Nady RMX-6 phantom power?

[StuartV]

My band's board doesn't have enough mic inputs. So, I was looking at getting a Nady RMX-6 rackmount mic/line mixer to use to do a drum sub-mix to run into the main board.

But, all the specs, including the PDF of the Owner's Manual, say that it supplies +15V phantom power to 3 of the mics (and none to the others). What is up with that?

I've never seen anything but +48V phantom power. Would this unit work with a Shure KSM109 or MXL604 condenser mic?

Thanks!

- Stu

[mshilarious]

Originally Posted by StuartV

I've never seen anything but +48V phantom power. Would this unit work with a Shure KSM109 or MXL604 condenser mic?

What is up with that is that Nady was too cheap to build a proper phantom supply into their board, so they just tapped the existing +15V power rail for the phantom supply.

I am 99% "shure" the KSM109 will work fine with +15V, because the SM81 and KSM141 do. I would be 100%, but the Shure website is somewhat broken right now

I am also fairly certain the MXL604 is an externally biased condenser, which often require the full +48V, and indeed the 604 is spec'ed at 48V.

You might also consider checking out a better board that doesn't have that issue . . .

[StuartV]

Thanks for the response.

I also got email back from a Nady sales rep. He said:

"Years ago condenser mics varied in the amount of power needed. Each manufacturer set their own design requirements that varied between 9 volts to as high as 52 volts. Except for some specialty mics most modern condenser microphones operate in the 9 volt to 12 volt range. 48 volts is a standard not a requirement. The microphone will use only the amount of power it needs. The RMX 6 should perform fine in whatever application you need"

The RMX-6 is only $90. Can anybody point me to another similar (rackmount, 6 or more mic inputs) mixer that I could use instead, that isn't horrendously more expensive?

[mshilarious]

Originally Posted by StuartV

"Years ago condenser mics varied in the amount of power needed. Each manufacturer set their own design requirements that varied between 9 volts to as high as 52 volts. Except for some specialty mics most modern condenser microphones operate in the 9 volt to 12 volt range. 48 volts is a standard not a requirement. The microphone will use only the amount of power it needs. The RMX 6 should perform fine in whatever application you need"

That's pretty much a lie. OK, I'll be nice and call it spin.

Condenser mics fall into two categories: externally biased condensers (sometimes called "true" condensers) and electret condensers. Electrets have permanently polarized backplates, so they are happy with just a few volts to run their internal electronics.

True condensers, on the other hand, need a high external voltage to bias their capsules. Most require +48V to do so. While it's true that a true condenser could run off of +15V, it would require a DC converter in the mic, which increases costs significantly, and could increase noise without proper design. Since +48V is a standard met by nearly all professional gear, there is little incentive for a mic manufacturer to do that (unless their capsule needs more than +48V, in which case they would, but they might still expect +48V to step up to the higher voltage).

I'd understand if a portable bit of gear didn't do full +48V phantom, that costs a lot of current for a battery power supply. But if the thing plugs into the wall, c'mon, it ain't that hard.

Just for grins, ask the guy if all of the Nady SCM microphone series works on +15V phantom

What would I do? I'd sell the main board and save up for a used Mackie 1604 or something, those can be rackmounted. It takes a few more rack spaces, but you'll thank me later when you have a fully functional mixer.

Trust me, I went from running a Tascam Porta with a Peavey RQ200 as a sub, to a 12 channel Peavey and finally a 16 channel A&H MixWiz. I mix with the Mackie at my church now, it can't touch the A&H (especially the EQ), but the used prices are pretty cheap. Eventually you realize it just isn't worth messing with a lot of toys cobbled together when you have a show to do.

[StuartV]

I hear ya', Ms. H. I too am generally from the Buy It Once school. But, funds are tight right now and if I can get going with stuff that is cheap enough to be considered throwaway (like a $90 6 mic/line mixer), then I will.

And I'll keep watching eBay for an Onyx 1640...

[StuartV]

Just for your entertainment, I asked the Nady guy about the SCMs. His response:

"The SCM mics also require 48 volts."