I'm about to start working on a new DIY band demo... Since this is a home grown production, we're going to record the basic rhythm tracks and overdub the rest as needed. In an attempt to isolate sounds, I'm running the bass DI (Monique), keys DI, and I'm going to run the guitar amp (my Fender Twin) as isolated as possible. The drums should be the only 'live' sound in the room. Luckily we have a 2 room practice space, and I'll put the guitar in the OTHER room (no door, though). My plan is to build an impromptu isolation box for the amp (which we won't be cranking anyway). My question with my Twin, do I risk overheating with this? The box is going to be double-thick corrugated cardboard, and it will be a couple inches taller than the twin, it will extend about 2 feet out front of the twin, and with a couple inches on each side. The inside of the 'box' will be completely lined in mattress topper foam. Most of the space in the front of the box (in front of the speakers with a bit of 'breathing room')will be stuffed with other 'fluffy' items (pillows or blankets). The top will be removable for access. There will probably also be additional 'damping placed OVER the whole box. Now the amp stuff: -Fender 135w Silverfaced Twin Reverb -4x 6L6 tubes plus 12AX7/12AU7's -We won't be running it cranked. It probably will actually be closer to idling, given we use it for clean tone and don't want extra volume in the room. We'll be running an afternoon of pre-recording rehearsals to get our 'sounds' and get everyone used to headphones and tweak the HP mix. The following day we'll be tracking 5 to 6 songs, and I can certainly 'open' the box during breaks or even every few takes. What's the tube amp consensus with this?