Cool tutorial for diy solina-like synth

Technology Synth-DIY
#1

https://janostman.wordpress.com/2016/01/15/how-to-build-your-very-own-string-synth/

#2

Is that the Roland Juno on an 8-bit chip guy?

#3

Hmm, didn’t know you could just pull a keyboard out of something and use it. This would be great for my Axoloti.

#4

Now it’s 8 naive sawtooth oscillators without any kind of anti-aliasing called a “solina”.

1 Like
#5

That’s that guy who likes to use big words for little things.

#6

Maybe his day job is in SEO?

#7

Schematics for ants

#8

He talks about a phaser and describes a chorus/ensemble.

#9

Alright, there’s a very simple flanger, certainly not the triple-LFO thing used in the Solina…

#10

Certainly not a phaser though, that uses allpass filters! Admittedly the effect is somewhat similar to a flanger but it’s still distinct…

#11

I may be wrong, but I think phaser and flanger effects are produced in the same way- with short , LFO-modulated delays, producing phase-cancellation when mixed back in with the original signal. I think the difference between the two effects is just the range of the base delay time (shorter for phasing, longer for flanging).

a|x

#12

Chorus is produced in basically the same way, I think.
The old string-synths used to have several of these modulated delay circuits running at the same time, for that characteristic thick sound.

a|x

#13

Historically, phaser effects were produced with all-pass filters. That’s the criterion I use personally to distinguish the two.

#14

Yeah, phasing and flanging both produce moving notches in the frequency spectrum but it’s how they’re produced and the resultant spacing of the notches that characterises them. A phaser doesn’t use a delay, it instead uses allpass filters to shift the phase of part of the spectrum. When this is mixed back with the original signal, the parts that are 180 degrees out of phase cancel. Phaser notches are much more widely spaced and fewer in number, the classic MXR Phase 90 is 4-stages and thus has two notches. Flanging creates a comb filter, much more ‘whooshy’ because of the large number of little notches, while feedback makes it metallic.

#15

Gotcha. I think I may have been mixing up chorus and phasing, in that case.

Or perhaps I’m just confused…

a|x

#16

Yes, the same guy.

Oliver, if you analylse the code it is anti aliasised.
Do all the calculations and you’ll se.

And t2k, mocking people doesnt work in neither your or my world?

Just some respect, please?

#17

> Do all the calculations and you’ll se.

I’ve done them and I don’t see anything. Care to explain how it works?

“DCOPH” is a sawtooth with aliasing, “integrators” doesn’t integrate anything at all since it’s a ramp counting down from 28 to 0 at each edge of DCOPH. I kind of get the idea that you’re trying to use these to generate a band-limited pulse that you would be integrating somewhere, but there’s no other code in sight.

Are you sure you have published all the code?

#18
#19

The integrators are count down slopes at 753Hz.
Lower trigger and they get flat, higher and the amplitude lowers.
But the requency is fixed at 753Hz.

The eight harmonic, the top of my keyboard, is still below half the samplig frequency and Nyquist rate. (in reality -48dB below the signal.)

If there are any overtones, because of staircase or other artifacts, in my signal they are beyond the DAC.

#20

And I’m giving it all away on the internet.

That was one of your Points, open source.
Not living up to that today?

Now it’s my turn.