Turtlerock Forum

I think I already know the answer to this one, but thought I'd check anyways.

If I have a preamp (or 8) that run XLR inputs and use an XLR to TRS cable to connect the inputs to a TRS patch bay (back of bay, top row - TRS at patchbay end). And I attempt to run an XLR to TRS cable into the front of the patch bay with my condensor connected to it. Will Phantom power travel over it and power the mic?

I'm guessing...no.

I'm just trying to get my head around patchbays and how I'm going to set it up in my project studio.

As long as all three conductors in the cables are connected it will work, no problems. It'd be a good idea to turn off the phantom when plugging the TRS connectors in though. (Tip/ring can short to sleeve on the way into the jack.)

Otto wrote:It'd be a good idea to turn off the phantom when plugging the TRS connectors in though.

Otto's gentle words could be put more bluntly. ONLY turn phantom power on once all connections are made, if you value your equipment at all. This is true whether or not you're are going through a patchbay.

You can check whether your patchbay will pass phantom power quite easily. Get a multimeter or cable tester and test the resistances. It should show 0 resistance (ie a direct connection) from XLR pin 1 to TRS sleeve, from XLR pin 2 to TRS tip and from XLR pin 3 to TRS ring. All other combinations (eg XLR Pin 1 to TRS tip and ring, XLR Pin 2 to TRS ring and sleeve, and XLR Pin 3 to TRS tip and sleeve) should show infinite resistance (ie an open circuit). 9 prods with a pair of multimeter probes takes about 15 seconds and sets you mind at ease.

NOTE: does NOT work with TS connectors. Don't even bother checking.

OK, I didn't think it was possible. I haven't purchased the patchbay yet. Soon. Thanks for the advice on ensuring that everything is plugged in, before switching on Phantom Power. I will need to be extra diligent with that.

I just did a quick search for a cable supplier and found www.giggear.com.au.

I'm guessing the 8 Channel XLR Male to TRS 8-Channel loom is exactly what I'm looking for. ($30 is cheap too!). This should be setup correctly already, no? Male XLR end goes into the 8 inputs on the M-Audio Fast Track Ultra 8R that I've just ordered. The TRS go into the patchbay.

8 Channel XLR Male to TRS
http://www.giggear.com.au/product.php?p ... t=0&page=1

I'm thinking about these TRS to TRS 8-Channel loom for the outputs on the Ultra 8R into the patchbay.

1/4" stereo to 1/4" stereo
http://www.giggear.com.au/product.php?p ... t=0&page=1

Does this sound OK?

If you buy a cheap loom make sure you check all the soldering/isolation. I bought one ages ago that had lots of poor joints with stray wire filaments shorting against the body of the connectors.

DwaneHollands wrote:OK, I didn't think it was possible. I haven't purchased the patchbay yet. Soon. Thanks for the advice on ensuring that everything is plugged in, before switching on Phantom Power. I will need to be extra diligent with that.

I just did a quick search for a cable supplier and found www.giggear.com.au.

I'm guessing the 8 Channel XLR Male to TRS 8-Channel loom is exactly what I'm looking for. ($30 is cheap too!). This should be setup correctly already, no? Male XLR end goes into the 8 inputs on the M-Audio Fast Track Ultra 8R that I've just ordered. The TRS go into the patchbay.

8 Channel XLR Male to TRS
http://www.giggear.com.au/product.php?p ... t=0&page=1

I'm thinking about these TRS to TRS 8-Channel loom for the outputs on the Ultra 8R into the patchbay.

1/4" stereo to 1/4" stereo
http://www.giggear.com.au/product.php?p ... t=0&page=1

Does this sound OK?

Thanks for the heads up. Can you point me to another company who you would recommend for higher grade cables?

They're the first one I found.

thirty bucks for an eight way XLR to TRS loom is dirt cheap. I couldn't even by good quality connectors for that.

is it still true "you get what you pay for"

in this case, it will probably be fine, not sure if it will still be fine in two years time though.

Ok thanks Rob! Might start with the cheapies first. Pretty much won't touch them once they're in, so they shouldn't have to deal with much wear and tear.

DwaneHollands wrote:Ok thanks Rob! Might start with the cheapies first. Pretty much won't touch them once they're in, so they shouldn't have to deal with much wear and tear.

Cable tie the loom to something inside your rack to make sure there's no strain on the connectors. Those cheapo looms can break over time (even if they are just sitting there) if there's any tension on the connectors at all.

Ah the joys of getting new gear... every time you buy something, you gotta buy more cables.

I've used those exact cables in a location rig for the last two or three years and still working fine here... I know its ridiculous in terms of parts and labor cost but I don't understand it either.

Wow Myles that pretty amazing. Looks like I'll go for them definetly. Hey thanks for the heads up too Nick on taking the strain off the connectors. I did not know about that!

Ok,

I have another basic question in relation to the patch panels and cables.

I have a Marshall JMP-1 tube guitar preamp that I'm going to patch into this patchbay. Together with my JCM 800 2 x 12 combo amp. (just the input on the JCM 800). I can't seem to find any information on whether the outputs on the JMP-1 are balanced or unbalanced.

Can I or should I use TS cables or TRS cables with the outputs from my Preamp to the input on my JCM 800. Can I patch this through my patchbay using TS cables or should I use TRS cables or should I not use the patchbay for this kind of stuff? I've got a Hafler T3 3 Channel Preamp aswell which I'd like to patch. I'd just like to have the flexibility of the patchbay so I can send stuff to my AMP to monitor or record with a mic and send a direct version straight from my preamp to mix with the room sound.

I'm wanting to get a tidier setup...getting a little obsessed with patchbays now!

DwaneHollands wrote:Ok,

I have another basic question in relation to the patch panels and cables.

I have a Marshall JMP-1 tube guitar preamp that I'm going to patch into this patchbay. Together with my JCM 800 2 x 12 combo amp. (just the input on the JCM 800). I can't seem to find any information on whether the outputs on the JMP-1 are balanced or unbalanced.

Can I or should I use TS cables or TRS cables with the outputs from my Preamp to the input on my JCM 800. Can I patch this through my patchbay using TS cables or should I use TRS cables or should I not use the patchbay for this kind of stuff? I've got a Hafler T3 3 Channel Preamp aswell which I'd like to patch. I'd just like to have the flexibility of the patchbay so I can send stuff to my AMP to monitor or record with a mic and send a direct version straight from my preamp to mix with the room sound.

I'm wanting to get a tidier setup...getting a little obsessed with patchbays now!

I think the "proper" way to do it on most unbalanced gear is to make a TRS-TS cable, with the negative (Ring) conductor soldered to the earth at the TS end.

That said, I use only balanced cable across all my gear and balanced patchbays and never have any dramas. This leaves pin 2/negative/the ring disconnected within the unbalanced inputs and outputs, which I'm not sure is the done thing, but as I said, never had any earth loop problems or anything.

Maybe Rob Squire is the best person to answer this one.

waitup wrote: Maybe Rob Squire is the best person to answer this one.

Oh cool. Is Rob Squire in the Building? Paging Rob Squire : )

Bumpsky for Rob....