If someone who is having this issue wants to try a set of my adapters modified to lift the case ground let me know. I will send a pair for your testing. @gb-70
I just tested that track that is causing the issue on my RME ADI-2 Pro FSR. This song does in fact trip the DC protection circuit when I engage digital input DC protection. Maybe the XS 4400 doesnāt go as low a frequency as the LL1948. My preamps are not DC coupled (itās capacitor coupled).
Look at timeline 1:18
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Does this still mean you think the ground lift can help?
Or do you think this track will have a problem on many DACās depending on how deep they go?
I had the issue at 0:30 as gb-70 described.
The timeline I referred to is meant for the linked video.
Yes 0:30 is what I have.
I think itās the song and the fact our DACās now go down to near DC with the LL1948.
Sending less signal to the preamp just covers up the real issue.
When I have more time I will measure this.
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I remember gb-70 mentioned he also had the issue with some sine wave plays. I also have some albums with such test tracks and could try tomorrow maybe.
As the effect is quite obvious I think I generally will continue to play with normal internal volume and see how often it happens. Didnāt experience it until that track so far.
What happens with your Jensen fitted DS? Ah forgotā¦your preamps are different.
Iāll have to dig out a preamp that is DC coupled.
Not sure what mine is, I couldnāt read anything of it. Maybe you can:
In a Stereophile review of the predecessor they wrote:
āthe bass was flat to 20Hz, even into 600 ohms, which suggests that the design is direct-coupledā
Does this mean itās DC coupled?
If itās solid state it probably is DC coupled. My ARās are Hybrid tubes. 6h30ās.
BTW. The RME I used is an awesome dac also. I use it to record direct to DSD 256.
Vinyl recordings sound awesome. I also use it when mastering from analog 1/2 track tape.
Yes, but most of them are ārecordedā with -20dB. They will work. I have another one with āfull scaleā sinewaves designed to discover room acoustic problems and they cause trouble. I will try to provide them for download. Just PM me if interested.
No itās tube. But their power amps are OTL, so the preamp could also be special.
Ok. If itās tube is on the input side it could still be DC coupled. Iāll look it up.
Itās all tube.
Thanks but I think then itās not necessary, then Iāll have the same results as you had.
Here is the inside of the AR. See the big output caps to the left?
Iād say your preamp is amplifying near DC (7 Hz until 400 kHz). 
The transformers cannot pass DC however they can go very low.
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Iāll be talking to my ee son tonight who is designing and building me some Jensen JT-11SSP-8MA cloneās that will fit our DS. Iāll see what he has to say.
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Ok. Found and hooked up an Audio Research LS 9 sold state pre. My DS with the big Jensenās has exactly the same issue. 
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Does the Jensen also have the grounding as the Lundahl or do we now know that the issue is independent of this?
Do you still think the issue is just cured by the Edcorās limitation in FR?
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Iām 99% sure itās from the track as all the testing we did in the past showed no issues. Letās wait till I talk to my son who is way smarter than me on these issues. The big Jensenās are far enough away from everything that would cause issues as far as ground is concerned.
I do think it is that the better core transformers are showing this issue more or at least exposing the problem with this particular track or unusually low and loud bass.
Also looking at how my RME responded to this track
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