Idea for remote activation of Boost switch in PV C30 amps... Enzo?

[Steve A.]

Here's my idea: attach a device to the control panel of the amp to push down on the plastic boost switch. You'd have a footswitch with one or two 9V batteries to supply the power to something like a small elctromagnet which would activate the push button. I thought of two different ways to mount it- maybe with a rubber coated magnet, or maybe have a clip that you would slip under the loosened input jack nut.

There would be an adjustment on the plunger that would shut off the 9 or 18 volts when it reached a certain position, so as to not damage the push button or drain the batteries.

Any thoughts on this? It sure sounds easier to do than adding a separate relay board to a Classic 30!

Steve Ahola

[Enzo]

Well, I know how much we all hate to take those apart, but that seems over the top to me. Hire a roadie to push the button for you.

I would use a relay. Why add a whole board for a relay? Just glue one to some convenient spot on the board. Glue it upside down so the legs stick in the air, then run wires from those legs to where they need to go. There are already DC supplies in the amp, there is already a relay even. I'd glue it right next to the panel button to keep the wires short. Should be room. There are smaller relays than the one in the amp now, so if space is an issue, you can find smaller ones.

You could wire the contacts in parallel with the existing switch. Leave the panel switch OFF when using the footswitch. Without the footswitch, the relay stays off and is out of the way, so the panel switch can be pushed if you like at some point. NO mechanical thing in th way, y'see.


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By the way, the panel switch is a push/push type, so if you did a solenoid button pusher, it just needs a quick pulse every time you want to switch the switch to the other state. A momentary footswitch would be all you need. Tap it, and it completes the battery to solenoid circuit and pulses the coil. No need for voltage sensing timer circuits. As long as you don't stand on the stomp switch an hour, the battery will last a long time.

If I were to do that, and I tell you I wouldn't, but if I did, I'd mount the solenoid on a little metal plate over the button, and the plate would be mounted to the cab under the handle bolt thing. Remove the handle end piece nearest the thing, drill a hole in the metal plate, sit the plate where the handle end was, line up the hole, and remount the handle end with the bolt running through the plate. Handle assembly holds it in place. Very simple, but my description might not be. Part of the plate would stick out over the panel switch and provide a spot for the solunoid to mount.

Solenoids com in push and pull types. I'd select a push type.

www.jameco.com sells some small solenoids, look at stock number 149762. it mounts with a threaded bushing like a pot or switch. It is 2.5" long and .6" diameter. has a .24" stroke. There are others similar with longer strokes.

But really, I'd find a relay much easier myself. ANd if you wanted, you could wire the reverb for always available and use that section of the existing footswitch to control the thing.

[Steve A.]

Enzo:

Well, my idea was something that mounted on the outside of the amp and could be installed by someone who knew absolutely nothing about electronics...

Do you think that the momentary pulse would be enough to engage the switch? I was thinking of various actuators used in HVAC that I am familiar with- which will have a microswitch to kill the power when a certain position is reached.

I do like your idea of just gluing the relay to an unused part of the board. I guess you would use a DIP socket for the connections- right?

With the relay board that I added to my modified Classic 30 boost switch 10 years ago, I think it would have been better to just add a new jack and footswitch, rather than patch it in to the reverb switch circuitry- people would screw that up and would then have problems with their reverb...

Thanks!

Steve Ahola

[Albert Kreuzer]

I like the roadie idea. Have been wanting to hire one for years

Cheers,
Albert

[Enzo]

Industrial processes have limit switches and stuff, but this is too simple for that. If you want to do the mechanical thing, the solenoid has a limit to its travel, it has a stroke length rating. Mount it so that the farthest reach of the stroke is appropriate for the situation. Then no electronic nonsense is required to limit travel.

The panel switch is normally activated by a momentary pulse of your finger pressure. It would not know the difference if a solenoid was doing the pushing. Mount a solenoid over teh switch and turn it on long enough to push the switch down. The switch has its own latching mechanism.

As to screwing up the existing circuitry, this solenoid will require power, so unless we build an external power supply for it, we have to tap into the circuits anyway.

In my humble example earlier, all the circuit was was a power source from the amp, and the solenoid and switch in series across it. The switch was momentary, so the solenoid was on whenever the footswitch was pressed. I doubt you could step on and off that switch fast enough that the solenoid wouldn't have time to activate the switch. But if that turned out to be the case, just step on th switch a little longer.

You know, photographers sometimes use remote shutter button activators. It is a rubber queeze bulb with a tube down to the camera. The end of the tube screws over the shutter release button. Squeeze the bulb, and the air pressure flows through the tube and pushes a little probe out the end. That probe activates the shutter release. Maybe you could adapt that idea. Totally mechanical, no electricity at all.

The "dead bug" relay mounting - on its back, legs in the air - is simple. Glue it somewher, and just solder wires to its legs. No need for DIP sockets. I mean you could stick a DIP socket on its legs and wire to the socket, but why bother. Once it is in there, I doubt I'd be pulling the relay in and out.

If you don't mind drilling a hole and mounting a new FS jack, then fine. I try always to avoid drilling chassis holes.

[Steve A.]

...You know, photographers sometimes use remote shutter button activators. It is a rubber squeeze bulb with a tube down to the camera. The end of the tube screws over the shutter release button. Squeeze the bulb, and the air pressure flows through the tube and pushes a little probe out the end. That probe activates the shutter release. Maybe you could adapt that idea. Totally mechanical, no electricity at all...

Wow- I like that idea even better than mine! And glam rockers could use it to powder their noses between sets...

Steve Ahola

P.S. The reason I suggested using a DIP socket for the relay was so there would no chance of heat damage to the relay from ham fisted solderers (or solder fisted hams!)

[Enzo]

Are you planning some sort of commercial kit?

[Steve A.]

Are you planning some sort of commercial kit?

Me- go commercial?

Nah, I just like to throw ideas out- or would that be up?

[Rob Mercure]

Steve,

While I'm with Enzo about using a relay if you really want to avoid opening up the amp (mess) why not just go completely mechanical and use a sheathed cable such as automotive choke cable? At the moment I can't remember where I saw them but I remember some footswitches that mechanically switched "something" but in any case there are industrial foot switches that are heavy enough for a totally mechanical system. I've got one that weighs about 4 pounds - cast iron - that used a push-push system with a roller "micro" switch (damned big for "micro") with an additional coil return spring. I got if from a commercial wholesale electronics supply house that was going out of business for a few dollars. If you can find something like one of these it would be easy to use it to drive a "choke" type cable to "push-push." I'm not sure how you'd attach it at the Classic 30 end but, if desperate, you could make a "QAD" ("quick and dirty") wooden "C" clamp that reached from the back of the amp to the front using an eye bolt and a nut expoxied to the wood - made out of walnut it could even be "pretty." (I can't visualize the C 30's panel right now - haven't worked on one for over 5 years - uncommon around here - but if there's a 1/4" jack close to the switch it could be used to anchor the "pusher.")

Just give you some options - isn't Neil Young's Deluxe setup similar using motors to drive cables that turn knobs?

Rob

PS: How are you doing - haven't communicated in a while. If you've got my old e-mail just add a "1" at the end and I'm at "gmail" now.

[Steve A.]

Steve,

While I'm with Enzo about using a relay if you really want to avoid opening up the amp (mess) why not just go completely mechanical and use a sheathed cable such as automotive choke cable? At the moment I can't remember where I saw them but I remember some footswitches that mechanically switched "something" but in any case there are industrial foot switches that are heavy enough for a totally mechanical system. I've got one that weighs about 4 pounds - cast iron - that used a push-push system with a roller "micro" switch (damned big for "micro") with an additional coil return spring. I got if from a commercial wholesale electronics supply house that was going out of business for a few dollars. If you can find something like one of these it would be easy to use it to drive a "choke" type cable to "push-push." I'm not sure how you'd attach it at the Classic 30 end but, if desperate, you could make a "QAD" ("quick and dirty") wooden "C" clamp that reached from the back of the amp to the front using an eye bolt and a nut expoxied to the wood - made out of walnut it could even be "pretty." (I can't visualize the C 30's panel right now - haven't worked on one for over 5 years - uncommon around here - but if there's a 1/4" jack close to the switch it could be used to anchor the "pusher.")

Just give you some options - isn't Neil Young's Deluxe setup similar using motors to drive cables that turn knobs?

Rob

PS: How are you doing - haven't communicated in a while. If you've got my old e-mail just add a "1" at the end and I'm at "gmail" now.

With an automotive choke cable, to heck with the footswitch... put a gear shift lever on your guitar!

You could connect it to a system of pulleys so when you shift it into 1st it activates one push-switch and when you shift into other gears it might even adjust some of the controls.

Good to hear from you!

Steve Ahola