Thanks for sharing informationThey sent me an email about this replacement board too saying that it was developed using the Volot that I returned to them. Here's a quote from their email to me on the 3rd of September that might be helpful:
"The amplifier in low gain and mid gain modes could lose stability. This did not always happen, only under certain conditions. This problem led to a sharp increase in energy consumption, which ultimately led to the failure of the power transformer. At the same time, the amplifier itself was not damaged and after replacing the transformer it worked normally. There was no risk for the headphones either, and the amplifier is additionally equipped with headphone protection. At the moment, an upgrade kit will be sent to all buyers from the first batch, which will eliminate all risks. Installing it does not require soldering and does not require special skills."
So @Aibek the new protection circuit will be sent to everyone who ordered a Volot from the first batch (not sure how to tell who is in the first batch though)
I also often use low gain at burn-in time