Phantom Power might be Bad?

Hi there,
This may seem like a silly question, but i can`t find the answer anywhere.

I have a mixing desk that supplies phantom power +48V
I use a condensor mic that is powered from the mixer. Now what I want to do is to put a samson s-com compressor/limiter in between the mixer and Microphone.

Will the phantom power damge the compressor? and will the power actually get to the Mic?

Cheers for the help.



diyAudio Member
2002-10-11 8:15 am
pinkmouse said:
You need to use the compressor on an insert or FX send/return.

Using FX send/ret for this purpose isn't good idea.

From s-com manual:


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I have worked on a commercial 'capacitor' mic preamp and the vagaries of supply.

Despite such limitations, it is possible, using constant current sources in the supply feeds, to obtain substantial overload margin/headroom but such a tack is rarely taken by either mixer companies or mic manufacturers. Obviously there are issues of noise when introducing a comp/lim into the chain at such an early stage especially given that the good mics only buffer the C and don't amplify at all.
pinkmouse said:
True, it's not ideal, but if you have no inserts it's better then using it across the outputs, which is the only other option.


if the console we're discussing here isn't equipped with a channel insert point then it is also unlikely that there would be an "on-off channel assign" switch. Also, the FX send is always placed after the channel fader, which means that you can't assign only the compressed signal to the mix out (thru the FX return) without sending the (uncompressed) original signal thru the mix buss. A better idea might be using Aux out, which is pre-fader assigned (if the console has one).

anatech said:
...Effects always go in the send-rcv patch.....

Effects always go in the FX send-FX stereo return path. Compressors always go in the channel-group-mix insert-return path.



Paid Member
2003-06-12 7:04 pm
Maine USA
> what I want to do is to put a samson s-com compressor/limiter in between the mixer and Microphone.

Mike levels are not normally high enough for a limiter.

> Will the phantom power damge the compressor?

Very possibly. The blocking caps are usually electrolytic and wired to expect zero volts on the output. +48V is high and may reverse-bias the caps. Failure can be quick and costly.

> will the power actually get to the Mic?

No way.

Use the insert points (or FX in a pinch). That's what they are there for.
On a powered mixer your only option may well be to put it into effects/ return. Some however have the ability to interrupt by means of RCA jumpers the mix from the power amp section.

On unpowered mixers I would take the output of the mixer into the input of the compressor limiter and the output of the compressor limiter to the next device in your chain. Make sure to adjust output so that clipping of devices will happen at the same time.
Mic and compressor

You could use channel 1 as a preamp, run channel 1 to channel two through the compressor. If you cannot unbuss the mixer, mod it to get a direct out. I agree with the posts about using fx loop unless your mixer doesn't have it. Other wise, grab a cheap Mic pre with Pantom and line out. $100 mice pre will suffice when going to a powered mixer. $100 mic pre is probaly cleaner than most powered mixers.