How to adjust analog VU meter sensitivity?

[EmbyrMusic]

Hey everyone! Not sure where to post this, but I’ve been researching for so long and can’t find anything!
I recently got an Optimus MPA-250 Power Amplifier for my recording setup.
I just changed the lights on the vu meters to LED, since one was burnt out, and I hated the green anyways.
I also wanted to adjust the vu meters since my speakers are efficient enough, that the meters barely move at a reasonably loud level. Even with the -20dB switch on.
So I tried to adjust the “trim” piece just below the light on each meter, and it appears that only calibrates the “0” level. How do I adjust for the “Peak” or top end level without bringing the zero level up with it?
I’m new to this, so if you can explain things to me as simply as possible, that would be great! Thanks!

 

[TrevC]

I see nobody has answered this. The only way to adjust this is to reduce the value of the resistors that feed the meters.

 

[Al ears]

I see nobody has answered this. The only way to adjust this is to reduce the value of the resistors that feed the meters.

Just seen this one.
I don't know of any other way to adjust the Span of these meters but then I have never had an amp with them as not sure of their value

 

[Gray]

I see nobody has answered this. The only way to adjust this is to reduce the value of the resistors that feed the meters.

Yes, maybe fit variables, make it easy to set the desired deflection.
(Or at least use variable to find value for fixed R).