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[Jannice Torres]

Hello everyone!

I'm new in this forum and also ne in the field of sound engineering.  I play the guitar in my church band.  We're a small group and had the sound system in place before e started playing.  Unfortunately, as it sometimes happens, the person who designed and installed the system, no longer goes to my church.  The only other person with knowledge has no time to troubleshoot.

The problem is that we plug the instruments, start playing and, in the middle of the song, some or all instruments stop being amplified.  They come and go and sometimes they never come back.  We have to unplug the cord from each instrument, wiggle the cable and plug it back in.  Sound always comes back if we do that and it will go away again during the next song or two.

System info (please bear with me, as I'm not all there with the lingo):
An Oooooooollllld snake with 4 male mic connectors and 12 female mic connectors in its head.  The snake goes from the stage to the back of the room, where an 18-channel mixer resides, inside an oooooooolllllld cabinet.  The cables look old and crunchy.  I'm afraid the problem is the snake, but I'm not sure.   Problem also happens with the mics.  As we're singing, sound comes and goes and most times it won't come back.

Things we're done to troubleshoot:
1. I've changed the lines to all instruments and the problem continues.

Things I have not done:
1. Have not changed the instruments to a different channel.  I guess, that would be next in order.  I just think the snake is soo old and dirty that it won't matter where I plug.  Whaaaaaaaa.... (sorry... venting...yes, I'm a girl...)

Questions:
1. How can I test the snake to make rule it in or out of the problem?
2. If the problem is the snake, can it be fixed by replacing whatever bad parts it may have?  We don't have money to buy a new snake.  I've seen them in catalogs starting at $800 for 100'.  Ours is 100'long.
3. I read in other posts about the Ebtech Swizz Army and the Behringer CT100 cable testers.  Ho can use these testers to test a snake?

Please feel free to ask questions and I'll try to find the info and post later. 

Thanks for your time.

[Jonathan Johnson]

Try using Electrical Contact Cleaner on the head end. Make sure you have good ventilation and extinguish all flames in the area. Put on safety goggles and rubber/latex/nitrile gloves. Protect the area around the head (large trash bag should do it). Spray the contact cleaner in each jack on the snake. Be careful -- watch out for sprayback when you spray into the connectors (that's why you put on the goggles).

The contact cleaner will remove the general lint, dust, grease, and gunk that has accumulated in the connectors over the years. Obviously, it will not tighten loose contacts that don't grip the mating contacts well. After the contacts are cleaned, you can more easily determine which ones are weak.

Replacing the XLR jacks is an inexpensive but tedious task. Each jack will cost less than $10, but the wires must be soldered. At the head end, it's easy; at the mixer end it is more difficult. I recommend using only Neutrik connectors, and I think most people on this forum will agree. (Readers: if you disagree, please do and state why.)

If either the outer jacket or the insulation on the individual runs in the snake appears brittle or cracked, throw away the whole thing and replace it. It's not worth repairing. I think you'll want to have at least 16 channels available so you can take full advantage of your mixer's inputs. A 16x4x100 (16 input, 4 return, 100') snake can be had online for as little as $300. I won't speak to the quality of different brands as I don't have the experience, but many others on this forum will be happy to share their opinions.

P.S. -- Are you using any adapters/DI boxes between the instruments and the snake? Have the adapters been tested or replaced?

[Art Hays]

Do instruments, mics disappear all at the same time and return all at the same time?  If so it seems like electronics (board or amps).  However I guess it might be both, e.g. if the snake is intermittently shorting out the phantom voltage and this takes out the board.

If it is the snake I would expect wiggling of connectors and cables to produce the problem as well as fix it.  Have you tried that?

To be sure it's the snake you could turn off phantom power and plug some instruments directly into the back of the board and see if the problem still happens.

To also test the board/amps alone what happens when you play a CD thru it at high volume?

[Jeff Bankston]

you could be overheating the amp(s) and the thermal protect shuts them down until they cool to the point where the thermal protect turns them back on.

[Tom Young]

Hello everyone!

I'm new in this forum and also ne in the field of sound engineering.  I play the guitar in my church band.  We're a small group and had the sound system in place before e started playing.  Unfortunately, as it sometimes happens, the person who designed and installed the system, no longer goes to my church.  The only other person with knowledge has no time to troubleshoot.

The problem is that we plug the instruments, start playing and, in the middle of the song, some or all instruments stop being amplified.  They come and go and sometimes they never come back.  We have to unplug the cord from each instrument, wiggle the cable and plug it back in.  Sound always comes back if we do that and it will go away again during the next song or two.

System info (please bear with me, as I'm not all there with the lingo):
An Oooooooollllld snake with 4 male mic connectors and 12 female mic connectors in its head.  The snake goes from the stage to the back of the room, where an 18-channel mixer resides, inside an oooooooolllllld cabinet.  The cables look old and crunchy.  I'm afraid the problem is the snake, but I'm not sure.   Problem also happens with the mics.  As we're singing, sound comes and goes and most times it won't come back.

Things we're done to troubleshoot:
1. I've changed the lines to all instruments and the problem continues.

Things I have not done:
1. Have not changed the instruments to a different channel.  I guess, that would be next in order.  I just think the snake is soo old and dirty that it won't matter where I plug.  Whaaaaaaaa.... (sorry... venting...yes, I'm a girl...)

Questions:
1. How can I test the snake to make rule it in or out of the problem?
2. If the problem is the snake, can it be fixed by replacing whatever bad parts it may have?  We don't have money to buy a new snake.  I've seen them in catalogs starting at $800 for 100'.  Ours is 100'long.
3. I read in other posts about the Ebtech Swizz Army and the Behringer CT100 cable testers.  Ho can use these testers to test a snake?

Please feel free to ask questions and I'll try to find the info and post later. 

Thanks for your time.

Losing some or *all* instruments is indicative of problems other than with the snake.

Troubleshooting requires a clearly thought out set of tests that eliminate elements in the signal path (as the cause) until you are left with the real culprit.

You single out instrument inputs. Do you also have vocal microphones ? How are they behaving ?

What mixer do you have ?

Is phantom power switched on ? Is it applied to all channels or individual channels ?

(read the manual or google if you do not know about phantom power)

Is any of the sound system equipment allowed to get very warm or hot ?

Please provide answers to the questions we have asked and we'll see where this goes.

BTW - whether it is related to your problems or not you should probably repair (rebuiild) the snake. Connectors cost FAR less than $10. each and you need to use the correct type of contact cleaner.

[Arnold B. Krueger]

The problem is that we plug the instruments, start playing and, in the middle of the song, some or all instruments stop being amplified.  They come and go and sometimes they never come back.  We have to unplug the cord from each instrument, wiggle the cable and plug it back in.  Sound always comes back if we do that and it will go away again during the next song or two.

System info (please bear with me, as I'm not all there with the lingo):
An Oooooooollllld snake with 4 male mic connectors and 12 female mic connectors in its head.  The snake goes from the stage to the back of the room, where an 18-channel mixer resides, inside an oooooooolllllld cabinet.  The cables look old and crunchy.  I'm afraid the problem is the snake, but I'm not sure.   Problem also happens with the mics.  As we're singing, sound comes and goes and most times it won't come back.

I've replaced/reparied  tons of mic and instrument cables, and even replaced a console with symptoms like yours, but never replaced a snake.

If the problem is with your snake then it will affect some channels and not others. Therfore changing channels can help.

I have repaired a snake, by replacing connectors at either end. This snake was at least 20 years old and heavily abused by some teenagers. Cost for the parts was minimal.

$800 for a 100 ft 12 by 4 snake seems at least twice too much for anything but an ultra-ruggedized touring snake which is overkill for a typical church. Find a different vendor, and/or set your sights down a notch. Let me recommend Markertek - my two best snakes are made-to-order 150 footers from them.

[Jannice Torres]

Hello everyone.  Thank you for responding!  I've tried some of your suggestions as time allows, others, I haven't tried yet.  I'll try all suggestions and post results as they become available.

I tried the spray cleaner.  Sprayed all connectors on the snake and the cables that go to the instruments.  I have yet to clean the other end, that goes to the mixer.  You are right, it's a tedious project!!  LOL  But, I'm making progress.  So far, with the snake head clean and instruments' cables clean, there has been no resolution to the problem.  Audio keeps going and coming intermitently.

I'll now answer some of your questions:

P.S. -- Are you using any adapters/DI boxes between the instruments and the snake? Have the adapters been tested or replaced?

Currently, there are two cable adapters, but no effect pedals. Instruments are connected as follows:
Guitar: "mic" type of cable (male to female) no pedals, cable adapter or effects box. 
Bass guitar: 1/4" stereo (male to male) directly to an 1/4" (female) to mic type (male) adapter, to the snake. No pedals or boxes.
Electronic drums set: 1/4" stereo cable (male to male) to an 1/4" (female) to mic type (male) adapter.

Do instruments, mics disappear all at the same time and return all at the same time?

No.  Mics are cut off at intermitent times, sporadically, but not at the same time.

If it is the snake I would expect wiggling of connectors and cables to produce the problem as well as fix it.  Have you tried that?

Yes, however, just wiggling the cable doesn't work.  I have to unplug my guitar (since I don't want to walk to the snake head to disconnect there), I unplug the cable from my guitar and plug it back in.  As I'm removing the cable I don't hear anything, but when I reconnect, I hear a pop and the audio comes back.  Actually, it's a loud pop and people get frazzled.  I'm now asking my sound person, by the mixer to shut down the system so I can unplug the guitar. The drums and the bass don't do this pop.

To also test the board/amps alone what happens when you play a CD thru it at high volume?

There is a CD player connected to the mixer, not going through the snake.  It works OK at any volume and audio doesn't cut off.

Do you also have vocal microphones ? How are they behaving?

Yes, we have two microphones.  They both do the same thing, come and go intermitently, not necessarily at the same time. But it has happened at the same time in the past.

What mixer do you have ?

I don't know. I'll find out tomorrow and let you know.

Is phantom power switched on ? Is it applied to all channels or individual channels ?

I'll read about Phantom power, as I don't know what that is.  DOn't explain it here if it's a long topic.  I'll read about it and answer your question soon.  Thanks for the suggestion and for your patience until I get more educated on these sound engineering issues.  You've all been very helpful so far.

Is any of the sound system equipment allowed to get very warm or hot ?

The mixer resides in a corner, 12 inches from each of two walls, one concrete with a window and the other drywall with a window to the hallway. 

This is actually a topic of aggravation on my part.  The room is used for so many events.  People keep moving the mixer to the corner, against the walls. I keep moving it out to use it on Sundays and provide proper ventilation.  They also push chairs and other furniture against it and against the cables.  I don't have a cover or way to prevent people from pushing stuff against the cables. I'm pretty sure there's gotta be some damage there as well.  Grrrrr.

[Matthias Heitzer]

I'll read about Phantom power, as I don't know what that is.  DOn't explain it here if it's a long topic.  I'll read about it and answer your question soon.  Thanks for the suggestion and for your patience until I get more educated on these sound engineering issues.  You've all been very helpful so far.

Phantom Power is is a supply voltage that is sent trough the snake and Mic cables (typically +48V). It is needed for condenser microphones, active DI-boxes and some other stuff. Guitars with XLR connectors ("mic connector") may need it. If the instrument has active electronics but doesn't have a battery compartment it normally needs phantom power.
Adapters from "mono 1/4" to XLR are generally not a good idea if you use phantom power. Those adapters short the supply voltage to ground.


The next time one channel disappears, set its fader and monitor sends to "off" and raise the gain (sometimes also called sense or trim). If it reappears suddenly the mixer propably has corroded insert jacks.

How is the CD player connected?

[Jonathan Johnson]

Guitars with XLR connectors ("mic connector") may need it.

Incidentally, if you have a guitar with an active pickup that uses a battery, do not leave the guitar plugged in when not in use. Doing so will drain the battery. Unplugging the guitar turns off the electronics. (At least for many if not all.)

[Jannice Torres]

Hello again. I have news. I found a button on the mixer called Phantom. On Sunday, I turned Phantom off and both mics and both guitars worked well the entire service!

Problem, the drums still cut off.

At the en of the service, without much time for testing, we switched the drum to a different channel and thesrums then worked well for a few minutes. Again, not much time for testing and we only switched and tested the drums.

Today, at practice, the drums were fine the entire hour but my guitar and both mics started cutting off again. so, this week, I'm going to buy a 1/4"-to-XLR connector forth drums and another for each guitar to eliminate the 1/4-to-XLR adapters.

I also finished spray cleaning both ends ofthe snake. I vacuumed and sprayed. The mixer and snake are clean. I also took pictures that I will post shortly.

So, in summary, I think I'm getting close to a permanent solution. I think the problem OS definitely that I don't understand the complexities of the system and I'm using whatever adapter or cable is laying around.

[Jannice Torres]

This is the mixer we have. May I please have a review?  Is it good or bad equipment?

The sticker says Pickup 18A FBT. I found a pic here http://www.lacicala.it/images/ecommerce/products/medium_260.jpg. I downloaded and am reading the manual.

[Matthias Heitzer]

If you want to plug guitars directly into a mixer, the solution is a "direct injection box" (DI).
It provides a suitable load impedance for the instrument, "balances" the signal to reduce the noise picked up by the cable and protects the phantom power from beeing shortet.

Good DIs can be quite expensive, but in most situations a cheap DI is better than no DI.
I'd suggest passive DIs since you seem to have a phantom power related problem.

Your mixer seems to have a built in amplifier, are there seperate cables that run to the loudspeakers?

[Taylor Phillips]

This is the mixer we have. May I please have a review?  Is it good or bad equipment?

I can't find much info about the Pickup 18A powered stereo mixer you have on the internets and haven't heard of the company either.  All I've figured out is that it is powered with two 400W amps.  You say the CD player plugged right into the mixer works without issues, though, so perhaps you should see if you experience problems if you plug the instruments straight into the mixer without the snake.  You mention that the mixer can be moved, so this shouldn't be too much of a hassle.  Have you checked the microphone and instrument cables going from the mics/instruments to the snake as well?  If you have cheap ones, they can go bad pretty quick.  Also, as Matthias said, get DI's for the guitar and bass, not 1/4" to XLR adapter cables.

[Nick Eide]

Try to plug in directly to the board to eliminate as many variables as possible.
Get a cable tester.
Are there channels that don't cut out?
Does it cut out when you are running half as loud as normal? If so your board (amps) or speakers could be over heating.

Where are you located? Maybe someone is close and could lend a hand?

[Jannice Torres]

I thought I had replied to this one last week but apparently I never clicked "Post".

I'm in Tampa, FL. In Town 'n Country (west Hillsborough Co)

This week, I'll get new cables for the drums and guitars and a DI box for the guitars.

No other news besides that. It's been a busy week.

On regards to moving the mixer, no, I can't. I only have a couple of feet of cable to move it in any direction. So, it would be a hassle to plug the instruments directly to the mixer. I'll trigger if the DI boxes don't work. I'm guessing I'll need one for each instrument, correct?

Any suggestions? I saw all kinds and prices on amazon. Of course I'll go with cheap just cause there's no money for more, butaybe I can find a good one on EBay.

[Matthias Heitzer]

To connect the drumset correctly, you might need DI's too.

If the drumset has balanced outputs, you could run a 1/4" TRS ("Tip-Ring-Shaft", sometimes just called stereo) to XLR-male cable to your stagebox and then use a XLR-female to 1/4" TRS adapter at the console end of the snake. This way, you can plug the drums into balanced line inputs, so you don't have to worry about phantompower beeing send to the drums.

If it doesn't have balanced outputs you should use a DI (or two, or a two-channel DI if you use the drums in stereo ) for the drums.

Most cheap passive DIs work pretty well, they might dampen the high frequencies a little bit, but in most cases it sounds better than sending the signal unbalanced through a 100' cable into a mic input.
Cheap active DIs can add hiss or noise, and they need some kind of powersupply. Often phantompower, with the option to put in a 9v battery.
Since your mixer seems to have a phantom power problem, and the batteries are just another potential point of failure, i'd buy passive DI's in your situation.
 
OR, you could buy an active multi channel DI (4, 6, with it's own power supply.

I normally do not suggest Behringer gear, (stay away from the DI20!, altough some are said to work fine, a lot of them add way too much noise), but the Behringer DI800 ULTRA-DI PRO is pretty good (i.e. hasn't caused problems or noticable irregularities in a neighboring church ever since it was bought some years ago) for it's price: ~100$ for 8 channels is hard to beat.

[Jannice Torres]

To connect the drumset correctly, you might need DI's too.

If the drumset has balanced outputs, you could run a 1/4" TRS ("Tip-Ring-Shaft", sometimes just called stereo) to XLR-male cable to your stagebox and then use a XLR-female to 1/4" TRS adapter at the console end of the snake. This way, you can plug the drums into balanced line inputs, so you don't have to worry about phantompower beeing send to the drums.

This a great idea. I didn't think of using a converter for the drums on the mixer side. Channels 11 or so, and up are stereo type.

But, how do I know if the drums have balanced output or not to then decide if it needs a DI box or not?

Thanks for all the wonderful ideas. I feel pretty close to a solution, if only I can hit the right combination. LOL

On Monday, I bought 3 cheap DI boxes from amazon.

http://www.amazon.com/gp/aw/d/B0027V760M/ref=mp_s_a_1?qid=1304041878&sr=1-1

  $37 for 3 boxes(price went up today. . ) no shipping. We'll see. I always say "you get what u pay for" I hope I'm wrong; it's all I can afford right now. 

I also got a Beringher cable tester.

Thanks. I'll come back to post results Sunday evening.


I bought 3

[Matthias Heitzer]

But, how do I know if the drums have balanced output

Just find out what make and model it is, and google usually knows where to find the manual.

[Jannice Torres]

Umm, ok. Sorry about the delay in updating you. The latest is that all instruments acoustic/electric guitar, electric bass, and electronic drums) are now going from stereo cables to DI boxes to XLR cables to the snake head.

Both mics are going directly to snake head via XLR cables.

The instruments are always on; sound doesn't cut off.

The mics continue to get cut off intermittently, unpredictably. I have to disconnect and reconnect the XLR cable from the mic to get sound back and sometimes that doesn't work and I have to ( hold tour breath) hit the mic with my knuckles to get it to pop back.

Hmm, I can't remember if the Phantom power needs to be on or off now that I have DI boxes. I read the three and that's not clear. Can someone specify, do I need Phantom power on when using DI boxes?

[Jonathan Johnson]

The mics continue to get cut off intermittently, unpredictably. I have to disconnect and reconnect the XLR cable from the mic to get sound back and sometimes that doesn't work and I have to ( hold tour breath) hit the mic with my knuckles to get it to pop back.

Have you tried a new mic with a new cable? Maybe you can borrow from another church to test? Could be something bad in there.

Hmm, I can't remember if the Phantom power needs to be on or off now that I have DI boxes. I read the three and that's not clear. Can someone specify, do I need Phantom power on when using DI boxes?

Only if it needs it. :-)

Generally speaking:

• Dynamic mic - no phantom
• Condenser mic - phantom
• Passive DI - no phantom
• Active DI - phantom (unless the DI has a battery)
• Instrument w/o DI - no phantom

Or, to put it another way: if it has electronics, it's active. If it's active, it needs a power source. If it's active and doesn't have a battery or power cord, it needs phantom power. Some devices have the option of either battery power or phantom power; there may be a switch.

Note that while most dynamic mics and passive DI boxes don't need phantom power, it usually doesn't hurt if phantom power is applied. This may be the case where you have a global phantom power switch (all or nothing) instead of individual phantom power switches on each input channel.

A few warnings about phantom power:

• certain vintage microphones can be destroyed by improperly applied phantom power. Or so I've heard.
• Do not connect an unbalanced microphone (1/4" TS plug) to XLR with a simple adapter; you could end up with a hazardous voltage present on the body of the microphone. If necessary, use an impedance matching transformer.
• If a microphone is on a channel that could have phantom power applied (even dynamic mics), do not use it near water such as a baptismal tank. Use wireless microphones instead.

[Jannice Torres]

Ok. Thanks for the DI/phantom breakdown. I'll check our setup and apply your suggestions. For the time being, we've stopped playing live and went to CDs until we can get someone to look at the problem. We're not quiting, just preventing a nervous breakdown, namely, mine. LOL. I'll keep you posted. Hopefully, we can figure it out and the solution may help other newbies who find this thread 20 years from now. 

[Jannice Torres]

If anyone lives in the west Tampa, FL area and is willing to come check our equipment, I will really appreciate it. I think we can even pay you for your services. Our mics are still not working right.

What is the going rate for system evals? 

[Greg_Cameron]

I doubt the problem is with your mics and snake. It's sounds like the mixer is the culprit by a good margin. Rent a powered mixer for a day from a local shop. If the problems disappear, you have your answer.

Greg

[ProSoundWeb Community]