Thursday, December 31, 2020

SOLA SOUND: Tone Bender MKIV, Tag Board Layout


SOLA SOUND TONE BENDER MKIV - TAG BOARD LAYOUT

SOLA SOUND TONE BENDER MKIV - TAG BOARD LAYOUT


12 comments:

  1. Hi mate,
    I always wanted to try germanium kin'a fuzz - I did this layout using a Asy33s for Q1&2 (hfe 60) and AC176K for Q3 (hfe 200). Voltages do not matchnto previosly displayed - passes o ly a clean signal.
    Should i stick to suuggested transistor values? Does hfe for Q1&2 are low .
    Thanks you for reply.

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    Replies
    1. Hello - do you have an audio probe to trace the signal? Hfe should not be a problem for Q1 and 2. I’ve used low hfe before and it’s not a problem. First thing to check is level coming off the collectors of Q1 and 2.

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  2. Hey I think and ac176 is npn. You need pnp

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  3. Hi Andy,
    I will check it with a probe...let you know later on.
    All the best from PL

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    Replies
    1. Good luck, and hello from Australia. Watch out for bad solder joins on tag board, it has happened to me before. Reflow the join if everything looks right, but isn’t working, and make sure the components have good contact.

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  4. I have swapped as follows: q1&2 MP25a (hfe30) and q3- asy33a (hfe60).
    Works, fuzz is touchy sensitive....i assume as will put recommended hfe level shouold work properly.
    Thankd for support - i will inform about progress.

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  5. Touchy sensitive = to be properly biased if i understand correct.

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    Replies
    1. I wouldn't worry about biasing too much - Tone Bender MKIII / MKIV are very forgiving, compared to MKI & MKII. I've made some with lower hfe transistors, and I quite like the sound - it can be a softer fuzz, that feels a bit squishy or spongey (hopefully these word translate OK for you). High hfe tends to sound tighter and more defined, almost a distortion at times, at least from my experience anyway.

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    2. Oh great that you got it working too... Remove the resistor between tone and volume if output level is low. Some people recommend replacing the 100k volume pot with 500k pot if you do this

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  6. Yes, totally agree.
    I will experiment with transistors for sure - ive got used to more agressive sound - let's see whatbwe can achieve here. Thank's again Andy!

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    Replies
    1. No problem - it's a fun one to play with as it's hard to go wrong. If you like a more aggressive sound, change the 2.2n capacitor to something larger. 3.3n or 4.7n work well, as this lowers the cut-off of the high pass filter, and you get more mid range bite. I prefer 4.7n myself.

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  7. Thanks for a tip....for this moment i will stick to schematic...fo sure will all a switch to have a comparision.
    I also prefer this jingly-bity sound.
    Greg

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