Meterbridge Soundcraft TS24

[Twosounds]

Hi
I need some advice on a led meter display from a soundcraft TS24.
I would like to implement these in another desk.
Here the circuit description :
Screenshot 2021-04-21 at 14.27.18 | TS 24 meter discription … | Flickr
Screenshot 2021-04-21 at 14.27.30 | TS 24 meter discription … | Flickr

Here the schematics :
Screenshot 2021-04-21 at 14.44.27 | TS 24 meter REC PCB | Twosounds | Flickr
Screenshot 2021-04-21 at 14.43.55 | TS 24 meter LED display … | Flickr

I adapted the PSU so I have the correct values (+/-7.5v and a +18V)
In the description the 24V is dropped to 18V with the Zener D1, so I bypassed it to get the correct value to the LED driver IC LM3914, but that does not seems to matter ( datasheets states 3-15V supply ).
All other connections are made (CTRL is VU mode, LO = -7.5V) and audio signal is present.
The meter is functional but the LED arrays seems to dim everytime the signal gets to hi/lo of his range. See here :
IMG_8726 | Meter Soundcraft TS24 | Twosounds | Flickr
https://www.flickr.com/photos/68606224@N08/51129387363/in/dateposted-public/

Any idea or tips before I dive in?

 

[PRR]

> 24V is dropped to 18V with the Zener D1

I see 11V.

 

[Twosounds]

Indeed, but manual state's :
'D1 is required to drop the 24V rail down to about +18V, suitable for the 3914s'