Boss - PH-1r ( Phaser )  [schematic]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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candletears7
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Post by candletears7 »

If there was a layout and/or a pcb, it would most likely be in this thread.

Anyway, a have one on my bench for a mod.
It needs to be truebypass and a volume trim pot put in to bring the effect signal down in comparison to the bypass, as there is a noticeable volume jump.

I'm using Millenium bypass and a dpdt switch to fit in the flip flip hole, but I need to hardwire the circuit always on.
Reading this:

http://www.geofex.com/Article_Folders/bosstech.pdf

I need to remove sW3 and jumper the source and drains of sW1 and sW2.

Given the schematic and pcb shots given earlier in this thread, could someone help me identify those 3 FETS?

Thanks!

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Dirk_Hendrik
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Post by Dirk_Hendrik »

There is no sw3 in this case.
Jumper the source drain connections of Q5 and Q6.
Sorry. Plain out of planes.

http://www.dirk-hendrik.com

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candletears7
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Post by candletears7 »

Brilliant. Thanks mate!

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candletears7
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Post by candletears7 »

all wired up with the trim and works great. I'll apply thinto another one I have to do, the hf2 hi band flanger. thanks again Dirk!

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birgitay
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Post by birgitay »

regen pot What is the value?

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modman
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Post by modman »

BOSS-PH-1R-SERVICE-NOTES.pdf
Boss PH-1R service notes 1988
(2.71 MiB) Downloaded 228 times
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