nyquist aliaser problem

[Gila_Crisis]

hi, i need some help.
i built the nyquist aliaser found on the jc maillet web page. it work but it doesn't do a ring modulator sound but is more like a fuzzy sound with some freq modulations in the background.
the transistors are BC550C and BF245A, opamp is a TL072. i think there's something worng with transistors and/or opamp.
can someone give me a hint?

chhers Joe

[Gila_Crisis]

well i was wrong the pedal sound right!'n'cool, simple i never used those king of "unmusical" noisy stuff  it's a new world!
btw this box got a lot of really nice sounds! from light ring mod to massive quasi octave fuzz one! i'm thinking to add the cv input.
the only things i must check are about the 9v. with a 9v battery it doesn't work like it should, with an adapter it works but i must add a filter to remove this annoying 60hz ffreeq of the ac voltage...

next project is the rattle crow!!!