I’m wondering what “rules” to follow in order to determine the minimal required mechanical distance between a set of KT-150 tubes and between KT-150’s and 6SN7 drivers. All running Class-A.
Just purchased 9 octal socket mounting plates with ventilation holes; 9 of these plates in a row means I need at least 57 cm chassis width. I guess this will give enough spacing and cooling.
Yes you may be right but given that you have asked for advice, and haven't started your build yet, why not space the valves as far apart as possible? It will be you that has to pay for new replacement valves, not the manufacturer or fellow DIY'er.
a commercial Hi-end amplifier with similar tube mounting plates -I’m sure I’ve seen more similar commercial