I only had the K11 for a week, because these are the conditions for renting Audio equipment at the store in my city.Oh how come you only had it for a week, did you return it to try other gear?
Trying different dac/amp is kind of like trying different food, you could "upgrade" from your amazing $20 burger that you really like to a $40 pasta, or $120 steak, or $240 super fancy foie gras.
But sometimes you just want burger or maybe you don't like foie gras? But maybe steak is nicer than a burger?
So unless you have patience or disposable income, it could potentially take a while until you find your "upgrade".
For example I think I started from Denon D2000, then bought and sold maybe 4-5 headphones then upgrade to D5200, then bought and sold another 2-3 headphones then bought Lawton TH900.
A lot of the time resolution goes up but tonal balance changes, so you're kind of getting better but also getting sideways.
K11 = neutral sounding
K7 = super neutral sounding
SMSL M500 III = warm sounding
K9 AKM = not sure
JDS Element III = slightly warm sounding
Aune S9C = not sure
So basically if you already like K11 I'd buy K11 first and use it for a while. Until the time comes you find it lacking then you could try other gear while sitting on K11.
Upgrading is not exactly as simple of a process as we think.
I've been doing this for a long time because it's my hobby so I don't mind trying different things for fun (even if it fails). But it does cost a lot of money over time.
Hope this helps lol.
EDIT: Though you could always try all the gears you want to try then circle back to K11 later, that works too lol.
Sometimes you don't know if you'd like something until you have it in your hands.
It was a new K11 at my place played +- 70 hours, I did not notice any change in sound. I hope that it had time to burn out.
I accurately returned it to try other DAC/AMPs
The comparison to food gave me a good preview of it all.
I will try different flavors.
My only fear is that I won't be able to combine it all in one device and will be forced to surround myself with hardware.
At least 2 sets that will play quite differently relative to each other.
Being in this store and doing the listening from a laptop, I was convinced that there was no difference between what I was comparing( K7, K9 Pro ESS, JDS Element III) even I was sure that they introduce nothing in comparison connection directly from the Pc motherboard.
Now I know I was wrong and I need to hear it all at home.