So when I turn my rack on, my sd-1 also turns on. Just something to accidentally forget while playing live (it always stays on and is in the back of rack)
Anyways, is there a mod for this?
Anyways, is there a mod for this?
Want to make my boss SD-1 to always be on...
- Thread starter JonWormwood
- Start date
AudioGeekZine
arsehole know-it-all
Jind
Grrrr!!! (I'm a bear)
- Mar 7, 2009
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In essence this ^^^ but I would just look inside - take the two wires leading to the switch, cut them, twist together and viola!
TheWinterSnow
Den Mørke Natt
From what I can tell its not really possible. Looking at the schematic the switch is just a Normally Open switch so it only completes the circuit when the switch is "stomped on" which reverses the polarity and changes which transistor is on (either the bypass or signal BJT).
AudioGeekZine
arsehole know-it-all
^^^^
I knew this was true but didn't know the technical reasons. You'd have to look into a true bypass mod, then remove that switch from the circuit.
The DOD and Boss pedals and probably most other mass produced ones use a momentary push button rather than a normal switch.
I knew this was true but didn't know the technical reasons. You'd have to look into a true bypass mod, then remove that switch from the circuit.
The DOD and Boss pedals and probably most other mass produced ones use a momentary push button rather than a normal switch.
TheWinterSnow
Den Mørke Natt
A normal two way switch would have better results, other than the fact that you could get a "TRVE" bypass that way. However the only way to have an LED light up when the pedal is not in bypass is to use a flip flop circuit. Its the voltage supply to the LED that makes the Signal Transistor unstable allowing the bypass transistor to start on as the "on" transistor upon feeding power to the pedal.
A little fun fact for the electronics buffs, a flip flop switch was the first digital computer, the nature of the device allows one bit of information to be stored. The LED being on or off is the digital binary code of a 1 or 0. Essentially you are using a binary switch to turn on or off a set of opposing transistors, giving you a digital output (the LED). This form of a switch is called a bistable multivibrator because is is stable indefinitely until a trigger acts upon it. These are what make up the processing units inside a CPU, however inside a CPU there are about 781 Million transistors (in groups of two, so 390.5 million flip circuits) to process each bit of information as every bit processed needs one flip circuit. One keystroke on your keyboard is 8 bits, so just imagine the amount of bit needed to store everything that is on a computer. Crazy stuff! So now on remember this, your pedal has a very small CPU inside of it
To the OP, your best bet is to find somebody who is fairly advanced in electronics to modify the pedal so that the wet signal transistor is the "default" on when the pedal is powered up. If you don't care about the LED indicating whether the pedal is on or not, jump pins 1 and 2 of Q1 and remove R14, the pedal will always be on as soon as you turn on your rack, although the LED will not be lit.
A little fun fact for the electronics buffs, a flip flop switch was the first digital computer, the nature of the device allows one bit of information to be stored. The LED being on or off is the digital binary code of a 1 or 0. Essentially you are using a binary switch to turn on or off a set of opposing transistors, giving you a digital output (the LED). This form of a switch is called a bistable multivibrator because is is stable indefinitely until a trigger acts upon it. These are what make up the processing units inside a CPU, however inside a CPU there are about 781 Million transistors (in groups of two, so 390.5 million flip circuits) to process each bit of information as every bit processed needs one flip circuit. One keystroke on your keyboard is 8 bits, so just imagine the amount of bit needed to store everything that is on a computer. Crazy stuff! So now on remember this, your pedal has a very small CPU inside of it
To the OP, your best bet is to find somebody who is fairly advanced in electronics to modify the pedal so that the wet signal transistor is the "default" on when the pedal is powered up. If you don't care about the LED indicating whether the pedal is on or not, jump pins 1 and 2 of Q1 and remove R14, the pedal will always be on as soon as you turn on your rack, although the LED will not be lit.
The 'true bypass' mod idea is what you're after - the switching on the Boss pedals is *NOT* the simple switching we all know and love. You should be able to handle these yourself - just leave out the switch at the end.
TheWinterSnow, if you *ever* say 'bistable multivibrator' again I may not survive the laughter. I thought mathematics had bad names, but at least we don't have any that sound like pornographic supervillains.
Jeff
TheWinterSnow, if you *ever* say 'bistable multivibrator' again I may not survive the laughter. I thought mathematics had bad names, but at least we don't have any that sound like pornographic supervillains.
Jeff
TheWinterSnow
Den Mørke Natt
hahaha will do, I won't say it again. Its called that because each side of the circuit will go back and forth in a resonant (vibrating) frequency depending on the value of the capacitors in the circuit, the astable, mono stable, bistable refers to rather the transistors are both unstable (and continue to flip on and off at a resonate frequency) mono stable where only one transistor will stay on, and bistable where both will stay on unless something triggers then to switch.
To my knowledge all pedals use a flip flop switch, thats the only way to have an LED light up without having the power being supplied through it, as all the components will pull more current than an LED can handle there generally will be some issues. looking at quite a few schematics, Ibanex, Maxon, MXR etc. all use flip flop switches
To my knowledge all pedals use a flip flop switch, thats the only way to have an LED light up without having the power being supplied through it, as all the components will pull more current than an LED can handle there generally will be some issues. looking at quite a few schematics, Ibanex, Maxon, MXR etc. all use flip flop switches
I know that's why the name came up, but it's still exactly why Transformers-ripoff porn is punishable by a thousand deaths.
It's possible to have proper LED behavior with a DPDT - it's obviously no trouble at all to have an indicator LED with a 3PDT, and you can look at a somewhat-old RAT for the idea with a DPDT. Flipflops are used when a fancier switching system is desired - in the cases you listed (except for some *old* MXRs) the flipflop is there because the designers wanted the impedance fluffer to be working the whole time. Pick up a RAT that's about your age if you get a chance - the one I'm thinking of uses a heavy-duty DPDT and still gives a status indicator LED and true bypass.
EDIT: By RAT standards you're actually looking for a *newer* pedal... I did what I should have done originally and searched for 'RAT dpdt', and the first hit there is a Muzique article about the thing. I was right about true bypass and LEDs, though, so *there*. Anyway, this is entirely irrelevant to OP.
Jeff
It's possible to have proper LED behavior with a DPDT - it's obviously no trouble at all to have an indicator LED with a 3PDT, and you can look at a somewhat-old RAT for the idea with a DPDT. Flipflops are used when a fancier switching system is desired - in the cases you listed (except for some *old* MXRs) the flipflop is there because the designers wanted the impedance fluffer to be working the whole time. Pick up a RAT that's about your age if you get a chance - the one I'm thinking of uses a heavy-duty DPDT and still gives a status indicator LED and true bypass.
EDIT: By RAT standards you're actually looking for a *newer* pedal... I did what I should have done originally and searched for 'RAT dpdt', and the first hit there is a Muzique article about the thing. I was right about true bypass and LEDs, though, so *there*. Anyway, this is entirely irrelevant to OP.
Jeff
TheWinterSnow
Den Mørke Natt
your right, the flipflop switches are actually bypassing the 2 op-amp circuits. The bypass is nothing more than bypassing the op-amps but the signal is still very much going through the amp.
yea looking at that again, the same switching circuit could be used with a 3PDT, honestly since that would work to I have no clue why the flip flop is used, as it takes up more space. If you use the switch after the buffer BJT, you can have the same switching functions of a flip flop and would take up less space. The only two reasons that I could think that they would use a flip switch is while a flip switch takes up more space a 3PDT switch makes the circuit easier to mod, the only other thing I could think of is that with a flip switch since it always defaults in the bypass mode it saves your battery life, not by much because the buffer transistors power on as soon as a cable is plunged into the input regardless if weather the LED is on or not. IMO not huge enough reasons to do it the way that they are making them.
Unfortunately given the fact that the boards of these pedals are PCB, and as extensive as the mod would be, I would say its just about impossible to do. You would have to rewire the whole switching circuit of the board which is scattered across the whole thing on a SD-1. You would be rewiring the flow of the circuit and a fairly large size of the circuit.
yea looking at that again, the same switching circuit could be used with a 3PDT, honestly since that would work to I have no clue why the flip flop is used, as it takes up more space. If you use the switch after the buffer BJT, you can have the same switching functions of a flip flop and would take up less space. The only two reasons that I could think that they would use a flip switch is while a flip switch takes up more space a 3PDT switch makes the circuit easier to mod, the only other thing I could think of is that with a flip switch since it always defaults in the bypass mode it saves your battery life, not by much because the buffer transistors power on as soon as a cable is plunged into the input regardless if weather the LED is on or not. IMO not huge enough reasons to do it the way that they are making them.
Unfortunately given the fact that the boards of these pedals are PCB, and as extensive as the mod would be, I would say its just about impossible to do. You would have to rewire the whole switching circuit of the board which is scattered across the whole thing on a SD-1. You would be rewiring the flow of the circuit and a fairly large size of the circuit.
I did something like it accidentally with an Ibanez SM7, a much less accessible pedal to mod - I don't think it'll be impossible, just... perhaps more trouble than it's worth, considering how little work it takes to activate a stompbox.
Jeff
Jeff
DanLights
Santa Hat Forever
Sit inside of rack behind shit. just something to not think about playing live
Mine does not.
