I don't think bypass mode also bypasses the high-pass filter circuit. It seems to only have an effect on gain/volume. The manual only calls it "volume bypass mode".
How likely is it that fan noise will negatively affect my listening experience?
Now I wonder if I should change to 2x A20 Mono instead. Newly released just 1 week ago.
That sounds like a defective unit. There are a lot of vendors on Amazon that do ship out returned things without even checking to see if they are defective. In my experience, @AIYIMA has backed their products well if you contacted them directly. Do you know if your unit was sold directly to you by Amazon or Aiyima on Amazon? I never detected any harshness with my A20 and Amir's tests always look at startup behavior. He would have mentioned it if a warm up was necessary.
The order details show it was sold to me by Aiyima Audio. Do you remember how your box was sealed? Not the shipping box, but the product box. My box lid was sealed with a massive blank white shipping label, which did not appear to be something that should be used with a brand new, unopened product.
Sorry but I do not remember how mine was sealed. I purchased it in 2025 if memory serves me correctly. I do recommend you contact Aiyima directly to report your problem. It should be under warranty and as I said earlier, their customer service when i had a defective preamp was excellent.
Looks like it's my speakers. Happens only when I first listen in the morning, even with different amp. The sound improves after a few songs. And it sounds great the rest of the day, even when I turn off and back on later in the day. So it's not the A20. Maybe the speakers are just stiff in the morning as they sat unused overnight...
Maybe, probably, definitely it’s your brain creating the apparent difference…
