phase 90 -how to true bypass?

[tele_guitarist]

Anyone know of a way to True bypass a newer phase 90?

[R.G.]

The simplest way is with an external true bypass box

[wampcat1]

(imaged being edited)

[Ben N]

OK, Brian, I'll bite:  Once you have desoldered the original switch and wired in the 3pdt, how do you fit the 3pdt in the box with that long board?

Ben

[mrsage]

Long live the Dremel:

[wampcat1]

OK, Brian, I'll bite:  Once you have desoldered the original switch and wired in the 3pdt, how do you fit the 3pdt in the box with that long board?

Ben

Lot's and lot's of vasaline, and/or bearing grease. j/k
Also, rehousing it doesn't hurt either, that way you can switch univibe mod/tremelo mods/ r28 mod/ waveform mod/ etc.

Thanks,
Brian

[R.G.]

I guess there is nothing that can't be "improved" as long as you're willing to sacrifice the patient. And if you ever want to sell it once it's "improved"?

As I said, IMHO the simplest way to add true bypass is with an external true bypass box. Unless you like to mod because modding is kewl.

[stinkfoot]

Wait a sec... if my eyes don't deceive me, the "simple TB mod" posted above will not actually make the pedal true bypass - the effect input is still hardwired to the guitar input, even in bypass mode.

To get true bypass, you need to break that connection by cutting a pcb trace on the component side, locate the effect input and output points, and fly wires from there to the new switch, like in the image mrsage posted.

/Andreas

[wampcat1]

Wait a sec... if my eyes don't deceive me, the "simple TB mod" posted above will not actually make the pedal true bypass - the effect input is still hardwired to the guitar input, even in bypass mode.

To get true bypass, you need to break that connection by cutting a pcb trace on the component side, locate the effect input and output points, and fly wires from there to the new switch, like in the image mrsage posted.

/Andreas

Hi Andreas - Are you sure? Basically that picture is doing the same thing a true bypass box would do, it is just shown running to the switch.
Thanks,
Brian

[stinkfoot]

Hi Andreas - Are you sure? Basically that picture is doing the same thing a true bypass box would do, it is just shown running to the switch.
Thanks,
Brian

Quite sure. On the component side of the pcb, you'll find a trace from input jack to the circuit input, which then continues on the back of the pcb all the way down to the DPDT switch.

Also, in the pic the 3PDT switch doesn't have a complete true bypass wiring - in one mode the input and output jacks are connected, and in the other it turns the LED on and connects the circuit output to the output jack. But the switch isn't wired to handle a connection from input jack to the circuit input, so the pedal wouldn't work with this wiring if there wasn't a permanent connection from input jack to circuit input.

/Andreas

[80k]

ah yep, i'd have to agree with andreas on this

[wampcat1]

Hi Andreas - Are you sure? Basically that picture is doing the same thing a true bypass box would do, it is just shown running to the switch.
Thanks,
Brian

Quite sure. On the component side of the pcb, you'll find a trace from input jack to the circuit input, which then continues on the back of the pcb all the way down to the DPDT switch.

Also, in the pic the 3PDT switch doesn't have a complete true bypass wiring - in one mode the input and output jacks are connected, and in the other it turns the LED on and connects the circuit output to the output jack. But the switch isn't wired to handle a connection from input jack to the circuit input, so the pedal wouldn't work with this wiring if there wasn't a permanent connection from input jack to circuit input.

/Andreas

gotcha!
Thanks -- I'll redraw for the folks viewing this thread.

Brian

[wampcat1]

Hi Andreas - Are you sure? Basically that picture is doing the same thing a true bypass box would do, it is just shown running to the switch.
Thanks,
Brian

Quite sure. On the component side of the pcb, you'll find a trace from input jack to the circuit input, which then continues on the back of the pcb all the way down to the DPDT switch.

Also, in the pic the 3PDT switch doesn't have a complete true bypass wiring - in one mode the input and output jacks are connected, and in the other it turns the LED on and connects the circuit output to the output jack. But the switch isn't wired to handle a connection from input jack to the circuit input, so the pedal wouldn't work with this wiring if there wasn't a permanent connection from input jack to circuit input.

/Andreas

Hi Andreas,

I have a quick question -- I did test it out and it worked fine -- I wired it so that the pads that were connected when the stock switch was "on" were wired to one side of the 3pdt, and the other side of the 3pdt switch was wired input - output jack. I was thinking that since electricity takes the path of least resistance that when the switch was "off", the trace still being connected to the input wouldn't' matter, since the path of least resistance is direct from input - output. Is that incorrect? Just trying to figure out an easier way -- I showed someone else who owns another pedal company and they were thinking it should be TB that way as well...

Thanks for your response, and time.

Here is the diagram in question:
http://www.indyguitarist.com/temp/phase-90_TB-indyguitarist_com.jpg

Take care,
Brian

[stinkfoot]

The theory you mention is exactly the same way Dunlop is thinking - a high input impedance to  the circuit will make it "invisible" to the guitar signal when you open up the direct path to the output jack. It's a nice theory, but it doesn't work in practice.

I know that I could definitely hear a change in tone when my RI Phase 90 was in the path. This was especially apparent when the pedal was first in line, fed straight from the guitar. The reason is simple - the permanent connection from input jack to circuit places the Phase 90's input stage in parallel to the input stage in the next pedal. This lowers the total input impedance, which - depending on the input Z of the next pedal, and/or if you have several "output switching only" pedals in a row - can load down the pickups.

For it to be true bypass, you have to physically remove the connection from input jack to circuit in bypass mode - there are no ways around that. (Ok, one... Voodoo Lab has a version that actually seems to work, using an optocoupler to kill the line to the circuit.) But if you keep the connection on the input side, you have to rely on the other pedals around this one to keep the signal intact (an active pedal in front of the Phase 90 makes a world of difference, for instance). The pedal will never be truly independent, so you can place it anywhere you like - without a proper TB wiring.

Also, if you weren't planning on removing the permanent connection between guitar input and the circuit, why bother replacing the switch in the first place? With the input jack -> circuit line permanently in place, the stock wiring does exactly the same thing as using a 3PDT would, but without having to cram the bigger switch in there.

/Andreas

[wampcat1]

Thanks Andreas, I'm following you now!

Just sent you a pm.

Take care,
Brian