Mic level out of SD 442 hot into SMQV

[sonicboomaudio]

Hi all,

I recently did a wireless hop with my Lectro SMQV transmitter. I came out of my SD 442's XLR left master, making sure to change the output level to "mic". I used an XLR to 5-pin adapter. I fed -20 tone out and the level going into the SMQV was still hot. I had to basically turn the audio level down to "0" on the transmitter to get the levels to match.

What am I missing? Is it because the XLR out is balanced? What do I have to do to fix the problem?

Thanks in advance,

John

[JT Mueller]

John, when you say XLR-5 pin adapter are you talking about a cable? How is it wired? Its important to note that the cable/TA5 connector can be wired for either Mic or Line level.

If you are using a cable that matches the output setting of your mixer and the signal is still hot it can be helpful to use an in-line pad.

JT

[Peter Mega]

Also, make sure the cable you're using is wired for servo input for the SM transmitters.

[Marc Wielage]

Yes, the Lectro MC-35 (or an equivalent, like the adapter cables made by PSC) should step down the level for an SMQV. I also turn down the output level at the mixer and at the SMQV input level just to avoid clipping. If it's still hot, you can drop in a Shure A15AS inline pad, which is adjustable 5dB increments from -15db to -25dB. This adapter has saved my butt on a few occasions.

I have run into occasions where a cable was labeled "MC35" but was not wired correctly, and was overloading the xmitter.

[jacefivesound]

mc35s and mc40s are not affected by the servo bias because they don't utilize the power pins. they are completely backwards compatible, at least to 400 series stuff.

[sonicboomaudio]

They are MC-40 cables. I thought if I switched the output side to mic level, then there wouldn't be a need for an additional inline pad, right?

[ncsoundmixer]

If the 302'a outputs are similar to the 442, you may want to have resistors put in your mixer to transmitter cable. Years ago when I first set up my 442 I found that hop headroom was lacking even when mixer output to hop input levels lined up with tone. I consulted with Trew Audio and they developed a set of TA5 cables with inline resistors both for my Lectro and Zaxcom hops. Results were excellent. I don't know enough about electronics engineering to explain this better but apparently the SD outputs need more "resistance" to play well with Lectro and Zaxcom hops.