It appears to me that the gain and limiter default settings are being used for PlexAmp no matter how I adjust the settings. I can visibly turn them off but I don’t hear any changes for any songs when I adjust these settings between the extremes (+6 and +0).
Also the same song played on other players is noticeably quieter than Plexamp so I’m assuming the +4dB gain setting is active and the limiter is probably also stuck on.
Is this a known bug in the latest version?
Thanks!
Are you restarting playback after changing the settings? They don’t take effect immediately, but rather are computed for current/next tracks based on settings at the time.
Thanks Elan, after restarting my iPhone I tested the same ALAC 24/96 file played three ways:
(1) Apple Music via CarPlay
(2) PlexAmp via CarPlay
(3) my cars USB interface from a USB drive
Good news, the file sounded superb in all cases and exactly the same via Apple Music and PlexAmp.
There was a small but noticeable difference in volume when playing the file directly via the USB drive.
So I don’t see the Limiter thing being an issue, it appears to be respecting those settings as you suggested.
I have no idea why the USB interface is a couple dB quieter but it’s not a big issue, just a curiosity to me. Any insight would be appreciated.
Meanwhile, can you please confirm that a downloaded ALAC file (in my case 24/96) is passed directly to the car’s DAC via CarPlay assuming all EQ settings and limiter settings are OFF? My car does support ALAC 24/96 files, I’ve been playing them via a USB drive.
Sorry if this is an annoying audiophile question — I’ve spent a lot of time building an ALAC 24/96 library of my LPs and CDs on Plex and I want to standardize playing those files “natively” wherever I go via Plex and PlexAmp.
Thanks
Sorry, I don’t have a clue either 
Not currently, no, we don’t do source matching. When we do, it will pass PCM, not the ALAC directly (there’s no advantage there).
It’s not, but the reality is that you’d be hard-pressed to ever hear any difference between 16/48 and 24/96, and I say that having done a number of ABX tests with different bitrates and formats. Especially in a car…
I think I am experiencing a similar situation in that my 2012 Prius (Entune) if I plug in via usb, like an ipod, I get cover art but the volume is significantly lower than if I connect via bluetooth. The volume is louder but no cover art on the infotainment screen.
Thanks — just want to clarify, when you say “source matching” do you mean that Plexamp passes 16/48 PCM for every file right now no matter what the source file type is?
So does an MP3 get converted to 16/48 PCM by Plexamp ?
Totally agree that unpacking ALAC to PCM is purely a technical exercise (like unzipping a file) and just as well that Plexamp does it.
Regarding the car audio comment, I actually have a super good audio system (Burmester 1600 watts, acoustic insulation glass, blah blah blah) BUT I agree that 16/48 PCM is honestly tough to distinguish (for me) compared to 24/96 even when the car is is in park and engine is off.
That said, being the purist that I am, do you plan to do “source matching” in the future?
It’s possible the higher resolution would make a difference for me using my good headphones and my Dragonfly DAC from my laptop for example. I also don’t want to speak for what other people can or can’t hear — seems like a logical feature to support it since source material, playback systems, and circumstances vary so much.
I guess I’m saying if the quality is there then using it fully is logical as circumstances evolve — DACs improve , speakers improve , etc…
I mean we don’t do source matching right now, so that’s what Plexamp passes. In the future we’ll adjust what we output to what the source file is (source matching).
Yup!
@elan FYI , I connected my Dragonfly DAC to my iPhone today and PlexAmp is sending 44.1 not 48 based on what it is displaying for my 96 files. Apple Music app is sending 96 fwiw
This slight difference is perhaps relevant for folks using 48 and 96 because 44.1 is not a multiple of those rates. At least that’s what I’ve been told 
Just a friendly FYI here
Looking forward to source matching and better integrated download support in the future!
It’s on the list, maybe it’ll be an excuse to get a Dragonfly.
Definitely! A couple notes on the Dragonfly for you:
I use the black one (version 1.2), it draws too much power for recent versions of iOS so you have to use the Camera Connection USB adaptor from Apple and power the iPhone at the same time it’s connected. The adaptor doesn’t cost much money, but it’s a little inconvenient because you connect the power cable and the Dragonfly both to the adapter and then that goes into the iPhone. It’s perfect though for beside use and also perfect for testing your iOS PlexAmp app because it does show the sample rate clearly of what is being sent.
On the Mac laptop the Dragonfly is awesome, but note that it uses the sample rate set in the Audio Midi utility not the source sample rate. At least this is how it works for me. So if I have set the Dragonfly at 96kHz in the Audio Midi utility then I get that sample rate for everything, presumably something ahead of the Dragonfly is upsampling. I don’t recall it working this way on earlier versions of the Mac OS X. So it may not be useful to you to test the Mac Plexamp app.
That all said, as a cost affordable and easy to use DAC /headphone amp, the Dragonfly is fantastic ($99 for the base model). The Cobalt version is $399 and draws less power, I’m not sure if the Cobalt version can be used without the iPhone being connected to external power. Maybe somebody out there has one and can let us know?
thanks for the notes!
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.
