Input Jack as Battery On/Off Not Working, Help!

Started by mascis, September 07, 2015, 09:17:46 PM

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mascis

I've built a simple two button switch for my fender amps reverb and tremolo, with LEDs. The jack lead is stereo so I'm presuming the trick where you connect the battery terminal to the middle lug on the stereo input jack won't work because I'm already using that lug.

How else do you get the input jack to act as an on off switch? My LEDs keep going dim because they get pressed in my bag between gigs.

Any help is much appreciated. Thanks.

R.G.

Quote from: mascis on September 07, 2015, 09:17:46 PM
I've built a simple two button switch for my fender amps reverb and tremolo, with LEDs. The jack lead is stereo so I'm presuming the trick where you connect the battery terminal to the middle lug on the stereo input jack won't work because I'm already using that lug.
Yes, that's right.

QuoteHow else do you get the input jack to act as an on off switch?
You can buy special jacks with switches that change when a plug is inserted, but none of the switch conductors are connected to the tip, right, or sleeve of the jack. They're rare, and hence expensive, but they do exist.

An alternative is to use the OUTPUT jack as the switching contact. That's better in many ways, but since you have stereo in, you probably have stereo out, so that's not much help.


R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.


R.G.

Neither listing has enough information for me to say for sure, but I think that the first one is not what you want, the second could be.

What I was referring to was a jack that has a switch section completely isolated from the tip ring and sleeve of the signal path. There is a mechanical lever inside that moves a switch position. The switches are usually either of SPST, or SPDT format. In either case, you use your ohmmeter to find which contacts are signal, which are the extra switch. Then you find the two contacts that are open when there is no plug inserted, and shorted when a plug is inserted. You wire your battery positive or negative through that normally-open switch contact. It becomes a power-on switch that operates when a plug is inserted.

I suppose this is a little retro, but you could actually put a physical off-on switch on the pedal.

Power switching with a jack and plug is what everyone does, but it's substantially useless with modern setups being on a pedalboard, not just pedals set on the floor. In a pedalboard, a great deal of work goes into the lacing-together of the pedals in order. It's very frustrating to try to unplug all the input jacks to turn all the batteries off.

Like true bypass, input- (and output-) jack switching is an answer to a problem we pretty much no longer have.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

stallik

Quote from: R.G. on September 08, 2015, 08:20:18 AM
Power switching with a jack and plug is what everyone does, but it's substantially useless with modern setups being on a pedalboard, not just pedals set on the floor. In a pedalboard, a great deal of work goes into the lacing-together of the pedals in order. It's very frustrating to try to unplug all the input jacks to turn all the batteries off.

Like true bypass, input- (and output-) jack switching is an answer to a problem we pretty much no longer have.
This is true but 9v DC sockets also have switching which disconnects the battery when a 9v connector is inserted so there is no need to disconnect the jacks. While most of the time, this makes the battery superfluous, there are times when being able to unplug the 9v supply and run on battery could be useful and it does leave the pedal ready to to lift off the board for instant use somewhere else where input switching could be useful?

I always wondered about the possibility of using rechargeable batteries and have them recharge when connected to the pedalboard supply or perhaps a big master battery for the whole board which did the same thing. Then again, if there's power for an amp, there's power for a 1spot...
Insanity: doing the same thing over and over again and expecting different results. Albert Einstein

disto

What model amp is it? I had a quick google and none of the fender footswitches with LEDs in them seem to use have a battery in the footswitch.

Do you have a schematic to show how you wired your pedal up?

mascis

I use it with two of my Fender amps, a 65 Deluxe Reverb Reissue and a 65 Twin Reverb Reissue. I don't think there's a way I can source power from those amps without modding the amplifier, which I don't want to do. Correct me if I'm wrong though.

I'd rather not put a power switch on the pedal because it'll likely just get switched on by accident when in transport, like what's happening with the switches now. I'd use a power supply from my pedal board but I often do jazz gigs without the board but still like to use the switch for term and reverb from the amp so it makes sense to just keep the switch loose in my bag.

Could anyone point me towards one of these inputs sockets with a switch on so I know what I'm looking for? Remember it needs to be a stereo socket. Or any other ideas?

Thanks for all your help guys

disto

#7
I can understand why you wouldn't want an external DC supply. A toggle switch would be a quick fix but theres nothing to stop it being switched in you bag.

It looks like smallbear might sell one but there is no datasheet or wiring diagram so you would have to check with him. It is hard to tell but from the description it looks like the switch is isolated from the jack lugs which is what R.G was describing.

http://smallbear-electronics.mybigcommerce.com/1-4-stereo-isolated-dpdt-switch/

From the ebay links I am guessing you are in the UK so might not want to order stuff from the US. Musikding sell a similar looking jack, but again there is no datasheet/wiring diagram.

http://www.musikding.de/63mm-Stereo-jack-isolated-with-2-SPDT-switches

hymenoptera

Do I understand this correctly, you just added a simple LED/battery/resistor circuit to the existing stomp switches in the pedal? So the batteries don't actually power anything but the LEDs?

Or did the pedal already take a 9v before and you just added the LEDs?

Just trying to understand the problem better.

"Radio Shack has nothing for anyone who's serious about electronics." - Jeri Ellsworth

davent

Just put in a small slider switch for power. Not likely to be switched jostling around in a bag.


dave
"If you always do what you always did- you always get what you always got." - Unknown
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mascis

Hymenoptera, yes that's pretty much correct, except I made my own pedal as apposed to modifying the existing pedal, but yes it's the same switch just with LEDs and a battery added. I was having trouble at gigs accidentally leaving the reverb on, if monitors aren't great I struggle to hear on stage whether the reverb is on or not, until I realise why my funk sound has been a washy mess for half a song.

Davent, yeah slider switch is a possibility, I'd still prefer the on/off via one of these input jack switches if I can find one though. Don't really fancy drilling that rectangle for the slider when there's still a chance it's going to get knocked in my bag either... Thanks for the suggestion though, that's a lovely finishing job on the image of that pedal.

Does any one know where I might be able to get one of these stereo jack sockets with a switch?

Thanks

hymenoptera

Quote from: mascis on September 08, 2015, 12:00:15 PM

Does any one know where I might be able to get one of these stereo jack sockets with a switch?

Thanks

That one at smallbear will work if you don't mind waiting for it to come in the mail.
"Radio Shack has nothing for anyone who's serious about electronics." - Jeri Ellsworth

duck_arse

https://www.rockby.com.au/searchresSql_12.cfm?select=33&subcode=6&offset=151
Stock No: 26625

this is the part you want, but it's in australia. (don't get the similar single pole type, the switch will be normally closed.)
don't make me draw another line.

R.G.

Quote from: stallik on September 08, 2015, 08:52:52 AM
Quote from: R.G. on September 08, 2015, 08:20:18 AM
Power switching with a jack and plug is what everyone does, but it's substantially useless with modern setups being on a pedalboard, not just pedals set on the floor. In a pedalboard, a great deal of work goes into the lacing-together of the pedals in order. It's very frustrating to try to unplug all the input jacks to turn all the batteries off.
This is true but 9v DC sockets also have switching which disconnects the battery when a 9v connector is inserted so there is no need to disconnect the jacks. While most of the time, this makes the battery superfluous, there are times when being able to unplug the 9v supply and run on battery could be useful and it does leave the pedal ready to to lift off the board for instant use somewhere else where input switching could be useful?
...Then again, if there's power for an amp, there's power for a 1spot...
Yep. Most pedalboards make it fairly difficult to remove a pedal, for several reasons, theft being one of them.    :icon_eek:

But yes, if your needs include needing to remove a pedal for standalone use, a battery would be useful, I guess. IMHO batteries are best left out of pedals on pedalboards because they will eventually leak; but that's yet a different problem. To me it makes more sense to put a battery into the pedal after removing it from the pedalboard and have a guaranteed-good battery, but that's just my peculiarities speaking.

QuoteI always wondered about the possibility of using rechargeable batteries and have them recharge when connected to the pedalboard supply or perhaps a big master battery for the whole board which did the same thing.
We toyed with the master battery idea for several years at Truetone (formerly Visual Sound) and eventually decided it was not worth the investment. There are two such items already on the market. One is from Sanyo and IMHO is a very poor implementation. Another is by the guys who do Pedaltrain pedalboards and is better to my personal estimation.

The note that if there is power for an amp, there's power for a DC power supply is the big killer. That applies to all but busking applications and similar off-the-grid stuff.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

mascis

Right, progress! I've just ordered a stereo socket with DPDT switch, I managed to find one here in the UK after you guys showed me those links of what I should be looking for. I'll use my ohmmeter to figure out what's what when it arrives like R.G. kindly explained, and let you if it works.

Thanks so much everyone