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Title: splitting mixer output to multiple amps
Post by: inganmarcelo on October 31, 2018, 07:47:57 PM
Hello guys.. thank you in advance for sharing your knowledge.

here is my problem...

I am trying to connect my mixer(balanced output) to 5 different old crown amp(unbalanced input) DC300A series IIs.

I came up with few options on my own, but they seem too much electronics since I am just splitting mono signal.
mono equipment seems obsolete these days...

1-multiple mono y splitter
2-Whirlwind SPLIT 6
3-headphone breakout box
3-a distribution amp/mixer

I am looking for very simple equipment since this is not for recording or live music.. its for a restaurant audio installation...

thank you in advance guys
Title: Re: splitting mixer output to multiple amps
Post by: Ivan Beaver on October 31, 2018, 08:06:43 PM
Simply parallel the inputs/or just a big Y cable with several legs.

Until you get to a large number of amps, you don't need to worry.

Basically if the combined impedance is 10x the source impedance you are good

So divide the input impedance of the amp by the number of channels to get the combined impedance
Title: Re: splitting mixer output to multiple amps
Post by: Mike Caldwell on October 31, 2018, 08:30:10 PM
Your breaking out some big heavy iron for what I assume is a background music system.

How close are the amps going to be to mixer, what kind of mixer do you have?

Are you running the amps in stereo or bridged mono, in bridged mono they will just about make it for a true 70 volt
system amp.

You will want to use a high pass filter on the system properly set for the speakers in the system as the amp has none hence why DC is part of it's model number!

If everything is close to each other you should be able to get by with Ying the inputs.
If there is some distance between the amps and the mixer maybe you would need a transformer at the amp rack to go from balanced to unbalanced.

The Crown manual shows connecting (-) to the sleeve (+) to the tip and leaving the shield float at the input when using a balanced source.

Back in the early 80's I had four DC300's and thought I had arrived!! I still have a couple D75's from that same era!
Title: Re: splitting mixer output to multiple amps
Post by: Keith Broughton on November 01, 2018, 06:05:46 AM
As Ivan said, you can "daisy chain" the inputs.
To avoid (possible) ground loop hum, connect pin 2 of the XLR output on the console to the centre pin of the RCA plug to the amp and pin 3 to the shell of the RCA plug.
Should be good to go.
Title: Re: splitting mixer output to multiple amps
Post by: Mike Caldwell on November 01, 2018, 08:37:35 AM
As Ivan said, you can "daisy chain" the inputs.
To avoid (possible) ground loop hum, connect pin 2 of the XLR output on the console to the centre pin of the RCA plug to the amp and pin 3 to the shell of the RCA plug.
Should be good to go.

That's exactly what Crown says to do and I described

Those DC300's have 1/4 inch tip sleeve jacks.

I was just going to attach a screen capture of that manual page but for some reason I can't. The image size is well below the max limit.

Title: Re: splitting mixer output to multiple amps
Post by: Keith Broughton on November 01, 2018, 09:57:48 AM
That's exactly what Crown says to do and I described

Those DC300's have 1/4 inch tip sleeve jacks.

I was just going to attach a screen capture of that manual page but for some reason I can't. The image size is well below the max limit.
!/4"...I stand corrected.My memory of those amps is a little..er..hazy!
I described the wiring as I suspect the OP might need some detailed guidance. :)
Title: Re: splitting mixer output to multiple amps
Post by: Art Welter on November 01, 2018, 02:46:49 PM
I was just going to attach a screen capture of that manual page but for some reason I can't.
Good information for those not familiar with retaining balanced operation when terminating to or from two conductor connectors, or how to employ passive DC and RFI filters.

But unfortunately "The upload folder is full", so the written descriptions of a shield lift will have to suffice for now  :'(
Title: Re: splitting mixer output to multiple amps
Post by: Jerome Malsack on November 02, 2018, 01:34:13 PM
Pyle makes a 1 to 1 transformer that can take the xlr in and give the unbalanced out on 1/4  for around 25 dollars.  in case the long run is needed. 
https://www.amazon.com/PYLE-PRO-PHE400-Eliminator-2-Channel-Outputs/dp/B00BARTW42/ref=sr_1_1?ie=UTF8&qid=1541180008&sr=8-1&keywords=pyle+hum+eliminator&dpID=41EaIabIA5L&preST=_SY300_QL70_&dpSrc=srch

yes cheap but could be a help. 
Title: Re: splitting mixer output to multiple amps
Post by: James A. Griffin on November 20, 2018, 08:24:22 PM
Pyle makes a 1 to 1 transformer that can take the xlr in and give the unbalanced out on 1/4  for around 25 dollars.  in case the long run is needed. 
https://www.amazon.com/PYLE-PRO-PHE400-Eliminator-2-Channel-Outputs/dp/B00BARTW42/ref=sr_1_1?ie=UTF8&qid=1541180008&sr=8-1&keywords=pyle+hum+eliminator&dpID=41EaIabIA5L&preST=_SY300_QL70_&dpSrc=srch

yes cheap but could be a help.

Have you actually heard this in action?   My experience with cheap Pyle DI's is that they sound like crap.   I can't imagine this sounding any better.
Title: Re: splitting mixer output to multiple amps
Post by: Tim McCulloch on November 23, 2018, 05:59:47 PM
Have you actually heard this in action?   My experience with cheap Pyle DI's is that they sound like crap.   I can't imagine this sounding any better.

They are suitable for mic level use.  I'd not pump +18dBv @20hZ thru one.