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Mark A. Beal
09-09-2008, 03:47 PM
We have a newly purchased Lectrosonics SMa/UCR411A combination and are getting terrible sound - terrible hiss and any movement of the wire sounds like a sheet of tin rattling. We've tried with a Countryman EMW purchased specifically for it and also a Sony lav that a co-worker brought in. The same mics sound okay when he connects them to his UCR195 system. If we connect the SMa to a line source (using an XLR line to TA5 adapter) it sounds okay.
I'm new to Lectros (I've only used G2s in the past) so I'm not really familiar with the menu options yet -- does anyone have any idea what I'm doing wrong?

Alex H.
09-09-2008, 05:15 PM
The "sheet of tin rattling" screams shorted connection or cable. If the mics work fine on any other system or connection, there may be a problem in the connector of the belt pack. Did you buy this system brand new, or did you purchase it used?

Gently wiggle the EMW's cable around near the capsule and see if that triggers the noise. Then do the same just above the connector. And then try wiggling the connector itself. You can also try the same things with the mic hooked up to one of the other systems where it seems to work without problem, just to be sure.

As for the hiss, dunno... there are a million reasons for that, including improper gain staging. Could be that the cable connecting the receiver to the mixer is of poor quality/construction. Try a different cable. If it's not the cable, try this: with the receiver powered on, keep the transmitter powered off and listen to your mixer's input channel to see if the hiss is still there. Then listen with the receiver's output level all the way down. Then listen to the input with the receiver powered off, then again with it disconnected entirely.

Remember only to change one variable at a time. See which one eliminates the hiss, then get back to us.

Mark A. Beal
09-09-2008, 08:54 PM
The "sheet of tin rattling" screams shorted connection or cable. If the mics work fine on any other system or connection, there may be a problem in the connector of the belt pack. Did you buy this system brand new, or did you purchase it used?


I bought them all new, but from different sources. The Lecto system came from B&H and the EMW from Trew. Since my original post, I've heard mention that the mic wiring has changed 400 series and the previous ones -- could this be the cause? Could I possibly have gotten a mic that was meant for an older model?

Alex H.
09-09-2008, 09:00 PM
Anything's possible. I'd call Trew and double-check on what they sent you.

But as for probable... meh. Incorrect wiring would more likely result in no signal, rather than what you described which is indicative of a short.

Bucknfl
09-16-2008, 08:30 AM
Call lectrosonics. There are 2 different ways for a lav to be wired and it could be incompatible. I can't quite remember but it could be wired either positive or negative bias.

ptalsky
09-17-2008, 07:25 PM
Yep, the SM series of Tx gets wired differently than the UM/LM series. It's described on the Lectro site, but you might also just want to call Trew and make sure they ordered the right version for you. You can also call Countryman - they are great to deal with.

Phil