You've basically got the first part correct.
The XPA Gen3 chassis has seven slots.
Each slot can actually hold a high-powered module which delivers a single channel at around 300 watts... or a stereo module that has two channels at much lower power.
(People often mix the two - using the low power stereo modules for back surrounds or height speakers.)
Each chassis has a single power supply - which is rated for a bit over 2.5 kW (2500 watts).
What you need to understand is that music is extremely dynamic.
This means that, when listening to typical music, maximum power is only required occasionally, usually for very short peaks, and even then rarely in more than one or two channels.
The rest of the time a channel will typically be delivering about 1/10 of its maximum power on average.
So, yes, if you were to run all of the channels in a seven channel XPA Gen3 amp, at full power, on a test bench, the power available to each channel would be slightly reduced.
However, in real world use, when playing music, the "two channels driven" rating can be delivered continuously to any two or three channels that ask for it, or to all channels for a short time.
The XPA-DR amplifiers are fully balanced fully differential versions of the XPA Gen3 amps.
This means that each channel of an XPA-DR amplifier uses two amplifier modules, occupying two slots, and delivers about twice as much power.
(So they're twice as powerful per-channel but limited to a maximum of three channels per chassis.)
The XPA and XPA-DR chassis use slightly different versions of the same power supply...
So an XPA Gen3 chassis can hold up to seven high-power modules or stereo modules...
And an XPA-DR chassis can hold up to three XPA-DR channels (each channel is a "dual module")...
But you cannot mix the two in the same chassis.
And, yes, you absolutely can buy an amp with more channels installed than you need and simply not run some channels.
(It won't gain you anything other than allowing you to buy spare channels that you might want later.)
You can also return a chassis to have more modules added later...
The price for additional modules is the same, whether you purchase them when you but the amp, or add them later.
(There is an extra charge that covers the installation and shipping... but it is pretty nominal... I think $50.)
The cost to upgrade the amp later by adding modules is basically the same as buying the modules when you buy the amp.
(There is a single nominal charge to install the modules and pay the shipping... I think $50.)
Each channel in an XPA or XPA-DR chassis is fully independent...
Each has its own input and output...
I'm not sure I understand the final question.
Modules that aren't being used draw very little "idle power"...
SO you absolutely could, for example, purchase an XPA-DR3 and only use two channels...
And, if you do so, it will have the same performance capabilities as an XPA-DR2...
(You'll just have "a spare channel"' if you ever need it.)
Hi to the Lounge Boards!
I don't know much at all about Emotiva, so I've got some basic questions about their amplifiers. Based on what I've seen on the Emotiva website, it would seem that one can purchase one of their Gen 3 power amps and, essentially, fill the "seven slot" case with up to seven single-channel "modules." I'm also assuming that there's one power supply handling all of these modules, which seems to explain why the output power spec decreases when a higher number of channels are driven at the same time.
Put another way, is an XPA power amp in the Gen 3 form named for how many amplifier modules are installed? For example, an XPA-7 Gen 3 power amp houses seven single-channel amplifier modules driven by a single power supply. Is this correct?
Although I've noticed that they're unavailable as I type this, I'm also wondering what the difference is between the "Gen 3" amplifiers I just asked about and the "DRX" differential power amplifiers? The price for the DRX amps is higher and the output power spec is also higher, but is the output power boost due to the use of more than one power supply in the DRX amps? Perhaps the DRX is an entirely different amplifier design?
In short, I'd like to know if my thoughts about the XPA-X Gen 3 power amps are correct and, if so, what's the difference between them and the more expensive XPA-DRX type amplifiers?
By the way, does anyone here know when the XPA-DRX power amplifiers will be available again?
EDIT: I just thought of one more question. Can all of the "multi-module" Emotiva power amps I just asked about be run a single channel at a time? For example, can the XPA-DR3 power amp drive only one channel or only two channels at a time?
Thank you for your help with this ~
Okla