I see posts where someone needs a way to do input selection and I thought I could take my design that included digital volume control and a remote and pair it down to a six input fully balance/single ended and a muting circuit controlled by two buttons on the front panel of the preamp. it would consist of two boards, a display with seven segment LED to show the input and mute status and the two buttons, size of 2.5"x2.5", and the input board with the relays and a voltage regulator 4"x4", input for 8-12vdc or 5vdc and not need the regulator. Also a little power supply board if you didn't have the above voltage already present in the preamp. The PS would measure 2.5"x3". Cost about $65 USD with PS, minus $15 USD without.
Anyone interested. I can post schematics and BOM, and Gerbers.
Anyone interested. I can post schematics and BOM, and Gerbers.
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Hi johnhenryharris,
That sounds great! Can you share pictures of your boards or the whole assembly? Schematics, BOM and gerber files are great as well, but the pictures help best to get a first idea of how it looks like I think.
Thanks
seyl3r
That sounds great! Can you share pictures of your boards or the whole assembly? Schematics, BOM and gerber files are great as well, but the pictures help best to get a first idea of how it looks like I think.
Thanks
seyl3r
If you look at the full blown boards which have the volume control and remote it would be the right half of the display board and the back half of the main board see
Preamp Control - Volume, input, mute, remote
posts #1, 143 and 144 for the pics.
I will post the schematics and board layout with gerbers and the BOM for this next board, tomorrow or the next day if work isn't too heavy.
Preamp Control - Volume, input, mute, remote
posts #1, 143 and 144 for the pics.
I will post the schematics and board layout with gerbers and the BOM for this next board, tomorrow or the next day if work isn't too heavy.
I'm very interested in seeing the schematics / Gerbers for this when you get the chance. Sounds like it could be just what I'm after.
ok so here are the schematics and front and back of the board layouts. This is for 6 inputs fully balanced, although you can populate only half of the selection relays for single ended.
Will double check the BOM and then turn gerbers and attach.
Will double check the BOM and then turn gerbers and attach.
Man it takes a while to check the accuracy of the BOM, get part numbers for Mouser and Digikey and plug in the cost, I like to know up front what a project will cost. So here is the BOM spreadsheet, zipped.
Well it didn't take long to find an error. I try to pay close attention to the analog signal traces and now I found I had the output on the left channel with the polarity inverted, which will not do, so I have corrected the Schematic and the board layout. Here you go.
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johnhenryharris:
Whats the difference between boards in post no 8 and boards posted here Preamp Control - Volume, input, mute, remote
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The boards in this thread do not have a volume control or a remote it is simply for input selection and muting, but is 6 inputs fully balanced. The main board has both digital and analog on one board and smaller than the full blown board in the first thread, with a separate power supply board and display.
The other thread, the third one in this series, is Single End with only four input selection but has volume, muting, and a remote. The Analog in on one board, digital on another board, a separate power supply board, and a display and remote board. The boards are smaller and can be stacked to take up less space inside a Preamp.
The first thread which you link is a fully balanced volume, input, mute and power supply on one board, with the first display and remote boards used in the third thread.
The other thread, the third one in this series, is Single End with only four input selection but has volume, muting, and a remote. The Analog in on one board, digital on another board, a separate power supply board, and a display and remote board. The boards are smaller and can be stacked to take up less space inside a Preamp.
The first thread which you link is a fully balanced volume, input, mute and power supply on one board, with the first display and remote boards used in the third thread.
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