Saturday, 30 September 2023

Barber Gain Changer

 Schematic is avaiable HERE.



9 comments:

  1. I built this but unfortunately something is wrong. No output. I briefly got some gain sound when wiggling the op amp, but nothing now. I will troubleshoot in the morning. Also, you have two (2) 'Tone 2' markers. Looking at the schematic, it seems the top 'Tone 2' should be marked 'Tone 1'. Looking forward to fixing this one.

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    1. Looks like there is a missing 1K resistor from pin 1 of the IC to the 15n capacitor (?)

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  2. Ok I stared at this for a while to figure out a way to get the 1k where it wants to go without changing the board configuration. I got it: put a cut @A1, Link A9&B9, move 2.2k to A5-A8, move 100nf to A2-4, put appropriate cuts under these two components. Delete cuts G7&G11. Drop in 1K C10-G10. Finally, move Gain Sw1 to Row A. Comparing this with the schematic, this should work. I hope to have some time this week to wire it up. Cheers!

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  3. Also, you’ll need to switch D3&4 to free up B9

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  4. Typo: put cut @A10, not A1

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  5. I can confirm that my above modifications to the layout work. It’s also a great sounding circuit! Damaraja is correct, 19C is Tone One. Thank you Ian for originally spotting the missing 1K!

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  6. the layout is updated.

    thanks guys!

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