LSAF 2012 [message #69582] |
Fri, 23 September 2011 22:19 |
Shane
Messages: 1117 Registered: May 2009
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Illuminati (3rd Degree) |
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Just curious what the powers that be have in store for us this spring?
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Re: LSAF 2012 [message #69583 is a reply to message #69582] |
Sat, 24 September 2011 00:08 |
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Wayne Parham
Messages: 18783 Registered: January 2001
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Illuminati (33rd Degree) |
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The hotel setup a registration page for us, so we're set for the same hotel, first weekend in May 2012. We'll get to do those fun Cinco de Mayo parties in Dallas at LSAF again this year, since it's that same weekend.
At Uriah Dailey's request, I developed an IR remote control based on the AT2313 and AD5206. It can basically be the brains for a preamp, with five inputs and six channels set as three left and three right. The remote has power, input select, volume, balance and mute buttons. The processor reads both a remote control and frontpanel buttons for power, volume up, volume down, pan left, pan right and input select. Should have some of them at LSAF, probably one running in a Lighter Note in Uriah's room.
You might notice the AD5206 is a linear device, but I have programmed the processor's firmware to send a logarithmic sequence to it so the volume control has an audio taper. This sequence is actually (much) more accurate than even the most expensive potentiometers, making this device attractive to audiophiles that might have otherwise chosen stepped attenuators.
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Re: LSAF 2012 [message #69586 is a reply to message #69584] |
Sat, 24 September 2011 00:47 |
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Wayne Parham
Messages: 18783 Registered: January 2001
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Illuminati (33rd Degree) |
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Yes, absolutely. The AD5206 can be used in place of a stereo potentiometer. They are available is several popular values, e.g. 10KΩ, 50KΩ and 100KΩ. So you can use this anywhere you might use a 50KΩ pot, for example.
The switch inputs are just make/break connections to ground. So a pushbutton toggles power, another pushbutton advances input selection from 1 - 5 each time it is pushed. Then there are buttons for volume up/down and balance left/right. Or you can leave the front panel blank, and just use the remote as the only way to control the preamp.
The outputs (besides the volume, which is a variable potentiometer) are all digital outputs, intended to drive a (mechanical or solid state) relay. Each control line sources a maximum of 40mA, but I'd suggest limiting that to 20mA. If more current is needed, just drive a small signal transistor or something, like a 2N2222. Drive the base, tie the emitter to ground and the collector to one side of a relay coil. Hook the other side of the relay coil to Vcc. Easy peasy. The available output pins are power, select1, select2, select3, select4 and select5. Those select lines select the channel, which would be hooked to a switching device (relay) through the AD5206 potentiometer. Lots of flexibility there to work with.
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Re: LSAF 2012 [message #69588 is a reply to message #69587] |
Sat, 24 September 2011 01:38 |
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Wayne Parham
Messages: 18783 Registered: January 2001
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Illuminati (33rd Degree) |
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It's not expensive. The remote control itself is a generic universal - just get any one you like. I prefer those that have the up/down and left/right buttons prominent, as opposed to the remotes that have vertically arrayed channel up/down and volume up/down. But any of them will work. Then there's the control board. I'd say by the time the boards are etched and deals are struck, it's probably going to be less than a hundred bucks for the completed control board.
Having said that, it's all still preliminary. The design is done, prototype is working. I can burn chips right now, and can probably have boards etched in less than a month. But I do need to figure out pricing and delivery model. I don't know if I'll make them available directly or just through OEMs. I have plenty of friends in the business that manufacture amps, preamps and kits, so it might make sense to make it available to them, and let them brand them and resell them. I need to work through all that first. Still, by LSAF, the business side should all be worked out.
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