Darkglass Electronics - Microtubes B3K  [traced]

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Re: Darkglass B3K

Postby POTL » 20 Jun 2018, 06:06

izikg wrote:
jmwreck wrote: I am having a problem with the Drive (B3k) because I got a cutting out sound, it seems that the distortion sound will get disconnected and all that's left is the clean sound,


Hi
I also get this cutting out when at high gain , I found that high frequencies noise is amplified and causing this problem on the drive opamp.
I suspect it has something to do with the filter before that opamp , but I just can not understand it.

does any one know this filter design or can explain that
B3K_pre_drive_filter.png


I also noticed that the BDDI has a similar filter
BDDI_PRE_DRIVE_FILTER.png


Thanks,


Hi
The first figure - R8 C8 - controls high frequencies.
1) When the switch is in the center position, the high frequencies do not change.
2) When the capacitor is connected to ground, the high frequencies are cut off, this is the classic RC-filter
3) When the capacitor connects to the resistor, this parallel RC-filter, like the Marshall, in this mode, high frequencies rise.
The second picture is Bandstop filter - the filter does not let pass a certain frequency. In this case, this filter cuts low-mid freq, the frequency of 320 HZ is cut completely and the frequencies near it are also severely cut off.
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Re: Darkglass Electronics - Microtubes B3K

Postby POTL » 20 Jun 2018, 06:22

Hello everybody
I watched the circuit today and read Douglas's reports on the forums, at first I thought this pedal was an original development, then I realized that Douglas collected it based on the MXR M80, Sansamp Bass Drive Di and CMOS amplifier as Red Llama.
So, if you want to copy B7K, then I advise you to look at the equalizer circuits from m80 and bass driver di.

Regarding the control of the middle frequencies, you can change the frequencies using the DPDT toggle switch (as in the original).
Below is the scheme, you just need to connect the toggle switch to C2 and C5
You need to copy the central part of the circuit 2 times and select the components for the desired frequencies, I hope this helps you to copy the circuit :D
Image
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Re: Darkglass Electronics - Microtubes B3K

Postby ray86 » 26 Jun 2018, 15:57

CD4049????
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Re: Darkglass Electronics - Microtubes B3K

Postby POTL » 26 Jun 2018, 17:55

ray86 wrote:CD4049????

Yeah, it's here.
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Re: Darkglass B3K

Postby zyu » 09 Aug 2018, 16:25

Harold wrote:Here's another schematic based on the GUMA: http://peperspedals.blogspot.nl/2017/02 ... cb-to.html and the update on that: http://peperspedals.blogspot.nl/2017/03 ... pdate.html

I also made a Vero out of it, but I still haven't checked it: http://diyl.sait.nl/guma-drive-darkglass-b3k

Hello!
One small mistake.
R5 should be installed before R4, and not AFTER it, as in your scheme.
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