[droht]

I just picked up a pair of Tannoy Reveal 502 powered monitors.  Nothing special about them, but they have a solid rep.  Input is 3.5mm, which I'm running from my iPhone 8+ (Apple Music) via a lightning-to-3.5mm adapter then a basic cable.  Sound is inconsistent, anywhere from below average to really awful, with vocals often disappearing almost completely.

I changed cables and played around with the settings on the Tannoys, and even resorted to RTFM, but could not improve.  Finally I tried running the 3.5mm input from my Macbook (Apple Music).  Success!  Sounds great.  Also sounds fine running 3.5mm straight from iPad (no adapter needed) to monitors.

So I'm wondering if my issue has to do with the phone or the lightning-to-3.5mm adapter?  I run headphones straight from the adapter with no issues, and have run 3.5mm from the adapter through a headphone amp with no issues. 

Any ideas?  Thanks.

[cody69]

You could be losing some signal from the adapter, especially if the iPad connection is working out for you.
I tried using cabled output from iPhone to amp, but the sound quality was awful -- I assumed the phone's DAC was much of the issue.
Good luck.

[richidoo]

It's probably the adapter. It's not just a cable adapter, there's a tiny DAC inside there. It's a well designed part, but with that small size it has some limits. It has enough power to drive Apple earpods, but not high current loads, or higher voltage.

Try reducing the output volume on the iPhone to half, then crank up the speakers to the level you desire. This will eliminate any voltage clipping and reduce the current load on the tiny DAC and might fix or reduce the distortion.

The Tannoy 1/8" input jack offers a 10kOhm load to the DAC, so that's not a problem, but the little DAC may be simply running out of voltage or current to drive the speakers at full phone volume. Even my Dragonfly Red DAC clips a little driving the aux input of my car at full phone volume. Turning down the phone to halfway, and turning up the car volume solves it for me. I also have iphone 8+

Should be a nice rig once you figure it out. 

[droht]

Thanks for the replies. I will have to fool around with this a bit more.