Guyatone Multi Octaver PS-009 - only dry sound

lbrutti · Post by **lbrutti** » 18 Nov 2022, 08:50

Hello everyone,
I have a Guyatone Multi Octaver PS-009 stompbox that stopped working all of a sudden: only dry signals comes out.
The pedal led ligths up regularly when pressing the footswitch, but no wet signal can be heard. Rotating pots has no effect.

I must admin i don't have a deep electronic knowledge, but for what i can see, no component is visibly damaged.

Does any of you has aver had this issue.

I attach pics of the pedal and board.

: back view of board

: front view of board

: pedal view

Thanks!

mauman · Post by **mauman** » 18 Nov 2022, 23:24

I'd start by looking at the switching, it sounds like the circuit is never engaging (pots don't work) even though the LED lights up. I don't have a schematic for you, though.

mediy · Post by **mediy** » 19 Nov 2022, 04:43

I think this has been repaired before. The wires soldered to the back of the board are not manufacturing technique, but are a common repair technique. On the solder side, towards the battery end in the centre, there is one component leg that is in place, but not soldered. From the photo it looks as if the pad may have lifted off the board. If so, then you will need to work out where it is supposed to connect, and solder it directly there with a piece of insulated wire - just like the 2 that are already in place.

lolbou · Post by **lolbou** » 19 Nov 2022, 11:01

mediy wrote: ↑19 Nov 2022, 04:43 From the photo it looks as if the pad may have lifted off the board. If so, then you will need to work out where it is supposed to connect, and solder it directly there with a piece of insulated wire - just like the 2 that are already in place.

No, that's one leg of the switch, it dosn't need to be connected anyway (the switch is working).

Look at the switching part in the schematic here for the PS series echo (it's the bottom right part).

You can see it is switching a FET (2SK30A) to enable/disable the wet sound. It may be identical in yours. Try and check it.

But your wet signal can get lost anywhere before this, so if nothing's wet, you basically get dry signal no matter how you switch the FET...

Tracing the wet signal with an audio probe can be helpful. The Guyatone echo was somehow Boss DM-2 inspired, so you may want to look for an old Boss octave schem for reference?

lolbou · Post by **lolbou** » 19 Nov 2022, 11:07

BTW i think the extra wires may as well be stock...

lbrutti · Post by **lbrutti** » 19 Nov 2022, 11:24

Thank for all the suggestions.
I will check the boss schematic abd audio probing.

I leave the post open for another week or so if someone has some more hints.

Thanks again