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**Tim Farrant** · 3rd August 2005

Certainly the best place to ask!

The cheaper meters will not conform 100% to the VU standard, namely this is the time it takes for the needle to rise to 0VU and fall back. The AL29 or AL39 meters are pretty close to the standard and are commonly found on a lot of gear and consoles.

You can drive the meter directly, if you use a 5k ohm trimpot between the output and the meter (instead of the 3.6k resistor they recommend), you can calibrate it for 0VU = +4dBu. The switch arrangement sounds fine. If the output is balanced, hook the HOT and COLD to the meter, with the 5k pot in one of the legs.

The rectifier diodes inside the meter generate distortion, and this may appear on the module output. In some cases I have measured 0.1% extra distortion added to the line with a VU connected directly. Using a buffer amp of some sort will eliminate this problem.

Hope this helps
Tim.

3rd August 2005	#2
Tim Farrant Moderator Join Date: Jun 2002 Location: New Zealand Posts: 2,309	Certainly the best place to ask! The cheaper meters will not conform 100% to the VU standard, namely this is the time it takes for the needle to rise to 0VU and fall back. The AL29 or AL39 meters are pretty close to the standard and are commonly found on a lot of gear and consoles. You can drive the meter directly, if you use a 5k ohm trimpot between the output and the meter (instead of the 3.6k resistor they recommend), you can calibrate it for 0VU = +4dBu. The switch arrangement sounds fine. If the output is balanced, hook the HOT and COLD to the meter, with the 5k pot in one of the legs. The rectifier diodes inside the meter generate distortion, and this may appear on the module output. In some cases I have measured 0.1% extra distortion added to the line with a VU connected directly. Using a buffer amp of some sort will eliminate this problem. Hope this helps Tim. __________________ "Come on, make my day" Dirty Harry (Clint Eastwood) Visit Buzz Audio