18Watt.com

Does anyone have an opinion about the value of mounting sockets with grommets vs directly to the chassis?

i've seen them used with ef86 tubes which can be a bit microphonic.

geoff 1965 wrote: ↑

Tue 06/04/19 10:47 pm

i've seen them used with ef86 tubes which can be a bit microphonic.

I would say that doing that is a compensation for a poor design - it is an attempt to get too much gain out of that valve, which should function properly if the internal shields are grounded and an external shield is fitted.

All tubes with grids are microphonic to some extent, but sometimes the effect is made obvious by its undesirability.

Sometimes the microphonic effect is desirable and adds to the sound. For example, I think part of the attraction in the 18watt sound is the interaction between the speaker and the output valves in the combo, rather than the head and cab configuration.

There is something to be said for shock mounting sockets to avoid feedback - this can be helpful to those people who like to play on the edge of feedback. Then again, you could say that those people only play that way to compensate for poor right hand technique. And shock mounted sockets are just one more thing to consider when something goes wrong. KISS.

"Sometimes the microphonic effect is desirable and adds to the sound. For example, I think part of the attraction in the 18watt sound is the interaction between the speaker and the output valves in the combo, rather than the head and cab configuration." From Zuceno.

That is a really interesting statement. I recall that being put forward many years ago (before I built my head/cab arrangement to suit other amps I owned at the time). But I never followed it up. I wonder if anyone has ever tested the theory to any extent.

Dd