What does M-34A mean ?

[Script]

Pulled two VU meters from a decommissioned Yamaha mixer. The case has a printed code but it doesn't yield anything on the interwebs.

Also there's "M-34A" printed into the transparent plastic housing. It's not a SIFAM meter. What does it mean ?Anything ? About the type / specs / behavior of the meter ? They sat on the output.

Thanks

 

[Script]

No one ? Well, I then I guess it doesn't mean anything

 

[musika]

What Yamaha mixer are you referring to?

 

[scott2000]

I thought I've seen that on some Teac vu meters but can't find it....There is info on some Akai decks that have M-34A on their meters though...

 

[Script]

I've seen that designator number on eBay also.

Anyway, meters are from a PM-170.

Subboard has IN60 diode bridge, a 15k across terminals and 220R to ground. No ballistics cap.