23-May-2015, 00:18
(21-May-2015, 10:23)Saint0 Wrote:Did a fresh install of V8.0. At first power up, the low freq beating rumble noise with no signal at high volume was gone; but SAM 2.0 hard clipping, glitches with ultra-low freq / subsonic single tone sweep was still there. I tested the unit again after playing a few tracks, and the low freq rumble with no signal problem returned, and it's repeatable.(19-May-2015, 15:58)NickB Wrote:(19-May-2015, 12:35)G51 Wrote:(19-May-2015, 09:28)Saint0 Wrote:(18-May-2015, 12:13)G51 Wrote: Hello, Saint0. Jeff Fritz, Editor of Soundstage.com, once evaluated the expert line (of course not V8.0.0) and said it was dead silent even in his sound-treated listening room. So what comes the problem of the low frequency heart-beat-like rumble and the sudden outburst of very loud noise we heard? Electrical interference from our home electricity network? The later firmware? Or any other factors? Saint0 did you plug the Expert line direct to wall socket or use a power conditioner?
I'm pretty sure power is clean. D250 is connected to PS Audio P5 with Shunyata Z-PC10 power cord, and the P5 goes to MIT 20A in-wall conditioner/surge protector. I'm surprised to hear the low frequency rumble & beating noise, as well as the glitches with SAM 2.0; both happened after the V8.0 update. Unit was clean and dead silent running V7 prior to the update.
I've contacted Devialet, they're supposedly looking into it. This is the first time I had problems with their F/W update.
I don't want to experience noise problem when supposingly playing the most advanced amplifier in the world. Hope Devialet acts fast. All in all, the views towards V8.0.0 are dividing.
Turned my D400 up to plus 30 dB last night and there is absolute silence on all the inputs - except phone for obvious reasons, I even asked SWMBO to listen as well just in case I had gone temporarily deaf due to the volume !!!
Hi NickB - I'm glad your D400 works OK with V8.0. You didn't play music at +30dB I hope. Do you have DPM On?
I checked my D250 again today, still generates a low freq rumble tone at above +10dB with no input signals (Digital 1, Coax), and turns into beating low freq rumbles with high pitch glitches (can be SAM 2.0 limiting on top of the rumble issue) at around +30dB with Subsonic filter On. I'll try disabling DPM tomorrow, and see if it makes a difference. May be one too many control-loops fighting with each other.
I got a reply from Devialet, their engineers are looking into it.
I tried power on/off the unit a few times, it looks like the low freq rumble problem is intermittent at first power up, sometimes the problem is gone at first power up; but always returns after playing music for some time. I've tried with DPM on & off, no difference.
V8.0 seems to work OK at normal listening level, around -20dB max, but unstable at the extreme limits.