First Build Pedal Chain Issues

[mbrooks93]

Hello all, I've recently been building my first stompbox, a dual 12au7 vavlecaster based on the following matsumin Vavlecaster design:
http://i706.photobucket.com/albums/ww70/2266vm/valvecaster2_zps8c1360d6.jpg

Its working, few kinks in the build I need to iron out but it works when I plug my guitar in one end and my amp in the other. The issue I'm having is when I plug the pedal in my current pedal chain (comprising of just a Joyo dyna compressor and 6 line eq pedals). The desired sound comes out of my amp when I run my guitar through the valvecaster first, but when I plug either of my pedals in before my valvecaster no sound comes through my amp, even when the pedal before has its true bypass on.

I have no idea why this happens, the only thing I can think is that I used mono 1/4" jack sockets for both the input and the output of my pedal whilst the others have a stereo input socket but its still a mono signal running through the pedal isn't it?

Its probably a really simple mistake I've made but any suggestions would be greatly appreciated

Thanks

[guitarpedalparts]

When in that scenario does the signal die even if the effect is bypassed, or only when enabled?

And have you double checked the wiring on your jacks, including the grounding?