timmiddleton Posted February 10, 2008 Share Posted February 10, 2008 Hi, I'm working on a bar install where we're looking to run an input from the DJ or live band mix at one end of the space to an amp driving six Control 1s at the quieter end of the space as delays from the main PA system. I've run in all the cabling but had missed the issue of differing line levels. Obviously our FOH mixer is outputting pro line level, but I'd not realised the amp the bar already owns to drive the Control 1s takes home line level. Is there a simple circuit I can build to drop pro line level to a more sensible voltage to be accepted by the home line level amp? At the moment it works OK for a moment then trips out as the input is too hot. I've looked at a few products online but with limited success (no pun intended!) thanks Tim Link to comment Share on other sites More sharing options...
MarkPAman Posted February 11, 2008 Share Posted February 11, 2008 Hi Tim Control 1s are 4 ohms. What is the amp & how are these wired. I think your problem may be here rather than with the input level. However you say the bar already owns this amp, so if it's been working OK up until now (and to the same volume level), then I guess I'm wrong. You should ba able to sort the input level by turning down the volume control on that amp. (What is the amp?) Link to comment Share on other sites More sharing options...
bruce Posted February 11, 2008 Share Posted February 11, 2008 If you have deep pockets, products like the Sonifex RedBox converters will do exactly what you want. For shallower pockets, and probably just as good a result, build a passive attenuator by sticking a couple of resistors inside the connector. Assuming an unbalanced "jack plug" connector at the amp input, connect the cable screen to "ground" (the sleeve on the plug) as normal. Connect the incoming "signal" core to one end of R1, and the other end of the resistor to the "tip" connection of the plug. Then take R2, connect one end of it to the "tip" and the other end to the screen. So you've built a potential divider. If you choose R1 to be about 10k and R2 4.7k you'll get around a 3x decrease in signal level.For balanced circuits, you can do something similar, but the circuitry involves a few extra resistors Link to comment Share on other sites More sharing options...
soundo26 Posted February 11, 2008 Share Posted February 11, 2008 there is no difference between your pro & home line levels! Line level is 1volt p-p. If you are taking a line level and trying to feed it into a domestic hifi amp just make sure you are going into the correct input, either the aux, cd or tape input NOT the phono input for a record deck. Be careful if you are running a long distance with an unbalanced lead as you might get a hum or radio signals inducted into the signal path> Link to comment Share on other sites More sharing options...
MarkPAman Posted February 11, 2008 Share Posted February 11, 2008 there is no difference between your pro & home line levels! Except for these differences:+4 dBu 1.228 V (USA) −10 dBV 0.3162 V (Homerecording) +6 dBu 1.55 V (ARD, Germany) Link to comment Share on other sites More sharing options...
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