- remote controlled with a motorized volumecontrol
The general idea with the FPRC5RX project and the diy motorized volume control was initially to make a standard diy analog stereo preamplifier. This page should eventually provide some pictures to give you an impression how it actually went along.
1. The “Series320” stereo analog preamplifier.
2. Using an fprc5rx remote decoder as a preamplifier controller
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The “Series320” stereo analog preamplifier. |
For reasons forgotten this preamplifier project goes under the name “Series320”. It will eventually become a standard analog stereo preamplifier and with the current tempo it will be completed sometime around 2012 or so :-)
One pretty obvious philosophy behind a diy audio preamplifier would be to focus on analog superiority, and then afterwards add an enclosure and some kind of support for usability such as an channel selector. In case you come in doubt then this preamplifier is done the other way round, and the audio itself will just be a pair of opamps stuffed away somewhere while the funny part is to make a remote controlled preamplifier suitable for the living room. Now you are warned.
The frontplate will most likely be made to look something like this :
The picture below shows the input selector stack consisting of 4 pcbs which hopefully later will match the frontplate layout. The 2 center pcbs are hosting the LEDs which will provide backlights for the texts (i.e. transparent text on black background) and the top and buttom pcbs hosts the associated switches (which cant be seen here!). The topmost pcb also incorporates the fprc5rx PIC processor. This stack obviously should have been made as just a single pcb mounted vertically behind the frontplate hosting switches and backlight leds if common sense had anything to do in this project.
This is the diy motorized volumecontrol prototype which will go straight into the preamplifier. The little pcb is just a stand-alone fprc5rx used for development.
Input selector, analog part and other might follow....
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Using an fprc5rx remote decoder as a preamplifier controller |
This is an example on how to make a remote controlled preamplifier based on the fprc5rx remote decoder. Except for the volume control this is pretty much the way the “Series320” preamp above is made. The input selector is made with relays, and a small DC motor is somehow connected to the volume potentiometer for a old fashioned remote volume control where the front has a volume knob.
The FPRC5RX manages the 1-of-N decoder make-before-break relay logic drive, both when channels are selected from the remote control and when they are selected from the frontplate push switches (the “Input X” box)
Using FPRC5RX terminology then the modes should be radio modes for all input selectors and normal mode for the two volume control pins. For instance a mute relay or a tone defeat should use the bastard BiToggle mode.
Oh, and talking about diy preamps, then this is a must see. This guy for sure got past the talking ! : http://www.mhennessy.f9.co.uk/preamp/
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