Fiio X1 amp sounds better than vintage receiver?

Playing around with my Fiio X1. I tried running it line out through my Sherwood 7200 receiver using my Audio Technica M50 headphones. While the receiver is very powerful and drive the headphones effortlessly, it is lacking detail and sound stage the X1 on board amp has. Just curious if this is to be expected or the way the headphone output on vintage receivers is setup is not ideal for use as a headphone amp?

 

Headphone-out on receivers are generally of poor quality. It's just there.

 

What you describe is often the sound that you get from the headphone jack of a vintage receiver. A receiver like that uses a resistor network off the power-amp to drive the headphone jack. The additional resistors means the headphone jack has a high output impedance. The high output impedance will noticeably affect the sound of some headphones. High impedance headphones will generally work better with such an amp than will low impedance headphones. High impedance headphones would be headphones with an impedance of 300 ohms or more. Low impedance headphones would be like your ATH-M50 which is 38 ohms.

For more than you will ever want to know about headphone amp impedance and how it can alter the sound of various headphones you can read the headphone amp impedance manifesto.

The Fiio X1 has an output impedance of under 2 ohms. The Sherwood 7200 is likely over 100 ohms (I couldn't find a measurement for it, will need to verify).

There is also the issue that powerful speaker amps are often not clean sounding for low power output. They're designed to drive speakers, not headphones. There are exceptions, like the Nelson Pass First Watt style amps and others. But most amps are going to be rather noisy for headphone use. A dedicated headphone amp (like from Schiit) will have lower noise and be cleaner sounding. That lower noise and cleaner sound will result in better detail and soundstage. And the more suitable output impedance will result in better dampening and a more lively (less dull) sound.

 

Fantastic explanation! Thank you. I opened the Sherwood up and I see the sand resistors attached to the headphone jack. I also noticed the headphone jack was wired backwords-turning balance to left shifts sound to the right on my headphones. Not sure if this was mistake or difference in TRS specifications from then to now.

Again, thanks for the info.

 

That's weird to have the headphone jack wired backwards. Must have been an error during manufacturing, or an error during someones repair of the amp later. Or the engineers designing the amp were so busy listening to The Beatles in mono that they never noticed. The wiring specs for the headphone TRS jack haven't changed.

You can connect a dedicated headphone amp to the tape-out jacks on the receiver. The tape-out (or tape rec) jacks are a good way to connect a headphone amp to a receiver like that. A reasonably good headphone amp will get you better performance than what you're hearing from the Fiio X1. Assuming that the source you're feeding the amp is also good.