• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Best way to mount tubes when used in an automotive environment?

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Even cooler- Milbert BaM230/235 from the 80's.

I didn't realize they were still active. Milbert, the Most Musical Amplifiers

Thanks for reminding me of these! I'll likely do either a similar build with 12AV5GA and screen drive/crazy drive, or a lean class AB2 with EL86 or 6P43E. Reminds me to look into the PSU they do.

Looks like they just PCB mount the sockets, and maybe just rubber dampers for the boards?

I can tell you what the military did back in the Tube Era (as I was an AT-3 in the NAVY doing intermediate level maintenance in 1973), they shock mounted the equipment, not the tubes.

Isolate your chassis.

Use it's mass to your advantage.

Laws of physics are the same now as then.

My plan so far is to mount the tubes on a sub-plate inside the chassis of the amplifier with chassis mount sockets, and then mount this to the amplifier chassis using rubber isolation studs for vibration protection.

Octal tubes will likely be mounted vertically, and I was considering the noval tubes horizontally with support at the nipple end of the tube, so that I can pack them together tighter and run 120mm fans under them as needed for heat abatement possibly. The amplifier chassis itself will likely end up mounted the same way to the car itself (73 super beetle) behind the rear seat, close to the centerline of the car when seen from the sides, so it isn't effected to much by body roll in corners. The car has been gone over, so it's relatively smooth (stiffer than stock for handling purposes) and isn't too terribly shaky except on very poor roads. It's a commuter car, so sees mostly relatively smooth highway miles.
 
I can tell you what the military did back in the Tube Era (as I was an AT-3 in the NAVY doing intermediate level maintenance in 1973), they shock mounted the equipment, not the tubes.

Isolate your chassis.

Use it's mass to your advantage.

Laws of physics are the same now as then.

Yep -It worked in MIG 25's in the sixties so I don't see why it shouldn't work now. My ex British Army Avo CT160 was still in use in 1992! I've seen a lot of old ex military tube stuff and the small tubes typically had cans on them and bigger tubes spring loaded retainers. Pretty much all internal wires were waxed cotton covered solid core, neatly whipped in harnesses and fastened regularly to the chassis and supports. Tubes were mil spec ruggedised versions, many of which are still available.
 
1625s were used in WW2 radio transmitters in fighter planes. I think they will do OK in a car.

And they are 6L6GA's internally so a 6L6 type circuit will work fine.

I think Tubelab has been down this road.

Twice.....My first car was a 1949 Plymouth with a 6 volt positive ground electrical system. The stock radio ran a pair of 6V6's in push pull through an oval speaker (5 X 7 or 6 X 9) in the dash. The power supply and audio amp was on a separate sub chassis, so I hunted for a second radio in junkyards and eventually found one. The radio in the dash came out and I mounted both power supply / amp chassis to a piece of plywood and stuck it in the trunk wired to a set of 6 X 9 inch car speakers on the rear package tray. I fed them with the output from my Panasonic cassette player and had the loudest car stereo in school. It sounded great to me but I was an 18 year old kid.....loud = good! Despite running that car (the tank) over everything in my path and even chasing some dirt bikes around on their motocross track the stereo never failed....until I ripped it out, rewired the car for 12 volt negative ground and switched over to an 8 track deck and a DIY solid state amp. There were no special mounting techniques used in that Motorola built radio. All octal tubes in decent, but standard sockets.

Fast forward many years. I had a 1999 Mustang with the factory Ford "Mach 460" stereo which had died. I got the brilliant idea to stick my 845SE amp in the trunk running off of a 700 watt power inverter. The electronics worked OK and it sounded nice when the cart wasn't moving. The rough roads in our neighborhood provoked a "twang" in the speakers with nearly every bump......Big transmitting DHT's don't like pot holes and one lost a filament, so that experiment ended.

I toyed with the mobile tube amp idea several other times, but never got to the point of installing one in a car.
 
I just used octal sockets in a 60W/channel mobile amp. The sockets were used ones so I tightened the contacts a little. Some Octal sockets use a cylindrical contact and some use what amounts to two 'rails' up the sides of the pin. Cylindrical is better IMHO.

A 100 Watt Tube-Type Car Stereo Booster Amp

The chassis was mounted in the 19" rack in the back of the van in the usual manner, but car-folks can do more compact work. I mean, this was just thrown together in 3-4 days as an experiment and it sounded so good with a pair of old Utah 12" ported 2-way enclosures behind the seats that there was no reason to ever remove it.
After a crash all the tubes including the screen voltage VR tubes were still fully seated in their sockets and the amp was later removed and checked. It worked but a large axial lead cap supported by its long leads had come loose at one end.
I think the peak Gs in the crash were about 10 for 100ms but there are pictures of the vehicle after so you can judge about whether you may have trouble with tubes staying in sockets. I suggest mounting tubes upright, base down. If not, then support them in some way and prevent them from moving out of the socket.
A good bumper saves lives
 
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