Radio Shack Sould Level Meter - Analog Meter

You might want to contact Rives Audio and ask them this question. They sell a system calibration/test CD that is specially-designed to accommodate the non-linearities of the Radio Shack meters ($18 at RivesAudio.com).

On the Rives site, they have a link to Radio Shack p/n 33-4050, so I assume they would recommend the 4050 series.

We've been in contact with Radio Shack over the last year. They informed us of the change over way before it was actually implemented. They even sent us the manual for review. However, what was missing was a unit for testing. We have one now, but did not get one in advance. They did tell us that the change was not performance related. It turns out the two appear to respond identically (at least within our tolerence of measurement). They did some cosmetic things with the new model and I believe they replaced some components internally (perhaps SMDs in some cases--although we have not opened the unit up) for more cost effective manufacturing.

I see it now on the Radio Shack website. Part # is 33-4050 (& not 31-XXXX)!

Looks better than the older one. Same flawed performance, I suppose, that needs appropriate compensation!