BIAB's very own MODULAR and other SYNTH TECH THREAD

[Rmonik]

Ohaider!

We don't get a lot of really technical questions here, and it's a pity, because they are the most fun. I decided to open this topic for anyone who has more advanced questions on synthesizer design, modular patching, other audio devices and even DIY audio!

I for one, want to take the plunge into the marvelous world of modular synthesis and DIY audio tech. Some people on here have a few bits of those to play with so i imagine they will be the ones answering most of the questions.

Please do not ask basic questions about sound design, we have other threads for that.

Questions can be about:
- What synth should i buy and why?
- Electronic circuitry and signal flow
- physics, waves, fourier transformations, different synthesis forms (AM, FM, additive, functions suchas syncing, ...)
- DIY audio circuitry, racks, cases, cables, ...
- visual tech
- controllerism

Non-questions are allowed too; about all of the above, if you want to share with us your projects or something you have encountered on the internet, reviews, ...

Pictures would be really cool too.

DO NOT BE AFRAID TO POST. We are BIAB, the friendliest music community out there, and we love to talk about music.

Rmonik

[Rmonik]

I'll start off; I have a question about CV. Obviously, audio is AC, and CV signals such as gates or envelopes are DC signals. However, oscillators are used as LFO's and vice versa. Do you have to offset an AC signal so it is DC to be able to use it as CV modulator or can you just plug it in a CV input as it is?

[runemopar]

If it's the same format, you should be able to plug it in as is, unless there's specific issues with doing that unique to the format or synth. I've used audio as modulation, etc... But I've never tested wether LFOs produce audio by themselves. I'd have to have a modular system with me to be sure on that one.

[Rmonik]

Well doepfer sells modules that are advertised as VCO/LFO so i'm guessing yes. So will the sinewave lfo not saturate at the 0 V area instead of becoming negative? It's kinda odd. This is the kinda thing you need to test first.

I'm also a bit confused about the dimensions of the euroracks. What exactly is 3U? Is that the width, height, depth? I'm guessing the height. Does that mean one row of modules? (so are modules usually 3U heigh?). Also, should i take depth of module into account when installing the power supplier, or will i have poenty of room?

[runemopar]

3U is the width, actually 1U is the height of each rack, and the height of all the modules too.

You'll have plenty of room with a standard rack, don't worry.

http://www.modularplanner.co.uk/ <-- this is really helpful. Generally Racks are 84hp wide, which is the unit you should concern yourself with, not Us. When you buy a module, it will tell you how much hp it takes up, and that website helps a lot with planning out your space and power when setting up racks.

For example in the specifications near the bottom: http://www.analoguehaven.com/doepfer/a100g6/

6u: 2 x 3 u (about 264 mm), 2 x 84 hp effective width (about 2 x 426.7 mm)

And at the very bottom: http://www.analoguehaven.com/doepfer/a108/

it requires 12 te/hp worth of space to fit in a eurorack frame.

and sorry for me using analoguehaven, it's just the best site I've used ever and most relevant to me. Also where I found muffwiggler

[Rmonik]

Analoguehaven is cool but it gets expensive for us euro folks. I still don't get it though, what does the 2x 3u mean in the picture above. Height? So is that 6 modules high then?

[runemopar]

as far as I know you shouldn't be concerned about it, it's some weird measurement... I really don't know, it has never mattered. Feel free to look it up further.

[BPT]

But I've never tested wether LFOs produce audio by themselves.

Yes and no. They do create an audio phase but it's below what can be felt as sub. I'm not ever sure speakers will actually bother to move when it's that low. It's possible that square or saw waves will produce clicks, though.

Analoguehaven is cool but it gets expensive for us euro folks.

All-round better prices here: http://escapefromnoise.com/en/

[runemopar]

Well then it totally depends on the frequency response of the speakers.

[BPT]

That or what you've done to the wave prior to output. I mean you can FM an LFO and see what happens.