djk Posted August 28, 2012 Share Posted August 28, 2012 Anybody that wants to re-engineer the unit rather than implement a simple fix is a green engineer. At work it costs us about $5K to do a DCN (document change notice) on a TEE (temporary engineering evaluation) vs $100K to spin a new design. It cost me $0.10 to add a 2.2K resistor at the end of a 100' Whirlwind snake that had unbalanced returns (and there was another 20' from the stage box to the amp rack). Quote Link to comment Share on other sites More sharing options...
leftwinger57 Posted August 28, 2012 Share Posted August 28, 2012 Quote Link to comment Share on other sites More sharing options...
babadono Posted August 28, 2012 Share Posted August 28, 2012 DrWHo/djk, Please do not take offense by my questions and comments. I am not in any way trying to be obtuse only trying to understand this. It looks like by your graphs DrWho that in the audible band the 2.2k resistor doesn't make as PWK used to say a "dimes worth of difference". Especially with the 100 ohm output impedance. Am I interpreting the graph correctly? babadono Quote Link to comment Share on other sites More sharing options...
DrWho Posted August 28, 2012 Share Posted August 28, 2012 Am I interpreting the graph correctly? Yep. With 100nF on your cable (3000ft of Belden 1176), you will be 4dB down at 20kHz with an 18k input impedance. Add the 2.2k resistor and you'll see a 0.2dB improvement. You gotta go all the way down to 100ohm in parallel to see a 3dB improvement (1dB down at 20kHz). Of course now your signal is attenuated by 6dB.... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.