keeping boss pedals on... Help please

[msurdin]

I have asked a effects builder on help doing this. He said to remove both wires from the momentary switch and attach them. This should keep the effects always on. In my case it didnt...

How do I do this? The effects I wish to do this to are the ge7 and bd2.
I will be removing the jacks and wiring it straight into a true bypass box.

But the main question is how do i make it always on.

Thanks so much!

Matt

[petemoore]

  I forget, I used to have boss pedals and sorta remember they'd be off when powered up. did the pedal originally go to the on state when powered up?

[soulsonic]

You could potentially remove the onboard bypassing system entirely - it involves removing the switching fets and jumping where they used to be. I don't have a pic of a layout or anything that I could show you with, but maybe someone else here does.

[msurdin]

All my boss pedals stay off when they get powered up.

Yea if you could show me how to fix that all up i would be forever greatful!...hopefuly we can find someone with it

Thanks

Matt

[R.G.]

This one gets asked enough that I'll write it up and post it at GEO.

The trick is to find the two flip-flop transistors and ground one of their collectors with a bit of wire. Shorting collector to emitter works.

One transistor forces it to stay on and one transistor forces it to stay off. FINDING the two transistors is tough, so what I have just done is convert this recurring question (i.e. how do I keep my BOSS/Ibanez pedal on) into the recurring question "How do I find the transistor that keeps my Boss/Ibanez pedal on/off?".

[petemoore]

  ...here's a ramble...
  Use a signal injector or audio probe:
  signal inject after first jfet to provide feedback as to when the output Jfet is passing signal while you're finding the two points which when connected allow circuit effect output signal
  Once you get that going signal inject from before the input Fet, then try your mod-wire where it promises to 'open the input fet...since the output is now hardwired 'on, when you get the input wire placed, signal should pass through the effect circuit.
  Alternately, you could:
  Audio probe After the first Jfet, until it's passing signal to the effect, then use the output jack to amp to find where the wire trips the output jfet to pass effect output.
  This would involve finding a 'tap point' which is in the signal path for the probe or signal injector, for that I'd set DMM to beep mode, pick an opamp input/output which looks to be in the signal path [reference schematic, but I think any opamp in/out pin will be 'live], find where on the board a testclip or tacked on solder wire [like a resistor leg], can be connected temporarily for monitoring the progress of the Jfet switching mod.

[Mark Hammer]

Two distinct-but-related challenges:

1) How do I keep the effect in effect mode?

2) How do I maintain status LED indication of mode?

The vast majority of Boss's modulation and time-based effects use but a single FET to connect the "wet" side to an output mixer stage.  All you need to do is solder in a jumper between the drain and source pins of that solitary FET and the effect will be "on" forever.  of course, you may not SEE that it is on because the LED corresponds to the current state of the flip-flop not whether the pedal has been "forced" to work.

The flip-flop circuit provides the electronic equivalent of a SPDT (or SPST) toggle.  I've seen some 3rd party projects in magazines where the same FET-diode-1M-.047-to-ground was used that you'd find in any Boss pedal, but the switching was done with a SPDT toggle or stompswitch instead.

[Belt]

I believe with Boss pedals the power supply determines the powering up status.  I think with the battery only, when you plug in, it's on.  And with the power supply, when you plug in it's off. 

[msurdin]

Would it be easier to not worry about the led, just if the effect stays on? I really dont care much for the led on these pedals...

[Mark Hammer]

Would it be easier to not worry about the led, just if the effect stays on? I really dont care much for the led on these pedals...

If an LED-less always-on pedal is good enough for you, then just jumper the relevant FETs to fix signal flow, using the schematic as guide and pull (or cut the trace) of the FETs used for bypassing.  This is essentially what people do when they want to (for whatever reasons) convert their Boss pedals to a mechanical true bypass stompswitch.

[msurdin]

Can you explain how to do that? I am still somewhat new at all the terms and i'm not good or know much about reading the schmatics..

Thanks

[Mark Hammer]

How about you list the pedals you want to do it for and I'll tell you how to do it?

[tonefreak]

The GE7: Looks like Q5 and Q4 that lead to D3 and D4 respectively can be removed and jumpered.

The BD2: looks like Q4 and Q6 or Q5 (hard to see in the schematic I'm looking at) that lead to D4 and D5 respectively.  Again, the hole from the pole of the FET that leads to diode neads to be jumped.  I remove the FET completely and use a lead clipping as a jumper.

[Mark Hammer]

Looks like someone has been to the Freeinformationsociety website!

The way that the FETs are used, and the specific choices made by Boss for the FET in any given pedal, will vary.  That's why I wanted to know what pedals so that some specific recommendations could be made.  There ARE generic things one can say that apply to all FET-switched pedals, but from the sounds of it, some concrete do-this-do-that info is desired before getting into more generic advice.

[tonefreak]

Can you explain how to do that? I am still somewhat new at all the terms and i'm not good or know much about reading the schmatics..

Thanks

Take the time to learn.  Find the schematics for the GE7 and BD2, and then trace what I have described above... you will see a trend.  Once you recognize that trend, you can pretty much do this type of mod to any Boss, Ibanez or any other pedal that uses switching FETs.

The key is to learn from here and then expand on that newly acquired knowledge.

[tonefreak]

Looks like someone has been to the Freeinformationsociety website!

The way that the FETs are used, and the specific choices made by Boss for the FET in any given pedal, will vary.  That's why I wanted to know what pedals so that some specific recommendations could be made.  There ARE generic things one can say that apply to all FET-switched pedals, but from the sounds of it, some concrete do-this-do-that info is desired before getting into more generic advice.

Hahahaha!  That's a great site, and there's another in Europe that has the actual service manuals... you probably already know of it!!

[petemoore]

  Led's not much use on the box, instead of having a dim spot, just wire the LEd/with resistor [4k7 er so] right to the PS for always on..[I'd just grab a 4k7 and leave the original current limiting R in the board].
 I didn't quite catch the layout...but you could always run the LEd's ground supply through a switch using 3pdt bypass w/led wiring...providing that the wire has to make it's way from LED to switch to the Gnd.

[msurdin]

so is it the parts on d3 and d4 on the ge7 i remove and jump?
and then on d4 and d5 on the bd2 gets jumped?
Can I see the schmatics u were looking at whenever u get a chance?

[Mark Hammer]

 

Silly me, I didn't notice that the pedals in question were mentioned at the start of the thread (guess I missed them because they were in lower case).

The BD-2 is a little tricky to do since there is not JUST the FETs but all the superfluous buffers and bias resistors intended to cope with the three FETs involved in the switching.  I think I'd wait until RG posts his writeup about having the flip-flop be always "on".  That may not deliver as "pure" a pedal sound as factoring out all the buffers, but it may end up involving less surgery than directly tackling the FETs.

[msurdin]

wouldnt changing the buffers and whatnot also change the sound that. I think it would.. I am throwing this in a true bypass loop. Personaly I love everything about it. I usually keep it on most of the time I play and i think the sound is great...so I was just trying to keep it on without changing anything else about it.

Thanks for the on going help guys!