help with a recent switching pedal build...

Orange Amps Technical Q&A's

Moderator: bclaire

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

help with a recent switching pedal build...

Post by mr_william » Wed May 19, 2010 4:06 pm

Hey there!...

It's been a while, I know! hope everyone's well!

so i decided to try to build a remote switchable true bypass loop pedal!...

basically, a box, 4 jacks, a 12v input and a relay switch (vey simple!)...

im using a stereo jack to my guitar.. tip and ring being for the guitar's signal (hot and ground)..
and ring and sleave being for a toggle switch, wich has the 12v current running down the stereo jack

i can now turn effects on/off, in the loop pedal, from my guitar! (happy days!)..

i'm sure your all now thinking, 'great idea will' and you'd be right! :D..

the only issue is, when i switch, it sounds like a gunshot..

i'm assuming (i have VERY little electronics experience, though high in common sence!) there is some way i can put a resistor somewhere in the circuit, to stop the bang when i switch between on/off!

i believe it would just be the same way you'd do it in a 3pdt footswitch?

Cheers for any help you can offer!

Will
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

misterMagoo
Orange Master
Posts: 2432
Joined: Wed Dec 02, 2009 4:53 am
Location: PA, USA

Re: help with a recent switching pedal build...

Post by misterMagoo » Wed May 19, 2010 5:20 pm

Sounds like a problem I had while changing my wah pedal to true bypass. I forgot to ground the input lug. It was such an unbearable pop to turn on the wah pedal that I stopped using it until I fixed it.

I would say make sure everything is grounded first, then if you still have that problem to start thinking about resistors. Is your toggle switch grounded on your guitar? Is the input at the box grounded? Those are the first places I would look.

So how do you use that toggle any way? I'm sure you could get some really cool effects with a rapid switching technique. Very intriguing!
-Joe
My mother wears army boots.

Image
RV50 mkI
AC30 combo

Hot tamale.

http://lifereformatted.wordpress.com/
Check out my blog - adventure, travel, and the meaning of life.

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

Re: help with a recent switching pedal build...

Post by mr_william » Thu May 20, 2010 12:21 pm

well its in it's prototype statages at the moment...

basically, its a 12v relay...

rather than the 6 pins that a dpdt footswitch would have, it's got 8... the other 2 for running 12v round. 12v on, swich moves, 12v off, switch off...

i'm using a tt, and sometimes use a boost (tubescremer/clean boost/treble boost)..

and also use the volume on my guitars a fair bit.. so if im 'away' from the pedals when playing, i thought it'd be cool to be able to turn on the boost from on my guitar.

so i use a stereo jack, tip and ring for the guitar (so it works without using a stereo jack) and then the ring to sleave with just an on/off toggle. the 12v runs thru the jack lead (i figoured it'd be ok, as phantom powers 48v..)

everythings grounded as far as i know? (all the sleves are connected!?!)... i've tested it with a multimeter etc..

the toggle ISNT grounded on the guitar though (i'll look into that!)...

if i were going to go down the 'resistors' route.. i'd have no clue where to begin!...

like i said previously, i get by pretty much on common sence alone!

Cheers for the responce!.. i'll see if i can get a demo up somehow?!..

Will
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

thenetsux
Orange Hero
Posts: 367
Joined: Mon Apr 06, 2009 1:58 pm
Location: Chapel Hill, NC
Contact:

Re: help with a recent switching pedal build...

Post by thenetsux » Sun May 23, 2010 3:20 pm

I recently added a basic channel switching pedal to my true bypass loop pedal. I found that there was bleed over from one circuit to the other, possibly due to sharing a common ground, creating a grounding loop. I ended up having to isolate all connections (input jacks, switches) of the switch pedal from the loop pedal and that took care of the pops and buzzing. I don't think you'd need to ground the switch that your using to engage your relay, but I can't say for certain as I haven't seen the schematic. If you are having a grounding issue, you can try placing a bleed resistor of about 1M on your ground. Good luck, very creative idea.
Image
http://www.myspace.com/systemsnc" onclick="window.open(this.href);return false;
http://www.myspace.com/thebandmake" onclick="window.open(this.href);return false;

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

Re: help with a recent switching pedal build...

Post by mr_william » Mon May 24, 2010 10:47 pm

as i said before, i have no knowledge of electronics hehe!.. just thought i'd try it and 'how hard can it be'...

i'll draw out a diagram of sorts tomoro and post it up, maybe help me elaborate on the idea...

if it works, it'll be a great addition to my band practice rig (dont take the full board!)..

just put a boost in the loop of the pedal i made, and turn it on/off from the guitar!...

Will
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

Re: help with a recent switching pedal build...

Post by mr_william » Tue May 25, 2010 3:47 pm

Image

it's a little crude...

the sleeve's are all sharing a common ground...

the relay's top 2 pins are for the 12v to pass thru, turning the switch on/off
the next 2 down are the fixed ones (usually found in the middle on a dpdt switch)
the next 1 are switch off
next 2 switch on

the 12 current runs down the stereo jack, into the guitar, which goes to an on/off toggle.

any ideas why it's popping? :$
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

Neiloler
Lord of Orange
Posts: 13310
Joined: Wed Mar 22, 2006 12:06 am
Location: USA

Re: help with a recent switching pedal build...

Post by Neiloler » Tue May 25, 2010 5:20 pm

I think what you may be experiencing is a bit of back emf (electromotive force) because you're starting and stopping the voltage going to the relay's inductive coil. What? I know. :)

A good place to start:
http://www.howstuffworks.com/relay.htm

Basically, the pop, I'm guessing, comes from the fact that you're opening and closing the 12v connection to the relay. Because of the inductive coil in there, when you either try to put current through or stop the current going through the coil, the inductive coil resists the change. (That's why current lags voltage in an inductor, but that's another topic for another time)

This resisting change thing is when the coil basically says "I don't like what you're trying to make me do to my magnetic field, so I'm going to align myself THIS way to look like I'm not changing instantaneously". When that happens, the coil will actually produce a backwards voltage, and probably produce a pop.

Electric starters in cars happen this way, a big inductive coil is "charged" up by running current through it, then the connection is broken, and a huge spark comes to the right place in the engine (spark plugs).

I'm guessing you'll need to put a diode in there to prevent the backwards emf (think "voltage") from blasting your other relay contacts somehow.

Here's some sites for info and such, the GeoFX site is particularly useful, read the last 3 paragraphs:

http://www.diystompboxes.com/smfforum/i ... ic=67705.0

http://www.geofex.com/Article_Folders/r ... _signa.htm

And way to use your loaf Sir Will, this is a cool project (I'm working on something like it :))

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

Re: help with a recent switching pedal build...

Post by mr_william » Tue May 25, 2010 7:53 pm

your brain is big!... neil! gunna give that stuff a read, i'll keep you and everyone else updated as to how i get on!....

neil, if you've ever seen 'billy maddison' (adam sandler film!) when he wins the spelling bee, against that little girl and shout's 'I AM THE SMARTEST MAN ALIVE!'... you should maybe try doing this some time (not the spelling against little girls!.. that would be weird!)
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

Re: help with a recent switching pedal build...

Post by mr_william » Tue May 25, 2010 8:21 pm

ok, i read that (i actually read the last link prior to starting!)...

as i said before, my knowledge of electrionics is pretty basic...

but i understand that it's building up a charge and when it changes, it's then makeing it bang...

(dc offset! i believe my old marshall dsl100 had this issue, something to do with them not settleing down at 0v)

so to prevent this, i need to keep the current running, around the relay when the switch is off... right?

so i need to bridge the power pins in the relay with something?! (diode? resistor? capacitor?)...

is this right, or am i way off?..

cheers for anymore help offered guys!

Will
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

OrangePaul
Orange Master
Posts: 2785
Joined: Sun Jan 24, 2010 12:21 am
Location: UK

Re: help with a recent switching pedal build...

Post by OrangePaul » Thu May 27, 2010 10:06 pm

http://www.rentron.com/PicBasic/relay-circuit.gif

Yeah try a diode across the relay coil (switch trigger as you describe it on your diagram) with the band on the diode connecting to the V+
If u imagine on this circuit above link here its just the same but you are doing the job of the transistor with the switch on your guitar.
Paul.
Paul.

Image

Neiloler
Lord of Orange
Posts: 13310
Joined: Wed Mar 22, 2006 12:06 am
Location: USA

Re: help with a recent switching pedal build...

Post by Neiloler » Fri May 28, 2010 7:36 am

Yup, like Paul says, I means that you're going to want to use a diode to prevent the current flowing when/where you don't want. Try it, and let us know how you get on.

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

Re: help with a recent switching pedal build...

Post by mr_william » Fri May 28, 2010 5:08 pm

cheers guys, i'll report back when i've modded it!
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

defrag
Orange Expert
Posts: 606
Joined: Wed Dec 19, 2007 3:51 am
Location: USA
Contact:

Re: help with a recent switching pedal build...

Post by defrag » Fri May 28, 2010 6:39 pm

FET-switching like you see in Boss effects pedals generally provides noiseless switching.
Boss isn't TB though but perhaps one could modify the basic flip-flop schem:

http://www.bossarea.com/forum/topic.asp?TOPIC_ID=1036

In addition, check out Jack Deville clickless TB switches:

http://www.jackdeville.com/clickless_switch.php
Mesa Roadster, Egnater Rebel, Orange Terror, Blackheart Giant • Ric 360MG, Schecter C1, Martin OMC15, Moog Phatty/6 Foogers, Korg microXL/Electribe MX • Alesis, Boss, Mackie, Peterson, Radial ( o )==#
http://gamefreaks.net/defrag/personal/music.html ♪♫

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

Re: help with a recent switching pedal build...

Post by mr_william » Tue Jun 01, 2010 10:37 am

ok, tried a diode across the relay coil!...

it reduced the pop took out a lot of the harsh high end of the pop...

i thought it could have been the switch on the guitar being amplified by the pickups, but i turned the volume off.. and it remained...

so the pop is reduced, and the harsh high end has been taken out... (with the introduction of the diode!)..

but theres still a pop!...

im gunna check the whole thing through, make sure things are as neat as possible! (it was origionally thrown together, as it's more of a prototype than anything else! :$..)

i'll report back again when changes are made!
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

mr_william
Orange Master
Posts: 2981
Joined: Thu Jan 18, 2007 11:25 pm
Location: Sheffield, England

Re: help with a recent switching pedal build...

Post by mr_william » Tue Jun 01, 2010 9:33 pm

ok, the diode helps a lot!...

things are a bit neater in there, and its not so thrown together!...

i tried it thru the orange (for the 1st time!)..

and the pop isnt as loud as on the practice amp (suggests the cheepo transistor amp has issues! - it does pop a lot when turned on/off..)

but there is still a small pop when switched...

it's easier to live with, and proberbly wouldnt be audiable in a band mix.. but i do think if i keep going with it, it'll be 'studio quiet'...

how are these 1 meg resistors used in the standard 3pdt footswitches?..

i think that will be my next port of call!..
Will.
Bink wrote:Will you're a genius!! :D
Randy Bass wrote:For the record, mr_william is a genius :D .
Image

Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests