Installs DriveRack 220i - can't bypass

urban79

Active Member
Alright this is a weird one for me. Our cafeteria sound system has been a headache from the moment they put it in - a mix of installers not knowing what they were doing, insufficient specs, and no one really looking after it. *Something* happened over the summer, and the Crown CDi1000 was inoperable. It was sent out for repair and came back no problem. Next the Alesis Multimix went, so I swapped it with a spare Rane mixer and temporarily everything was fine. Then two weeks ago I get a call that the system is making "elecrical sounds". Sure enough, there is electrical noise that I can't explain. After removing all inputs, I finally narrowed down the source to the DriveRack220i - with nothing plugged in, I have a clipped signal showing on both the input and the output. Before I go and attempt to get the district to pay for that as well (with a new PA system coming in the summer) I'm trying to simply get by. My thought was I could temporarily bypass the DriveRack and plug the output of the mixer directly into the amp - they're even euroblock/pheonix connectors so it was a simple swap. Unfortunately I get no sound. Am I missing something stupidly obvious? I've looked through the system settings without finding anything that jumps out of me.

For the record it's a 70v system with around 18 speakers spread out around the room. Thoughts before I pull all my hair out?

Thanks!
Chris
 
Alright this is a weird one for me. Our cafeteria sound system has been a headache from the moment they put it in - a mix of installers not knowing what they were doing, insufficient specs, and no one really looking after it. *Something* happened over the summer, and the Crown CDi1000 was inoperable. It was sent out for repair and came back no problem. Next the Alesis Multimix went, so I swapped it with a spare Rane mixer and temporarily everything was fine. Then two weeks ago I get a call that the system is making "elecrical sounds". Sure enough, there is electrical noise that I can't explain. After removing all inputs, I finally narrowed down the source to the DriveRack220i - with nothing plugged in, I have a clipped signal showing on both the input and the output. Before I go and attempt to get the district to pay for that as well (with a new PA system coming in the summer) I'm trying to simply get by. My thought was I could temporarily bypass the DriveRack and plug the output of the mixer directly into the amp - they're even euroblock/pheonix connectors so it was a simple swap. Unfortunately I get no sound. Am I missing something stupidly obvious? I've looked through the system settings without finding anything that jumps out of me.

For the record it's a 70v system with around 18 speakers spread out around the room. Thoughts before I pull all my hair out?

Thanks!
Chris
@urban79 Queries:
Are all of the speakers 70 volt, all speech and / or music range NO SUBS?
What functions is the drive rack performing for you:
Combining stereo sources to mono?
Time alignment?
Level changes; mic level up to line level?
Breaking system up into zones?
Do all units have power?
Have you tried substituting another basic mixer for the Rane?
Pulling you hair out will NOT be the answer.
Toodleoo!
Ron Hebbard
Calling @MNicolai
Toodleoo!
Ron Hebbard
 
@urban79 Queries:
Are all of the speakers 70 volt, all speech and / or music range NO SUBS?
Yes all of the speakers are 70 volt, and there are no subs.
What functions is the drive rack performing for you:
Combining stereo sources to mono?
Time alignment?
Level changes; mic level up to line level?
Breaking system up into zones?
Honestly, until this issue, I wasn't even sure the DriveRack was programmed at all... I would not put it past the contractor to have simply stuck the box in the rack and charged us for it without programming it...
Do all units have power?
Everything in the rack has power.
Have you tried substituting another basic mixer for the Rane?
I have not because I don't have another rack mixer - I could try a regular format mixer.
Pulling you hair out will NOT be the answer.
Agreed!

Toodleoo!
Ron Hebbard
Calling @MNicolai
Toodleoo!
Ron Hebbard
 
@urban79 Definitely try another mixer, rack mounted or not, to prove what's working which will put you on the road to what's not working.
Is your system limited to speech use or are you running music through it as well?
Toodleoo!
Ron Hebbard
 
The pinout of the phoenix connectors of the dbx and the Crown are different, so if you just unplugged one, and plugged it into the other, that could explain the lack of sound. dbx is Gnd/+/- and Crown is +/Gnd/- Add in a slightly miswired or unbalanced Rane means no signal at all.

Phoenix plugs have several traps. There are a wide variety of phoenix plugs made, and some of them are not cross compatible, with different diameter pins and such, so even if it fits, it might not make contact. The solution is to always keep the original phoenix plugs on the respective piece of equipment, and swap the wires.

Give each wire a good tug after tightening the screw, because some brands of phoenix plugs are notorious for having the wire go into a void and not get clamped. I have been caught by that several times. The other thing is to ensure the wire is stripped long enough. A phoenix clamped onto insulation will not make a connection.
 
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The pinout of the phoenix connectors of the dbx and the Crown are different, so if you just unplugged one, and plugged it into the other, that could explain the lack of sound. dbx is Gnd/+/- and Crown is +/Gnd/- Add in a slightly miswired or unbalanced Rane means no signal at all.

Yep, there was the idiocy on my part - I didn't check the pinout. At least I have sound now - I'll look into the DriveRack later to see if I can find the source of noise, but at least it's now not a mission critical issue as I head into tech for the musical!

Thanks all!

Chris
 
Alright this is a weird one for me. Our cafeteria sound system has been a headache from the moment they put it in - a mix of installers not knowing what they were doing, insufficient specs, and no one really looking after it. *Something* happened over the summer, and the Crown CDi1000 was inoperable. It was sent out for repair and came back no problem. Next the Alesis Multimix went, so I swapped it with a spare Rane mixer and temporarily everything was fine. Then two weeks ago I get a call that the system is making "elecrical sounds". Sure enough, there is electrical noise that I can't explain. After removing all inputs, I finally narrowed down the source to the DriveRack220i - with nothing plugged in, I have a clipped signal showing on both the input and the output. Before I go and attempt to get the district to pay for that as well (with a new PA system coming in the summer) I'm trying to simply get by. My thought was I could temporarily bypass the DriveRack and plug the output of the mixer directly into the amp - they're even euroblock/pheonix connectors so it was a simple swap. Unfortunately I get no sound. Am I missing something stupidly obvious? I've looked through the system settings without finding anything that jumps out of me.

For the record it's a 70v system with around 18 speakers spread out around the room. Thoughts before I pull all my hair out?

Thanks!
Chris
Mayhaps a full reboot of the DR? It's the last thing to try after more likely and/or obvious things bring no conclusion. Not sure where dbx customer support is these days (used to be in Utah), but a phone call to them might bring some suggestions.

That the mixer also failed (correct, or was it a false alarm due to the DR?) sounds like a lightning strike or other "voltage where it shouldn't be" damage. Was the cafetorium used over the summer? I have a number of potential 'pilot error' and "volunteer's adapter cords" ideas that could have put speaker-level voltage on an input, or sent 120VAC up a ground wire... are there any signs of burnt wiring or PC board traces, Phoenix connectors, anything melted?

@FMEng hits all the points about checking terminations and the different wiring of Phoenix connectors between different devices...
 
Mayhaps a full reboot of the DR? It's the last thing to try after more likely and/or obvious things bring no conclusion. Not sure where dbx customer support is these days (used to be in Utah), but a phone call to them might bring some suggestions.

That the mixer also failed (correct, or was it a false alarm due to the DR?) sounds like a lightning strike or other "voltage where it shouldn't be" damage. Was the cafetorium used over the summer? I have a number of potential 'pilot error' and "volunteer's adapter cords" ideas that could have put speaker-level voltage on an input, or sent 120VAC up a ground wire... are there any signs of burnt wiring or PC board traces, Phoenix connectors, anything melted?

@FMEng hits all the points about checking terminations and the different wiring of Phoenix connectors between different devices...

Anything to a full reboot beyond removing power for 15-20 seconds? I tried that already several times. Each time after the full boot up I get noise back. I'll call after the show closes if nothing else has come of it.

I totally agree that there was some anomaly over the summer - the room isn't really in use, but the sound system is always on as it is technically the only PA in the room for announcements (and therefore our lockdown signal). The mixer is definitely dead, as was the amp. The only thing that bugs me is that while the amp and mixer could have conceivably been toasted in one event (the mixer didn't get tested until after the amp was fixed), the DriveRack continued to work post that event for a period of several months. However I don't like coincidences and this is a huge one.

No melting, no burnt smell, and no changes of wiring that I know of (other than what I just did). HOWEVER, the system is a hodgepodge - there are two different 70v signals coming into the mixer - one from our school-wide PA system and the other from the backstage monitors. There are also 3 mic inputs and a wireless receiver. As I said, I have no reason or confidence in the programming of the DR. I'll try to get into the programming again after the show.

Chris
 
Anything to a full reboot beyond removing power for 15-20 seconds? I tried that already several times. Each time after the full boot up I get noise back. I'll call after the show closes if nothing else has come of it.

I totally agree that there was some anomaly over the summer - the room isn't really in use, but the sound system is always on as it is technically the only PA in the room for announcements (and therefore our lockdown signal). The mixer is definitely dead, as was the amp. The only thing that bugs me is that while the amp and mixer could have conceivably been toasted in one event (the mixer didn't get tested until after the amp was fixed), the DriveRack continued to work post that event for a period of several months. However I don't like coincidences and this is a huge one.

No melting, no burnt smell, and no changes of wiring that I know of (other than what I just did). HOWEVER, the system is a hodgepodge - there are two different 70v signals coming into the mixer - one from our school-wide PA system and the other from the backstage monitors. There are also 3 mic inputs and a wireless receiver. As I said, I have no reason or confidence in the programming of the DR. I'll try to get into the programming again after the show.

Chris
@urban79 You're worrying me when you posted:
"there are two different 70v signals coming into the mixer - one from our school-wide PA system and the other from the backstage monitors. "
I hope your 70 volt signals are transformer coupled and properly padded down to line or microphone level to suit the mixer's inputs, also pay attention to balanced, unbalanced and grounding.
Calling: @MNicolai @FMEng @Ancient Engineer @TimMc @all others. . .
Toodleoo!
Ron Hebbard
 
Consider an intermittent power issue with perhaps big back EMF from when an inductive load like kitchen vent fans kick on. Also potential neutral to ground voltages higher than ok. These can keep on frying stuff. Sometimes installing an isolated ground AC ckt can shortcut otherwise difficult transient issue chases, or the "what fried today?" mambo.

driverack pgming is a PITB. Be sure to use pc software for it, even if you need to get a usb to serial adapter. Dax tech support can screen share with you.There are 2 modes once you are logged in, and much of what you need to access is hiding in super user mode. Really bad design...

220i is long discontinued. Useful functions in there include dynamic feedback suppression and limiting to save downstream eqpt.
 
@RonHebbard I worry myself on a daily basis! I'm reasonably sure there have been few if any precautions taken, besides me running the secondary feed (the monitors) through a DI box in an attempt to provide some protection. Otherwise the system is as delivered by the contractors. It was a terrible design and one that I'm hoping is rectified in the near future - I do wonder what potential damage this could have caused in the process though. To be fair, it's chugged along for 10 years this way, and while the sound quality is terrible, it passes what it needs to...
 
@RonHebbard I worry myself on a daily basis! I'm reasonably sure there have been few if any precautions taken, besides me running the secondary feed (the monitors) through a DI box in an attempt to provide some protection. Otherwise the system is as delivered by the contractors. It was a terrible design and one that I'm hoping is rectified in the near future - I do wonder what potential damage this could have caused in the process though. To be fair, it's chugged along for 10 years this way, and while the sound quality is terrible, it passes what it needs to...
so if each 2ndary feed is run thru a ground-lifted DI box, and you have tested or eyeballed the inside of those DI boxes to ensure nothing looks smoked ... the isolation is probably ok, distortion and gain-staging issues notwithstanding.
 

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