Soulution preamp DC-offset protection


Good morning,
I've just bought a used but mint Soulution 721 preamp. It has replaced a Spectral DMC30SS Series 2. Apart from the sonic differences between the two, I'd like to know more about the DC-offset protection that the Soulution preamps have. Soulution claims that the input signal is permanently monitored for DC-components and at a level > 15 mV a high-class coupling capacitor is switched into the signal path. If DC-offset has decreased, the coupling capacitor is removed automatically after 15 seconds. During the first listening hours, I noticed that this capacitor switched on at least 5/6 times (a capacitor symbol appears in the display and after 15 seconds, when it's removed you hear a mechanical "click" sound). I'm wondering if this is normal or maybe it's a symptom that requires further investigation. I read that the DC-offset could came from the recordings itself and, actually, if I play the same CD and the same song, the DC-offset protection circuit of the Soulution switches on every time in the same point. Maybe it just something I did not realize before because the Spectral preamp showed me nothing of all this. It could be something like "if you don't see... you don't worry". Can someone help me to understand if I have to be worried or not? Thanks a lot!!
katfnc
My dilemma is: when I had the Spectral preamp I was simply unaware of this thing just because the Spectral doesn’t have this kind of protection (or perhaps it doesn’t show anything to the user)? Because I don’t hear anything wrong with the music... I think I will try to use a balanced connection between the CD player and the preamp, just to see if the same thing occurs when using another input and with another type of connection...
when I had the Spectral preamp I was simply unaware of this thing just because the Spectral doesn’t have this kind of protection
Probably because it didn't need it. We don't have a protection circuit on our direct-coupled output either; in 29 years of production the preamp has not seemed to need it.
@atmasphere: I didn’t meant to imply any kind of criticism towards Spectral. I had Spectral equipment for some years (after a long time spent with Levinson Reference) and I liked them a lot. I was simply try to understand what happens now because nothing has changed apart from the preamplifier and the strange things is that the DC-offset capacitor switches on always in the same points of the same CDs/songs (I’ve just tried again 10 minutes ago) so it seems that in those points something arrives at the input of the preamplifier and makes it react by switching on this DC-offset capacitor. Anyway I’m gonna change the input and type of connection and play the same song to see if anything changes. And I have already written also to the manufacturer. I hope they will answer me...
I would check the CD processor to see if that preamp indicator light is functioning properly. Download a 0 dBFS test signal at 50 or 50 hertz and burn it to a CD. Play the disc and measure for DC at the outputs with a DMM. If it is zero (or below 3 mV) then I would test the CD at that point where the cap light comes on.
In the meanwhile I’ve swapped the cables between CD player/preamp and preamp/power amp. Now I have a balanced connection between CD player and preamp. Symmetrical input # 1 instead of asymmetrical input # 2. Things got worse. With this connection the cap light comes on much more than before, practically it lights on, remains on for 15 seconds (it’s the minimum time of activity that the manufacturer indicates in the manual) then goes off for a couple of seconds then it turns on again and so on... I have used the same song that with the unbalanced connection made the cap light comes on one time only at 5’17”... Pretty annoying.