Preamps and patchbays

[gcjammin1]

I recently read in a recent thread that you shouldn't run phantom power through a patchbay when using preamps. I run all my pre's through patchbays so I can route them easily. Is this wrong? If so, how should I set up my pre's?

Gcjammin1

[DAS]

There are two different questions here really.

1) Running the output of your preamp through a patchbay is not an issue at all. There is no phantom power there.

2) The input to your patchbay from a microphone is an issue. But I do it in my studio, as it makes it easy to route different mic jacks in the studio to different preamps. You just need to be very careful and not repatch things while phantom power is on. If you do you can possibly damage the mic amp, and you will certainly send a huge pop of audio through the preamp as well so you better make sure you have things turned down. If you can consistently address these precautions it shouldn't be a problem. But a mistake can be costly.

[Audioholic]

gcjammin1
In the Studio where I work as well, we have several booths etc and rooms, so we have to trigger phantom from the console to the mics. As DAS said, be very carefull with your patches, as several people have fried ISDN box inputs from careless patches. Maybe a good practice would be to disengage phantom when not using it, but when you have all of your patches set correctly, turn down your channell volume all the way, as you will spike the channell, and then engage your phantom. It just takes a little extra thought before patching.

[michaelhoddy]

Patching phantom powered inputs on a conventional bantam or 1/4" bay is a bad idea. If you mistakenly hot-patch a cable, you're effectively shorting the phantom supply momentarily, which aside from the huge noise, can really mess up a mic preamp. In addition, my experience tells me that (for whatever reason) patchbay jacks with phantom running through them require a LOT more cleaning than non-phantom jacks, probably because of the residue produced by arcing between the jack and cable. My current studio has some of these, and I have to clean them at least twice as often to keep them working (I didn't design the patchbay setup here, or I wouldn't have done it this way).

There's also the issue of having a dirty patch screw up a great take. It's happened more than once.

The way I prefer to do mic patching in studios now is with XLR rackmount patch panels and short XLR cables. I've done this a couple places now. They're definitely bulkier and a little less convenient, but the connections don't short out or get dirty, you can't toast your gear, and it still affords the flexibility of being able to vary your routing between the live room and the preamps.

I still use bantam TT bays for all the line level stuff, back end of the mic pre to the converters, signal processing, inserts, and such.

I have Ace Backstage in California make panels for me. They have a bunch of different frame sizes, and can use pretty much any connector you want. I usually use Neutrik non-latching XLR's, simply because they're more convenient to patch quickly in and out to.

[DAS]

I have had mic I/O on high quality TT bays in my studio for about 8 years now. I have never cleaned most of the points and they are perfectly quiet. I do have a very high quality HVAC system, and I did buy very high quality TT bays, and cables, and finally, I do remember to turn phantom off whenever I patch.

I guess everyone's mileage will vary.

[dpd]

wow - I guess I just would avoid patchbay type connections at the low levels of mic outputs. I'd be concerned about non-linearities of a bad connection, especially in him EMI environments like mine (radio station transmitters on the property).

As the above have said, YMMV. I'd be super-cautious to ensure you maintain the patchbays, etc if you choose to do this

[gcjammin1]

Thanks for the response guys. I do keep my phantom power off until I'm ready to use my mics and turn it off when not in use.

Gcjammin1

[DAS]

More....On Sweetwater's Euphonix desk, which was in Studio A until replaced by a D|Control last year, all mic points were at patch bays. Again, no (or minimal) problems. The be clear, these were Euphonix branded patch bays that came pre-configured with the intent to handle the mic patching (nothing special done, just set up that way from the get-go - every point on the tower HAD to be at a patch bay). If it's good enough for Euphonix...

[michaelhoddy]

Yeah, lots of really high-end legit guys do their mic patching on patchbays, so it's certainly an accepted way of doing it. I've just had a less-than-stellar experience. Personal taste.

The big downfall to my preferred way of doing things (XLR patch panels for the mic lines/preamps) is that you can't wire normals, so the lines always have to be patched for the thing to work.

[DAS]

In the "new and improved" Studio A we decided to avoid all of this.

We wired multiple (mic) jackfields in the various rooms the same, and then ran those lines directly to the preamps.

So in other words, jack number 1 is the same everywhere (it's all normalled) behind all the panels. When you plug into number 1 (no matter where you access it in the studio) you are connected to mic pre X. Jack number 2 is connected to mic pre Y, etc.

It works great. It requires a little pre-planning during setup for larger sessions, but the signal path is pure, and there are literally NO patch bays in the studio. All routing is done inside Pro Tools. The preamps show up in the software by name. It's actually a lot easier than the old way of doing things.

Yes, the obvious drawback is that if I decide I want to use preamp F on the snare instead of preamp D, I do have to walk out into the studio and repatch the mic line itself. I can live with that. I need the exercise.

[Foreverain4]

my routing is explained here, if you want another way of doing it..

http://www.sweetwater.com/forum/show...?threadid=9571

none are right or wrong, just what works for you..