Ben, I am sorry to read this. Not sure how it happened or why.
Dear Community
I just read was Ben happened. Not 2 1/2 weeks ago I was playing also with my PWD in different compbinations with JRiver. 1st connected via Network and Bridge, 2nd connected via USB. I use to take balanced output from PWD to my preamp (classe ssp 800) and balanced to my power amp (classe ca 5100). Suddenly while switching from network/bridge to usb no music any longer at all. I 1st replaced my power amp for checking what has happened (I still have an old power amp). Music was playing again. So I thought my power amp has come to a dead end and I brought it to service. They checked the device. Thanks god nothing really happened with the amplifier with the exception that the device stood out of service for exactly one hour. The service told me this happens because the amp receives direct current. I thought resonsible for all this trouble must have been the classe SSP 800. But now I read this thread and I’m not that shure any longer.
Best regards and hopefully Ben find a solution that doesn’t streched his moneypocked to much.
Jayla
I don’t mean to give rise to speculation - but this is curious. I’ve heard a little pop once in a while going from one source to another, but nothing major. Is it possible that while switching between inputs there is energy somewhere in the circuit that could get passed along as DC? It would seem really unlikely to me, and potentially catastrophic to the DAC to have any amount of DC in it. Could the switches one hears when going from source to source be implicated? I assume everyone has these units properly grounded…
Thanks guys. I think it's the PWD/Bridge. I did have the volume all the way off (mute) when I turned off the switch. I have been playing around with the JRiver MC18, which entails switching between EMM and MC18 for comparisons. In doing this, I have noticed some instances when the Bridge acts strangely (as in being confused as to which server it is trying to communicate with). It is during a switch to the JR server that I suddenly lost music via the Bridge. That is when I heard some static "hash" emanating from the left channel; at which point I muted, then turned off the DAC and experienced the loud pop. The Krell amp is relatively new and has been working flawlessly. I can't help but suspect the Bridge (PWD?) - especially since others have reported similar issues...
Hi Ben,
what I really don't understand is, why it hit your tweeter and your midrange-system when the reason was direct current for damaging the system - or did I missunderstood you? Usually I would expect your bass-system to be dammaged, no?
Best regards
Jayla
I don’t know if this will help, On the left hand column of Jrivers , you will see your perfectwave dac show up that is, if your dac is connected to the internet. If you want to use usb it seems you now have to select Player in that column in order to get sound through usb. Of course when you switch to usb through the dac. This is what I found.
jayla:
DC is just a suspected culprit. I truly do not know what caused my tweeter to fail. Upon turning the PWD off via the rear switch, I heard a very loud “crack,” which I can only assume was an electrical discharge of some kind. I assume it was DC, but I really don’t know for certain. Whatever it was was loud and instantaneous…
Very sorry to hear about the speaker damage. I have KEF reference speakers with very similar drive units and did a replacement of one of the mid/tweeter drivers a few years ago. Afterwards I ended up with a slight imbalance between the speakers, so KEF ended up replacing both drivers with matched units and everything was fine after. Good luck with everything
what I really don't understand is, why it hit your tweeter and your midrange-system when the reason was direct current for damaging the system - or did I missunderstood you? Usually I would expect your bass-system to be dammaged, no?
Best regards
Jayla
When a direct current feds your speakers windings the tweeters will meld down in just a second. This can happen for example when the poweramp reaches the clipping point.
The bigger the windings the longer it takes to meld them and it takes a higher current to meld them.
So tweeters are the weekest.
I suspect that a bass unit will be damaged when you overpower your speakers with low frequencies for a longer period.
Yes, and DC is the ultimate in low frequencies. Unless you are biamping and bypassing the crossover or have no crossover then the tweeter will never see DC - the the crossover blocks all frequencies below the crossover point including DC.
J.P.
When a direct current feds your speakers windings the tweeters will meld down in just a second. This can happen for example when the poweramp reaches the clipping point.
The bigger the windings the longer it takes to meld them and it takes a higher current to meld them.
So tweeters are the weekest.
I suspect that a bass unit will be damaged when you overpower your speakers with low frequencies for a longer period.
As J.P wrote: Usually a tweeter will never see any DC because of the cross-over. Completly different to clipping. If your amp is in clipping-mode it is producing nearly endlessly high frequencys with lots of energy running to your tweeter- this will kill your tweeter in very short time (of course not if your amp is protected and went in what is called soft clipping - nothing for tube based amps). But who knows?
Best regards
Jayla