Op-amp output impedance

[egellings]

I can't count the pixels on my 1080p S22 or my 1440p S9, but I can see the difference the extra pixels make on the sharpness of text. Food for thought

Once the text gets so sharp that adding more pixels doesn't make a visible difference, then there's no point in adding them. You've crossed the finish line. The race is over. Stop running.

 

[mike7877]

Once the text gets so sharp that adding more pixels doesn't make a visible difference, then there's no point in adding them. You've crossed the finish line. The race is over. Stop running.

I agree...

 

[mike7877]

Once the text gets so sharp that adding more pixels doesn't make a visible difference, then there's no point in adding them. You've crossed the finish line. The race is over. Stop running.

BTW, this:

"Does anyone know why the output impedance is so vastly different between the headphone and RCA jacks? Did Topping just put a resistor on the RCA out op-amp, or?"

Was the purpose of the thread. Not sound quality

And my mention of the slight discrepancy of THD+n on the output was a variable I thought might be useful in determining how the two op amps on the HP out were configured, vs. the single op-amp on the RCA outs.

edit: Personally, my "good enough" is -102.
I'm extremely happy with -108, and anything past 112/113 I see as completely pointless performance.
But, like most people I wouldn't choose 113 over 120 if all else was equal.

(this is with standard IMD test of 60Hz / 7kHz being 10dB worse than THD+n, as is common enough)

 

[mike7877]

2 resistors of 1.5ohm each would give such an output R.
The resistors can be as low when the DC offset is low enough.


Can be any of the topologies.

Also, in random reading of DX1's specs again - stereo separation is -86dB at 1kHz on the headphone out, and -112 on the RCA jacks.
Does this give a more definitive clue to how the two op amps might be working together on the headphone out?

 

[solderdude]

It says something about the common/ground resistance of the headphone out socket and maybe the PCB layout.
Stereo separation of >60dB is already more than sufficient. There are no recordings that are panned harder than that anyway.
Not even the early Beatles recordings were panned that hard because of the tape and vinyl channel separation could not reach that.

Do either of them result in signal degradation?

Every amplifying device will add to signal degradation.