Turret board isolation

[bnwitt]

Is anyone in here using any type of isolation on their combo amplifier turret boards?  By this I mean nylon standoffs, O-Rings or fiber washers between the board and metal standoffs or bolts or maybe between the metal standoffs and chassis.  I'm just curious if anyone has done this to reduce sympathetic vibration from the speaker/cabinet to the board components.  The old Fender fish paper itself seems to reduce this effect but a rigid G10/FR4 board bolted with metal stand offs to the metal chassis not so much.

[kagliostro]

HBP did this on his 25L15

but this has effect only on tubes, not board







http://el34world.com/Forum/index.php?topic=14263.0

Ciao

Franco

[pompeiisneaks]

I've almost exclusively used metal standoffs, and never heard any problems with it so far.  I've also so far only seen metal type standoffs in most other amps, but my experience is still pretty limited.  I know Doug sells some nylon standoffs, but I accidentally over tightened them once and shy away from them now.

I think tubes, especially types like EF86 that are prone to microphonics, can and should be mounted on some form of vibration limiting mount, though.

~Phil

[Ed_Chambley]

I use stiff springs and a hexhead bolts and lock nuts. Reason you may wonder. Cause I have them and don't have to  buy. These things are stiff very stiff.


Years ago I used roll pins.  I really hate to use threaded standoff. One bolt and one lock nut with some sort of sleeve.


Usually 1 in the center and 1 on each corner for 5 total.


When building on turrets and g10, a lot of people build tight because it looks good, but if you leave a bit of lead for expansion this takes care of the problem.

[sluckey]

I use the 1/2" and 3/4" threaded aluminum standoffs that Doug sells.

[tubenit]

I only use nylon washers and I cut a rubber washer that has some fiber in it and use a hole punch for the rubber washer for the bolt.
The nylon washer sits on top of the rubber washer.

Never had one come loose and I am thinking it may help some?  Certainly hasn't been a problem for me.

With respect, Tubenit

[p2pAmps]

I use the 1/2" and 3/4" threaded aluminum standoffs that Doug sells.

Same here except I have kinda settled in on 5/8" aluminum

[bnwitt]

I use the 1/2" and 3/4" threaded aluminum standoffs that Doug sells.

That's what I use as well.  Every time I've had an issue with cabinet vibration making it into the signal, it has been a less than perfect solder joint on a board component or tube socket pin which I found via chopstick-ing.  I was just curious what everyone was doing.

[jojokeo]

This is a non-issue if you’ve been in electronics long enough. Mount the turretboard very securely and if no locknuts use lockwashers and threadlock compound. Any material that can degrade, will degrade over time and many heating and cooling cycles such as rubber compound material. It compresses, then shinks, then cracks. UL certification would not allow for doing this or any other less than long term hokey attachments with high voltage circuitry. Caulking capacitors is the thing to do since they are the only real noise making possibility mounted to a turretboard aside from certain relays.
Tubes and sockets mentioned earlier are not normally mounted directly to turret boards therefore not applicable to the original question. But even most of these degrade over time or become loose and should be monitored regularly. And if they do become loose, then the method could actually worsen the microphonics situation.