available, I snatched it from him.

Put the controller PCB and transformer in a remote box, but added a six-conductor umbilical cable to the motor box, so that the speed controls can remain in the original location.

Works like a charm, and unless my memory deceives me, it seems to sound better. Hard to imagine a tiny 7-watt motor, belt driven, having much effect on a 28# platter, but hey, I'm thrilled!

Thanks again Mr. Guy, you are the man!

Attachments:
Old-Regulator-Controls.jpg
Old-Regulator-Controls.jpg [ 667.68 KiB | Viewed 8844 times ]
Old-Supply.jpg
Old-Supply.jpg [ 325.61 KiB | Viewed 8844 times ]
Uderside-platter.jpg
Uderside-platter.jpg [ 270.65 KiB | Viewed 8844 times ]

Author:  Stuart Polansky [ June 14th, 2017, 1:00 am ]
Post subject:  Re: Mark KelleyController

Progress Pics

Attachments:
New-Controls.jpg
New-Controls.jpg [ 660.08 KiB | Viewed 8843 times ]
New-Pots.jpg
New-Pots.jpg [ 401.86 KiB | Viewed 8843 times ]
Old-Controls.jpg
Old-Controls.jpg [ 331.05 KiB | Viewed 8843 times ]

Author:  Stuart Polansky [ June 14th, 2017, 1:01 am ]
Post subject:  Re: Mark KelleyController

Progress pics

Attachments:
Plinth.jpg
Plinth.jpg [ 412.53 KiB | Viewed 8843 times ]
Controls-on-plinth.jpg
Controls-on-plinth.jpg [ 355.39 KiB | Viewed 8843 times ]
Motor-box-plinth.jpg
Motor-box-plinth.jpg [ 361.41 KiB | Viewed 8843 times ]

Author:  Stuart Polansky [ June 14th, 2017, 1:03 am ]
Post subject:  Re: Mark KelleyController

Progress pics

Attachments:
Controller-left.jpg
Controller-left.jpg [ 355.74 KiB | Viewed 8843 times ]
Heat_Sink.jpg
Heat_Sink.jpg [ 425.65 KiB | Viewed 8843 times ]
PCB.jpg
PCB.jpg [ 453.29 KiB | Viewed 8843 times ]

Author:  Stuart Polansky [ June 14th, 2017, 1:04 am ]
Post subject:  Re: Mark KelleyController

Progress pics

Attachments:
Finished-Rear.jpg
Finished-Rear.jpg [ 371.23 KiB | Viewed 8843 times ]
Controller-rear.jpg
Controller-rear.jpg [ 287.81 KiB | Viewed 8843 times ]
Controller-right.jpg
Controller-right.jpg [ 375.31 KiB | Viewed 8843 times ]

Author:  Stuart Polansky [ June 14th, 2017, 1:05 am ]
Post subject:  Re: Mark KelleyController

Finished

Attachments:
Controller.jpg
Controller.jpg [ 310.41 KiB | Viewed 8843 times ]

Page 1 of 1 All times are UTC - 5 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
https://www.phpbb.com/