Standalone Mono-Synth

MIDIbox SID
1

This thread is basically just to see if anyone is interested in something that i’ve been thinking about for a while. I’ve unexpectedly got myself a 6581 SID, and I was thinking of things to do with it, and I was inspired by two things the ‘clones’ thread somewhere hereabouts, and a lovely little SIEL MONO I just fixed for a friend. I really appreciate the simplicity of its approach, and I was thinking of making something similar, based on the SID.

I’ve been thinking of integrating a single 6581 MBSID and Core module into a 3 octave keyboard, with external controls for things such as envelope etc. I’m not sure how many analogue inputs the MBSID core will support, but i’d like to have controls for everything, ie:

Envelopes

ASR for VCA

ASR for VCF/Pulsewidth

Filter

HP/BP/LP Switches (can use 1 or more simultaneously)

Cutoff

Resonance

LFO

2 x LFO’s with variable waveforms

Rate

Depth

Patchable to VCA, VCF, pulsewidth, and Pitch/VCO

Waveforms

3 x Pushbuttons to select waveforms for each oscillator (ie, sine, pulse, triangle and Noise).

Level controls for each voice.

I also thought it would be a good idea to have patch cables, to route the control voltages. For example, to patch LFO 1 to the filter, or to the LFO for Psuedo sample hold etc. In this way, it’s possible to build up a semi-modular synth, a little like the MS-20.

Obviously, the amount of controls available will depend on the amount of CV that the core supports (I count 17 seperate analogue parameters). I know that all this is possible with the existing design and control surface, but it’s not the same as having a nice little Mono synth like the SH-101 in front of you just begging to be tweaked!

Obviously i’m going to have a  full MBSID + Control surface too, I just want something that doesn’t need me to read an LCD or whatever. Ideally, this design wouldn’t even need an LCD. Wherever the knobs/sliders are set, that’s what they’ll sound like.

Ermm, ok that’s turned into a bit of a waffle but you get the general idea of what i’m poking at.

Is this a realistic project for me to get myself involved in? I have a lot of time on my hands, so designing PCB’s and stuff is not a problem, some of the code might be though!

2

Hi Jaicen,

Is this a realistic project for me to get myself involved in?

if you have programming skills: yes of course, it’s just an alternative user interface

Without programming skills the only possibility is to ask somebody who did this before.

Have you already seen Alkex’s MIDIbox SID? -> http://www.midibox.org/forum/index.php?topic=6553.0

it doesn’t fit with all your requirements, but maybe it will give you a good starting point.

Best Regards, Thorsten.

3

Thanks for that TK, i’d seen that before so perhaps that was subconsciously influencing me!

I think this may be a project for a bit further down the line, i’m not sure I have the technical ability to pull it off just yet.

4

New Here…Hello

I was thinking somting along the same lines

Small Sid Keyboard with realtime Cut rez osc envelope?possible? how difficult?circuit wise

Waiting on my kits…

?Could anyone tell me if it’s possible to add realtime cutoff and rez to basic midibox sid?with 10k pots?Sorry for many lack of knowleage

Thanks ya’ll!!

5

Hey dude didn’t I already tell you to read the ucapps.de website, this forum, and the wiki?

Yes, I did… http://www.midibox.org/forum/index.php?topic=6390.msg45007#msg45007

Go do that now, come back in 2 or three days when you’re done, and you’ll have found your answer.

It pisses me off that instead of taking the answer you’ve been given, you’ve tried asking the same question again in another place. Grrr.

6

Not here to piss any one off.. ???

Theres alot of links And I’m limited to computer use.

I have been reading site when i can over the last year downloading pages and reading at home

Thank you for your help

Thai

7

I’m sorry to hear you have limited internet use, I’m sure that makes this a bit difficult. You will probably be happy to hear that I am working on an offline copy of the ucapps.de site, which I will make available for download as a bit torrent file. This might be some time away though, so I’m not sure what you could do in the meantime. If you don’t mind my asking, whay is it that your internet access is limited? Perhaps we can find another way…

8

Limited excess is because I can’t afford to get high speed at the moment ???

But I keep downloading pages and find I’m Learning,as i tend to read to pages

over and over..

That downloads a good idea esp for others in future.

Plus to hardcopy such cool info!

Ohhhh I’m Excited to build!

9

That does make things harder, but at least your time on the net is not limited. The most important info is text, so you’ll be able to get that :slight_smile:

You should use the search engine of the forum to find information specific to your needs, it will save you reading unnecessary info. For example, there was a recent thread about pots vs encoders, you should check it out :slight_smile:

10

The thing about encoders is that when changing patches, their position might change, so you won’t be able to tell by looking at them what their value is. If you’re going for simple, then definitely use encoders. If you’re used to other programmable synths, it’ll be pretty much the same.

The point of this thread was to design something different to the usual patch based MBSID, something more akin to a real analogue synth where the pots are used for all the programming, thus dispensing with patch memories and lcd controls. Essentially this means that anything you want to control on the synth needs a dedicated CV control, whereas with the standard implementation, you can program everything using one encoder and the LCD.

11

Those pic of the sid keyboard ! ! ! AWSOME

I love to make something like that.

Please any more links on the info etc. behind it.

VERY COOL

12

I want to make somthing like this on my first midibox attempt?

(with out modular setup) 2 octave to din? what hardware is required (other than keys)? diodes? ic? how much firmware adjusting,How difficult? thanks for all your info greatly appericated!

Stand alone synth would be STELLER!

13

I would just gut an old one or two octave midi controller and just use the keyboard portion then hardwire the midi out to the core

14

I have 2 octave keybed (which i could build new case around with 2 pieces or metel 2 pieces of wood)

I have midi jack from other keyboards but not from the original keyboard with key bed..

thats it,I just wire the keys to core then core to midi?

seems to easy

I got to do more reading…

noobn’

15

Well the keybed will need its own processer to deal with the midi so I would just wire the midi out fromt the controller directly to the core

16

That’s definitely what i’d do I think. I had considered using a DIN module with 32 on/off switches mounted under a keyboard, but honestly that’s a lot more work than I can be bothered with, especially when MIDI keyboards are so easy to come by. I used to have a small one I bought for £30 which I’d use if I could find it!

As far as the original Standalone synth idea goes, i’ve pretty much abandoned it as I don’t think it’s worth the effort when the existing options work so well. I’m looking at designing a single module  synth which will be compatible with the AOUT LC module on here. It’s based on the ASM-1 synth from here:http://home.swipnet.se/cfmd/synths/friends/stopp/

At the minute I don’t plan to have any patching etc as it’s doing my head in. Features will be:

Single VCO with saw + square (simultaneous) and sub osc (Squ)

LFO assignable to PWM or Filter (may just replace this with a CV control from the AOUT)

Glide

Simple state variable VCF

ADSR & VCA

Thoughts are welcome  on anything. It’s just at the ‘thinking about it’ stage so nothing’s set in stone. I need to speak to the people at ASM before I do anything anyway.