Questions for synthesists with ribbon controllers

[BJG145]

...just one more thought, which is that the Artiphon has this rubber fretboard thing going on, where it doesn't feel natural or comfortable to have more than a semitone per fret. But normal ribbon controllers don't, and can cover several octaves over the same length. I think the Continuumini covers a couple of octaves within its 50cm or so, while the Persephone has a scale control with increments that go up to several octaves IIRC. When I've finished "Morse Machine" (patent pending) I'll be able to do some more testing and see how far I can ramp up Yoshimi's pitchbend setting.

[Folderol]

Very pleased with the results you got
I take your points about using separate notes with portamento. It wouldn't really work except in very specific cases.

[BJG145]

Resistors galore...600 for £3.95.



The FSR strip will take a bit longer to arrive as it's coming from China, but I think I've got everything to mock up a basic ribbon now....

[Martin Walker]

I think you ought to start a DIY channel Ben - your posts are invariably fascinating, most creative, as well as educational

[Folderol]

Resistors galore...600 for £3.95.

Are they all the same value?
I was given a large bag of 39k 5% resistors in the late 1960s. I still have one or two

[BJG145]

I've been tinkering around with some designs, and I think I'll go for something Persephone-like.



Talking about it is one thing though, building it is another. DIY was never my strong suit, but I'm hoping the tech at the Hackspace might help me put it together. First induction session on Monday. So...we'll see. (Thanks for the encouragement!)

[Folderol]

Is your ribbon three wire or two wire? i.e. potentiometer or rheostat.
If the latter, you need to feed it from a constant current source, not a resistor. Otherwise you'll get a non-linear result, and pitch bend uses a linear input which is then converted to log by the synth.

[BJG145]

It's three wire...or it was.

Soldering remains a mystery to me. You wouldn't have thought it would be difficult to attach three wires to three pins with a roll of solder, a tin of flux, a fine-tipped soldering iron and a magnifying glass, but the stuff just won't behave for me. It just doesn't stick to the pins. So I did my usual thing of cursing over it for five minutes until two of them eventually broke off.

I think you ought to start a DIY channel Ben

It would have to be a comedy programme.

This iron is clearly too hot. I'll save what's left of the ribbon for the Hackspace.



(I think the old fluxed solder I was using was probably the main problem; it kept crumbling away. Apparently this happens if it gets humid.)

[Folderol]

Ouch. Get yourself a reel of multicore solder and throw what you've got away.

The situation is recoverable - just.
Iit looks like you used solid core wire - get rid of that too. You want very fine mulitcore flex. I cut up an old Centronics printer cable for this sort of thing - it's perfect
You won't be able to solder to the resistor element itself but there is enough of the tab left to make friction contacts. For this I would make a tiny clamp out of a couple bits of insulating board (paxolin) with something like M2 holes just beyond the width of the tape, then carefully scrape way the insulation from one side of the tape, lay this on one clamp piece insulated side down with a tiny dab of glue. Lay the bared wires on the strip and the other clamp piece on top, and bolt it together. Very fiddly, but I've done similar before.

[BJG145]

...right, thanks for that. I wasn't optimistic about being able to solder wires directly to the traces, so clamping sounds like a better idea.

[BJG145]

These people at the local Hackspace are going to be handy to know. They use a Slack workspace. I just posted up some thoughts wondering how to assemble that Persephone-esque shape out of laser cut parts, and less than half an hour later someone had modelled it as a laser design using OnShape, and posted up a link to the files.

[Martin Walker]

Wow - your local Hackspace is being extremely helpful Ben!

[Folderol]

Wow - your local Hackspace is being extremely helpful Ben!

They are indeed!

[BJG145]

After pondering this knackered sensor for a couple of days, I've decided to abandon it and get another one. I've been reading about soldering these things, and in fairness they do seem like delicate creatures - especially the FSRs; good job I read about that before it turned up.

I hadn't realised that the pins on the sensor are designed to be plugged directly into a breadboard. I just want to get on with the Arduino testing stage without extra complications, so, I've ordered a replacement...and a breadboard.

[Folderol]

Psst!
Want some 60/40 solder

[BJG145]

I'm done with soldering for now. I've got a pack of crocodile clips.

I'll probably use these 'Amphenol CFI clincher connectors' for the final version, based on the clamp principle.

[adrian_k]

Psst!
Want some 60/40 solder

I might have misunderstood, I frequently do, but I’m just about to buy some and would be happy to buy yours, if that’s what is going on here!

[Folderol]

Well it was intended as a joke, but I do have some if you fancy a bit of lead poisoning (although I've not come across anyone who eats it). How much do you need and where are you? I wouldn't charge for it unless you want a lot.

[BJG145]

Psst!
Want some 60/40 solder

[Folderol]

The only thing I'd challenge is the cigarette - I don't smoke!