DIY VU Meter : level problem with panning hard L/R

[blinkerss]

hi there

first time in here, and first time ever i'm doing and DIY project

i'm building an analog VU METER, with basic scheme from http://sound.westhost.com/project128.htm (for balance input and gain setting), and with russian made rectifier K157DA1 that i got from ebay http://www.ovchin.narod.ru/radio/k157da1.html (for the VU movement), also added one DPDT switch to select between TWO level calibration (-18dbFS and -6dbFS), and using 15v 200ma DC power supply

i'm building 2 separate circuit for each channel, the only thing that share with both channel is the power supply

but there's problem occur when the signal is hard panned (100% Left/Right)

here's the video on youtube that showing the problem

http://www.youtube.com/watch?v=spgjLpmHjCc

- 0dbVU = -6dbFS
- when the panner set Right 80% - Left 20%, the needle show relatively correct value
- but when the panner set Right 100% - Left 0%, the needle show false metering, both of the the Right and Left needle shows 50% level
- vise versa for the other channel

i'm attach the circuit diagram that i build on the PCB

any help for this problem?

thank you so much