#696

It looks worse than it actually is, all they’re doing here is holding the pulse nodes together as I haven’t put any banana jacks on yet and providing +/- from the 9v battery.

I’ve only really got back into DIY in the last year or so and not finding these too tricky, the single-sided PCB’s require a bit more attention and patience but double-sided boards like these Rolls are fairly easy.

3 Likes
#697

The answer is “in some jacks” … Serge separates unipolar from bipolar voltages. 8v is a little higher than the standard Serge range (5v), but shouldn’t hurt anything.

I also think it won’t necessarily break anything to send a negative voltage to a unipolar input, but it also won’t necessarily do what you want it to.

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#698

lol woah! mine is definitely in the wrong way, but i’m pretty sure it still works to some extent. looking at it alongside the others makes it pretty clear. thanks for the tip!

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#699

Mine worked too, but was a bit concerned about its longevity seeing as the +V pointy bit of the battery connector points right at it :slight_smile:

#700

That electrolytic polarised cap is in the circuit just to prevent power supply ripples and spikes, so the circuit will work with it connected the wrong way, but the capacitor might go pop at some point!

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#701

Has anyone looked at approx. current drain on these paper circuits incidentally?

For instance, if you start putting different boards together to make a system of some kind can you get away with running a couple from one 9v battery or should each board have its own power?

Thinking specifically of a Grassi and an Ultrasound in an enclosure.

#702

that should be fine! i don’t know what the draw is, but i have 7 of rollz circuits running on a single 9v. i just daisy-chained the power wires from one circuit to the next.

1 Like
#703

Here’s the final Solar Sounder i have been working on - Trains At Night. The 2 smaller PCB’s, Gyuto Monks and Mourning Doves I should get back from fabrication next week. Not sure they will work, so will build 1 of each first to check. This one is 80x225mm (3.15x8.85 inches)

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9 Likes
#704

The Lil Sidrassi I built has some hum (more of a bleedthru of the oscillators than a mains hum really) when nothing is being touched, and loads of hum if you just touch the ‘volume’ peg and not the others. Partly avoided by just learning to play it by touching the other pegs first then the volume peg but still a bit annoying. Noise gate pedal works OK but I’d like to try and improve it so that’s not neccessary, any ideas appreciated, or let me know if you’ve built one and it doesn’t hum/bleed

#705

The output circuit is a 2N3819 FET. The board supports an LM386 chip for driving a small speaker, but you could bypass that chip and output straight from the FET to a jack for plugging into an external amplifier. I’ve not done this, I found this off Pugix site.

Alternatively you could try wiring up the way the Rollz 5 is wired up. I had a lot of mains hum on my Spikering but it went completely when I shared the speaker / power wire using that type of output jack. The setup is shown in the Ultrasound pic.

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3 Likes
#706

Thanks for that, useful info. Will have a look, yes should be easy now you mention it bypass the amp. Hopefully even have the option of both :slight_smile:

#707

which pcbs would one need if they wanted to make like a half-sized rolzer

#709

If you’re feeling adventurous then they’re quite easy to build on stripboard / veroboard.
Each “pulse” in the Rolz contains just four components: a NPN transistor, a 22K resistor, a 470K resistor and a (electrolytic) capacitor. You can also build the LED driver from a NPN transistor, an LED and 2 100K resistors.
Are you wanting to use banana jacks?
I could produce a layout, as long as people don’t think it’s stepping on Peter Blasser’s toes, or the toes of the PCB producers like @mlogger.

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#710

i sure wouldn’t mind a breadboard layout if nothing else that way it sits somewhere in the middle and shouldn’t be too toe steppy :slight_smile:

#711

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Each bar of the Rolzer is 2 x 6 Roll, 1 x 3, 1 x 4, 1 x 5 Roll. Each bar has the same capacitors in them depending on the speed. That means every output on each bar has an identical tempo defined by the cap value in the bottom (see pic) So say you want 4 bars, All that x 4. Because there are 7 bars it allows you to put identical capacitors on each bar and and have a range from 1uf to 10u and mix between the 7 bars.

For me, I don’t need that many Rollz. You can get complex rhythms by getting 2 of each Roll and putting different cap ranges from 1uf to 22uf on each individual roll output then cross patch between them. The only difference physically with the Paper Circuits PCB and Rolzer is there is no LED and also the Rolzer is on SMT boards instead of the older through hole design.

3 Likes
#712

There’s no problem from me :slight_smile: They are very simple and quick circuits to make. I was actually thinking of putting each Roll (6,5,4,3) on 1 board, instead of as separate small boards, but prefer to continue working on the missing Osmond files circuits.

The reason I did the PCB’s was because I didn’t want to mess with physical Paper Circuits and couldn’t understand why Peter hadn’t released PCBs, even after he put the Osmond files on the site for anyone to use. So the PCB’s are identical duplicates to Peters because I used his Osmond files. All I did was duplicate the top layer, so they became 2 layer, 2 sided boards instead of 1 layer 1 sided boards. I didn’t alter the designs or schematic in any way. I also shared this info to everyone, so they could do themselves. Like an open source thing.

What actually happened was many people didn’t want to batch order PCB’s (minimum order is 5) based on the instructions I gave, so contacted me for individual boards. I had so many excess boards from working out how to make the PCB’s in the first place, I decided to sell them.

I think tbh many of the hardcore Ciat people, who were originally interested in these circuits over the years now have what they need, so there isn’t such a big demand for them, like there was originally.

All I want to do at the moment is to put the missing Osmond files paper circuits on PCB so that’s the reason I started working on the Solar Sounders.

3 Likes
#713

yes, I am. a layout would be really great.

this is exactly how i was construing a ‘half’-Rolzer! and likely how i would want such a module internally oriented, perhaps w gradated banana jack colors to indicate highest-lowest range capacitance.

same.

the current main obstacle for me is the construction of an enclosure, i.e. drilling holes in aluminum etc.

#714

Here’s a breadboard / stripboard layout for a 3-roll and a 4-roll.
It’s easy to create 5 & 6 rolls, but I’ll leave that as an exercise for the reader! :slight_smile:

The red out here is like on the CL Rolzer - it’s positive going, around 8v if you power this from a 9v battery with diode reverse polarity protection. These are the outputs to connect to the inputs of the Ultrasound filters, the AV Dog and the Gongues. It should be safe to connect to a Eurorack system but check your module specs first.
The black in / outs are the sandrodes, connect these to each other to get interesting rhythms. Don’t connect these to any other equipment, they are negative voltage and potentially high current.

The symbol in the middle is an LED.
Thanks to Peter Blasser, Meng QI, mlogger and Richard Brewster (Pugix).

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I’d recommend building this on breadboard before getting the soldering iron out! There may be mistakes.

6 Likes
#715

Dogvoice testing with Eurorack envelopes / triggers…

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#716

Sorry for the silly question but what other components have you added in order to get the LED’s to work with the 220K resistor?

I’m aware of how Richard Brewster has his via the adapted CGS LED Driver, just wondered how you did yours? Thanks for any info.