I installed an Allen transformer in my '67 Bandmaster head. Pretty much plug 'n play except for some chassis drilling for the mounting holes and putting in a switch so I could choose between 4 ohm or 8 ohm.
The only glitch was reversing the 6L6 leads. 5 seconds on, a loud screech, and shut down.. Resolved that issue..
Put it all together, plugged into the CRex, and it's glorious.
Channel 2 warms up as usual.
Channel 1 does not. The amp has to sit and idle for a minute or more and then Channel 1 comes in normally.
Not a tube issue. I have multiple sets of tubes and have changed/swapped all of them. (except for the power tubes). Same issue.
I did do the Robinette mod so that the vibrato works on both channels. But that was months ago and it's been fine.
Any ideas?