Phase 90 clone works, but there's some hiss..

[bancika]

I have completed phase 90 build from tonepad board this weekend with few mods:
* Vibrato switch
* 22K resistor replaced by a linear 100K pot with 20K resistor set between outer lug and wiper which makes it's range about 17K-100K.
* Added 500K pot in series with 1M resistor that goes to the trimmer as depth mod.
It works quite nicely, I found trimmer sweet spot that gives the most phasing; those last two mods don't do much change but I had spare holes so I added them.
The problem is, there's annoying hiss, especially when I run it through overdrive. At clean it's barely audible, but at higher gain it's just too loud. It's also present when I turn down volume pot on my guitar to zero.
Any ideas what might cause this?
Thanks

[bancika]

(bump)...anyone 

[MikeH]

I'm not sure if there's a problem in your build, but I find a lot of phasers to be noisy, so I generally run them after amplitude based effects like distortion and OD, etc, because, obviously they'll just amplify any noise that comes before them.  Sorry, that was probably no help at all... You're welcome!!

[mdh]

What do you mean by hiss?  Is it a constant background hiss, or is it in time with the LFO?

[bancika]

Thanks for replies guys.
It's a constant high frequency hiss that doesn't depend on LFO or pot settings, as far as I can tell.
Cheers