Yes, the Peachtree GaN 400 amp and the LSA GaN Voyager amp are essentially the same.....same manufacturers modules and power supplies (unless a pic of the inside of the Peachtree shows different). These amps are NOT zero feedback. Right on the Peachtree site it says "low global negative feeback". The reviewer who thought it was zero feedback is WRONG.
This new Peachtree GaN 1 amp uses modules from the same company.....but these are indeed zero feedback as there are no analog stages to take feedback to. For this reason, they wiill not measure as good as the ones with feedback (ASR will not like these one bit). However, they are full "digital amps" like the Technics.....that is, they change the digital PCM signal directly in software to PWM (class D type of structure).......so you elimiinate your DAC and preamp and cables in between. The company that makes the modules (Elegant Audio Solutions) claims these "digital direct" amps sound better than the analog versions. The parts and execution of the output stages are the same in both modules (I have the brochures here).
So yes, you will hear quite a difference between the analog ones and the direct digital ones.....I hope the direct digital sounds better.....I am all for less is better......but we shall see.....er...hear.
The reason why the GaN 1 will list for $2K is that it uses a single stereo board and smaller power supply than the GaN400. The GaN 400 uses two stereo boards bridged and a larger power supply.....hence the $3K price.