Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: TIMBO on December 31, 2012, 04:51:49 am
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Happy New Year guys, I thought i'd start it with a real head scratcher. I've nutted out the circuit on the amp and it works fine but i can't for the life of me work out how to add a foot sw.
The switches on the amp are a push button latching that has a 12v LED and the switch is similar to Dougs relays where the bottom pins marked "C" is common and when the button "out" the top pins are connected and when the button is "in" the middle pins are connected.
So i have it wired so that when the button is "out" it turns the relay ON (this will disengage the FUZZ circuit,RELAY A and the OD, RELAY B ) and when the button is "in" the relay is OFF (engaging the circuit and also the LEDs to show that that effect is on.
That was the EASY part, NOW HOW DO I ADD A FOOT SW. for the two effects :think1: :BangHead: :sad2:
Switch explained :-
Bottom pins Common
Middle pins connected (button in)
Top pins connected (button out)
Outer middle pin + side of led (left side)
Outer middle pin - side of led (right side)
Anyway, if anyone can help that wuold be great. Thanks
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I don't understand your question well enough to give you a direct answer?
And I don't know if this ARCHIVES thread on relays and foot switches would be useful or not in this situation?
http://www.el34world.com/Forum/index.php?topic=14348.0 (http://www.el34world.com/Forum/index.php?topic=14348.0)
With respect, Tubenit
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Hey Tubenit, I look at the archives and was unable to use any of those ideas. I think that that main is that the relay needs to be off to turn the effects on, the reason for this is so the relay doesn't effect the circuit (cause buzz) but if the relay was on to engage the effect then i could use a switch jack as in the archives.
Anyway i'll give it some more :think1: Thanks
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ME thinks i've got it..........
SHEET 2:-
Stereo switch jack used, this works even when SW. A and B are on or off but NO indicator LEDs to show whether FXs are on or off.Although a battery could be put into the pedal box to power LED :think1:
Sheet 3:-
Proberly the better option to use a DIN connector similar to Ts setup on the D'Mars but as i see it the toggle swithes on the amp need to be in the OFF position for the foot sw. to work, RIGHT.
On this one i have done the same, SW.A and B have to be on (relay off and LED on)which is fine this will indicate that the foot sw. is in use and the effects can be turned on or off by the footsw.
An added 12v supply can be added to power the indicator LEDs on the foot sw.
Any more options would be great. Thanks
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You could wire the panel switch and footswitch in a common "3-way" configuration. Then you could turn the relay on or off from either switch. Functionally like a common 3-way light circuit in your living room.
Edit... added drawing
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Ooooooooooooooo,That sounds great, A little over my head so you might have draw me a picture. Thanks
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WOW Steve
Which idea :thumbsup:
That is a GREAT one !
Franco
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And if you need a dual 3-way footswitch, use this. One switch will require a 3 conductor cable. Each additional switch will require 2 additional conductors. So, a dual footswitch would require 5 conductors between the amp and footswitch assembly. 5 pin DIN connectors would look neat. I'd probably just use a small barrier terminal strip and stakeon lugs (because I have'em already).
Don't even think about adding a LED to the footswitch with this arrangement unless you're willing to increase the # of conductors to the FS.
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Thanks Sluckey, Always good info. :icon_biggrin: