phoenixengr
Responses from phoenixengr
| Stylus-Drag..Fact or Fiction? "Cogging is a function of the number of poles; the rotor experiences a regularly irregular rotational force due to the naturally varying intensity of the magnetic fields produced by the stator. The rotor is therefore constantly inconstant in ... | |
| LP12- Power Supply- Need education @daveyf- I believe that is correct. If I’m not mistaken, it also uses feedback from the platter for accurate speed control.Mark Kelly had an innovative design for a brushed DC motor controller that did not require speed feedback from the platter, ... | |
| LP12- Power Supply- Need education There are two types of DC motors: Brushed (DC) and Brushless (BLDC). Even with a brushed DC motor, the current through the windings must be reversed as the motor rotates; this is done automatically by the brushes and the commutator ring, so a st... | |
| Need to adjust the speed every time I turn on turntable AC motors are locked to the drive frequency, but the wall power frequency does vary a small amount over short periods. This will manifest itself as a wavering on single notes, but will not show up as speed drift over longer periods of time. Long... | |
| Need to adjust the speed every time I turn on turntable This is a common problem with BD tables. It is caused by a combination of belt slippage (which can be cured with proper tension) and belt creep which cannot be cured, but can be compensated for with feedback. No matter how accurate the motor speed... | |
| Roadrunner reapearance @mantistech-The 3 phase motor from SOTA is a low voltage motor (24V); the standard VPI motor is 115VAC. The Condor controller is powered by a 24VDC wall wart and produces 3 AC waveforms for the motor, the frequency, voltage and phase depends on th... | |
| Roadrunner reapearance @slaw- The PBN tach is a bit of a misnomer. The tach counts pulses from a high speed clock (18.518kHz) so it will produce a reading of 33.333 when it takes 1.8S for one platter revolution. However, it is counting the period of rotation, not RPM, s... | |
| Roadrunner reapearance @digital3The new SOTA motor should fit in the Prime SAMA housing with little or no modification. The AC input on the SAMA will be replaced with a low voltage connector and the motor should bolt into the same holes as the Hurst motor. | |
| Roadrunner reapearance @rodman99999- You can download the motor spec sheet here:https://sotaturntables.com/products/eclipse-package/ The mounting holes are nearly identical to the Hurst 59 series motor (within 40 mils on center). The motor has a ¼" shaft, but comes wi... | |
| Roadrunner reapearance SOTA had inquired about producing the Eagle PSU that would be compatible with existing 120VAC synch motors and they are free to pursue that option if it makes sense. When I originally discussed this with Christian, we came to the conclusion that ... | |
| Roadrunner reapearance The new SOTA website is up and running:https://sotaturntables.com/products/eclipse-roadrunner/ | |
| Cogging! The facts are that almost all motors/drives cog to some extent. Its caused by the finite number of torque pulses delivered to the platter. Its similar to the smoothness of a car with a 4 cylinder motor vs a car with a 6, 8 12 or 16 cylinder ... | |
| Redpoint Motor Controller How much was the motor from Galibier?You can build your own 3 phase BLDC controller for ~$100. A compatible motor is ~$60.http://www.diyaudio.com/forums/analogue-source/307918-3-phase-class-amp-diy-bldc-motor-drive.html | |
| 300 rpm motor for VPI Agree with brf; difficult to see how the motor could cause a channel imbalance.However, I've found the Hurst motors to be very inconsistent; I have some that are very noisy, others are near quiet, but they all exhibit vibration. I believe the i... | |
| What direction is VPI headed? I also agree about Bill, he had a great design but working with him seemed next to impossible. It's not that difficult really. You just need an attention span longer than 5 minutes and someone that can understand what they're looking at. Not l... |