CGS stomp box adaptor issues

[JoeMorris]

Hi all,

I'll set out my stall immediately - Im basically a novice when it comes to DIY electronics. I've built quite a few pcb based projects but thought Id move into veroboard to try and extend my skills a little.

I have some DIY pedals that I use with my synths and the levels arent ideal so the Ken Stone stompbox adaptor caught my eye, especially as the PCBs are sold out and it's a simple circuit so seemed like the perfect excuse to give a stripboard project a go.

I haven't got a modular so I wanted it to have a built in 15v bipolar supply. I used the power circuit design from the big stomp box adaptor (designed to use a module as a stompbox)

http://www.cgs.synth.net/modules/cgs46_sba.html

and added it to the audio circuit from the small stomp box adaptor

http://www.cgs.synth.net/modules/cgs60_sba.html

(designed to use a stompbox in a modular - essentially my application)....

The problem is, I get terrible hum and distortion (very very loud) - in fact the output pin from the TL071 is very distorted.

I have used a common ground rail for the power supply part of the circuit and the audio part of the circuit - could this be the problem?

Thanks
Joe