NAD 3020e output impedance and aux/cd

[MrNice13]

Have a look at @solderdude site- he sometimes measures impedance response https://diyaudioheaven.wordpress.com/headphones/measurements/

If Amir has tested them I think he does too- sure other reviewers too.

668B look pretty stable.

Thanks dude I think if I use pretty flat non coloring headphone at a normal listening sound it sounds good but if you crank it too much the sound get really loud and all weird.

An 56-Ohm headphone can be driven by a headphone jack with a 220-Ohm output impedance, but there will be poor damping control.
It will give the headphones a bloated (louder, less detailed) bass and other weird sounds.
I would suggest investing into a modern headphone amplifier.

 

[twsecrest]

Superlux 668B, Dt770 80 and 250.

A headphone amplifier, like the JDS Atom or Schiit Magni, with their low output impedance, would be better (better audio detail) for driving your headphones.
You can connect the head amp to the RCA line-outputs, on the back of the NAD.

You might try to also post your questions on the website forum Head-fi.

I own all three of your headphones, never use them, as there is better.

 

[solderdude]

HD668B will sound fine.
About +3dB bass opposite a low output R It will not sound muddy, just slightly bassier.
DT770-80 will have about 2.5dB more midbass/warmth
DT770-250 will have about 1dB more midbass/warmth

Some low imp. headphones will sound crap, other won't change their sound at all.

In the old days most headphones were between 300ohm and 2kohm. For those a high output R was no issue. There were some cheap headphones around with 8ohm speakers in it.

Headphone outs were an after-thought. It was just the speaker out through a resistor to attenuate the signal for lower imp. headphones.

 

[MrNice13]

HD668B will sound fine.
About +3dB bass opposite a low output R It will not sound muddy, just slightly bassier.
DT770-80 will have about 2.5dB more midbass/warmth
DT770-250 will have about 1dB more midbass/warmth

Some low imp. headphones will sound crap, other won't change their sound at all.

In the old days most headphones were between 300ohm and 2kohm. For those a high output R was no issue. There were some cheap headphones around with 8ohm speakers in it.

Headphone outs were an after-thought. It was just the speaker out through a resistor to attenuate the signal for lower imp. headphones.

https://diyaudioheaven.wordpress.com/headphones/measurements/

With the superlux tested even with high output impedance the sound is not changed maybe bassier like you said. Cool so it cannot damage my equipement by any means.

 

[solderdude]

Cool so it cannot damage my equipement by any means.

Indeed, and the amp also cannot damage the headphones either.

 

[MrNice13]

I live in Europe so I cannot get these. I know the Magni would be cool. I don't have the budget for 400$ cans so. Right know I can hook a smsl 793ii to the NAD but I use it for my TV and my gaming amp.

A headphone amplifier, like the JDS Atom or Schiit Magni, with their low output impedance, would be better (better audio detail) for driving your headphones.
You can connect the head amp to the RCA line-outputs, on the back of the NAD.

You might try to also post your questions on the website forum Head-fi.

I own all three of your headphones, never use them, as there is better.

 

[MrNice13]

Thanks!

So I can technically plug a RCA to 3.5 from the back of the NAD. A 3.5 to 3.5 into my USB C dongle and stream tidal from my phone and having good audio. I don't see the reason to buy another DAC if the Samsung do the job.

Indeed, and the amp also cannot damage the headphones either.

 

[solderdude]

You can use the headphone out from an USB dongle DAC using a 3.5mm TRS jack to stereo RCA cable into the NAD and listen to speakers or headphones from the NAD.
You won't need another DAC unless you want more functionality , bitrate support or connectivity (other inputs than USB-C).

 

[MrNice13]

You can use the headphone out from an USB dongle DAC using a 3.5mm TRS jack to stereo RCA cable into the NAD and listen to speakers or headphones from the NAD.
You won't need another DAC unless you want more functionality , bitrate support or connectivity (other inputs than USB-C).

Thanks again.