Bellum Fuzz MkI

manfesto

Active member
@PedalPCB is the 680p on the silkscreen possibly a misprint? The tone control had a *very* wide imbalance with a 680p, replaced it with a 100n and it functioned as expected (which maybe isn’t what DBA was going for) with a relatively even sweep from bassy to trebley, instead of insanely bassy for 20% then a crazy scoop from 20-50% then just progressively more nasal?

Other than that, I built it with 2N5088s (all around hFE 270-300) and 100n caps and it fired up straight away and sounds just like the demos.

I did socket the 27K and tried with and without; with the 27K there was a noticeable volume drop but not much change in the character of the distortion, so I left it out and wouldn’t really recommend bothering unless you’ve got germanium diodes to spare.

(left the diodes in just in case though)
 

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manfesto

Active member
Not a misprint... Yet another one of the absurd variations of the original floating around.

The board is marked 680n, but 680p is what was installed. Which one is more correct? Your guess is as good as mine. :ROFLMAO:

I'm still looking on a daily basis for an original so I can trace it myself.
At this point I’d bet dollars to dimes that if you did get an original you’d find yet *another* variation lol
 

Bobbyd67

Active member
@PedalPCB is the 680p on the silkscreen possibly a misprint? The tone control had a *very* wide imbalance with a 680p, replaced it with a 100n and it functioned as expected (which maybe isn’t what DBA was going for) with a relatively even sweep from bassy to trebley, instead of insanely bassy for 20% then a crazy scoop from 20-50% then just progressively more nasal?

Other than that, I built it with 2N5088s (all around hFE 270-300) and 100n caps and it fired up straight away and sounds just like the demos.

I did socket the 27K and tried with and without; with the 27K there was a noticeable volume drop but not much change in the character of the distortion, so I left it out and wouldn’t really recommend bothering unless you’ve got germanium diodes to spare.

(left the diodes in just in case though)
Hey manfesto!

I just got done with my build last night. I used the values on the silkscreen so 680n and 680p and all 2n5089.... Like any DBA clone builds.... it didn't sound anything like the demo's xD. I haven't had the time to troubleshoot yet but I have looked on other forums for where to start ! Like you the 680p tone cap makes the tone knob sound way off and it looks like anything between 100n to 220n to even 680n makes it sound better.

My question to you is did you first try using 680n caps on all the other big box ones on the silkscreen and then switched to 100n ones? I have seen a Vero and trace that used those 100n value so I am curious what troubleshooting if any you had to do to make it sound good :p.

I did socket my transistors so first thing I will try is switching to 2n5088 but I get a feeling I will have to swap out all the 680n cap too xD.

Like pedalpcb said there's so many different takes on the values flooting around for this circuit :/
 

manfesto

Active member
Hey manfesto!

I just got done with my build last night. I used the values on the silkscreen so 680n and 680p and all 2n5089.... Like any DBA clone builds.... it didn't sound anything like the demo's xD. I haven't had the time to troubleshoot yet but I have looked on other forums for where to start ! Like you the 680p tone cap makes the tone knob sound way off and it looks like anything between 100n to 220n to even 680n makes it sound better.

My question to you is did you first try using 680n caps on all the other big box ones on the silkscreen and then switched to 100n ones? I have seen a Vero and trace that used those 100n value so I am curious what troubleshooting if any you had to do to make it sound good :p.

I did socket my transistors so first thing I will try is switching to 2n5088 but I get a feeling I will have to swap out all the 680n cap too xD.

Like pedalpcb said there's so many different takes on the values flooting around for this circuit :/
Nah I went with all 100nFs (except for the tone cap) out the gate, @Mir9 in another thread posted a gut shot of a production pedal with all 100nFs in it, so I thought it’d be a good first bet
 
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