I have an Aesthetix system (Rhea Signature, Calypso, and Atlas). I am very happy with the system and it sounds great.
I don't keep track of how often tubes need replacement, but not really very often for the Calypso and Atlas.
The Calypso has 4 tubes and the Atlas has two tubes so tracking down and dealing with a tube that is going bad is not very difficult.
Tubes deteriorate with time and usually one goes bad before the others. All you have to do is swap left for right for each pair (12AX7 and 6DJ8/6922) in the Calypso and with one or two swaps you will know which tube is bad as the issue will move from one side to the other.
You can just replace them all when one goes bad. I would determine which tube was bad so you can discard it and keep the good tube as a spare. You should call Aesthetix to find out the price of a factory tube set for each.
You should use balanced connections between the Calypso and Atlas. I found that sounded better than single ended (RCA) connections.
I don't keep track of how often tubes need replacement, but not really very often for the Calypso and Atlas.
The Calypso has 4 tubes and the Atlas has two tubes so tracking down and dealing with a tube that is going bad is not very difficult.
Tubes deteriorate with time and usually one goes bad before the others. All you have to do is swap left for right for each pair (12AX7 and 6DJ8/6922) in the Calypso and with one or two swaps you will know which tube is bad as the issue will move from one side to the other.
You can just replace them all when one goes bad. I would determine which tube was bad so you can discard it and keep the good tube as a spare. You should call Aesthetix to find out the price of a factory tube set for each.
You should use balanced connections between the Calypso and Atlas. I found that sounded better than single ended (RCA) connections.