running power to DI Boxes

[Frank DeWitt]

[quote=bcastle;303045

I am a novice, but have been reading everything I can get my hands on regarding church sound and have been over time trying to make our sound system more reliable and eliminate as much hiss as possible.

I want to work with the equipment that we have on hand first before buying anymore di boxes.[/quote]

Your statement above really hits home with me. I took over the sound in a church that thought hum and hiss was normal. I hated it and wanted it gone. I learned how through a number of forums and now have a quiet system. I wrote an article on the subject here.
http://www.tfwm.com/newsletter-audio-010311-guest

I think you are right to start with what you have. Get rid of the worst problems first. I know a sound system, even one in a old church with odd wiring can be made quiet.

What sort of new cables are you running? Why. This could be a very good thing, or of no value.

Frank

[bcastle]

We have 4 stage boxes on our stage, each with 2-XLR and 2-1/4 mono jacks. the xlr's were wired somewhat correctly, but the soldered connections would come loose from time to time. Each jack was ran to my snake under the stage. The mono jacks were wired wrong as well. The person before me twisted both signal wires together and soldered it together on one pin and then soldered the shield to the other pin. Now granted you can do this to make an xlr act as an instrument cable. it does not and will not help your case if the xlr jack on the other end of the same cable is wired for xlr and plugged into a snake. So i ripped every single cable out (16 total) bought 8 stereo 1/4" jacks so i can at least use a balanced 1/4" TRS if i have to since now all my instruments are running through a di box somewhere.

I have also moved 2 amps to my stage for trial to run 3 separate monitor feeds. With a little creativeness, I ran my aux sends from mixer back through the snake (totally legit) then used a female to female xlr couplers at the snake box, since my xlr cables going to my snake from the previously mentioned stage boxes are the male end. Finally a short little xlr cable to my amp and then speaker cable to the speakers. A lot of work, but since my minister of music has a band with lots of gear/cables its easy for us to do trial runs on top of the stage and see what works best for our particular situation. I plan on dropping an 8 channel stage box to either run more xlr jacks or put in 1/4" monos and run speaker wire to them. This will only happen if I get suitable power in the closet behind the stage where my snake box is. Out of 16 total jacks i only have 13 hooked up now until i finish our set up.

I know I was kinda all over the place. Hopefully this enlightens you. Oh and we had problems with a behringer mixer. It had problems, had to put it out. Got a new 32 yamaha mg 32 and absolutely love it.

Since rewiring everything, I don't have any hums. just the occasional hiss, but thats generally because of bad EQing and easily fixable for the most part. Still have lots of learning. But it is fun and i enjoying having the privileged to lead our sound team. Our system has done a complete 180 from completely unreliable to consistent sound.

[bcastle]

Oh the cables were about 4-5 yrs old in some cases. I have a cable tester that rocks despite being behringer. I always, always, always reuse a cable if i can, you just never know what you need and i really dont enjoy cutting a brand new perfectly working $35 cable if i have some bulk stuff lying around that I can add a $5 connector too to. Now with that said I had some cables that didnt quite reach my snake from the stage boxes so i did have to sacrifice 2 rather long cables so i didnt have a connection under my stage.

[D.R.HADDOCK]

Get rid of the behringer di's.
We have some and they are noisy.
All other di's are fine but the behringers are too noisy.
Use phantom powered di's.
Good di's are not expensive.

[Frank DeWitt]

Originally Posted by bcastle

for consideration of the di box selection question from above i guess it would help to let you know what instruments i run...

-my electric guitar with chorus and/or distortion pedals or my ovation acoustic/electric guitar ( i eventually plan on using 2 separate channels for each guitar on our new mixer because the eq set up and gain is so different for each guitar. and i didnt have the space on the old one)
-worship leaders acoustic guitar through an digital effects box (yamaha i think)
-a korg electric piano (has all kinds of outputs, just not balanced. i do have a left and right. the piano doesnt have its own speakers)
-a yamaha electric piano (has speakers, but only output is a headphone jack and the speakers turn off when a cable is plugged in)
-a third electric piano (cant remember type, has speakers and left and right outputs, speakers stay on all the time)
-electric drums
-bass guitar

Only one of these might need a active (powered) DI (The base guitar, if it has a passive pickup (no battery in the base.

Passive DIs need no power They use a transformer and a resistor. The good ones will give you very good sound.

Personal opinion, The good ones use a Jensen transformer.
Disclaimer, I build and sell DIs

Frank

[Steve Vanciel]

Originally Posted by Frank DeWitt

I learned how through a number of forums and now have a quiet system. I wrote an article on the subject here.
http://www.tfwm.com/newsletter-audio-010311-guest

Frank,
Excellent article! Have you heard any of Bill Whitlock's (President of Jensen Transformers) presentations? He is quite the evangelist for dispelling the voodoo of signal noise issues. Also has some excellent articles posted on the company's web site.

So often the hum and buzz that is blamed on lighting or power issues are really the results of sloppy wiring practices and connectors as you illustrated so well in your article.

Another common electrician's error you can look for is the presence of the bonding screw in branch circuit panels. Per the National Electrical Code, this bonding screw should only be used at the entrance panel to tie the system neutral to earth ground. If the screw is not removed from branch panels, you have created that many ground loops and compromised the effectiveness of the safety grounding system.

SteveV
ETCP-CEE
Orlando, FL

[Steve Vanciel]

P.S. Just saw some new DI products at the Jensen booth at InfoComm recently. They even have some that are DIN rail mountable. Many different configurations for various connector inputs and outputs.

SteveV

[Frank DeWitt]

Originally Posted by Steve Vanciel

Frank,
Excellent article! Have you heard any of Bill Whitlock's (President of Jensen Transformers) presentations? He is quite the evangelist for dispelling the voodoo of signal noise issues. Also has some excellent articles posted on the company's web site.

SteveV
ETCP-CEE
Orlando, FL

I have not met Bill Whitlock but I have read his white papers and he is a active contributor on the www.synaudcon.com forum. He is very active there and was quite helpful when I was developing the DI box I sell. (I use Jensen transformers.)

BTW He has been silent on Syn Aud Con for a while. You might pray for him just in case.

Frank

[D.R.HADDOCK]

Have you considered using passive di's,
They dont need any power !
Especially on things like keyboards
where levels are usually quite high,
so the small loss of a passive di wont matter much.
It would solve all your problems.