Monday, 3 August 2020

Fairfield Circuitry Unpleasant Surprise


22 comments:

  1. Hello.
    Nice layout, as usually, buddy!

    I tried it, too. Probably we like the same thing!
    My layout is still UNVERIFED:
    http://guitar-fx-layouts.42897.x6.nabble.com/file/n49055/jcjL21q.png

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  2. Would love to see more of Fairfield Circuitry, their pedals are phenomenal!

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  3. Hello, how are you? thanks for the tagboard! do you plan to do this project? DMB Lexi pedal
    schematic here.
    https://www.freestompboxes.org/download/file.php?id=35673&mode=view

    https://www.freestompboxes.org/viewtopic.php?p=281518#p281518

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    1. Yes, sure! I'll take look at it and post a layout in a couple of days.

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    2. It appears that the schematic is based on a faulty pedal. Not sure if it worth doing a layout for it....

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  4. Just built and boxed this. Played it for about an hour tonight, everything works perfectly. The only hiccup is a very slight pause when toggling the “g” switch. Not sure if this happens on the original, but otherwise sounds identical to the videos. It’s an amazing sounding circuit, thanks for posting!

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  5. Hi. I didn't built it, but do you have any bias issue with the jfet? It seems make the difference. I'd like to have the right voltage.
    The drain of the Q1 is aroung 4.00-5.00v, the Q2 drain... I don't know, as usually I emulate the schematic, and it has around 0.4v.

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    1. My layout has been verified, too.
      http://guitar-fx-layouts.42897.x6.nabble.com/file/n49295/Fairfield_Circuitry_The_Unpleasant_Surprise_Fuzz.png

      Just pay attention to the voltage at the J201s drain: around 4V for Q1 (acting with the 16k resistor), around 0.5V for Q2 (acting with the 33k resistor).

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    2. Hi. I measured my Voltage at Q1 Drain and I get around 5.3V. So would you recommend replacing the 16k resistor with something higher to lower the voltage?
      Also my Onset-Pot needs to be quite open to get sound out(almost half way). But wouldn't this get worse if I lower the drain voltage of Q1?
      Also thank a lot for the layout. Was a blast building it

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    3. If you want to aim at 4,5v for Q1, you could try a lower value for 16k....maybe 12k. Not sure if it would affect the behaviour of the Onset control.

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  7. finally got this working after a few weeks of procrastinating, made a little audio probe setup which led me to two resistor misplacements that eluded all of my searching for weeks! My Q1 is around 4.5v and Q2 around 0.4v-0.5v FWIW.

    With the C switch engaged this thing turns into a really great fuzz, I'd love to see more Fairfield stuff! Thanks for a great layout!

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  8. I've always wanted to see a layout for their 900 fuzz pedal...pro tools have to settle for this ultimately.

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  9. Hey -- thanks for this, Quick question the build calls for 2 x 2m resistors. Finding these difficult to obtain. would 2.2m work? or to far out?

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    1. tracked .5 watt version. Built and working as it should. thank you!

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  10. Hi! Can anyone advise on how to wire the SPDT-switches?

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    1. Should T SW 3 have no contact at all?

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    2. That's how I have it - nothing connected to T SW3 - and it works for me.

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