riddle me this...

[kurtlives]

I am hooking my iPhone to this little preamp then into my tube stereo amp.
http://www.beavishifi.com/projects/JFET_preamplifier/Beavis_HIFI_JFET_Ipod_Preamp_Schematic_v1_1

The output of that little JFET preamp goes to a single 3.5mm stereo jack. This stereo jack goes to a stereo cable/dual RCA cable. The RCA cable goes to my stereo amp. The stereo cable/dual RCA cable works 100%. However, whenever I try to use this setup only one channel works. The audio stops at the 3.5mm stereo jack. I tried two different stereo jacks, both stop the signal.

If I use a single RCA jack for the output of both channels and connect those to my stereo the system works.

What am I missing here... 

[kgull]

What 1/8" jack are you using? Some normalized mono jacks look a lot like a stereo jack (for example).

[kurtlives]

What 1/8" jack are you using? Some normalized mono jacks look a lot like a stereo jack (for example).

I am using something that looks very similar to that. Though I tired another different jack and same results.

[kgull]

See if any of the 2 pins short together when you either plugin or unplug the cable. If so you've got a normalized mono jack.

[kurtlives]

See if any of the 2 pins short together when you either plugin or unplug the cable. If so you've got a normalized mono jack.

Signal pins short together when nothing is plugged in.

Never heard of a normalized mono jack, I will have to read into them...