I have a Red Wine Audio Isabellina HPA LFP-V DAC/amp that I bought in 2010 (about $2500 in 2010 dollars) when it was considered by some to be an end game product. I’ve done some tube rolling with it and currently have a Mulllard 1980s E88cc NOS valve in it. Since I bought my Hugo 2 I put it...

I recently pulled out from storage my Red Wine Audio Isabellina HPA LFPV edition and stuck a 1960s mullard tube in it. The amp has a built in DAC which from memory is 24/96 limited. Theres no line in for overriding the DAC. I know tube amps are recently becoming more popular in certain...