Wednesday, July 13, 2022

ANALOG MAN: NTK Sun Face

I saw this Gray Bench teardown video the other night, and the values looked a little different to what I'd seen on other Sun Face schematics, so here it is.

If you don't feel like watching the video, the key difference: 51k resistor on the collector of Q1.  The rest is all pretty standard for a Sun Face, although it does mention biasing the collector of Q2 to 5v, which is a little hotter than the usual 4.5v that is often referred to for fuzz faces.

ANALOG MAN NTK SUN FACE - VERO LAYOUT

ANALOG MAN NTK SUN FACE VERO LAYOUT FOR GUITAR FX

And if you think this is a lot of vero for not many parts, you are correct.   It’s still kind of small, and will easily fit in a 150b enclosure, so why bother making things hard for yourself by crowding a board?  Besides, you’ll need some room to lay the germanium transistors flat.
 

GRAY BENCH SUN FACE TEARDOWN

The full schematic is shown at the end of the video.



6 comments:

  1. They seem to vary from transistor to transistor. My RCA Sunface is on Dirtbox Layouts and it uses 62k in place of the usual 33k resistor.

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    1. Thanks Ben - I saw the voltages you listed in the comments too. Very handy. I think I might have some RCAs floating around too.

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  2. Legend I watched that episode. I've built a few of the sunface pedals from other layouts. Very intrigued by the difference on this one. Where do you buy the pots with a centre notch. ?

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  4. Struggling with this one a bit. Getting nothing, but it looks a bit different to other layouts in terms of the input and position of the sundial. Will have a better explore later.

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    1. Hi Ben.

      The layout should be fine, the position of the sun dial and internal trimmer doesn’t matter, as they’re still providing the same amount of resistance between the output cap and the collector.

      I’d be thinking about the 51k resistor. Stock fuzz face is 33k. Your transistors might not like 51k.

      Fuzz faces can be annoying to bias … but a good one is a glorious thing.

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