Preamp Control - Volume, input, mute, remote

I found a few obsolete parts in the bill of materials that I couldn’t work around through the primary venders or the alternative parts listed.

1. Line 35, D1, Bridge Rectifier, 2A 4-SIP, KBP package, mfg. part KBP204G-G. For this, I was able to find a similar product from Digikey by Comchip Technology, # 641-1735-ND.

2. Line 97, U1, Linx Technologies, input encoder, 8-DIP package, mfg. part LICAL-ENC-LS001. This is not an area I feel technically competent enough to find a substitute.

3. Line 114, AAA Battery holder, Eagle, mfg. part 12BH431A-GR. If you are going to use your own remote-control shell, then you can find your own alternative. If you are planning to use the shell the remote control board was designed for, available from Peter Noerbaek for $40.00, then you don’t have that option.

Another problem part is the bulk 24 wire ribbon cable (line 57). While it is available through Mouser or Digikey, the quantity is far more than required for one or two projects and the pricing is prohibitive. Any help on these parts would be appreciated.
 
for the bridge rectifier KBP204G is a good part number and KBP210G is the replacement part number.


I will call Link Tech and see what would be a good replacement chip.


for the battery holder any side by side 3 AAA battery holder is good.
you could use 12BHC431A-GR or 12BHC431/C-GR


looking at the Mouser website I see they see the ribbon cable by the foot under part number 191-2801-124
 
Ok the bad news is Linx Tech has discontinued the LS encoder and decoder.
The good news is Linx has a DS series that is encoder and decoder in one chip so you buy 2 of the same and the way it is used determines whether is encodes or decodes. The part number is LICAL-EDC-DS001 and Mouser has 1500 in-stock at $3.52 USD.
The rest of the bad news is the original part was an 8 pin DIP and this chip is a 28 pin SSOP so the schematic for the display board and the remote will have to change and then I will have to re-layout the PCBs and post new gerbers for these 2 smaller boards.
I will post new schematics soon, then the gerbers for the new Rev of the display and remote board.
No changes to the Main board, thankfully.
 
I have re-laid out the remote board. The ref designator were all over the place so I went back to the schematic and did an auto renumber. So here is an updated schematic, only the ref des have changed, and the new gerbers. After I post the new display board schematic and gerbers I will have to update the Bill of Materials.
 

Attachments

  • PAC-RemoteR2-schem.pdf
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  • PAC-RemoteR2-board.pdf
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  • PAC-RemoteR2.zip
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And here is the new display board Schematic, gerbers and a visual of the board.
Note the header, that the ribbon cable from the main board, is soldered to the back of the display board and the ribbon cable plugs in on the back. It is mirrored so the signals will not be right if you plug to the front side.
 

Attachments

  • PAC-RemoteR3-Gerbers.zip
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  • PAC-DisplayR3-board.pdf
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  • PAC-DisplayR3-schem.pdf
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updated Bill of Materials

The last piece in the update of the display and remote boards is the BOM.
Notice the resistors are also changed to ones with smaller body lengths of 3.5 mm just to make things fit on the board easier. I also changed the values on the timing resistors, they should still set the frequency to 38kHz but with the increased values it should lower the current used, like the 7555 CMOS version of the 555 is very low power, it saves battery power.
 

Attachments

  • DigitalVolumeControl.zip
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Preamp Faceplate

Here is a picture and the drawing files for the faceplate. This will give you dimensions for your own faceplate. The Window and four buttons is for preamp control. The smaller window and three button holes is for a DAC that was built into this preamp.
 

Attachments

  • Preamp Faceplate5.jpg
    Preamp Faceplate5.jpg
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  • Preamp Faceplate_dwg.zip
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  • Preamp Faceplate_DXF.zip
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