Help Tonepad Phase 90 Pop

[antonioalvino]

when I turn on the Phase 90, you hear a loud pop of true bypass.
I put resistors on the jacks in 1m and 100k on the jack out
always the same, any advice?
many thanks

[Seljer]

Though its not drawn on the schematic, there are 2 pads right next to the input on the PCB where you can put a pulldown resistor on the board. Try adding that.

[deadastronaut]

as simon suggested..and use wiring 5 from this diagram

http://www.tonepad.com/getFile.asp?id=76

never had a problem with this diagram..

[aballen]

You can always go with an optotron or a relay bypass from 1776.  I'm find of the optotron myself. 

My only objection to these are that they are a bit more pricey than a simple 3pdt, but you get what you pay for.  They work great.

[duck_arse]

do you have any boss-type pedals in your chain when using the p90? if so, disconnect them all, and try the p90 again.

[GibsonGM]

I've been using 3PDT for like 12 years, sometimes with a pulldown, etc, and NEVER have an issue with pop, even on the most high gain builds I do.  The optotron might be a great thing, in terms of tech and whatnot, but don't disrespect the 3PDT, please!!   Ha ha.

POP just means there is DC somewhere you don't want it.  2 things at different potentials...that should be cured.  100s in these pages have used the known cures for it, with awesome results.

[antonioalvino]

yes, i have 2 boss pedals in chain

[duck_arse]

the boss pedals are designed without pulldown resistors, so they store a bit of charge to "share" w/ true bypass types. get into the bosses, add pulldowns.

[Mark Hammer]

duck is correct.

This is confusing for many people since the source of the pop is not the pedal you are turning on and off, but another one you may not even be using at that moment. 

Boss, and other pedals that use electronic switching internally, often do not use any pull-down resistors on their input since they do all of their bypass switching between the input and output buffers they use.  So, from their point of view, the only time the input cap is left "hanging", unable to drain off, and susceptible to popping, is when you first plug in.

The problem with using true bypass pedals with such e-switched pedals is that the brief moment that the stompswitch contact going to the output jack is going in between your effect and bypass, it is mimicing the circumstances that exist (even if only for a few milliseconds) when you first plug into a Boss pedal.  When this happens, you may notice that if you hit the stompswitch a few times in succession, turning the DIY (or commercial) pedal on and off a few times, the popping disappears.  It does this because the input cap on the Boss pedal has drained off.

So, as duck suggested, the solution is to provide a constant path for that input cap to drain off.  The simplest way to do this is to solder a resistor between the hot and ground lugs on the input jack of your Boss pedals.  Something like 2M2 is probably suitable, without providing much loading.

[Fp-www.Tonepad.com]

Very nice Mark. This can also happen with amps, I've found amps that have some DC at the input and they also can make some pedals pop when switching.

[antonioalvino]

I tried the pedal alone, guitar, Phase90, amp
always the same, does the same pop
even without LEDs connected

[GibsonGM]

If you did what Duck and Mark suggested, to your BOSS pedals, and the Phase 90 pops (alone), then I think:

1) measure for DC AFTER the output cap. If detected, you need a new output cap.   The *pop* is caused by DC sitting there, and you 'let it out' by actuating the switch...like a knife switch arcing in an old sci-fi movie.   A well-built effect has NO DC at the output.  Can't describe this better than Mark did above, anyway.

2) your switch is somehow miswired or broken.

Is this a purchased pedal, or DIY??  Sounded DIY, so go in, look for DC!  You should be able to measure across your output jack for that.

[antonioalvino]

Thanks to all for the help, I solved with this type of wiring

http://www.madbeanpedals.com/tutorials/downloads/StandardWiring_MBP.pdf

Happy New Year

[Kipper4]

Yep TonePad offboard page 5 is a favorite around here

[duck_arse]

antonio, can you now remember/show/tell us how your new wiring differs from your old wiring? that way, we are all prepared for the next time someone asks ......

[antonioalvino]

is right, before I had this type of wiring

http://www.beavisaudio.com/techpages/StompboxWiring/StompboxWiring.gif

[GibsonGM]

And that was somehow related to 'pop'??  I'm not seeing it....