I need help wrapping my head around a patchbay

[matta]

Hi Guys,

I am thinking about taking the plunge and getting a patchbay. For years I?ve
managed to get by without one as my system didn?t dictate the need for one
(I had a digital console that fed the ADAT of my soundcard and I didn?t use
any outboard gear) but with my DIY stacking up it is soon going to become a
nightmare to interface everything and patchbay seem like the logical
step/solution.

The bay in question I am looking at is the Neutrik NYS-SPP-L Bay, which is
has 48 1/4? balanced jacks divided into 2 rows.

From the research I?ve in the search done it seems the convention is to have
your outputs above your inputs on the bay.

I have decided to go for a balanced bay as 80-90% of my gear will have
balanced +4db outputs, but there will be the occasional piece of gear that
will have unbalanced prosumer gear that will be ?10db that needs to get
patched into the bay and then into the input on my soundcard (which is now a
Digi002R)

I guess my main question is now to wire in gear on 1/4? balanced jacks that
is not balanced? Should I wire them all as balanced even if they are
unbalanced? I don?t plan to run phantom through the bay at all if that is
concern.

Through my search it seems as if this should not be a problem as the cable
run will be less than 2-3 meters, but I?m just not sure how to wire it all
up.

I found a post that linked to a balancing box that Kev designed, but I don?
know if I need to go to that extreme if the cable run will be as short as I
indicated it will.

Any help would be much appreciated.

Thanks

Matt

 

[smallbutfine]

Hello Matt,
I have that NYS-SPP in my rack because it was cheap, easily configurable between half-normalled, split and isolated from the front without dismounting from the rack, and because of the name neutrik suggesting to be no total crap for the money.
I also have bought a *to be soldered* switchcraft bay for very cheap at ebay, which i never used because it is a long jack patchbay (is it called bantam? however, i can put *normal* jacks in but somewhere / rec.audio.pro i read that this will not be very good for the tips of the cables, dunno really if true).
The neutrik has a not really solid feel. i managed sometimes the stereo and mono plugs to be not fully inserted. That's really disturbing, because you think of everything else first normally...
Next, due to the 48 jacks on 1 HE it is not possible to insert some of the bigger quality jack next to each other...(ok i can live with that, others maybe don't, depends on your existent cable equipement).
On the other side it's fast to configure (maybe in a live rack) and every module pcb can be replaced fast and easily, neutrik even has special "insert modules" to be bought optionally (stereo - double mono)...
If your setup is to be changed from time to time with your equipment it is no bad deal all in all (i use it even in the mastering section).
On the other hand, i paid half the price new for the undisturbable switchcraft at ebay, which should be professional in handling for sure...very "heavy metal" that could last a hundredandfifty years configurable in every way, but has to be soldered.
If you wanny go the symmetric way you should think about going XLR...
And be careful when patching symmetrical signals with phantom power (better avoided) because there's a good chance to damage some gear sometimes...

To your mean question: I never had bigger problems using stereo jacks for all my equipement (unbalanced and balanced).

If your way patchbay - soundcard is not that long (you mentioned 2-3 meters, depends on the "electrical environment" at this path really) and your soundcard has unbalanced ins i would not use a dedicated DI, if it is symmerical ins i would forsure and even would try to get something like a good active splitter with iron to be flexible in my racks outs (one way to soundcard, one to grapical eq for live, one to a DAT-recorder or whatever).
I'm going the unbalanced way to my unbalanced soundcard ins (breakout box, inca 88) 1,5 m out of the influence of mains cable and such and never had noise or hum problems (lucky me...).

i recently bought a dead cheap 16 ch active DI / Splitter box (OK, NO iron in there... :wink: ) for 33? new from an official dealer (!!!) that is called ETEK MultiDI (an italian B*ringer aggressor...).
I've seen them in the gear lists of some studios googeling before buying...
Original price was around 150?, i think *very* overpriced...
Looks pretty crappy inside from the schematic point of view but stability seems pretty OK.
Unbalanced ims can be paded by 0, -20 or -40 dB, impedance can be switched between 400k, 22k, 2k2 Ohms, ground lift is possible and channels can be linked with crappy looking switches (all from the front, 16 ch, 1 HE...). :?
It uses the rarely used BA4560 SINGLE row package (SIP) opamps (16 pce) :? which maybe could be upgraded with "castrated" quadruple opamps of better quality (cut the legs of one side except the power pin, bend the pins of the other side up nd wire the power pin down! See pin layout of the packages!). i plan to try that on the channels i want to use in split mode first, maybe with some spare MC33079 to see if it's worth the effort.
i have to make some research first before giving *real facts* on this one ( i mean the kind of real-life information PRR and others are asking for if gear is discussed :grin: ).
But if it's a really usable unit with a bit of tweaking it's a bargain.

hope this helps (to confuse you a little bit more :wink: )

cheers

Martin

 

[matta]

Hi Martin,

Thanks for the insight. It all does indeed make sense. I think I am going to be happy with the Neutrik, thanks for your analysis on it, most helpful.

My soundcard has balanced ins on TRS 1/4" jack so I plan on wiring them as such, likewise the outputs as such.

I guess my main thing was if I should wire my unbalanced signals from thing like sound modules etc as balanced even though they are unbalanced.

In theory I should get a drop in level from -10 to +4, will this be okay?

Thanks

Matt

 

[daArry]

Hey Matta,

I'm am a similar crossroads now too...

Not sure if you fancy balancing ya -10 bits to +4 to keep the patchbay fully balanced, but following this thread: http://www.groupdiy.com/index.php?topic=5760&start=0&postdays=0&postorder=asc&highlight=balanced

I made up a lil pcb (havn't made or tested it yet tho):

ready2print bottom side:
http://notapplicable.co.uk/audiolab/bld/BLD_bottom.pdf

top overlay:
http://notapplicable.co.uk/audiolab/bld/BLD_top.pdf

Best,

 

[DrFrankencopter]

Umm, guys, +4dBu, -10dBV and balanced vs unbalanced are two seperate issues.

I have lots of gear that's +4 and unbalanced. +4 vs -10 simply defines how 0dB is defined. If you connect a +4 unbalanced output to a +4 balanced input, you get a 3dB drop versus conecting a +4 balanced output. The same happens when you connect a -10 out to a -10 in. When combining +4 and -10 you end up with meters that don't correspond from one device to another, and gain staging may prove difficult (you might be working your +4 devices at low gains to stay within the headroom limits of your -10 gear, or, your -10 gear may not be able to push enough signal into your +4 devices to let you operate the controls in their normal range).

Balanced vs Unbalaced, I'd opt to keep the patchbay as balanced friendly as possible. You may want to dedicate certain patch points for things like lifting shields, and polarity swap. Handle unbalanced devices at their connectors, not at the patchbay side...this way if you upgrade, your cabling is still compatible with any balanced equipment you replace it with.

You may want to consider a couple of isolation transformers (1:1) in the patch bay, and a couple of -10/+4 level converters...might come in handy.



Cheers,

Kris

 

[Rob Flinn]

Personally if I was in your position I would be looking for a second hand "B" gauge patchbay.

The difference is that B gauge sockets are designed to be plugged in & out of all day long (they originate as telephone patchbays) & a regular jack socket isn`t.

The B gauge jack plugs are a bit like a stereo 1/4" but the tip is narrower.

These bays are expensive new, but cheap second hand & will last a lifetime. They hard wire on the back so you save a fortune on plugs & you can normalise it any way you like with some wire.

 

[daArry]

soz, heat must be gettin to me this page cooled me down: http://www.montagar.com/~patj/db_db.htm

 

[smallbutfine]

I guess my main thing was if I should wire my unbalanced signals from thing like sound modules etc as balanced even though they are unbalanced.

In theory I should get a drop in level from -10 to +4, will this be okay?

As you mentioned "sound modules" it is possible that it is *fully OK* not to handle the level drop with dedicated electronics anyway. I did that all the time in the past never having any troubles with it. (I use my equipement rack for synths *only* at the moment, with noise and headroom not really a problem for me, feeding my mixer unbalanced with an el cheapo multicore...)
I'm only looking for balanced pro level solutions to make everything more stable, secure, compatible and "repeatable" when testing new configurations.

greetings

Martin

(Yes i was a little bit OT with my last post, just some thoughts regarding my own equipement...maybe of use for some of the threads readers :wink: )

The B gauge jack plugs are a bit like a stereo 1/4" but the tip is narrower.

HA! that's what my switchcraft patchbay is... BTW i got mine for 20? on ebay NOS.

@daArry: Thank you very much for the link. Very clear information!

 

[clintrubber]

neutrik even has special "insert modules" to be bought optionally (stereo - double mono)...

FWIW, those can be had at RS and I can confirm that those Neutrik-insert modules fit
another Chinese-made balanced patchbay of a certain brand.....

















OK, PX1000