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If you want to do a redo let me know and I can send you one.I took it out on purpose because its test conditions are different than what I use now.
If you want to do a redo let me know and I can send you one.I took it out on purpose because its test conditions are different than what I use now.
And that's the fallacy... "it's trivial".It is trivial to design the feedback system to have the circuit free of overload recovery issues. It is trivial to test with transient/impulse signals.
Would any competent turnable have any rumble serious enough to require filtering out in any case?It isn't only rumble.
Since a seismic sensor like a pickup cartridge/arm combination only starts to produce an accurate transduction from around 2x the natural frequency of the mass on the compliance (the exact value depends on damping which is forced to be in the "wrong" place for excellent performance on a record player) ALL of its output below that frequency will be inaccurate and boosted so is best removed anyway, even if the record player has low rumble.
No. I have results and I can give a proof. I never use reasoning based on beliefs.And that's the fallacy... "it's trivial".
While for passive networks is just simple reality.
It would be good to redo. Thanks.If you want to do a redo let me know and I can send you one.
I have seen woofers on high-end LP systems at shows beat themselves to death with silent oscillations.Would any competent turnable have any rumble serious enough to require filtering out in any case?
I don't doubt you have results. I tried it both ways and like it better the passive way...No. I have results and I can give a proof. I never use reasoning based on beliefs.
I have a Schiit Mani 2It would be good to redo. Thanks.
ThisI don't doubt you have results. I tried it both ways and like it better the passive way...
Most of the implementations NFB are not great because is not that "trivial" like you said.
Throwing in an OpAmp is trivial. But not that great IMO.
Maybe not.Would any competent turnable have any rumble serious enough to require filtering out in any case?
FWIW - here is my frequency response measurement of a Bugle3 using the inverse RIAA filter I designed...
View attachment 273930
My filter includes the 50kHz "Neuman" compensation, so there is no treble rise.
I can vouch I would want to see a redo of the Duo. I imagine even in your current tests it would be fine, but it's nice to have confirmation.It would be good to redo. Thanks.
That doesn't seem to reflect that extra Neumann pole, did you stop including that?
It's in there. That's why the ASR measurements shows it to rise.
View attachment 274122
Not everyone is a fan of the 3.18us corner, but I am, as explained in my paper above. As it turns out, that Neuman cutter head amplifier had a two-pole rolloff at 50kHz (think 2nd order Butterworth) using NFB. I add a single pole turn at 50kHz to partially compensate. The idea isn't so much about amplitude response, but rather phase (transient) correction. Yes, adding the zero in my phonostage EQ offers up a bit of "airiness" to playback, but more importantly it helps to retain the timing of upper harmonics. To me, this is the difference between hearing an actual violin (woody and flawed) instead of synthetic mimicry. Things like cymbals and piano seem to become slightly more realistic. IMHO.
Does your reverse RIAA device also include that pole, and that is why the ASR graph shows it but your graph does not?
Yes, especially with ported speakers, but that's caused by warps and ripples in the vinyl not being filtered out by the arm-cartridge mass-compliance, not rumble, which strictly speaking is bearing noise and expected to be low in any decent TT.I have seen woofers on high-end LP systems at shows beat themselves to death with silent oscillations.