phoenixengr
Responses from phoenixengr
| How important is low W & F performance anyway? Right concept, wrong formula. The relevant formula is for rotational inertia which for a uniform flat disc is : I=m*r^2/2. Inertia is directly proportional to the mass, but proportional to the radius squared, so where the mass is located is more... | |
| How important is low W & F performance anyway? @dover The torque curve is shaped like a sine wave with minimum torque at 0° and maximum torque at 90°. With no load on the motor, the rotor and magnetic fields are aligned (0° lag); as the load increases, the rotor will start to lag the magneti... | |
| How important is low W & F performance anyway? One would assume that it would increase the resistance to stylus drag, but obviously does not eliminate speed variations. This is what I addressed in my previous post. Why would it change the resistance to stylus drag? Unless the brake is ope... | |
| How important is low W & F performance anyway? The motor has four shaded poles, so it is not quite synchronous, instead slipping slightly with the braking effect and stylus drag. Personally I think stylus drag is tiny compared to the eddy current brake, which could explain why these decks ar... | |
| How important is low W & F performance anyway? @richardbrand The review of the Holbo and your experience with the Garrard further confirms my suspicions about whether high specifications equates to good listening experiences, although in both cases with your tables the issue is absolute speed ... | |
| How important is low W & F performance anyway? Why asking for that goal? along the title of your thread and what you posted in your answer to my question makes me to think why are you asking those questions? Because having spent a great deal of time and effort to achieve that goal seems... | |
| How important is low W & F performance anyway? @billstevenson The image has to be on a server somewhere (dropbox etc.). Click on the postcard looking icon when composing a message and provide the link to the image file when the pop up window is shown. This blog doesn’t seem to like large ima... | |
| How important is low W & F performance anyway? This is the readout of the same .wav file taken with Multi-Instrument software: T The reading is higher than the polar plot software, but I believe their BW is also 200Hz. | |
| How important is low W & F performance anyway? This is the readout of the development software used to program and tune the controller. The upper right window shows speed error and there are ~13 peaks in 0.147 seconds corresponding to ~88.88Hz: | |
| How important is low W & F performance anyway? This is the same .wav file but with a 100Hz BW: I If you count the peaks there are exactly 20 from 0-45° or 225mS; that yields a modulating signal at 88.88Hz or 160 pulses in 1.8S (360° or 1 rev). This correlates w... | |
| How important is low W & F performance anyway? I agree with what's been said about listening to the LP/arm/cart as in the end, that is what we are doing. But as an engineer working on a motor controller, my job was to make that contribution as small as possible. Also agree that measuring it ... | |
| How important is low W & F performance anyway? As I said, the choice is yours. It hard to imagine how I could possibly care less either way. | |
| How important is low W & F performance anyway? I have not measured the Gran Prix; I just found their specification interesting to say the least. If I ever have the chance, I would be very intrigued to do a deep dive on its performance, but not so intrigued that I would be willing to buy one ... | |
| How important is low W & F performance anyway? Is it me or have you left out any reference to the manufacturer, the model numbers and specifications of the tables in question? I purposely did not list any of that information to prevent undo controversy. You can either choose to believe wha... | |
| How important is low W & F performance anyway? Were the turntables in question using the same test specs as the manufacturers, IEC, CCIR, DIN? Are you asking about my test method or the mfr’s test method? The mfr’s published specs do not indicate which method and/or weighting they used... |