Amp rack questions

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djtrumptight
Posts: 823
Joined: Tue Dec 15, 2009 6:08 pm
Location: Detroit,Michigan

Amp rack questions

#1 Post by djtrumptight »

I recently ran across a great deal ($75) on a Road Ready 8 space amp rack which I have already built a caster board for since I had 4 heavy duty casters laying around.
I also installed a break out panel on the rear for quick connections.My questions are:

1) I built a Neutrik power connection on the break out panel and I made the cord about 20 feet long,will that cause a problem ?
2) should I make that cord shorter ?
3) there will be times when I will be running 8 subs and will be putting another QSC GX7 in the rack (the loose Neutriks at the bottom of the rack are for that amp,already connected to the panel.
Should I use a signal from my empty #5 and #6 outputs on my DCX2496 or can I use a splitter like the one near my mixer in the picture and share that signal with both sub amps ? Any pros or cons ?
Thanks fellas
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Attachments
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Built:
2 Autotuba's MCM 55 2421
8 T48's 24"wide 3015 LF
2 DR 250's melded Deltalite II 2510
2 DR 250's flat Deltalite II 2510
2 SLA HT systems
1 Table Tuba Dayton DCS 255-4
2 T 39's 20" wide 3012 LF
1 T-18 13" wide MCM 55 2421
2 SLA Pro's

djtrumptight
Posts: 823
Joined: Tue Dec 15, 2009 6:08 pm
Location: Detroit,Michigan

Re: Amp rack questions

#2 Post by djtrumptight »

Also,can I safely run 3 amps from the same power conditioner ?
Built:
2 Autotuba's MCM 55 2421
8 T48's 24"wide 3015 LF
2 DR 250's melded Deltalite II 2510
2 DR 250's flat Deltalite II 2510
2 SLA HT systems
1 Table Tuba Dayton DCS 255-4
2 T 39's 20" wide 3012 LF
1 T-18 13" wide MCM 55 2421
2 SLA Pro's

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Amp rack questions

#3 Post by Bruce Weldy »

djtrumptight wrote: Wed Jun 26, 2019 9:47 pm Also,can I safely run 3 amps from the same power conditioner ?
My power cable to my rack is 25ft. So, no problem

I run 5 power amps in my rack off of one Furman. So, no problem with 3 GX7s.

To daisy-chain those amps, just build or buy a TRS to TRS 1/4" cable to run between the two. The 1/4" and XLR on those amps are parallel. So, no problem....

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

djtrumptight
Posts: 823
Joined: Tue Dec 15, 2009 6:08 pm
Location: Detroit,Michigan

Re: Amp rack questions

#4 Post by djtrumptight »

Thanks Bruce,so the XLR splitters in the last picture I posted wouldn’t work to split the signal between the 2 amps ?
Built:
2 Autotuba's MCM 55 2421
8 T48's 24"wide 3015 LF
2 DR 250's melded Deltalite II 2510
2 DR 250's flat Deltalite II 2510
2 SLA HT systems
1 Table Tuba Dayton DCS 255-4
2 T 39's 20" wide 3012 LF
1 T-18 13" wide MCM 55 2421
2 SLA Pro's

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Amp rack questions

#5 Post by Bruce Weldy »

djtrumptight wrote: Thu Jun 27, 2019 11:15 am Thanks Bruce,so the XLR splitters in the last picture I posted wouldn’t work to split the signal between the 2 amps ?
I didn't see that in the picture....

They work, but then you are sunk if you want to add another amp to the chain. Most of those are built with crappy connectors and have lousy strain relief.....but, strain relief really shouldn't be an issue in this case.

So, fire away! If you add another amp at some point, you can address it then... I run three amps for my subs, so the first one gets the xlr, then the other two are chained with the TRS to TRS....hand built with Neutrik connectors.....just cuz I'm kinda' anal..... :mrgreen:

And my stuff don't break!

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Amp rack questions

#6 Post by CoronaOperator »

djtrumptight wrote: Wed Jun 26, 2019 9:44 pm Should I use a signal from my empty #5 and #6 outputs on my DCX2496 or can I use a splitter like the one near my mixer in the picture and share that signal with both sub amps ? Any pros or cons ?
I run my subs off of just 1 channel on the processor. Reason being is that if you want to make any changes you only have to do it in one place, not 4. Save the extra channels for when you need to add a fill speaker or something. Use the splitters like you have or Bruce's idea with 1/4. Doesn't matter how you daisy chain the amps as long as it works.

3 amps on one circuit might work for you. I usually run my sub amp off a separate circuit than the rest of the system. I guess you'll find out if you trip the circuit breaker with that many amps on 1 circuit.

I like to label my breakout panel L/R. etc on the top lip. Makes hookups brainless especially if you are reaching from the front and are looking at it backwards.

Unless you need the visibility, go get yourself some black 12/3 sjoow cord. I have a strict "no orange or yellow cords" on the stage policy.

*** I should add that in the US for stage use, code does technically specify that all cords on the ground be SOOW (a heavier duty version of SJOOW). It takes some persuasion, but 12/3 soow will fit the blue powercon. 14/3 is also acceptable for 15 amp circuits.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

NukePooch
Posts: 371
Joined: Mon Jun 30, 2014 8:07 pm
Location: Berea, Kentucky

Re: Amp rack questions

#7 Post by NukePooch »

CoronaOperator wrote: Thu Jun 27, 2019 4:46 pm Unless you need the visibility, go get yourself some black 12/3 sjoow cord. I have a strict "no orange or yellow cords" on the stage policy.
I actually got dinged by a fire marshal who said that Orange cords are for 'temporary emergency usage only'.
I do everything in my power to avoid orange cords. In this case, I had used all of my available black cords and used one orange cord to run a short LED light chain.
Fire marshal was cool, I explained I was out of my handwired black cords. He said it was good for the night, but he didn't want to see them any more if I could help it.

Years later, I joined a church that wired EVERYTHING with orange cords...projectors/lights on ceiling, all stage/video/audio, etc. Made my eye twitch, LOL. Took me 2.5 years to get rid of them all.
Built:
4 Jack 112L- 3012HO, melded array
17.5 wide AutoTuba with Infinity 860w
6 Wedgehorn W6 w/ Panel Mount Piezos
2 T48 Slims (15" wide) with 3012LF
4 T48 Fattys (32" wide) with 3015LF

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Amp rack questions

#8 Post by CoronaOperator »

NukePooch wrote: Thu Jun 27, 2019 5:43 pm I actually got dinged by a fire marshal who said that Orange cords are for 'temporary emergency usage only'.
I do everything in my power to avoid orange cords.
Orange cords are like neon lights to marshals that say "come inspect me!" You could technically use any color you want if they make it but it has to be the right type and have the ul listed writing right on the cord saying what it is:
southwire-portable-power-cords-55808745-64_1000.jpg
Although the NEC (national electrical code) says you have to use extra hard usage cord (SOOW) for anything over 6 feet for what we do (sjoow is okay for under 6 foot runs), the code itself isn't legally binding by itself, final say comes from your AHJ (authority having jusisdition). Your AHJ could be a fire marshal, electrical inspector or anyone else that has the authority where you live over your wiring practices. "Most" inspectors would be completely fine with SJOOW for our size shows, especially if routed away from vehicle and foot traffic. Only way to be absolutely sure is to call and ask. SOOW cord is heavy, expensive, takes up too much space and is a pain to use, it's like wrestling lead garden hose.
Last edited by CoronaOperator on Fri Jun 28, 2019 12:19 pm, edited 1 time in total.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Amp rack questions

#9 Post by CoronaOperator »

I forgot to mention location of breakout panels. The only reason to put them on the back is because you have no room on the front OR you want to be able to put a locking cover on the front to stop people mucking around when your not around (in between setup and show time, overnight, etc). Having them on the back is a pain, your always reaching around it especially when your rack is up against the wall. Down low on the front is much easier to work with.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

djtrumptight
Posts: 823
Joined: Tue Dec 15, 2009 6:08 pm
Location: Detroit,Michigan

Re: Amp rack questions

#10 Post by djtrumptight »

Thanks for the heads up fellas,i will get the black 12/3 cord,i would hate to be in the middle of a show and have to deal with an Inspector or Fire Marshall.The reason i put the panel on the back is because once i put another amp in the rack there will be no more space on the front and most of my set ups are for DJ's or myself when DJing so once i wire everything up i rarely have to go into the back of the rack for anything but i always place it sideways near a wall which leaves access to the back and airspace for the amps to breath.
Built:
2 Autotuba's MCM 55 2421
8 T48's 24"wide 3015 LF
2 DR 250's melded Deltalite II 2510
2 DR 250's flat Deltalite II 2510
2 SLA HT systems
1 Table Tuba Dayton DCS 255-4
2 T 39's 20" wide 3012 LF
1 T-18 13" wide MCM 55 2421
2 SLA Pro's

himhimself
Posts: 599
Joined: Fri Nov 13, 2015 9:34 pm
Location: Vancouver BC & Bloomington IN

Re: Amp rack questions

#11 Post by himhimself »

Thanks for the tip about the breakout panel being on the front of the rack. Never really even though about that before. For my little rack, I don't have an extra slot to make it work, but I can on my big rolling rack. Glad i saw this while I was building my panel - made the leads longer so that they can reach from the front of the rack to the rear of the components.
2xT30 (20", 3012LF)
2xT30 (21", 3012LF)
4xOtop J-array (Beta12, melded/straight piezos)
Truck Tuba (MCM)
Next up: 2xJack12 or family of table tubas

Bruce Weldy
Posts: 8301
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Amp rack questions

#12 Post by Bruce Weldy »

himhimself wrote: Sun Jun 30, 2019 3:31 pm Thanks for the tip about the breakout panel being on the front of the rack. Never really even though about that before. For my little rack, I don't have an extra slot to make it work, but I can on my big rolling rack. Glad i saw this while I was building my panel - made the leads longer so that they can reach from the front of the rack to the rear of the components.
The position of the breakout panel really depends on the size of the rack and where it's going to be. My breakout panels are on the back because my rack never goes on stage. It's always in front on one side or the other and the cables are all exiting the rear for a nicer look. It's a tall rack, so it's easy to get to all the connections.

I built out a rack for a local venue where the rack will be up against the wall, so I put the breakout panel up front at the bottom.....that way no cables are hanging down over the front of the amps, driverack, or drawers.

Bottom line - there are no hard and fast rules. Spend some time thinking about the location of the rack and how you are going to use it....that will determine front or back.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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