Thanks @Amiers . Wow, there are some deals to be had on eBay. Which is awesome since I have one dead unit and another with its Protect light on. I intend to inspect those amps more closely and make sure that at least the issue isn't further down the line (especially with the one in Protect Mode), but it's good to see that I can get cheap replacements.
@Les Just a thought on your 150 Ohm output tap. Long ago, before manufacturers began providing constant voltage output taps, some manufacturers provided a multitude of impedance taps. It's said: "You NEVER forget your first." My first was a dark brown and cream Stromberg Carlson from their pre grey finished days. The outputs were a pair of parallel wired 8 contact octal sockets with each providing one common contact and seven different output impedances. From memory, the output impedances were: 4, 8, 30, 60, 125, 250 and 500 Ohms. I tested them all but only ever seriously used the 4 Ohm tap. Up here, Hammond Manufacturing, in Guelph Ontario and nothing to do with the Hammond Organ Company, used to offer all manner of power and audio transformers including transformers to source and bridge your constant voltage output lines as well as a range of impedance matching transformers for folks running high impedance speaker lines.We use these for monitoring and I'm trying to look up some specs, but can't find a model number.
Also, I assumed they were 70v, but the 150-ohm thing is throwing me off. What's that all about?
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@Les Check your amp's manuals, they MAY list their taps both ways, constant voltage and impedance, in their manual but possibly only one way on their chassis graphics. Bogen used to have the low end of their output secondaries tied to ground but they also provided a link you could unbolt if you wished to run your output floating [Which MAY have only been legal at 10 and / or 25 volts.] In my mind, your NEC ALWAYS required one end of 70 volt lines to be bonded to ground. I believe I'm also recalling Bogen providing an option for grounding the center-tap of their 25 volt outputs. I never installed any balanced output installations. I THINK this may have been something your NEC liked to see in school installations.@RonHebbard - Thank you for that pearl of wisdom. I guess that begs the question, where is the 70v output? I checked one of the ceiling speakers that this is connected to and it has a 70v transformer (Atlas Soundolier tapped at 8w with remote volume control, for those playing along at home).
@Les Page six of an on-line TOA manual shows detailed information for wiring their outputs. It lists info for constant voltage as well as impedances of the various output taps of a variety of modules. One model I remember reading was listed as having an 83 ohm output. I've attempted a 'cut and paste' of an on-line page for you but who knows what's going to materialize here when I key in Control V.@RonHebbard - Thank you for that pearl of wisdom. I guess that begs the question, where is the 70v output? I checked one of the ceiling speakers that this is connected to and it has a 70v transformer (Atlas Soundolier tapped at 8w with remote volume control, for those playing along at home).
I couldn't see where the 150 Ohmer was/is but have used such on AMP that was bridged.We use these for monitoring and I'm trying to look up some specs, but can't find a model number.
Also, I assumed they were 70v, but the 150-ohm thing is throwing me off. What's that all about?
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I couldn't see where the 150 Ohmer was/is but have used such on AMP that was bridged.
@Les A couple of comments.My goodness. I think I might just tap off a speaker already in the chain.
(This is the project where I am adding 8 speakers to the sparsely-laid out speakers already in the chain)
The pictures presented by Les (the OP) were for the top two devices, which are only mixers (no power amp section, TOA M900MKII), so this was for the Line Level output (either 600 Ohm - Line Level, or 150 Ohm Mic Level), as this signal feeds a separate set of devices.
@Les ; Purely as a guess: Stage Page is probably just what it sounds like, an input from a microphone, or paging output of the SM's ClearCom to "Page" the stage as in: "Attention ladies and gentlemen, places please for act one, act one beginners." Stage Program is probably an input from a monitoring mic, or monitoring mic mixer, feeding performance audio into the system for denizens of the various back stage areas who want to hear the production and follow along. Why is "Stage Program duplicated on each amp?"Sounds like I've been misunderstanding this system the entire time. So these two components on the SM console are mixers and probably drive these amps in the booth. Guess I've been barking up the wrong tree.
Novice question: What is the difference between "Stage Page" and "Stage Program", and why is Stage Program duplicated on each amp?
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