iFI Pro DAC dropping it's connection to the SMS-200 after format changes during playback

@support -

Glad this thread got reactivated.

I’ve been testing out my new iFi Pro iDSD DAC and ran into a similar problem, which I disgustedly reported to iFI. Now, it seems as though it might be a Roon problem.

I know the OP uses ROCK, but I run Roon under Windows 10. I don’t use DSP, but the DAC upsamples to 702K. The other day I couldn’t decide what I wanted to listen to, which resulted me switching from a track recorded in aac to one in flac and back again.

Doing so caused the DAC to drop its USB connectivity. My SMS-200 could no longer discover it. Turning the DAC off/on resolved the problem.

Does this sound like the same thing?

Hey @xxx,

Thanks for the report! So we can better understand what you’re experiencing here, please verify the following:

Does this same behavior occur when the iFi Pro iDSD DAC is connected directly to the Core via USB rather than connected to the SMS-200?

Does this behavior occur with other devices connected to the SMS-200?

Were the mentioned AAC and FLAC files of the same bit rate and sample depth?

Are you able to reproduce this behavior consistently? Have you tried a different USB cable?


Yes, using the following Tidal albums in the order I have listed them.

Both 44.1. The Prine album was 16 bit. The Jones album, which is AAC, is 24 bit.

Yes, didn’t make a difference. As a matter of practice, I use the cable that came with the DAC. It’s brand new.

Whew, that’s a lot of unplugging/plugging and device moving about. Before I do that, can you try to recreate using two albums I’ve supplied?

BTW - It seems that @Simon_Arnold3 is experiencing the same problem and he has different equipment than I do -

Also, I should mention that I don’t use any DSP.

Just added both albums and played tracks from them in the order you suggested.

I listened to all of Knockin’ On Your Screen Door

and then played Barbecue Bob In Fishtown after the second John Prine track started

and did not have any problems.

Clearly my Chromecast Audio DAC is not nearly as sophisticated as yours. The only other option I have at this time is a Pi with a HiFiBerry Digi+ Pro feeding a Sony STR-DN1080 using a coax cable. The Sony is a 2018 model and presumably has a better DAC although still not as sophisticated as yours.

I did notice the Prine tracks played Lossless TIDAL FLAC 44.1kHz 16bit 2ch while the Jones tracks played as Low Quality TIDAL AAC 44.1kHz 24bit 2ch.

Not sure I helped much.

Thanks for the reference to the Glenn Jones album, not one I would have found on my own. It may be a Low Quality stream but it sound good and I’m enjoying listening to it.


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Did you try this one? -

And in a similar vein -


Listening to Marisa’s album now and I like it. Will follow up with the other Glenn Jones album when it finishes.


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@dylan -

OK, I give up. Yesterday, I recreated the problem twice. Today, no matter what I do, I can’t recreate.

I guess, close this, at least for now.


Hey @xxx,

I appreciate the information here. I’ve passed your information above along to the team so they can investigate further. If you see this behavior return please let me know and we can take a closer look.


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Since the last update to Roon it’s not been happening all the time to me either where it was before. It’s frustrating as it will happen when you least expect it.

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