[ProAudio] VU meter permitted overdrive with a sine wave...

[Bob Katz]

Thanks, Crispin. So it looks like +6 VU at 1 kHz Sine for a minute or 
two ought to be acceptable. Not comfortable, but acceptable.



Best wishes,



Bob



On 1/28/21 1:47 PM, Crispin HT wrote:
>
> The Sifams we use are a taut band design – a rectangular wire takes 
> the current in and out of the coil, suspended in a magnet.
>
> The torsion on the wire counters the electric force to make the meter 
> stop at the desired level.
>
> When you overload it, the meter needle stops the coil from rotating 
> anymore, and as you pass more current through it, the coil will start 
> to move away from the centre of the magnet, stretching the taut wire, 
> and potentially grounding the coil on the magnet.
>
> My guess is you can put a lot more than +6 into it without damage for 
> a period of time, a bit like heatsinking on a semi, high overload for 
> a short time, low overload for a long time.
>
> I’m guessing + 12VU should be OK for a longish period ( 4 x voltage, 
> 16 x power), but YMMV
>
> Kind Regards
>
> *Crispin Herrod-Taylor
> **Managing Director, Crookwood**
> *www.crookwood.com <http://www.crookwood.com/>
>
> /Tel: +44 (0)1672 811 649
> Mobile:+44(0)7910 637 634/
>
> //
>
> */Sign up for our great newsletter here 
> <http://crookwood.com/newsletter/>!/**and keep up to date with the 
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>
> *From:*ProAudio <proaudio-bounces at bach.pgm.com> *On Behalf Of *Bob 
> Katz via ProAudio
> *Sent:* 28 January 2021 17:27
> *To:* proaudio at bach.pgm.com
> *Subject:* [ProAudio] VU meter permitted overdrive with a sine wave...
>
> This list has been remarkably silent, but I am very grateful that it's 
> around when I have a question to ask AUDIO EXPERTS.
>
> Who here knows the acceptable rating of a standard mechanical VU meter 
> above 0 VU with a sine wave?  If I recall correctly, they are designed 
> to accept as high as +6 VU or even higher. For example, when doing 
> testing of a tape recorder for headroom. It's still ideal to shut off 
> the meter, but in some cases that's not possible.
>
> Thanks and happy New Year!
>
> Bob
>
> -- 
>
> If you want good sound on your album, come to
> Bob Katz 407-831-0233 DIGITAL DOMAIN MASTERING STUDIO
> Author: *Mastering Audio*
> Digital Domain Website <https://www.digido.com/>
> No trees were killed in the sending of this message. However a large 
> number
> of electrons were terribly inconvenienced.
>          
-- 

If you want good sound on your album, come to Bob Katz 407-831-0233 
DIGITAL DOMAIN MASTERING STUDIO Author: *Mastering Audio* Digital Domain 
Website <https://www.digido.com/> No trees were killed in the sending of 
this message. However a large number of electrons were terribly 
inconvenienced.

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