Long story short, headphone impedance for audio interface. Having trouble mixing for quite a while, never knew to check for those things until today. While researching, noticed people talk about impedance/audio quality singling out the dedicated headphone output. I happened to have an RCA (red and white) to 3.5mm adapter and a 3.5mm to 1/4" adapter. So now running my high quality studio cans through two adapters for the RCA outputs of audio interface instead of the front headphone panel.

I FEEL like I hear an improved quality difference, but I'm not sure if that's real or one of the many placebo effects we get in the mixing process.

So here's my question: what's the science behind doing it this way? Am I still losing any audio quality or something going through the back and these adapters, or is this an effective juryrig until I get a proper solution going for it?

 

No idea what audio interface you have but TYPICALLY, RCA (phono) jacks are setup to carry LINE LEVEL signals. Line level circuits (by themselves) are not made to drive any sort of speaker or headphone. They will generally require a power amplifier device to properly drive a set of speakers or a headphone. Not real sure how you could be getting any kind of quality out of that current setup. If your phones are too high an impedance for the actual headphone jack the safer and better sounding solution would be to connect a small headphone amplifier to that current set of RCA jacks (assuming they are an output) and plug your phones into the amplifier. Selection of the amplifier would depend on the impedance needs of your phones themselves. Or you could simply get a set of phones that are a better impedance match for the headphone out. Suggest looking at your audio interface manual/specs to determine what impedance is optimal for your headphone out jack.

 

Last edited: Dec 2, 2025 at 8:43 PM

What kind of headphone amplifier would work there? Doesn't have to be RCA, I have 1/4" output jacks as well, I'm just not good at trying to shop for the "right" hardware solutions and researching/trying to figure this shit out on my own has proven exhausting and ineffective.

 

Most decent headphones amps have very low impedance so they will work with anything out of the box. If you want something cheaper, look for Fosi Audio. Something more expensive, FiiO or Topping. If you're living in the US, Schiit Audio is somewhat expensive but lasts very long. I'm still using my Schiit Magni 2 daily for over ten years, and this unit has enough juice for any headphones that currently exist (or existed in the past).

Most amps will be RCA because they're unbalanced, if you want 1/4" you're going to pay premium for it. And that's not always an improvement, there are many people who say balanced amps are actually noisier than unbalanced, which is quite a paradox in itself. You're also going to need to replace the headphones cable for a balanced cable, which also costs premium.

Edit: worth noting that you can connect a 1/4" output into a RCA input from an amp, if you don't want to lose the RCA output in the interface. Most interfaces will accept unbalanced 1/4" to RCA cables just fine even though the output is balanced. In this case, both RCA and 1/4" will perform the same since they're unbalanced.

 

Last edited: Dec 2, 2025 at 8:57 PM

Unfortunately, you didn't mention which audio interface you're using!

The headphone output is specifically designed for headphones; some manufacturers offer excellent quality, while others don't.

Here's an example: The Audient ID14, for example, supports headphone outputs up to 600 ohms.

Headphone Outputs
LINEUP:18dBu = 0dBFS
THD+N @ -1dBFS:0.0009%
DYNAMIC RANGE:125.5dB A-Weighted
CROSSTALK:>116dB
FREQUENCY RESPONSE:±0.25dB 10Hz to 40kHz
MAXIMUM LEVEL @ 30R:2.59V Peak, 1.827V RMS, 223mW
MAXIMUM LEVEL @ 62R:4.18V Peak, 2.95V RMS, 280mW
MAXIMUM LEVEL @ 600R:7.72V Peak, 5.46V RMS, 100mW
1/4” TRS JACK:Tip (Left), Ring (Right) & Sleeve (Shield)

 

I would assume your headphones use a 1/4" phone plug for a connector. Your audio interface should typically (unless it's designed as a smaller overall size) use a 1/4 phone jack to deliver audio to headphones. If your headphones impedance is very high you'll need an amp that can drive HI-Z phones. If your interface headphone jack is not capable of driving your current phones there are inline amps (that plug between your interface 1/4" jack and your phones) that would amplify the signal coming from the headphone jack. These are generally a bit higher in background noise. There are also amps that will plugin between your RCA output and your headphones. Your phones then plug into a 1/4" jack on the amp. These (depending on the design of the amp) are generally lower in background noise. Regardless of the type of amp you get you will have to supply DC power to it via (wall wart), usb DC adapter, or a battery - just depends on the design of the amp device. The example below is ~35$ from amazon. This one is spec'd to drive impedances from 18Ω-600Ω which covers a very wide range of headphone models.

Here's a typical example of the latter type from amazon

 

Last edited: Dec 2, 2025 at 9:26 PM