The last one (with no overshoot) was used just only for that measurement.
Re listening, I do not think I can hear any difference between linear phase and minimum phase filter (1 and 2). For sure I would get a zero result in a DBT. In a SSST, I think I hear no difference as well. As I have become skeptical, I hear much less in a SSST than I did before 😀
Re listening, I do not think I can hear any difference between linear phase and minimum phase filter (1 and 2). For sure I would get a zero result in a DBT. In a SSST, I think I hear no difference as well. As I have become skeptical, I hear much less in a SSST than I did before 😀
O.B. Sorensen, High Frequency Testing of Gramophone Cartridges using an Accelerometer, Technical Review 1976-2, page 25
https://www.bksv.com/media/doc/TechnicalReview1976-2.pdf
See review I linked a few posts back. I don't own one. I don't play CDs at home now.
Small DC motors used in situations where accurate speed and constant speed with varying load are needed come in different types.
Some actually have centrifugal control with tiny bob weights on the end of sprung arms. Once at the design speed the weights move out and break the circuit to each winding. These were often used in car cassette players in the early 80's and the torque was amazing. Not so sure on the RFI aspect though.
Others (which yours might be) used a simple two transistor circuit and series resistor which was used to sense back emf from the motor. A preset pot allowed the initial voltage to be set (and so the speed) and then any load change on the motor altered the back emf and this was sensed and the drive voltage increased. Really simple but the resistor had to match the motor characteristic, otherwise you could end up with a motor that increased speed on loading.
Others used an IC to do the same.
Small DC Motor Speed Controller CIRCUIT (TDA7274)_Circuit Diagram World
And the best of all used a control circuit with true rotational feedback from a sensor (usually magnetic) that generated a sine wave output that could be compared to a reference oscillator. True feedback control.
Jakob: A great find, thank you. Been looking for something like that for a while. It going to take some careful examination but might answer some questions we have been debating over cantilever resonances vs vinyl deformation.
You´re welcome.
We had a similar topic in another forum a couple of month ago so i already retrieved that information from my library back then.
It´s an interesting approach although imo tricky in the realization if high measurement accuracy is the goal.
Combination of both methods should nevertheless gain more insight.
We discussed this here somewhere months ago that's why I slipped and said electrostatic actuator rather than accelerometer. There was someone that made tiny piezo actuators with IIRC self resonances >100kHz.
I remember that discussion, but this is the first time I have seen measurements with actuator vs test record. I am hoping in the B&K results to find some evidence of transmission lines in the cantilevers.
When I posted the constant velocity plots out to 48K (as it turns out I don't have any 192K A/D) LD thought we saw some.
Please don't make me search for something, when a simple answer will do (or at the very least, provide the post number). You said that you use a 297 Quid Marantz (or something like that). What is the model number? I am singularly disinterested in what some reviewer says, or does not say about a product, unless the review is accompanied by a full suite of technical data and a full description of the type of topology used. Reviewers cannot be trusted. Ever.
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So it's ok for me to have to search again for the link to the test results that I posted, but not OK for you to? Sorry, not playing that game.
There was certainly an inkling. We now have a number of plots for different cartridges to also compare. It would be satisfying to overturn a long held belief based on 40 year old data 🙂
Well, that's not the case at all. Here are your words:
"As I said £270 of Marantz is better than red book in all parameters."
You don't need to search for anything at all. You just need to look at the front panel of your Marantz and read off the model number. Is that too much to ask?
Would it be too much for you to read the posts?? He says he has no CD player. Marantz reviewed in Stereophile was CD-5004, IMO.
The post is here:
John Curl's Blowtorch preamplifier part II
The post is here:
John Curl's Blowtorch preamplifier part II
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The CD5004 and CD6006 use delta sigma conversion. They are not true multi-bit DACs. The CD80 used a true multi-bit DAC. IME, such machines sound better than those that use delta sigma conversion. That said, I note that there a number of modern multi-bit DACs available. I expect that these will sound better than the old CD80.
We have a recent 20bit one but the architecture requires a de-glitcher for audio, I've seen one but I don't know if it will ever see the light of day since it was very complicated.
Hi Scott,
That's too bad. It would be great to have another true multibit DAC to use. Deglitchers are something the industry can easily handle as they did before.
-Chris
That's too bad. It would be great to have another true multibit DAC to use. Deglitchers are something the industry can easily handle as they did before.
-Chris
No the DAC is there in the catalog it's just that de-glitching to an appropriate level it is a bit difficult. The proposed de-glitcher to get SOTA audio performance was rather imposing definitely not a switch, cap, and op-amp. The solution was from a potential customer so I can't share it.
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