DMA-1240ADS Multi-Channel Amplifier

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Check out our Voice Assistant Mounting Kits for the ultimate way to power and hide a voice assistant device (VAD) in the ceiling of any room and connect its audio into the Voice Assistant Inputs on the DMA-1240ADS.
With its ADSTM (Auto Detect and Switch) circuit, the DMA-1240ADS opens a realm of possibilities that enhance your audio experience. Here are a couple suggestions for how to use this remarkable 12-channel amplifier:

Add a source (with our without a built-in voice assistant like Alexa) that’s unique to a zone in your Whole-House Audio system, that can even be used when the system is in stand-by or powered off.
Connect a zone’s variable output from your whole-house controller (MC-66, Lync 6, Lync 12) into the Line Inputs on your DMA-1240ADS as you would for any traditional Whole House Audio setup. Connect a source, such as a music streamer or voice assistant device like the Amazon Echo Dot or Echo Input, into the Voice Assistant Input. In this way, the zone can use the Whole-House Audio system just like any other zone in the house, but whenever the source plugged into the Voice Assistant Input is active it takes priority over what is heard in that zone.
Imagine adding a music streamer to a kid's room or guest room. Let the child or guest know that streamer is dedicated just for them and all they have to do is start streaming to it from their smart phone in order to hear the audio in their room. Volume is controlled by their phone.  That is, the Whole-House system doesn't even need to be turned on and you don’t need to “teach” anyone how to use the app or keypad.
If the music streamer includes a voice assistant like Alexa or Google Home, you will hear the voice assistant's responses through the same speakers before the amplifier returns to whatever audio you were previously listening to.

Use without a WHA system but still allow every room to choose between two audio sources.

Like the DMA-1240, each amplifier channel on the DMA-1240ADS can be assigned to amplify the source connected to either its own Line Input or one of the two Bus Inputs (labeled Input 1 and Input 2).  With the DMA-1240ADS, that source will still be heard as long as the source connected to the Voice Assistant Input is silent. Once the ADS circuit detects a source signal from the Voice Assistant Input, it will automatically switch to that source and will only return to the previous source when the source connected to the Voice Assistant Input has been silent for a period of time you specify (0.5 to 30 seconds) using the Delay Knob.
Some notes about setting up the DMA-1240ADS:
Amplifier channels on the DMA-1240ADS will switch to the Voice Assistant Input whenever the input signal reaches a minimum threshold of approximately 7mV. The amp will switch back to the other source whenever this threshold is not met for a period of time set by the Delay knob (about 0.5-30 seconds). When both input sources are simultaneously playing, the auto-switching works best when the Voice Assistant Input signal is consistently above the threshold.
For the Echo Dot and Echo Input, we recommend using a volume setting of around 5-10. A setting of 10 (max) is equivalent to a fixed level output from traditional audio devices like a CD player. If you stream music through the Dot at very low levels, you will want to turn off the other source connected to the amp channels or increase the Delay time to prevent the amp from auto-switching to the other source.
For most users, setting the Delay knob to near minimum will work best with Alexa.
Maximum amplifier level is set one time on the front of the DMA-1240ADS.  When used without a Whole-House Audio system, volume for sources connected to the Line Inputs, Bus Inputs (In 1 and In 2), or Voice Assistant Inputs, must be controlled by the sources themselves. Volume for Echo devices is controlled using the Alexa app and by voice, and volume for the other source is controlled by that source (note: to use a TV as one of your sources, the TV must have an analog variable output).  When used with a Whole House Audio system, volume is typically controlled either by a keypad in the room or via that system's app: the HTD MC App for mid-level systems and the HTD Lync App for advanced systems.


Here is a quick overview of the product features- the key word is "flexibility":
  • 12 channels of full-range digital amplification (operates significantly cooler than most multi-channel amplifiers)
    40 watts RMS per channel into 8 ohms with all channels driven
    60 watts RMS per channel stable into 4 ohms
  • Each channel is stable to 4 ohms, so you can safely connect two 8 ohm speakers to each channel for a maximum of 24 speakers; example: 6 stereo zones with up to four speakers in each zone
  • 2 side-by-side channels can be bridged to create a single 120 watt channel (8 ohms only)
  • You decide the combination of 40 watt and 120 watt channels (up to 6 channels at 120 watts each) into 8 ohm load
  • Two stereo inputs are available to every channel
  • A separate input is also available unique to each channel (for whole-house audio)
  • Each channel can independently be selected to play the left, right, or combination (mono) of Inputs 1 and 2
  • Maximum volume output for each channel can be easily adjusted from the front panel so that you can balance overall sound levels throughout your home (example- limit how loud the speakers can play in your kids' rooms)
  • All connections are gold-plated for optimum performance
  • Amplifier can be turned on and off manually or automatically as needed when an input signal, or trigger (for whole-house audio) is detected
  • Protection circuitry and signal lights make sure you don't overload each channel with too many speakers (a channel will go into protect mode if the impedance drops too low)
  • Dimensions (HxWxD):  5.5" x 17" x 15.75" not including power cable and volume knobs- Add 1" in back and front for proper clearance. For rack-mounting purposes, the DMA-1240ADS is considered "3U".
  • Weight: 23 lbs
  • Top vented: allow 4" of space above and adequate air flow around amplifier
  • Stand-by power consumption: 5 watts
  • Color: Dark Charcoal Black
  • 3U Rack-mount brackets sold separately