substitute

Hi, I'm looking to build this tapeop hampton summing circuit...
https://tapeop.com/interviews/37/diy-jfet-mic-pre/

I think you need a paid subscription to read down the article far enough to get to the summing amp application but here's a screen shot. I can't find a stereo 100k log fader on mouser. How critical is this value?



Thanks


substitute

Re: How critical is the fader value in jfet hamptone summing circuit
« Reply #1 on: May 20, 2020, 04:12:20 PM »
forgot to click notify me of replies...

ruffrecords

Re: How critical is the fader value in jfet hamptone summing circuit
« Reply #2 on: May 20, 2020, 07:32:13 PM »
This design can be improved. The 150K bus resistors are unnecessarily high and can be usefully reduced to 47K. There is no reason then that the 100K cannot be reduced in a similar proportion. So a 22K or 25K pot will do. For line level signals you can usually get away with a 10K bus pot but you will some extra make up gain to compensate for the extra loss.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

substitute

Re: How critical is the fader value in jfet hamptone summing circuit
« Reply #3 on: May 20, 2020, 11:08:22 PM »
Quote
This design can be improved. The 150K bus resistors are unnecessarily high and can be usefully reduced to 47K. There is no reason then that the 100K cannot be reduced in a similar proportion. So a 22K or 25K pot will do. For line level signals you can usually get away with a 10K bus pot but you will some extra make up gain to compensate for the extra loss.

Cheers

Ian

Thanks Ian, much obliged


 

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