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DIY Stompboxes => Building your own stompbox => Topic started by: epezukka on April 15, 2019, 07:13:02 AM

Title: Musket Fuzz Debugging
Post by: epezukka on April 15, 2019, 07:13:02 AM
Hi everyone!

I'm new one here, hopefully the topic is in correct forum.

I have made few pedals myself, so I'm still pretty novice building pedals. I recently build Musket Fuzz copy on veroboard (https://tagboardeffects.blogspot.com/2012/02/blackout-effectors-musket-fuzz.html). Aaand I'm having some trouble to get it working.

I got sound coming through but when Fuzz is engaged it's really farty and there's no sustain at all. And Pre-control affects sound a lot. When it's in zero there's no sound at all. It's almost like a volume pot. All the transistor are not 2N5089, but I dont think that's the issue here. I have checked unwanted bridges and cold solde joints.. Can you guys advice where to go from here? What might be the issue?? I can post images if it helps and measure transistors voltage if it's suggested.

Thanks in advance,

-Elmeri
Title: Re: Musket Fuzz Debugging
Post by: bluebunny on April 15, 2019, 09:50:27 AM
Welcome, Elmeri!

Yes, voltages would be very useful.  (You could take a look at the sticky "Debugging" thread, too.)  Pictures too.  So what did you use in place of the 2N5089s?

For anyone else who wants a look, here's a schematic from Fred Briggs' blog:

(http://4.bp.blogspot.com/-KZB01T96UlQ/T_xgFxm5T_I/AAAAAAAABws/TBKuaILhTiE/s1600/musket_schem.png)

Fred notes the following subs, btw: "R27 470k -> 10k, R17 10k -> 56k, C6, C9 47n -> 100n, C11 100n ->47n".  At a quick glance, I think these are reflected in the layout from |v|ark's blog:

(https://4.bp.blogspot.com/-hcKj_r0n8_w/UuZmsU2qS8I/AAAAAAAAF_4/YtZAB-84cmo/s1600/Blackout+Effectors+Musket+Fuzz+2.png)
Title: Re: Musket Fuzz Debugging
Post by: antonis on April 16, 2019, 07:13:42 AM
10k for R27 turns PRE control pot into SUSTAIN one (like in original Big Muff..)

At lower pot setting signal is attenuated by a factor of 0.091 (ignoring 100nF cap reactance..) which should still be audible although not enough for satisfactory Sustain full range setting..

Check for wrong R27 value (1k perhaps..??) and if not, try to replace it with a bigger value one (100k, say)