Miasma: Function Generator (DIY PCB based on Befaco Rampage)

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skautkurt
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Post by skautkurt » Mon Dec 16, 2019 9:02 am

Anybody in Europe got panel + pcbs? looking for a set.
cheers

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by koooch » Fri Dec 27, 2019 1:00 pm

Just finished my Miasma build. Everything seems to work fine except one thing. TRIG inputs works sort of like a gate, not a trigger (signal rises only when TRIG input is high, but when it reaches the top it falls down as it should even if the signal is still high). Weirdly enough, triggering the cycle manually with center switch works fine and as expected. Same issue on both channels, all ranges. With CYCLE switched on it doesn't start cycling unless the gate signal is long enough for signal to reach the top. Any ideas?

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squarewavesurfer
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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by squarewavesurfer » Fri Dec 27, 2019 4:18 pm

koooch wrote:
Fri Dec 27, 2019 1:00 pm
Just finished my Miasma build. Everything seems to work fine except one thing. TRIG inputs works sort of like a gate, not a trigger (signal rises only when TRIG input is high, but when it reaches the top it falls down as it should even if the signal is still high). Weirdly enough, triggering the cycle manually with center switch works fine and as expected. Same issue on both channels, all ranges. With CYCLE switched on it doesn't start cycling unless the gate signal is long enough for signal to reach the top. Any ideas?
What are you using as the external trigger?

What board version? you may need to post a photo of the pcbs to figure this part out as I'm not sure the revisions are indicated.
WTB: Verbos Scan & Pan; Verbos CV Processor; Harvestman Hertz Donut MK2; Mutable Instruments Ears; Make Noise Tempi; Grayscale Make Noise panels; Mutable Instruments Factory panels

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by koooch » Mon Dec 30, 2019 10:05 am

squarewavesurfer wrote:
Fri Dec 27, 2019 4:18 pm
What are you using as the external trigger?

What board version? you may need to post a photo of the pcbs to figure this part out as I'm not sure the revisions are indicated.
I've tried different sources like Arturia Beatstep Pro, clock modules like 4MS QCD etc. all with the same result. Board is based on files from Sin Phi site from Oct 20th 2019, so I guess this is the latest one?

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squarewavesurfer
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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by squarewavesurfer » Mon Dec 30, 2019 10:29 am

koooch wrote:
Mon Dec 30, 2019 10:05 am
squarewavesurfer wrote:
Fri Dec 27, 2019 4:18 pm
What are you using as the external trigger?

What board version? you may need to post a photo of the pcbs to figure this part out as I'm not sure the revisions are indicated.
I've tried different sources like Arturia Beatstep Pro, clock modules like 4MS QCD etc. all with the same result. Board is based on files from Sin Phi site from Oct 20th 2019, so I guess this is the latest one?
A few other users in this thread have posted about their Miasmas seeming to have the trig and input swapped (one seeming to behave like the other). Maybe have a read through (search "trig"), send them a message to see what they have done to troubleshoot. Although I can't say I have experienced this with my own module, I'll try to do some testing when I get a chance.
WTB: Verbos Scan & Pan; Verbos CV Processor; Harvestman Hertz Donut MK2; Mutable Instruments Ears; Make Noise Tempi; Grayscale Make Noise panels; Mutable Instruments Factory panels

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by koooch » Thu Jan 09, 2020 6:29 am

Got that fixed finally. I replaced 2n2 THT caps (C7, C8) with 1n SMD caps and everything seems to work fine now.

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by kevin0 » Sun Jan 19, 2020 4:34 am

Anyone in Europe have a PCB/panel? Would loveto build one of these

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SphericalSound
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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by SphericalSound » Tue Jan 21, 2020 2:30 pm

kevin0 wrote:
Sun Jan 19, 2020 4:34 am
Anyone in Europe have a PCB/panel? Would loveto build one of these
+1 !

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by MatrixModulator » Sun Feb 02, 2020 7:37 pm

Hi everyone, it's been a while now the Sin Phi Miasma is realeased and multiple updated versions are out, that makes me wonder how is it even possible no one noticed the EOC2 (right channel) is not grounded therefore not working at all...!?!? I was testing it today and noticed i was just getting a weird sine waveform out of EOC2 ... i did simple continuity test.. i saw this... rewired with a resistor leg and bingo it works like the EOC1 left channel now. (i had to rewire the left channel rise attenuverter too but this is fixed in the new pcb revisions i think) anyway i checked the up to date files on his website, the gerbers and kicad files have this error, you can see the ground tab of the EOC2 not attached to the pin on the schematic pdf.
83942146_10151446604634984_6190247187318833152_o.jpg
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Lemmy
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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by Lemmy » Mon Feb 03, 2020 4:41 am

I'll check mine later - I tend to use the left hand side of the panel and augment with options from the right, so it's quite possible I simply haven't used the right side EOC. At the same time it is not the most straightforward module and not always intuitive what the expected behaviour should be. Which doesn't stop it being great for experimentation.

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mush
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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by mush » Tue Feb 04, 2020 2:49 am

It won't be a problem for most users. If you patch within a system you have lots of other paths for common ground reference. It will be a problem if you only patch the eoc to another system that has no other connection to the system you have your miasma in. And that is a highly unlikely scenario as you probably have some kind of mixer for audio from both systems... But yeah, it seems to be a miss from the designer, but not a problematic one in my opinion.
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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by SphericalSound » Wed Feb 26, 2020 1:50 pm

Looking for a pcb set/panel.

If someone has spares I would love to buy one set.

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by Whelm » Tue Mar 03, 2020 9:00 pm

SphericalSound wrote:
Wed Feb 26, 2020 1:50 pm
Looking for a pcb set/panel.

If someone has spares I would love to buy one set.
You might have more luck ordering PCBs from oshpark. I believe you can do so using the KiCad files.

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by woodster » Wed Mar 04, 2020 11:17 am

I think it's worth pointing people to this page by Mcop.
Couple of interesting mods relating to the Ring Mod output and Cycling behavior -

http://www.mcop.co.uk/diy/mods-and-stri ... fications/

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by Sin_Phi » Thu Mar 12, 2020 10:50 pm

Been away a while and probably time for me to fix some of these issues. I am a hard drive crash, a few versions of KiCAD, and a whole new PC away from my original files so a bit of understanding that I have re-routed and re-populated this thing a few times now to keep it up to date. Every KiCAD footprint has changed now and has to be replaced.

The new version will be clearly labeled and the old versions will stay up on the site with notes about fixes that have been found (thanks mcop and everyone in this thread).

One complaint I did see out there was about the panel being the wrong size, someone must have used my very early files. That has been fixed for years and those files are no longer available on my site.

I likely will not build the updated version for a few months given the current supply chain issues. I probably try the mods on one of mine in mothballs though.

tldr; going to make some fixes, will be a bit given changes in my development environment and KiCAD

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by skautkurt » Wed Apr 01, 2020 6:11 am

Is there a way to calibrate the miasma without help of an oscilloscope? Maybe by ear with the help of an oscillator? Due to self isolation I sadly don't have access to one right now...

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by FLOz » Wed Apr 01, 2020 2:30 pm

I have one set of version 1.01 here? What is the issue with this version? Is it not worth it to build it?

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by SphericalSound » Wed Apr 01, 2020 4:53 pm

skautkurt wrote:
Wed Apr 01, 2020 6:11 am
Is there a way to calibrate the miasma without help of an oscilloscope? Maybe by ear with the help of an oscillator? Due to self isolation I sadly don't have access to one right now...
You can use the computer as oscilloscope.

If not, use the ear. Try to get the "softer" possible sounds (triangle versus "rampish")

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by skautkurt » Wed Apr 01, 2020 6:26 pm

SphericalSound wrote:
Wed Apr 01, 2020 4:53 pm
skautkurt wrote:
Wed Apr 01, 2020 6:11 am
Is there a way to calibrate the miasma without help of an oscilloscope? Maybe by ear with the help of an oscillator? Due to self isolation I sadly don't have access to one right now...
You can use the computer as oscilloscope.

If not, use the ear. Try to get the "softer" possible sounds (triangle versus "rampish")
Didn't even think about that! :doh: thanks. Any suggestions for a program that works well (maybe you guys have a favorite :) )?

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by shabax » Mon Apr 13, 2020 3:24 pm

Hi! I'm close to finishing a build but I'm currently confused about the Main PCB.
On the layout on the module's page, you can see 8 through-hole transistors that need to be soldered above the 857 and 847.
However, there are no reference to these parts in the BOM (Q5-8) and no reference on the board itself for the right side of this.

What should be there?

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Re:

Post by socom93 » Mon Apr 13, 2020 3:45 pm

skautkurt wrote:
Mon Dec 16, 2019 9:02 am
Anybody in Europe got panel + pcbs? looking for a set.
cheers
Would love to find one too !

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by emmaker » Mon Apr 13, 2020 4:36 pm

shabax wrote:
Mon Apr 13, 2020 3:24 pm
Hi! I'm close to finishing a build but I'm currently confused about the Main PCB.
On the layout on the module's page, you can see 8 through-hole transistors that need to be soldered above the 857 and 847.
However, there are no reference to these parts in the BOM (Q5-8) and no reference on the board itself for the right side of this.

What should be there?
OK I'm guessing here, project has issues with documentation and board revs.

Looks like there is at least 2 revs of the board. The one on page 1 of this thread and the one on the website are different. One on page 1 doesn't have a rev number and the one on the website does. You always put a revision number on boards.

Looks like the one on page 1 has T1, T2, T3 and T4 as SMDs. Looks like the one on the website has T1, T2, T3 and T4 as SMDs and pads for discrete transistors. So GUESSING I'd say that you install EITHER the SMDs or the discrete transistors NOT BOTH. You might look up the data sheets for SMDs, BC857 and BC847 transistors and ohm out (ohm meter) the pads verses the schematic to verify this.

Good luck.
Jay S.

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by JoshMH » Tue May 05, 2020 4:05 pm

I have five pcb/panel sets (version 1.04) that I just got in the mail, but I don't think I'm going to use them. If anyone would like to buy them, send me a message. This is my first post here (long time lurker), but if you're concerned about reliability check my Reverb feedback -- https://reverb.com/shop/joshuas-gear-emporium-378.


The reason I'm not planning to use them is that I've made some of my own mods and improvements to the KiCAD files and I'm going to test out my version. The changes are:

1) Updating the footprints and symbols to ones included in the most recent version of KiCAD. (This was actually pretty easy. I opened the .sch file in Notepad++ and used Find + Replace, plus some manual edits.)

2) Made the 4QX output no longer inverted and have less gain (see http://www.mcop.co.uk/diy/mods-and-stri ... fications/, although my circuit is slightly different). Also added a pin jumper on the back that allows you to switch between summing (not inverted) and 4QX modes.

3) Added diodes and pin jumpers between the cycle gate inputs and trigger switch. This allows you to choose whether applying a gate to the cycle input will cause it to start cycling automatically (like Maths) or require a trigger to start cycling (no change). (See same link above for diode mod.)

4) Fixed the EOC2 output from not being grounded.

5) Tweaked some of the tracks from being too close to pads.


It seems like these might be some valuable edits to other people, but:

1) Am I allowed to redistribute my edited files? Also I don't really know where I should upload them. Maybe I can send them to Sin Phi directly and he can look at the changes and post a new version?

2) I should finish my prototype and test it before sending my changes to other people...

Also please let me know if there are other bugs or mods that haven't been mentioned yet!

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by smiler » Wed May 06, 2020 3:53 am

Per the web site the licence is CC BY-NC-SA 4.0 so you are allowed to publish as long as you stick to that license. I'd put the files on github.


That being said I'm eagerly awaiting the updated version from Sin_Phi :)

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Re: Miasma: Function Generator (DIY PCB based on Befaco Rampage)

Post by SphericalSound » Wed May 06, 2020 12:05 pm

Great!

I´ll be getting one or two too when ready

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