Variable HPF (20kHz and up) and active rectifier would tell you what's happening out of audio band but present as a single number.....no spectral info but would give you something to go on.Indeed, transformer-trick already shows a lot in combination with the alpha lab there even seems to be some correlation....but the 20kHz can only highlight a possible trend that might proceed in the MHZ range (that is out of range)..
Sniffers and stuff, I am familiar in the world of EMC design and measurement...and yes it can be rather revealing..
Member, RNMarsh had involvement with design of Monster AC power conditioners, he might have some numbers.
Dan.
I don't have any suitable/calibrated measurement gear at this time so no can do, perhaps somebody else is able to. The permanent (DC) magnetic 'beams' are modulated by audio band and higher order modulations and this is picked up by suitable coil at quite some distance according to the sensitivity of the coil.....I found that an old school car ignition coil secondary worked very well as iron cored directional transducer, even alarmingly well !.
I built a portable battery powered amp/speaker, I forget the gains but the result was very sensitive, enough so to easily listen to loadings on the HV system of electric train movements when 60m or more from the HV lines/tracks. Around the house things buzzed and hummed magnetically, especially the crt tv of course. This was prior to SMPS days......it would be interesting to take a modern magnetic listen around the house, including phones, routers, bt devices etc. A sensing coil same diameter as VC/gap mounted in front of the dust cap might be interesting/useful to the guys presently doofing it out on the JC BT thread ?. A coil mounted to the magnet assy to detect magnet changes according to drive signal ?.
Dan.
So...bought a EVO3 isotek SIGMAS. Obvious change in sound of my system...but the main question was....is it better? Did measurements, spectrum (they did a good job but I am not blown aways by the attenuation curve). Did some minor mods and plugged in again, similar sound...significant difference. Checked the impedance, hardly any added by the filter. Checked the amp pulse response w/wo, no difference.
So, not everything can be easily measured (nothing new here since our hearing can be more sophisticated )
Now, with the "new" sound, mellower had some minor tweaks on the mid-level of my horn setup but never got where I wanted it. Focus in center seemed to be spread and even though bass seemed to be more controlled I missed the attack in one way of the other. Today, stacked up several of my reference recordings and in the end I can conclude that the EVO3 should not be used for the two SET amps.
The source components are still attached to the EVO3 SIGMAS.
Expensive experiment, but worth doing and learned an awful lot again ;-)
Cheers,
Arno
So, not everything can be easily measured (nothing new here since our hearing can be more sophisticated )
Now, with the "new" sound, mellower had some minor tweaks on the mid-level of my horn setup but never got where I wanted it. Focus in center seemed to be spread and even though bass seemed to be more controlled I missed the attack in one way of the other. Today, stacked up several of my reference recordings and in the end I can conclude that the EVO3 should not be used for the two SET amps.
The source components are still attached to the EVO3 SIGMAS.
Expensive experiment, but worth doing and learned an awful lot again ;-)
Cheers,
Arno
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I'm pleased someone got something out of this thread - or have I missed the details in some hidden link?
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