The necessity for absolute tt speed control
- Thread starter spiritofmusic
- Start date
I will measure the power consumption of the A80 capstan motor later and will report.
Aproximately 24 W. The frequency is 50 Hz, the Studers operate the capstan in a servo system at mains frequency controlling the amplitude. For 60 Hz operation we must change the capacitor, if you want to operate at other frequencies you must tune the capacitor.
No, what would you like to know I can post again? Is it just the picture that you need?
david
Yes we could all need som audio porn
Here it is next a typical tt motor. Studer motors are about the same size as the small motor in the pics.
The one on the right is about what you used to get in a typical high end tt, of course these days it's mostly dc motors.That does look very powerful
David
The Condor PSU will not drive your Studer motor. It is designed to work only with the BLWS-172 series BLDC motors which are rated at 12W. The PSU runs the motor at ~12W at start up, then reduces the power to ~9W for lower vibration. If you connect the output of the Condor to any other load, it will most likely destroy the output amps.
The other problem with doing this: The Condor starts the motor at 2Hz and ramps up to 20Hz for 33 RPM at the platter; the BLWS has 4 poles and RPM=60*freq/pole pairs =600 RPM. Neither of these frequencies will produce the desired result through a step up xfmr.
The Condor/Eclipse package should be more than capable of driving your platter. If you want to use the Studer motor, look at the SG4 DIY kit:
https://www.diyaudio.com/forums/analogue-source/298018-diy-4-phase-sinewave-generator-turntable-motor-drive.html
I believe DIY member ralphfcooke has done a 3 phase version to drive a Papst motor using step ups and conventional class D amps.
The other problem with doing this: The Condor starts the motor at 2Hz and ramps up to 20Hz for 33 RPM at the platter; the BLWS has 4 poles and RPM=60*freq/pole pairs =600 RPM. Neither of these frequencies will produce the desired result through a step up xfmr.
The Condor/Eclipse package should be more than capable of driving your platter. If you want to use the Studer motor, look at the SG4 DIY kit:
https://www.diyaudio.com/forums/analogue-source/298018-diy-4-phase-sinewave-generator-turntable-motor-drive.html
I believe DIY member ralphfcooke has done a 3 phase version to drive a Papst motor using step ups and conventional class D amps.
Good suggestions, but why not replacing such big efforts with a virtual signal generator? After optimization we can generate a file and put it in a very cheap audio portable (iPod like) device to use it permanently - playing the file from the beginning starts the turntable, stop or pause stops it.
I have a few signals permanently stored in this way - when I need them I just connect the appropriate vintage iPod that no one wanted any more ...
BTW, the generator has a sweeping feature that can be used to develop a progressive start.
The Condor/SG4 reduces the voltage after startup to reduce vibration. Your iPod scheme could do this, but then you would need a very long file for continuous play as looping the file will not work. Even without a reduced voltage step, looping will produce a discontinuity when it reaches the end and loops unless you match the ending phase with the starting phase. The Condor/SG4 are 3 phase controllers and phase, amplitude and frequency are agile to optimize performance. The Condor can adjust all 3 in real time as the frequency ramps between start up and run or between 33/45/78 RPM. Both the SG4 and Condor store different parameters (frequency/phase/voltage) for each speed (33/45 in the SG4, 33/45/78 in the Condor) The Condor can accept feedback from the RR tach and compensate for drift as the table warms (typically 0.2~0.3 RPM change if uncompensated). The SG4 is a DIY kit and cost ~$50 to build. The Condor is a commercial product and is $725 including the motor.
As always, there is more than one way to skin a cat. The iPad route has been tried before and is a viable solution, just not a very elegant one, IMO.
As always, there is more than one way to skin a cat. The iPad route has been tried before and is a viable solution, just not a very elegant one, IMO.
Phoenix, my rim drive could be a candidate for the Condor it's been suggested. What considerations are uppermost?
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