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

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: Kent, Joe., analogdigital, infradead, lisa, parasitk, plord, sduck

Post Reply
User avatar
squarewavesurfer
Common Wiggler
Posts: 218
Joined: Tue Jan 27, 2015 2:43 pm

Post by squarewavesurfer » Sat Nov 17, 2018 5:34 pm

Im interested in a pcb and panel if someone would sell a set.

User avatar
Sin_Phi
Common Wiggler
Posts: 115
Joined: Fri Feb 06, 2015 10:10 am
Location: L.A. (Palos Verdes)
Contact:

Post by Sin_Phi » Sun Nov 18, 2018 2:36 am

TheMentat wrote:
Sin_Phi wrote:The symmetry trimmers are 10k and the attenuverter trimmers are 100k. Will updated the KiCAD if it has the wrong values.
So the excel BOM is the correct one? I noticed a couple of other differences...
Not sure where you got an excell BOM from, but the one on the site is a PDF http://www.sinphi.com/synths/miasma/Miasma_BOM.pdf that has been updated as recently as my last build.

User avatar
TheMentat
Common Wiggler
Posts: 163
Joined: Thu Nov 30, 2017 1:48 am
Location: Ocean Park

Post by TheMentat » Mon Nov 19, 2018 1:22 pm

Sin_Phi wrote:
TheMentat wrote:
Sin_Phi wrote:The symmetry trimmers are 10k and the attenuverter trimmers are 100k. Will updated the KiCAD if it has the wrong values.
So the excel BOM is the correct one? I noticed a couple of other differences...
Not sure where you got an excell BOM from, but the one on the site is a PDF http://www.sinphi.com/synths/miasma/Miasma_BOM.pdf that has been updated as recently as my last build.
There are Excel files in the KiCAD archives. I'll go with the PDF. Thanks!

mattfearsatan
Common Wiggler
Posts: 57
Joined: Mon Mar 24, 2014 2:01 pm

Post by mattfearsatan » Tue Nov 27, 2018 4:27 pm

Hey there folks,

I've been excited about this project since it was announced, but was hoping for some sort of group-buy or something.

Ah well! I might have a go at ordering the PCBs myself - DIY forum after all!

However... every time I look at fab places it seems like such a complicated process with so many options / or seems prohibitively expensive. Does anyone have any advice / a saved project with a fab house they could share / an idiot's guide to PCB buying?

Sorry if this is too OT.

User avatar
TheMentat
Common Wiggler
Posts: 163
Joined: Thu Nov 30, 2017 1:48 am
Location: Ocean Park

Post by TheMentat » Tue Nov 27, 2018 5:14 pm

I’m expecting a 10-pack of the boards tomorrow. If they turn out ok I’ll part with some of them.

For what it’s worth, i think it only cost me about $35 for 10 from PCBway.

User avatar
whyfarer
Common Wiggler
Posts: 167
Joined: Sat Mar 11, 2017 11:44 pm
Location: The Questioning Zones

Post by whyfarer » Tue Nov 27, 2018 5:34 pm

I would love a board if/when you decide you have extras.

User avatar
pandereteiro
Learning to Wiggle
Posts: 7
Joined: Thu May 05, 2016 7:23 am
Location: Spain

Post by pandereteiro » Fri Nov 30, 2018 6:00 pm

Will the pin out of this Mouser reference (858-P0925NFC15AR10K) work for the B10k dual gang?

By the way, I got a spare pcb/panel, should anyone need it.

Sin_Phi wrote:1. All pots are linear.

2. That is a dual gang pot with Dual In-line Pins (DIP). The B10k dual gang part from Thonk is the plug and play fit https://www.thonk.co.uk/shop/alpha-9mm-pots/ others like from Small Bear Electronics http://www.smallbear-electronics.mybigc ... -pc-mount/ will require that you solder up some resistor legs to make them work.

*I am not selling any pcbs, have your own made or pick up some off a community member.

User avatar
whyfarer
Common Wiggler
Posts: 167
Joined: Sat Mar 11, 2017 11:44 pm
Location: The Questioning Zones

Post by whyfarer » Fri Nov 30, 2018 6:40 pm

pandereteiro wrote:By the way, I got a spare pcb/panel, should anyone need it.
I'm interested. PM will be sent in a moment.

User avatar
Sin_Phi
Common Wiggler
Posts: 115
Joined: Fri Feb 06, 2015 10:10 am
Location: L.A. (Palos Verdes)
Contact:

Post by Sin_Phi » Fri Nov 30, 2018 6:48 pm

The pin out will work. Note, if you use the D shaft version it will be facing the opposite direction of the usual.

I have considered doing a version with the pots arranged so that flatted D pots could be used, but it would require a PCB outside the 100x100mm sweet spot to achieve a good spacing. Would be like $20 extra for 10 boards, which honestly isn't so bad.

User avatar
pandereteiro
Learning to Wiggle
Posts: 7
Joined: Thu May 05, 2016 7:23 am
Location: Spain

Post by pandereteiro » Sat Dec 01, 2018 5:13 am

Thanks!

Cliff´s K85 and K88 knobs allow you to position the marking whenever you want, so it shouldn´t be a problem. Those who prefer 6 mm knurled shafts can use this option (same pin out, just 5 mm longer shaft): 858-P092N-QC20AR10K. Right now I see no option for 6.35mm round shaft

Sin_Phi wrote:The pin out will work. Note, if you use the D shaft version it will be facing the opposite direction of the usual.

I have considered doing a version with the pots arranged so that flatted D pots could be used, but it would require a PCB outside the 100x100mm sweet spot to achieve a good spacing. Would be like $20 extra for 10 boards, which honestly isn't so bad.

User avatar
MatrixModulator
Wiggling with Experience
Posts: 492
Joined: Fri Nov 28, 2014 10:35 am
Location: Montreal
Contact:

Post by MatrixModulator » Tue Dec 04, 2018 9:19 pm

May i ask what is P7? It is for the case where one would not use the ad633 it has to use a jumper on this p7 to activate the inverted sum out? If i use the ad633 i dont put a jumper there? Thanks
ImageImageImage

User avatar
Sin_Phi
Common Wiggler
Posts: 115
Joined: Fri Feb 06, 2015 10:10 am
Location: L.A. (Palos Verdes)
Contact:

Post by Sin_Phi » Wed Dec 05, 2018 3:54 pm

The jumper is for when you want to use the inverted sum out.

Leave it unpopulated if you are going to use the AD633.

In the BOM you will see it noted as "summing jumper". I will make this more explicit in the footnote.

User avatar
MatrixModulator
Wiggling with Experience
Posts: 492
Joined: Fri Nov 28, 2014 10:35 am
Location: Montreal
Contact:

Post by MatrixModulator » Thu Dec 06, 2018 10:49 am

Sin_Phi wrote:The jumper is for when you want to use the inverted sum out.

Leave it unpopulated if you are going to use the AD633.

In the BOM you will see it noted as "summing jumper". I will make this more explicit in the footnote.
Ahh sorry i used the xlsx file mostly, forgot about the pdf bom. Thanks for confirmation, can't wait to power it up :D :love:
ImageImageImage

User avatar
MatrixModulator
Wiggling with Experience
Posts: 492
Joined: Fri Nov 28, 2014 10:35 am
Location: Montreal
Contact:

Post by MatrixModulator » Sat Dec 08, 2018 5:48 pm

Can someone check please, it seems the kicad file and pdf have mismatch value for r56 and r57 on the "main board", are they 100k or 110k ?
Thanks :)
ImageImageImage

User avatar
MatrixModulator
Wiggling with Experience
Posts: 492
Joined: Fri Nov 28, 2014 10:35 am
Location: Montreal
Contact:

Post by MatrixModulator » Sat Dec 08, 2018 6:54 pm

Sin_Phi wrote:
Don't know which version of the BOM you are working off of, but R56 and R57 should be 100k not 110k. Doubt that is causing issues.
Sorry, i just see your reply, so it is 100k afterall. Maybe change the pdf file on your site? It is the bom pdf linked on the miasma page, it says they are 110k. (main board) There is also 2 other bom file types in the zip file, both says they are 110k, xlsx and csv.

Edit: seems like xlsx and csv are not in the zip file anymore, my bad. But that 110k eror is on the bom pdf.
ImageImageImage

User avatar
ehafh
Common Wiggler
Posts: 240
Joined: Thu Jan 22, 2015 11:07 pm
Location: illinois, usa
Contact:

Post by ehafh » Mon Dec 10, 2018 10:36 am

I'm interested in buying several pcb/panels, if someone is ever selling them feel free to PM me. Not seeing them online anywhere at the moment, and definitely no shortage of backlog. So I will wait till these show up in some shop / forum. Really excited though, have been watching the info on this module for a while. Congrats on finishing it! :hail:

edit: I see it's not going to appear in shops. I am just curious what the thought process is behind that approach. Without any offense etc, really just curious. In my mind it would just be cooler if the tech were available easily for people to build and explore. There's so many options on the market putting a barrier into the process of making one is confusing to me. I as a builder have nothing but options (and backlog as evidence of that heh).

Please consider making this readily available.
It would probably bolster interest in all your other modules, art and cool projects on the website!

User avatar
Sin_Phi
Common Wiggler
Posts: 115
Joined: Fri Feb 06, 2015 10:10 am
Location: L.A. (Palos Verdes)
Contact:

Post by Sin_Phi » Mon Dec 10, 2018 2:51 pm

@ehafh the not in shops part is pretty simple, the Non-Commercial (NC) part of Befaco's license. I have agreed with them not to sell through shops. Getting the boards made yourself is maybe $30 shipped if you aren't also getting the panels.

@MatrixModulator pulled all the csv and xslx out of the zip on the site so people can avoid confusion in the future. The pdf BOM has been updated with comment on the jumper.

User avatar
MatrixModulator
Wiggling with Experience
Posts: 492
Joined: Fri Nov 28, 2014 10:35 am
Location: Montreal
Contact:

Post by MatrixModulator » Mon Dec 17, 2018 5:19 pm

Sin_Phi wrote: @MatrixModulator pulled all the csv and xslx out of the zip on the site so people can avoid confusion in the future. The pdf BOM has been updated with comment on the jumper.
Cool :) i don't want to be a :omg: but r56-57 still show 110k instead of 100k in the pdf bom from your site. :hmm:
ImageImageImage

pppier
Learning to Wiggle
Posts: 20
Joined: Sun Feb 26, 2017 3:06 pm
Location: Italy

Post by pppier » Sat Dec 22, 2018 2:09 pm

so, are mod needed on board v1.01 (the green one)?
I built 2 and I have the inverted RISE A CV IN behaviour in both boards...

User avatar
MatrixModulator
Wiggling with Experience
Posts: 492
Joined: Fri Nov 28, 2014 10:35 am
Location: Montreal
Contact:

Post by MatrixModulator » Tue Dec 25, 2018 8:21 pm

Happy Holidays everyone :)

I have a question (hopefully a quick one) about the attenuverters if anyone can help please :S

I noticed when using positive clockwise setting on the attenuverters knobs of both sides of miasma, using positive voltage into the cv inputs of the attenuverters, the rise gets longer (as i expected) but the fall gets shorter. (using the same positive cv volage at it's input). Like if the Fall cv in reacts in a reversed way compared to the Rise cv in using the same positive voltage to control them.

Other than that everything seems to work fine. Is it normal ? or i screwed up my build?

I was looking at the rampage manual to get some more insight but it doesnt have the added attenuverters so... Thanks a lot :)
ImageImageImage

pppier
Learning to Wiggle
Posts: 20
Joined: Sun Feb 26, 2017 3:06 pm
Location: Italy

Post by pppier » Wed Dec 26, 2018 1:38 am

I built 2. finally I inverted pin 1 and 3 of L RISE CV IN pot to have the expected behaviour
(green pcb, V1.01) but only on the LEFT side, in my case
now it works as expected.

(at least, I expect positive cv (attenuverter in CW so positive) fasten the cycle time of rise or fall job. is what I had on 3 cv in on 4 so I modded only the inverted one...)

balance pot (for MAX, MIN, L>R and RM) seemed to act strangely at CW and CCW settings but it's due to the unipolar nature of L and R signal, using bipolar external signal (at L & R inputs) it like i remember from rampage (and rampage manual)

Nick Barnard
Learning to Wiggle
Posts: 13
Joined: Thu Jan 04, 2018 4:29 pm

Post by Nick Barnard » Sun Dec 30, 2018 7:46 am

Just to say thanks for making this! Nice straightforward build :D

Think I'll change most of the knobs for smaller ones, a shame the sifam collet ones cover the ramp shape decals, if I thought about it a bit longer I'd have moved the graphics around a bit before getting them made.

Image[/img]

synthpriest
Common Wiggler
Posts: 131
Joined: Wed Feb 24, 2016 6:02 am
Location: inside the machine

Post by synthpriest » Mon Dec 31, 2018 8:23 am

Anyone has a spare PCB/panel set to part with?
Or alternatively could you point me to an appropriate plant to have both the PCB and panel fabricated? :guinness:

aragorn23
Common Wiggler
Posts: 174
Joined: Wed Jul 26, 2017 6:02 am
Location: Johannesburg, South Africa
Contact:

Post by aragorn23 » Tue Jan 15, 2019 11:18 am

MatrixModulator wrote:
I noticed when using positive clockwise setting on the attenuverters knobs of both sides of miasma, using positive voltage into the cv inputs of the attenuverters, the rise gets longer (as i expected) but the fall gets shorter. (using the same positive cv volage at it's input). Like if the Fall cv in reacts in a reversed way compared to the Rise cv in using the same positive voltage to control them.
I'm experiencing the same thing. Did you ever figure out the issue?

aragorn23
Common Wiggler
Posts: 174
Joined: Wed Jul 26, 2017 6:02 am
Location: Johannesburg, South Africa
Contact:

Post by aragorn23 » Tue Jan 15, 2019 11:19 am

Hey all, quick question: I've built two Miasmas and they're both working 100% except that on one of them the cycle mode stops cycling on the longest range setting on the right channel. Any suggestions of where to look to fix this?

Post Reply

Return to “Music Tech DIY”