Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: lkrasner on May 26, 2015, 02:20:51 pm
-
I'd like to add a mute switch to my amp. Basically, I built it without a standby switch, but the guitarist who will be playing it wants something to quickly mute and unmute the signal as a switch. My though was just use a switch to float the guitar input and short the first valve to ground. However, I accidentally bought an SPST switch, which I don't think will really work at all, so, my question is this: Can I use the SPST switch in a good way that won't cause bad popping, or if not, what is the best way to implement a mute switch.
-
If the amp has a push/pull output then just connect the SPST switch between the two control (signal) grids. Works very well with no pops. Look at the Standby switch on this old Silvertone 1484.
http://el34world.com/charts/Schematics/files/silvertone/silvertone1484.pdf (http://el34world.com/charts/Schematics/files/silvertone/silvertone1484.pdf)
Don't run long unshielded wires to the switch. Keep'm short.
-
If the amp has a push/pull output then just connect the SPST switch between the two control (signal) grids. Works very well with no pops. Look at the Standby switch on this old Silvertone 1484.
http://el34world.com/charts/Schematics/files/silvertone/silvertone1484.pdf (http://el34world.com/charts/Schematics/files/silvertone/silvertone1484.pdf)
Don't run long unshielded wires to the switch. Keep'm short.
It is single ended unfortunately. I have an effects loop, so that could be a good spot, however, the switch will be located right next to the input, which is why I though switching the input wold be a better idea since wires would be short.
-
Connect one side of the switch to ground. Connect the other side to the grid of the preamp tube, or the tip of the input jack, or the wiper of the volume control.
-
Why a switch and not something simple like a volume pedal?
-
Why a switch and not something simple like a volume pedal?
The guitar player wants a switch. Otherwise,he'd do what I do and twist the fricken volume knob. :icon_biggrin:
-
Or even any tuner pedal worth having mutes the signal when engaged. Maybe he switches guitars a lot? That could be why he wants a mute so he can do that quietly? Turning down the master volume while switching solves that.
Yeah a mute switch on an amp is pretty dang rare. Well, that's all a standby switch is good for but that's another topic for another day...
If he's dead-set on a switch on the amp, then I guess use the SPST you have and just shunt the input signal to ground right at the input jack. That's what a switched input jack does when there is no cable plugged-in.
-
Shorting the guitar will work.
A naked guitar can be sorted very easy, leaving negligible signal.
A hot pedal (pedal board) may be harder to short. However there should be significant reduction. Not so you can rock-out while the preacher is speaking softly, but ample for any normal gig.
Jack, 1K series, SPST to ground, then on to your conventional first stage input. (The 1K reduces the chance of hurting some over-pepped pedal with the short, though pedals harmed by shorts usually get weeded-out very quickly.)
-
If you want to mute whilst changing guitar these are excellent:
http://www.neutrik.com/en/audio/plugs-and-jacks/professional-1/4-plugs/silentplug/ (http://www.neutrik.com/en/audio/plugs-and-jacks/professional-1/4-plugs/silentplug/)
There's a little sleeve that slides against a spring, operates a reed relay and shorts the plug. Friend of mine gave me one and it I used it at a gig where I changed guitar several times with zero clicks, pop's, hum, buzz etc.