DeVerm;352231 Wrote: > Another thought: > > Your scope should have a test-square-wave output on the front. It's > analog and you should calibrate your probes on it using the little > adjustment-screw (capacitor). > > Also, something that Mr. O observed already > (http://forums.slimdevices.com/showpost.php?p=348946&postcount=46) but > I'd like to repeat it here because it's the 2nd more obvious part of > the distortion: > > 1. phase distortion. When you bring that to the picture, it means that > the tops are not horizontal anymore. Look at fig. 6.7 here: > http://www.tpub.com/neets/book23/101a.htm > You normally get this when passing the signal through a filter and the > higher the order of the filter, the more tilted it gets. But where's > the filter in the TACT? (a digital software filter shouldn't do that > and I'm not familiar enough with DSP's to tell if they cause phase > distortion like this...) > > 2. AM modulation. The 2 kHz modulation is obvious and this is the 2nd > harmonic of the fundamental. Measuring at different frequencies will > show if it's a persistant 2nd harmonic modulation. I have no clue yet > where this can come from... > > cheers, > Nick.
Nick - thanks - I will check the scope calibration Arguably the TACT is one big fliter - but when in bypass mode the digital filter has its co-effecients set to zero so it should just pass through.. I'll post some more pictures later thanks Phil -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal...SB3+Stontronics PSU - Altmann JISCO/UPCI - TACT 2.2X (Linear PSU) + Good Vibrations S/W - MF Triplethreat(Audiocom full mods)- Linn 5103 - Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Townsend Supertweeters, Kimber & Chord cables Outdoors: Boombox+Creative Sub (If I remember to turn it on...) ------------------------------------------------------------------------ Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=53345 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
