A couple of years ago I bought a pair Sound Professional-CMC-8 mics (2 mics w/ 1 input jack) which I used a couple of time before I realized that the mics needed there own power supply.
I then thought I'd bought the correct item which was a Sound Professional-SPSB-11 but when I tried it the Edirol the peak light came on with input level on 1, so third time unlucky.
So I was hoping someone could tell me where I'm going wrong.
I also bought the SPSB-11 off Ebay and on the description it says it has a "selectable bass roll off (bass reduction) filter is built in which provides seven different bass roll-off frequencies to choose from". From this description I'm assuming there must be a switch to do this or is there something I'm missing. Any help would be appreciated
Those mics may or may not require an independent power supply. I think they can run on plug-in power supplied by the recorder. It depends on the volume of the show.
The SPSB-11 should work and will not provide much (or any) gain, so not sure why that issue would arise (though perhaps if acquired used there could be a problem or short in it?).
For quieter shows when I ran the SPSB-11 I ran it into the mic input. The levels (with CMC-25s) were not high enough running it into the line-in to get any signal. I'm told that on a loud show you can run it into the line-in and have enough signal to work with. I've never been to one where that was the case though.
Bass roll off should have little effect on your levels. You don't really need it with these mics though. To turn it on or off you open the case and there is as set of 4 tiny switches in there that let you determine the desired frequency. There are instructions on SP's website at a link (somewhat buried there).
So let's go back to the start:
With the mics and no battery box you would need to plug into the mic-in and have the recorder's plug-in power turned ON (to send power from the recorder to the mics).
*With* the power supply you probably need to plug into the mic-in but you need to have the recorder's plug-in power turned OFF (or you are sending power from the recorder to the power supply!).
"Plug-in power" or whatever that recorder calls it should be switchable in the menus on the recorder.
On a very loud show with the power supply you may be able to run line-in and get enough signal. Plug-in power setting would be irrelevant since the line-in section does not provide that.
I suggest testing at home:
With the power supply plugged into the mic-in with the recorder's plug-in power turned OFF. You should find some (low) levels in that environment.