#62

Those were scavenged from some spare toggle switches I had. If I recall those are easier to find in red, black and white.

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#63

Ps Iā€™m really curious to know how many of these have been built

#64

Iā€™d be in for one!

Anyone want to be the 3rd?

#65

so tempting but I know I wont have time to build it myself

somebody help these guys out!

#66

Has this version been tried yet?

Way cool.

Another idea: 16 sliding pot controlled attenuverters feeding a summing mixer.

Anyway, Iā€™d be game for going in on a group buy of any version.

I also see that maybe some spare/extra boards were previously ordered, wonder if those are spoken for by now?

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#67

Great!

Yeah I was wondering that tooā€¦ thatā€™s why I revived this thread.

#68

It has so not been tested.

I had a quick look and didnā€™t like old meā€™s routing, so have tidied that up and also added a label as to what each standard is.

Untested because, personally, I donā€™t need one, and itā€™s a slightly expensive board to get made owing to size. Switch and jack are where they are because I still donā€™t have pay-for Eagle.

Iā€™ve stuck it on Github for now - https://github.com/infovore/16n-faderbank-minijack - but am happy to remove if @tehn/@shellfritsch are unhappy. All thatā€™s on Github is the EAGLE files. Similarly, Iā€™m happy to put the other things - code, CAD - there if appropriate. Although that would imply that my hack really needs testingā€¦

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#69

Still need to test my i2c hack; was too focused on the Teletype expanders to get around to it. I know that the unit works as a USB MIDI device - I use it regularly. Just not sure if my i2c hack functions. Iā€™ll post when Iā€™ve figured that part out. :wink:

I donā€™t have any spare boards. I only got two back from OSH - the third was damaged in production. (They were kind enough to credit me for it. Nice folks!!)

The one thing that I did learn is that Tung Oil is a HORRIBLE finish for this kind of thing. It still stinks after all this time of airing out and is also still slightly oily. Sigh. I will be recutting the body when I get my hands on a laser cutter.

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#70

I love the look of this.

I have pretty much no DIY experience (Landscape all flesh only) but have been dreaming about maybe making a simpler alternative version of this. Essentially turning this into a 16 channel passive attenuator with faders - with the 32 jacks in the convenient space next to them.

To turn all / some of them into CV sources, these could then be fed with a multed CV offset from the modular. Now you have a fader bank that requires no external power and should be pretty simple to DIY. Given that it wouldnā€™t need the PCB or teensy it should also be pretty cheap.

The first problem I thought of is that if you passive mult an offset then the more destinations it goes to, the weaker it becomes - and as you increase one fader, the others will reduce their output a little. Now if you send the offset through a buffered multiple, I believe this problem should be resolved, or at least really reduced. I tested this with my 4 channel passive mult and I get only a tiny bit of voltage drop when using a buff mult.

Would love to hear your thoughts!

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#71

I definitely got distracted thinking about what it might take to do a small-ish run of the original thing, with a well-located 3.5mm stereo MIDI jack. It turns out that even for low volumes - like, 10 - my usual European manufacturer will do a board that size for about ā‚¬35 - itā€™s at the point where OSH becomes less effective.

I also contemplated the rather neat configuration mechanism the CV.OCD uses - configuring from a webpage via WebMIDI Sysex - so if you wanted to change the CCs on offer, you wouldnā€™t need to piss around with arduino - but I think that might be a step too far.

Then I went back to workā€¦

3 Likes
#72

Given that it wouldnā€™t need the PCB ā€¦ it should also be pretty cheap.

The faders need to mount to something, as do the jacks. A PCB gives you mechanical support for the faders and jack sockets, it connects them all together in a way thatā€™s far more reliable than tons of flying wires - and it would be tons of flying wires - and it can be assembled far faster.

Even for DIY projects: value your time. Itā€™s only ā€˜cheaperā€™ if you can put it together as fast, and itā€™s as reliable.

Bear in mind that the PCB cost from OSHpark is pretty much as expensive as the board gets - OSH are designed as prototyping service; high quality boards that are a little expensive but fast and very low volume. Even going to 10 or 20 you could save by going to a more general-purpose manufacturer.

#73

Thanks for the feedback.

Both faders and jacks could just be panel mounted could they not?

Just to clarify I was thinking about making a one-off prototype rather than a batch and wiring up 16 attenuators seems to require relatively little wiring (Basing this on Doepfer DIY page and the Thonk ATATAT documents)

#74

You can normally panel mount faders with a m2 bolt - make sure you get the size and depth right from the data sheet

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#75

So I think Iā€™m going to go ahead with my plan on this.

Essentially I will modify the design so that it is 16 passive attenuators. However these will be grouped into 4 sets of 4 and within these groups, the inputs will be normalled to the ā€˜group master inputā€™ using switching jacks. This will allow faders to be used either as fader control (with a buffered CV offset at the group master input) or individual passive attenuators.

I have sourced alternative faders (http://uk.rs-online.com/web/p/potentiometers/2499418/) which are 50kĪ© instead of the original design which was 10kĪ©. I believe this will reduce the load on the buffered signal (coming from MI Links with OPA4171 OP amps). Schematic for 1 group is below.

image1 (4)
image1 (4).JPG480Ɨ640 60.1 KB

My electronics knowledge is pretty poor but I think this all seems OK. My only concern is the potential strain on the Op amps but I believe this should be OK?

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#76

I would recommend buffers for that design, otherwise all your variable resistors are in parallel to groundā€¦ so if you try to use the normals youā€™ll have the position of the subsequent sliders affecting the output of the others.

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#77

My plan is to use Mutable Instrument Links - Iā€™ve demoā€™d this with the SSF/WMD quad passive attenuator and all seems good. My concern was whether the Op amps in Links would be able to drive the 4 parallel faders ( I donā€™t know how to do the maths to work this outā€¦) though this was more of a concern with my original design which had all 16x10kĪ© faders in parallel together.

#78

I guess with 50k faders you may not notice it for most things. Itā€™s less of a problem of loading the output and more of one of getting a signal that isnā€™t altered.

#79

Great thanks for the feedback. Iā€™ll be sure to share the results here :slight_smile: