Guyatone WR-2 volume drop

[Nuts]

Hello everyone !
I have a Guyatone WR-2 wah rocker, it sounds good, but when I turn it on, there is a noticeable volume loss.
So I want to know if this problem exist on every WR-2, or if mine is just a defective one.
The second thing is if there is any mod I can do to fix it ?
Any information about this pedal would be welcome

[Mark Hammer]

How much of a drop?

[Nuts]

I recorded somwthing with my phone just to demonstrate the volume drop

https://www.dropbox.com/s/hyup4lnwsaibr2u/Voice%20498.m4a?dl=0

[Nuts]

Another thing that I've noticed is that when this WR-2 pedal is connected to my other pedals in my pedalborad, some pedals that come after it in the chain will create pop noise when I turn them on 

[Mark Hammer]

Are the pedals after your WR-2 true bypass or electronically-switched?

[Nuts]

Some of them are true bypass, the other ones has a buffer (boss).
The true bypass ones do the pop noise. Only when the guyatone wr-2 is in the chain. when it isn't there are no pops.

[Mark Hammer]

Consider this possibility:  https://www.diystompboxes.com/smfforum/index.php?topic=112946.msg1044060#msg1044060

[Nuts]

Thank you
what about the volume drop ? do you think that this is just the nature of that pedal, or is it defective ?