Does leaving multiple headphones plugged into an amp lower the audio quality?

[hfcobra]

Just a question that I've had lately since I have 2 headphones and my IEMs plugged into my amp all at once. I do this to swap between them since I change devices several times a day.

Usually I unplug my IEMs when using headphones so they aren't overdriven at the headphone volume level but other than that everything stays plugged in all the time.

Am I lowering the quality of my audio by doing this? I did some A/B testing to see if the volume levels changed but I couldn't notice anything.

Using Topping A90D amp and driving HD800S, Focal Clear OG, Thieaudio Monarch Mk2.

 

[Lambda]

Am I lowering the quality of my audio by doing this?

Yes.

I did some A/B testing to see if the volume levels changed but I couldn't notice anything.

So as you tested yourself the effect is very minimal and depends mainly on the output impedance and current the AMP can supply.

 

[DVDdoug]

I can possibly. It's easy enough to test by plugging-in and unplugging the unused ones while listening. Or, the volume may just drop. The lower the impedance the more effect it's likely to have and the IEMs probably have the lowest impedance (but you are unplugging them anyway).

P.S.

I did some A/B testing to see if the volume levels changed but I couldn't notice anything.

I guess I didn't read carefully!

You might be stressing the headphone amplifier. If you have all of the impedance specs, including the spec for the headphone amplifier/output, here is the formula for resistors (or impedance) in parallel. Higher impedance (or no load = infinite impedance is OK but at some point the impedance is too low.

 

[hfcobra]

Ok I will probably unplug the HD800S from the amp then since it's a pretty high impedance set.

Surely the 55ohm Focals and a 32ohm set of IEMs won't overstress the amp?

 

[Lambda]

Surely the 55ohm Focals and a 32ohm set of IEMs won't overstress the amp?

the lower the impedace the more "stress" (Current) for the amp

 

[hfcobra]

the lower the impedace the more "stress" (Current) for the amp

Ah I didn't think that was the case. Why does lower impedance mean more stress? My high school physics class told me that more resistance means more voltage to overcome it.