Synthmonger "mini"-guitar synth

synthmonger · Last edited by synthmonger on Thu Oct 09, 2008 10:03 am; edited 1 time in total

I've been working on a guitar synth the past few days. I'm building a mini and mega version. Basically the mega version has more sub-octaves, pwm, and a vca for A/D controls.

I'm stuck on the layout. I just can't decide how I want things laid out. Ideally, I want each section (mixer/pwm/EF, etc) together but trying to lay them out symmetrically has been difficult for me. The posistion of the knobs must follow to the layout in order to fit in the case properly. Any suggestions would be greatly appreciated!

Just to let you know I'm not using 1v/oct frequency converter to control the vco's and it tracks pretty darn well. I'm sync'ing 40106 vco's that are based around my design. It's a fairly simple circuit that is a helluva lot of fun to play with!

The layout doesn't have the stompswitch or led indicator on there yet, but it'll go in the middle towards the bottom. The back will have vc inputs for each pwm, vco freq, and vcf.

SM_mini_guitar_synth.png

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StephenGiles · Joined: Apr 17, 2006 Posts: 507 Location: England

Sounds just like my cup of tea, look forward to hearing samples!

synthmonger · Posted: Thu Oct 09, 2008 9:59 am Post subject:

I'll post some later tonight. The ones I recorded so far were done before I built a proper tracking section, vcf, pwm or envelope follower. I'm waiting until I have the design done before I post good quality videos/samples.

StephenGiles · Joined: Apr 17, 2006 Posts: 507 Location: England

http://www.4shared.com/file/21289268/ee1dd026/CClark_synth1.html
http://www.4shared.com/file/21289267/7ea2cdb7/CClark_synth2.html

Talking of the 40106, have you seen this? Also, please take a look at these, which use an interesting type of sweep generator.

http://www.4shared.com/file/39556305/8587cb8c/EHcrashpad.html
http://www.4shared.com/file/37898877/e1132137/spacefilter.html

synthmonger · Posted: Thu Oct 09, 2008 4:21 pm Post subject:

Where exactly is the 40106 in those designs? All I saw were 4046's.

StephenGiles · Joined: Apr 17, 2006 Posts: 507 Location: England

synthmonger · Posted: Fri Oct 10, 2008 10:17 am Post subject:

synthmonger · Posted: Sun Oct 12, 2008 10:41 am Post subject:

I nixed the layout and have decided to build two different boxes. One for voice another for control. The voice will have the fundamental, sub-octave, and 2nd sub-octave, with ring modulation, vcf, vca and possibly an aliaser. The control box will have a couple EF's, LFO's, S&H, 2-4 photocells and maybe dual joysticks.

I will also be building one giant box that includes everything.

Here are some samples I recorded using an MT-240 on the 'accordion' setting. All raw, recorded in cool edit pro and no digital effects -other than lowering the amplification and adding a fade out. I haven't conditioned the signal yet so the tracking isn't anything to brag about. These demos give you an idea of it's interesting sonic capabilities.

I am using just the outputs of the digital ring modulation section.

StephenGiles · Joined: Apr 17, 2006 Posts: 507 Location: England

That is an amazing sound. Many thanks.

richardc64

Interesting samples.

synthmonger · Posted: Sun Oct 12, 2008 7:42 pm Post subject:

Well actually I'm syncing the 'vcos' with an amp tied to a diode facing the input of one 40106 oscillator. I'm using another gate of the 40106 as a high frequency exponentially controlled VCO that is driving a 4066 switch. The input to the switch is connected to the input of the sync'd 40106 oscillator and the output of the switch is connected to the output of the 40106 oscillator. The switch is basically an easy peasy VCO/resistor. I'm getting -.06 to 500k resistance on +9v power. I haven't tested the resistance with different power supplies yet.

I tested the same VCO/resistor method with a number of things with 100% success (toy voice changer, BPF, LPF, aliaser, to name a few). One super-awesome-cool-fun thing to do, is controlling 4 40106 gates with one vco/resistor that each have optional manual frequency control. The best thing about the VC resistor is the sync/linear/expo control via the vco driving the switch.

You can use 1 of 2 switches (4053) to act as a vco/resistor too (i.e. voltage divider). I haven't tested out the 1 of 4 (4052) or any other electronic switches yet.

Now all I need to figure out is voltage controlled capacitance!

I'll post schematics of my guitar synth after I get everything finished. For now, here's a tri/square vco with a few different control options. Also, you'll need to add some extra circuitry to get a symmetrical triangle wave. If you leave it as is in my schematic it's a lil floppy.

EDIT: The VC resistor is in the VCO schematic. just leave off everything after the switch. Use the input and output pins on the switch as a floating vco resistor.

VCO_switch.png

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snufkin · Joined: Apr 06, 2007 Posts: 57 Location: the world

this is amazing i look forward to more updates

StephenGiles · Joined: Apr 17, 2006 Posts: 507 Location: England

How many 40106 chips will be needed, so I can put in an order?

loss1234 · Posted: Mon Oct 13, 2008 5:07 am Post subject:

what program is that .sch file from ????

synthmonger · Posted: Mon Oct 13, 2008 7:28 am Post subject:

synthmonger · Posted: Mon Oct 13, 2008 7:33 am Post subject:

StephenGiles · Joined: Apr 17, 2006 Posts: 507 Location: England

StephenGiles · Joined: Apr 17, 2006 Posts: 507 Location: England

How's it going Synthmonger?

richardc64 · Posted: Sat Oct 18, 2008 10:00 am Post subject:

Do I understand this correctly, 'monger? You're NOT doing any F/V conversion, but only syncing your oscillator to the input signal? If so, that's pretty slick.

synthmonger · Posted: Sat Oct 18, 2008 4:19 pm Post subject:

inlifeindeath · Joined: Apr 02, 2010 Posts: 316 Location: Albuquerque, NM

hey synthmonger, did you ever have any success with this design?