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phoenixengr

Responses from phoenixengr

SUT - electrical theory and practical experience
@rauliruegas  My point about the specified impedance along with the output voltage was to make the necessary gain calculations easier.  In your Lyra example, using a 10 Ohm load with a 7 Ohm impedance cart will drop the output level by 4.6dB, whi... 
SUT - electrical theory and practical experience
Some observations: I always found the specs for a cartridge confusing: 0.25mV output at 5 cm/second.  Into which load?  Open circuit?  Load=Cart impedance?  Load=recommended impedance?  Why not state the output voltage and the impedance at which ... 
Widow with question: Rega TT-PSU or Rega Neo TT-PSU?
The picture you posted is the Neo and it is newer than the TT-PSU-2.   There is an on-line resource that will explain the differences and list price of each unit: http://www.turntablepsu.com/rega.html    
Is the VPI Forum Down Again?
There may be another motive for shutting down the original forum:  Mat and Harry posted numerous times eschewing any sort of digital electronics, digital readouts, closed loop feedback, tachometers, speed correction and BLDC motors.  Two years ago... 
TT speed
Perform the demonstration in the last paragraph of my previous post.  Keep the platter stationary and move the stylus from the outer groove to the inner groove area and measure the distance from the stylus to the tape when located at the inner gro... 
TT speed
The OP is correct and his numbers are spot on target. The math to prove it is not difficult. If the position of the cartridge changes by 20° from beginning to end of the LP, it will lengthen the time of the play back by 100mS: 20°/360°=1/18th of ... 
Possibly Dumb Question re:Battery as a power supply
The LM317 has a drop out voltage of ~3V, so I doubt it regulates the battery output to the table. NiMH batteries need to be charged at 1C and negative delta V slope detection, thus the higher voltage input, the PIC processor and complex charging c... 
Possibly Dumb Question re:Battery as a power supply
@terry9- ELECTRICAL CHARACTERISTICS (Vin = 19 V, IO = 500 mA, TJ = Tlow to 125°C (Note 17), unless otherwise noted) That is the standard disclaimer at the top of the chart of parameters. It is the operating point used in all of the measurements be... 
Possibly Dumb Question re:Battery as a power supply
millercarbon: Never misunderestimate the ability of the forum to overthink even the simplest things. Full disclosure: I converted AC to DC battery, did none of that, and it was audibly quite a bit better. Just not that hard. Unless you make it so.... 
Calling all Sota fans.
I have no idea why. It is a 3 phase AC synchronous motor. Synchronous motors are best for turntables because they will automatically adjust torque to maintain the speed dictated by the AC signal they are given. It happens instantaneously. I sus... 
Phoenix Eagle Versions?
The original Eagle used a class AB output amp and was rated for 15W max.  The wall adapter was 48VDC and 60W.  Starting at SN 620240 the output amp was changed to a class D type and the output was rated for 25W.  The wall adapter was 24VDC and 60W... 
I finally get it!
A 1mm error in effective length implies a 0.1mm difference in overhang and a 0.1 deg difference in cartridge alignment. This should not be a drama. Read the articles. @olddearsWhere are you coming up with your numbers? A 1 mm difference in effecti... 
I finally get it!
slaw-VPI has their metal work done by MDI, a very competent machine shop in NJ, so I don't think it is machining tolerances.  VPI assembles the parts, made by other companies for them, so it may be an assembly error.From what I can tell, part of t... 
Turntable power supply/motor’s role in SQ for belt drive TT
You may want to look at the motor/controller offered by SOTA:https://sotaturntables.com/product-category/eclipse-series/  
Recapped Valhalla or new Herculis II?
https://www.diyaudio.com/forums/group-buys/349742-turntable-tachometer-motor-speed-controller.html#post6086530