Hi jvvita!
The subject of feedback in amplifiers is a deep topic with many details and specifics that consider the type of amplifier, the price point, and the desired subjective outcome.
So first, it’s important that we specify what kind of amplifier we’re talking about. Is this a Class D power amplifier? Is it a Class A power amplifier? Or is this a line-level preamplifier circuit?
Linear power amplifier output stages contribute high amounts of distortion and in the case of the Class AB output stage, highly objectable high-ordered products. Due to the highly nonlinear behavior of Class AB and D output stages, feedback is a must in order to achieve good sound. It’s HOW this feedback is applied that is so critical. The technique and attention to detail, specifically what is going on in the open-loop circuit, is what determines the sonic outcome. Focusing on just maximizing the feedback can certainly be done - and you can bet dollars to donuts that THD will be minimized.
The difficult task of maximizing this loop gain while still providing the amplifier with ample phase margin (>90 degrees) has, in my experience, compromised some of the open-loop characteristics I’ve associated with top notch sonic performance. Can good sound result from high feedback designs? Absolutely. Is it the best we can do? I don’t believe so. Given certain designs such as Class D amplifiers, it most certainly offers the best solution to mitigate the innate compromises of the design.
Now for line level preamplifier circuits - When implemented correctly, integrated op amps offer amazing performance for their size, cost, and efficiency. These op amps use high amounts of feedback and VERY aggressive dominate pole compensation in order to make them adaptable for many environments, designs, and engineering development expertise. This design technique also optimizes traditional audio specifications such as THD, IM, FR, etc. What’s interesting is when you look at the designs of video op amps and how their design method changes in order to adapt to different challenges and spec optimization. There are a lot of hints there and if you’re interested in learning more about this I would recommend looking at how video op amps differ from “audio” op amps - both in performance and topology/design.
Now whats even more interesting is that with line level circuits we can actually make open loop designs that perform extremely well and even have a few superior objective advantages over audio ICs. They may be harder to produce, more expensive to produce, harder to design, run a lot hotter - but in high end audio it must always be about achieving higher subjective performance than the mass produced mainstream stuff regardless of the difficulty or expense. As audiophiles, we are willing to go above and beyond to get to the next level and I think audiophiles deserve to have gear created by designers that respect that philosophy as well.