patchbay with xlr inputs?

[Charlie_M]

I finally moved my gear off the top of my desk and into a proper rack. This is wonderful because:

1. It frees up some desk space

2. I got a big enough rack that I can add a drawer or two for cables and stuff which will help me a lot with clutter

3. I can set my laptop on top of the rack and that leaves it at a comfortable height for working - thus freeing up even more desk space.

4. It looks friggin cool!

What I have in there now is a digi002 rack and an ART tube mic preamp (with built in tube comp and eq)

I found that I like to use the tube pre for both vocals and bass, but it's a pain having to rotate the rack around to swap out cables and stuff.

I'd love to have a patch bay to enable me to swap things around from the front, but for this to work I believe I'd need it to have an XLR input on at least one of the patches. I'm not seeing that out there.


Here's what I'm trying to do:

• Mic out is xlr / bass out is 1/4"
  
• bass out and into patch bay
• mic out and into patch bay
  
• patch bay out and into the ART tube pre
  
• Goal is to be able to select which input goes into the pre via patch cable.

Is this doable? Is there a better way that I'm not seeing? I've seen xlr to 1/4" cables but that would leave me without a way to get phantom power out to the mic I believe.

Thanks in advance for any tips/insight.

[AfaraWayland]

"Is this doable? Is there a better way that I'm not seeing? I've seen xlr to 1/4" cables but that would leave me without a way to get phantom power out to the mic I believe."

it's do-able, and no, a balanced TRS to XLR mic cable should not cut you out of phantom power. I do believe the cable must be balanced, as your mic's output is certainly balanced. (meaning it has 3 pins at the connector).

However, it might behoove you to get a patchbay that will pass phantom power. (by manufacturers spec's)


-------
How many inputs/outputs do you want in the patchbay?

I suppose one for each input/output you are using with the 002, namely, analog in's and outs.

You could wire the mic 1-4 inputs and the analog 5-8 to your patchbay, perhaps dedicate one of those channels to the tube pre output.

-and/or-

You could even wire the patchbay so that on the tube pre, that has TWO inputs, be given two inputs on the patchbay, (on patchbay/not 002) one is for the pre's mic input, and one is for the bass/D.I input.

[remember that the bass input (or instrument D.I) is an unbalanced input, whereas the mic is balanced...(3pins)]

-----

You could accomplish what you want with a balanced TRS patch bay.

Make a dedicated channel for the mic, and just run a mic cable out from a patchbay to whereever your mic is, [ i mean from the back of the patchbay, this will require a quick and easy soldering job.] -that way way you can change mics if necessary.

Make a dedicated channel on the patchbay for the tube pre input for BOTH mic input and D.I input. >>>using a TRS balanced patchbay will allow you to direct-plug into the 1/4" patchbay input with your instrument, yet the patchbay will route the instrument to the tube pre's D'I' section.

Give one channel on the patchbay to the tube pre output.

Route the patchbay tube pre out to a dedicated input (5-8) of your choice, and select +4db on the 002 input switch (rear of unit)

by my count you've used 4(ins) + 1(out) patchbay channels so far, fill out the rest as necessary.

also, don't be afraid to solder the patchbay rear connections. you can use standard connectors at the mic and 002 ends.

someone else chime in if I'm leading him astray.

[AfaraWayland]

mic cable >>>patchbay channel
(rear connection, labled "Mic" on front panel of patchbay)

Mic pre (MIC) input >>>patchbay channel
(rear connection, labled "Mic Pre" on front panel of patchbay)

Mic pre (D.I.) input >>>patchbay channel
(rear connection, labled "Mic Pre D.I." on front panel of patchbay)

-2 methods for mic pre output-

Mic pre line output >>>direct to 002 analog input (choose 5-8)
(rear connection, labled "oo2 input #/mic pre output" on front panel of patchbay)

-0r-

Mic pre line output>>>patchbay channel
(rear connection, this would allow further routing/processing before signal is sent to 002.)

++++this would require a patchchannel for the 002's inputs+++

remaining channels could be routed like thus:

4 mic cables out to studio/or studio tieline>>>4 patchbay channels
(rear connection, labeled as "studio 1-4")

oo2 mic inputs 1-4>>>4 patchbay channels
(rear connection, labeled as "oo2 mic inputs 1-4")

remaining oo2 analog ins>>>3-4 patchbay channels
(rear connection, labeled as "002 analog ins 5-8")


...etc

[Charlie_M]

What you're describing is exactly what I want to do. The thing is a searched around on musiciansfriend.com and didn't see any patchbays offered with XLR inputs or phantom power. Maybe I'm using the wrong search term? I asked one of the guys in our local pro audio shop here (not the guy I usually work with he was out that day) and he wasn't aware of one.

I really wouldn't need that many in/outputs on the patchbay but... whatever the standard is (8,16, whatever) is probably plenty for me and I'd probably just go for that. My thought is that I only need a small # of channels for this need (like you described) but I'm sure I'll come up with additional needs down the road.

Can you tell me of where to get such a patchbay with both XLR and 1/4" unbalanced inputs? Thanks !

[AfaraWayland]

I dunno of any with both, though they may exist,

I really suggest sticking with a 1/4" TRS (tip ring sleeve) balanced patchbay, like this:

http://www.zzounds.com/item--BEHPX1000

If you reaaaallly don't want to solder, you can get TRS to XLR conversion connectors for the channels that need it.

the behringer will require conversions,

however, for more cash, and if you like hand soldering...

http://home.flash.net/~motodata/patc...arterinch.html

something like this will work.


BY THE WAY, a patchbay will not supply phantom power, but it will pass the pre's phantom power. This should be (of course) if it is a balanced patchbay.

[Charlie_M]

OK thanks man let me just make sure I understand that last statement about the phantom power.

If I take the mic XLR cable and attach that to a XLR/TRS converter cable, and plug that into a balanced patchbay, and then go from the balanced patch bay to the tube mic pre XLR input using a TRS / XLR converter cable, then the phantom power from the tube mic pre will reach the mic?

As long as that's true I'll just get a balanced patchbay and spring for a couple of cables to convert from XLR to TRS and then back again.

Now... if I do that will the balanced pathcbay also work for unbalanced signals if I want to do that at some point or would I need a seperate unit for balanced and unblanced?

I think we are converging on a solution.... Thanks !

Charlie

[AfaraWayland]

that should be true. patchbays in large studios are set the same way basically, they have studio tielines, from which the (mics) are sent to the patchbay,

the preamps in a console/outboard gear (like tube pre) provide the phantom for mics , and it travels through the patchbay to the tielines, to the mics.

phantom power is just a DC voltage sent down the wire to the mic, and it powers the mic's active circuits. It doesn't care about a patchbay as long as there is a discrete path for it to follow. The DC voltage actually runs to the mic in direction, while the mics' AC voltage output is simultaneously running in the other.


the advantage of a TRS patchbay would be that you could setup an unbalanced DI channel for the tube pre DI input. Since an instrument cable is only Tip Sleeve, or lead and ground/shield, the ring section of the Tip Ring Sleeve connector would be bypassed. and since the tip is always the 'hot' lead or + lead, my theory stands correct.

XLR patchbays would require conversions for unbalanced guitar cables, plus, they usually have less channels, and can be more expensive.


balanced vs unbalanced:

So, to sum up, if you had a Tip Ring Sleeve TRS connector patchbay, you could route a channel to the pre's DI, and then plug your bass directly into the patchbay...

however, cable distances of under 20ft are suggested. any logger than that I would suggest a DI box that you run from another patchbay channel.

unbalanced audio signals like guitar and bass and keyboard outputs start to pick up a lot of hisssss and other noise when the runs are longer than 20ft. (maybe shorter). So , balance the distance of the cable travel with the placement of the musician in the studio.

just keep the player/instrument within 10-15ft from the patchbay when playing and he should be fine.

as long as you stay within the 20ft unbalanced cable rule, you can hook up (keyboards, bass, guitars) directly to patchbay inputs.

[Charlie_M]

OK Thanks for that explanation I learned a lot and know just what to do now. Looking forward to trying it out !

Charlie

[Andrew07]

Hey dude I have three 7-channel XLR-XLR patchbays that I use with my Digi 002 and outboard stuff. I made em myself and you can get all the stuff at markertek.com. Redco.com also makes really good stuff (although I've only used them for cabling in the past)

[brandondrury]

Great thread, dudes! I wish I could have jumped in earlier but I was out of town.

The DC voltage actually runs to the mic in direction, while the mics' AC voltage output is simultaneously running in the other.

Technically, AC voltage goes in both directions, changing directions very quickly back and forth. (That's where the "alternating" part comes from).

unbalanced audio signals like guitar and bass and keyboard outputs start to pick up a lot of hisssss and other noise when the runs are longer than 20ft. (maybe shorter). So , balance the distance of the cable travel with the placement of the musician in the studio.

Agreed. On top of that, with the bass and guitar, the impedance of the cable begins to have a negative effect on frequency response. Going to line level as early as possible is a good idea with bass. (I like the Sansamp quite a bit).

Brandon