Hi.
I´m thinking about try to make a footswitch for this amp and according to the schematics shared in the forum we can find a press switch to make the switching between Clean/Overdrive, my initial idea was to use a relay activated by the footswitch or the amp switch after cut the lines ti isolate it.
I understand a few things about electronics but not enough for this project.
Any sugestions will be welcome?
Many thanks in advance
I´m thinking about try to make a footswitch for this amp and according to the schematics shared in the forum we can find a press switch to make the switching between Clean/Overdrive, my initial idea was to use a relay activated by the footswitch or the amp switch after cut the lines ti isolate it.
I understand a few things about electronics but not enough for this project.
Any sugestions will be welcome?
Many thanks in advance
S1? OK, it would be replaced with a DPDT relay, and a footswitch would be used to turn the relay on and off. You would remove the switch itself, and wire the relay contacts to the points on the circuit board where the switch was. You now control the relay with a footswitch, but no longer have the panel switch.
To keep the panel switch AND have a footswitch, makes it more complex. It would be exceedingly clumsy (in my view) to try to insert the relay in between the switch circuits, so if I HAD to have both, I'd remount the switch off the board, and use the switch to control the relay. Put the footswitch jack in series with the panel switch, and use a cutout jack. Now you can have both, but the panel switch must be in the closed position for the footswitch to work.
The relay coil will need power. You have 15v supplies for the op amps, you could use one of those, and add a dropping resistor for a 12v relay. Or you could fashion a voltage drop off the main rails, or even fashion a new small supply off the transformer. But depending what you do, common relay voltages are 5v 12v 24v.
To keep the panel switch AND have a footswitch, makes it more complex. It would be exceedingly clumsy (in my view) to try to insert the relay in between the switch circuits, so if I HAD to have both, I'd remount the switch off the board, and use the switch to control the relay. Put the footswitch jack in series with the panel switch, and use a cutout jack. Now you can have both, but the panel switch must be in the closed position for the footswitch to work.
The relay coil will need power. You have 15v supplies for the op amps, you could use one of those, and add a dropping resistor for a 12v relay. Or you could fashion a voltage drop off the main rails, or even fashion a new small supply off the transformer. But depending what you do, common relay voltages are 5v 12v 24v.
Thank you for your answer Enzo.
Regarding the relay solution, my main consern is the possible "noise" the coil can cause. Dont know if is a just a possibility or something to be realy conserned about.
Power the relay, regardless the source, is not a problem I belive.
Regarding the relay solution, my main consern is the possible "noise" the coil can cause. Dont know if is a just a possibility or something to be realy conserned about.
Power the relay, regardless the source, is not a problem I belive.
High gain guitar amps are full of relays, they have used them for decades. You will want to snub the relay coil with a reverse diode, but that is common practice with relays.
Thanks Enzo
What is the most common relay used for this kind of application?
Many thanks in advance
What is the most common relay used for this kind of application?
Many thanks in advance
Any generic small signal relay will work, select appropriate coil voltage. Small ones fit your space.
We could also use pairs of small JFETs, but I think you might understand the relay approach better.
We could also use pairs of small JFETs, but I think you might understand the relay approach better.
Hello Astrostar,
Can you post a picture of the switch placed on the pcb. I think to have a sollution so that you can use both the panel switch and the foot switch.
I do not remember exactly how its done. Yes, a dpdt pb switch but I need a pic.
Cheers
Can you post a picture of the switch placed on the pcb. I think to have a sollution so that you can use both the panel switch and the foot switch.
I do not remember exactly how its done. Yes, a dpdt pb switch but I need a pic.
Cheers
I´m sorry for late response.
Yes, Tarzan it is a DPDT (on/on).
I was about to make it with a relay activated by the original switch to closing/opening OD/Clean channels as Enzo also sugested.
I already spread the switch pins to the sides to remove it from circuit and just control the relay.
Any other point of view is welcome.
Thks
Yes, Tarzan it is a DPDT (on/on).
I was about to make it with a relay activated by the original switch to closing/opening OD/Clean channels as Enzo also sugested.
I already spread the switch pins to the sides to remove it from circuit and just control the relay.
Any other point of view is welcome.
Thks
The picture of the switch in place.
An externally hosted image should be here but it was not working when we last tested it.
Having put it together and tested it I must say it worked quite well, very low, if any, noise came from the relay to the speaker but, I dont know if this is very useful once the sound volume difference from Clean to Overdrive is huge, this means the if you are playing on Overdrive and switch to Clean the volume drops and we have to turn it up alot to be eard. I guess it would need some kind of compressor...
Well JonSnell... it worked, the Clean channel become much louder but in the quick test I made (just a 10k in parallel to bring it down a bit) I don´t know but is seams the sound lost mids and highs... I did not test tone controls.
Thanks
Thanks
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