• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Versatile and comfortable passive pre-amp

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
@Voxxonline: have a look at the measurement-protocol that Uriah attached to the LDRs:
Both pairs are very well matched and you need not worry which pair to use as either Serial or Shunt pair.
You can do a final adjustment, if you like to: apply a constant DC-voltage to the input of both channels. A stable 5VDC would be nice, for example.
Measure the voltage of the output connectors of both channels and adjust by means of the potentiometer, if it is necessary.

Best regards - Rudi
 
Ivan, any additional component (like a buffer, for example) in the music signal's wire will not improve the sound quality! On the contrary!
The line buffer's task is to drive an amplifier with low input impedance (< 20K) or to drive the signal over a long RCA cable.

You cannot use a 4.5V battery.
Your version of the VCPre has 2 onboard 7805 voltage regulators.
One is for the PIC µProcessor and the 5VDC analog voltage, the other one is to provide power to the motorized potentiometer.
A 7805 voltage regulator needs as least 7.5VDC as input voltage.
Please use a small EI38 print transformer rated at 7.5 - 9 VAC.

Best regards - Rudi
 
Versatile Pre BOM?

Rudi,

I'm just getting around to building the VCPre. It's next on my list of projects. Is there an 'official' BOM that calls out the component number and their value available. I did find one in the thread, but not sure if it's complete or blessed by you.

Thanks, Rick

Happy New Year too!
 
BOM

Does anyone have a text-based BOM that's simple enough to upload and attach to a message/post, or even paste into a post? I'm flying blind here trying to manually create a BOM from schematics and PCB layouts! I'd like to get an order in the mail for this projects and others ASAP. I'd rather not re-create the wheel if I don't have to. :) Thanks in advance. - Rick
 
Rick, the BoM has been deleted after some time of inactivity (?). I cannot access it either.
I remember that PALMITO did a Mouser-BoM.
Please ask him for his BoM.

I have attached a list of components created by the EAGLE layout software.
The components missing are: the LCD and the LM35 temperature sensors.

Best regards - Rudi
 

Attachments

  • VCPre_115VAC.zip
    1.2 KB · Views: 82
Rick, the BoM has been deleted after some time of inactivity (?). I cannot access it either.
I remember that PALMITO did a Mouser-BoM.
Please ask him for his BoM.

I have attached a list of components created by the EAGLE layout software.
The components missing are: the LCD and the LM35 temperature sensors.

Best regards - Rudi
Thanks so much for the info Rudi. - Rick

That Excel file in the zip was a BIG help once I converted it.
 
Last edited:
Does anyone know what the Mouser equivalent, or Manuf part no. would be for this style PCB connector? Thx. Rick
 

Attachments

  • PCB Connector.jpg
    PCB Connector.jpg
    18 KB · Views: 248
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.