high output impedance can me a problem for sensitive iem’s. Any reason why every amp isn’t made to be low impedance? Is it based on the design limitations? Cost? Could an amp have a dial to control the output impedance kind of like a volume or gain switch?
It’s a compromise.
Circuits with 0 or low feedback, which are sometimes considered to sound good have higher output impedance.
Designs with lots of feedback get better measurables and lower output impedance.
Feedback can also be local or global a lot of ways to make an Amp.
Depends what your optimizing for.
There is also a lot of scope between 0.01 ohms and 50 ohms.
Yep by the end of this summer we will be seeing massive reviews/comparisons between the D90/A90 from Topping and M400/SP400 (to be released in June) from SMSL. I probably will wait until the end of summer to purchase a new amp/dac combo as active bookshelves are up next. But I’ll be watching the A90/SP400/RebelAmp prices and see if any used ones pop up.
Definitely do a writeup on this one. Topping has been outperforming itself of late. You always talk about how you can do better than THX amps for improving the sound quality of a lot of higher end HPs. Getting the feeling that this one will do well in scaling up to high end cans.