[bigshot]

Get someone to help you do a blind comparison.

If it is making the sound "warm", it's probably just rolling off some of the high end. I don't know why that would be a good thing unless you don't like upper treble.

 

[gregorio]

I think this time the jitterbug is only bringing a very subtle difference...

Yes, the measurements I've seen do bring a very subtle difference. Unfortunately, it's a difference for the worse! They add noise/distortion, which is exactly the opposite of what they claim to do. So they're actually worse than snake oil, as snake oil doesn't help but it doesn't make the condition worse either. Fortunately though, the noise/distortion they add is very subtle and you shouldn't be able to hear it. I'd recommend a blind/double test as the only way to ascertain for sure if you can actually hear that added noise or just think you can. Or, you could just remove it from your playback chain and simply not have that additional noise/distortion in the first place!

G

 

[amirm]

It would be interesting to see the ifi products too, they are one of the most popular in this community. Each one of them has a different technology (galvanic isolation, usb filters, usb cables...).

They are indeed. Here is an example of iFi iPurifier: https://audiosciencereview.com/foru...i-ipurifier-s-pdif-digital-audio-filter.2189/