Move Q11–Q14? If there was somewhere obvious and easy to get to then maybe. If they really have a heat problem then maybe a solid, pcb mounted, extruded heatsink would be my first step. But considering the 120mA indicated on the schematic they shouldn’t be working hard. I have spaced out Q1 and Q2 and given them significant copper pads top and bottom. The position isn’t ideal but hopefully with the equivalent components and the copper to sink heat into, they should fare better than the original parts. I like your thinking on the power distribution but had put together a different approach . How about a variable Voltage supply feeding J7? My problem is finding a regulator that will run on the available line voltages. The 32V at J5&6 is such an easy candidate. But as you point out: “ Another reason is that the J30 IIRC is mostly for control circuitry and not audio so putting the VFD grid on this keeps the supplies for the amplifier sections away from noise.” My version (1C) with the emitter follower (that evolved a bit) added, is pretty much done. But, VFD Grid or alternate display options when the VFD finally gives up, an AUX Power Supplies option could be useful. Using 1C as the base I have made the board 28mm longer and added the PSU unit there. So Version 1D. Will Route a couple of slots across the board on the current boundary. Don’t want the mod? Just snap it off and throw it away. So, minimally invasive of 1C pcb and there is space in the chassis. New fuse off J30 feeding 2 x DC to DC Converters. The one I have sketched in is a V7824W-500. 52V in, 24V 300mA out. That’s for the Grid Supply. So V Out on J7 is adjustable 7-22V 250mA. In the space underneath the fuse holder I am going to place a 64pin STM32F4 MPU that wakes up when it gets warm and then wakes up occasionally to monitor the system. It could also drive an alternate display, but let’s start simple. As the MPU is to be minimally invasive of the 1C board I may add another 2 layers to the PCB to route the tracks to thermocouples that could be added near power components and other A/D devices. Plus my wish for a remote volume control would be step nearer.