![]() ![]() The designers of the VU meter therefore took a different approach. Since a VU meter is a mechanical device, it can never reflect the instantaneous signal peaks of complex audio signals. The original designers of the VU meter were tasked with finding a way to measure complex audio signals with a simple technology. In the broadcast industry, loudness monitoring was standardized, in 2009 in the United States by the ATSC A/85, in 2010 in Europe by the EBU R-128, in 2011 in Japan by the TR-B32, and in 2010 in Australia by the OP-59. Purely electronic devices may emulate the response of the needle they are VU-meters in as much as they respect the standard. In effect, the scale ranges from −20 VU to +3 VU, with −3 VU right in the middle (half the power of 0 VU). The meter was designed not to measure the signal, but to let users aim the signal level to a target level of 0 VU (sometimes labelled 100%), so it is not important that the device is non-linear and imprecise for low levels. For this reason many audio practitioners prefer the VU meter to its alternatives, though the meter indication does not reflect some of the key features of the signal, most notably its peak level, which in many cases, must not pass a defined limit.Ġ VU is equal to +4 dBu, or 1.228 volts RMS, a power of about 2.5 milliwatts when applied across a 600- ohm load. This has the effect of averaging out peaks and troughs of short duration, and reflects the perceived loudness of the material more closely than the more modern and initially more expensive PPM meters. The mass of the needle causes a relatively slow response, which in effect integrates or smooths the signal, with a rise time of 300 ms. Movel it back and forth several times and this will hopefully fix the problem.The original VU meter is a passive electromechanical device, namely a 200 ♚ DC d'Arsonval movement ammeter fed from a full-wave copper-oxide rectifier mounted within the meter case. These switches have openings and in any of the openings, try to spray a considerable amount of contact cleaner. This is a switch that is commonly known as the record/play. In opening the deck, you will see a slide switch which is attached in the mechanism along with a linkage or rod. If there is a motion to the right upon turning it off, then there is something that drives the meter gauge to the left when the deck is turned on. Turn the power off to see if the needle in the meter gauge remains to the left. Power on the device and closely observe the meter gauge and the deck during stop mode. After this procedure, reassemble the box and try to observe if you will encounter the same problem. For plastic mechanical parts do not use lubricating fluid, instead use silicon oil. After all dust particles are cleared, try to drop some lubricating fluid on the mechanical parts. ![]() If it is filled with dust, you may use the blower or a small vacuum cleaner to eliminate possible causes of malfunction. Cautiously remove the covering of the assembly. Use your screw driver and remove the screws. These things may sometimes require cleaning, you may need to open the assembly and try to see if there are many dust particles in the system. If only one channel and one meter gauge is working, try to spray a little amount of DeoxIT at the back portion of your VU meter, particularly the IN/OUT. If either of the gauges work, then probably something is wrong. For VU meters with 2 gauges, it intends to measure sounds converted to voltage interpretation on the left and right speakers. There are different kinds of VU meter and it will depend on how the manufacturer designed the gauges, but they will usually function similarly. ![]() To know if your VU meter is malfunctioning, try to observe the gauges if they are working the way they should. ![]()
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