Is there a such thing as a Phantom Power remover/filter?

[Patsquatch]

I am looking to buy the Focusrite Sapphire Pro40, but it only allows you to select phantom power for input 1-4 or 5-8. Just incase I need to turn off phantom power for just one of the tracks wile leaving it on for the others, is there something I can make to put inline to block +48v?

Thanks

[Scodiddly]

A transformer or a pair of capacitors will stop DC.

Some people may recommend cutting the ground (pin 1), but that is not a reliable method since the attached gear might get a ground connection some other way and still end up seeing the 48 volts.

[Scodiddly]

A transformer or a pair of capacitors will stop DC.

Some people may recommend cutting the ground (pin 1), but that is not a reliable method since the attached gear might get a ground connection some other way and still end up seeing the 48 volts.

[Patsquatch]

thanks. any idea on specs?

[Scodiddly]

What's your budget? You could certainly get something nice from Jensen in a transformer, or call maybe ProCo or Whirlwind for some inline isolation dealie. Isolation transformers, basically - 1:1 ratio. Voltage ratings really don't exist because they're not an issue in this application - just about anything you can buy with an XLR will be plenty good enough.

For capacitors, you'd put them inline on pins 2 and 3, and you're looking for probably something in a 10uF or bigger electrolytic rated for 50 volts - put the + terminal towards the mic preamp and the phantom power. Maybe add a pair of high value resistors (100k?) on the mic side (- terminal) to ground, to drain off any DC voltage that might have found its way through.

[Scodiddly]

What's your budget? You could certainly get something nice from Jensen in a transformer, or call maybe ProCo or Whirlwind for some inline isolation dealie. Isolation transformers, basically - 1:1 ratio. Voltage ratings really don't exist because they're not an issue in this application - just about anything you can buy with an XLR will be plenty good enough.

For capacitors, you'd put them inline on pins 2 and 3, and you're looking for probably something in a 10uF or bigger electrolytic rated for 50 volts - put the + terminal towards the mic preamp and the phantom power. Maybe add a pair of high value resistors (100k?) on the mic side (- terminal) to ground, to drain off any DC voltage that might have found its way through.

[Snarl 12/8]

Pat, you know that you only need to remove phantom for some ribbons, right? It won't hurt dynamics. You could also use the Cloudlifter, if you're talking about ribbons. It gives you a gain boost, powered off the phantom, while stopping the phantom from reaching the mic. Kindof a "twofer" for your application.

^IIRC.
_________________
Carl Keil

[Patsquatch]

Thanks I'll try that.

I built a couple of those tape op mics that run off a 9v and I was told that Phantom can break them. Not sure if true but don't want to test it.

I know phantom won't break a dynamic but I also heard that it's not great for them. Again not sure if true. I do hear a pop and some static when i turn phantom on with a dynamic so something is going on.

I also have a tube with it's own power supply. Any idea what phantom would do to it?

[Nate Dort]

[Jeff White]

[Snarl 12/8]

You're right about the tapeop omni. I'd be more worried about have the Jensen on that than on the SM7b. Ebtech Hum Eliminator might be another choice if you don't want to DIY something.
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Carl Keil