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Vox AC30 / 6 TB ,all valve combo from 2002

Ideally identifying which and dismissing the roady would make more sense for this locally based, but made big-time band. Failing that - concerning cut grommets encircling valves to act as retainers in inverted amps. Lining the holes in the chassis where the valves pass through . a/ fairly rigid rubber of otherwise standard trunking grommets b/ fairly tight to the glass envelopes to function as retainers. c/ obviously they do no take much a jarr to cause breakage as no obvious damage to the cab.

The 4 o/p valves have spring retainers. One of the ECC83 quite neatly split in a ring where the grommet lies and white cap. I am thinking of running my plaited, high temperature silicone cord "rope", over the tops of all 6 of these small valves , located over the top "pips" and anchored to the chasis at the ends. Any comments pro or con ?

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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Reply to
N Cook
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Don't the ecc83`s have screening cans on them? that`s the usual method of keeping them in their sockets and protecting them.

Ron(UK)

--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com
Reply to
Ron(UK)

for

retainers

obvious

"rope",

"pips"

No skirts around the bases on the pcb or on the chassis so screening cans were never used on this model. It would be quite a work up to introduce cans on this. The chassis holes are about 3/4 inch above the valve bases, perhaps that gives a certain amount of screening

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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Reply to
N Cook

Do the bases have those little 'pips' to clip a retaining spring into?

Maybe a decent flight case is the answer, and a more careful roadie!

Ron

--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com
Reply to
Ron(UK)

I think the problem is not retention of the miniature tubes, but the fact that their socket (some distance under the chassis) obviously was jarred and shifted/vibrated enough to cause the tube envelope to hit the chassis hole.

I think that enlarging the hole or stiffening the chassis is your only choice. Retainers keep tubes in their sockets, but do not stop the socket from moving under the hole.

Tim.

Reply to
Tim Shoppa

The old valve TV's used to have a wire clip over the top of the valce to stop them falling out.

Reply to
Marra

on

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I had an AC30CC in recently. I don't like how they did that grommet thing on the preamp tubes. They really don't do *anything* besides provide damping to the glass envelope. What I would do is enlarge the chassis holes and put in larger grommets. Make sure the tube can be worked out of the socket with the grommet in place...don't go too small. Then the idea of strapping them down with some sort of retainer isn't a bad idea as long as yer in there.

Reply to
boardjunkie

sense

pass

and

cans

I can really only probe through the chasis holes but the bases seem smooth sided. I won't be desoldering wires etc to remove the pcb when all else is fine. I've made a mounts to one bolt for each transformer , remove all 6 grommets and tie down the valves using the glass-melt-draw pips on the valve tops. I usually use this plaited silicone cord or sleeving to stop a line of emiter resistors (well split into 2 so there is a joint to anchor to) from vibrating in combo amps .

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

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Reply to
N Cook

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