Behringer JT4000m Midi Controller Prototype

I've started work on a midi controller for the little JT4000m synth...  it's all a bit chaotic on the breadboard but it's mostly working with only a few bugs to iron out. Will post more soon...

JT4000m Midi Controller

V1.02: Graphics Update for JT4000M

 

https://www.behringer-jt4000m-editor.co.uk/
New:

Old:

Graphics Update for Behringer JT Mini Editor

 I've managed to sit down and find some time to update the graphics for the JT Mini editor:

New Version:

Old Version:

Helios-One Arduino Synth - Part 2

**Update**

The full build guide is now available here: 

**End of update**

It's been a while coming, but thanks to lock-down I've finally managed to finish part 2 of my simple Arduino synth, the impressively titled 'Helios-One'.  Don't expect it to sound like it's name.  Although maybe, a bit like lock-down, perhaps it sounds 'sick'.  

Here's part 1 of the tutorial in case you missed it.  In that part we set up an Arduino to work with midi, and also a switch to change between wave-forms.

In this version we add Attack and Release envelopes to the synth.  We could add a full ADSR envelope, but the Arduino only has so many free inputs and I'm trying to keep this simple.  If you still want to, you could figure it out by looking at the code I'm sure, but when we add more features down the line, you won't have enough inputs unless you start using a multiplexer.  Maybe we'll end up doing that anyway, we'll see.

You'll need two potentiometers (I'm using B10k ones)

Connect center pot pin to;

A5: for Atk

A4: for Release

connect the other pot pins to ground and 5v. 



To stop mis-triggering on the attack I have two 1k resistors in parallel (amounting to 500 ohms resistance) on the ground input of the attack pot.  You could put two 200(ish)ohm resisters in series instead (it doesn't have to be exactly 500 ohms), or play with the code...  maybe set the int val of the atkVal to something over 20 instead of 0?  The resistors work for me, so I'm sticking to that.

Here's a link to the code;

https://github.com/gary909/Helios-Arduino-Synth-V2

When you upload the code, remember you need to disconnect the RX pin on the Arduino.  You also need to have the Mozzi and Midi library's installed on the Arduino software.

Hopefully part 3 won't take me quite as long this time around.

Thanks.

Another Arduino Synth

Here's an unfinished synth I found in the drawer.  I promise I'll go back and finish it one day, but for now back in the drawer it goes...

PT2399 Quad Reverb

I constructed 4x PT2399 stock reverbs and joined them together.  Sadly I forgot to record any of the results.  Sorry.

Random Synths

Some random synths and things from when I first started out building them...

New Drum Machine PCB's Have Arrived

Will be on sale soon if you're interested...

Helios-One Arduino Synth - Part 1

**Update**

The full build guide is now available here: 

**End of update**

*************************************************
Part 2 now available;
https://bloghoskins.blogspot.com/2020/06/helios-one-arduino-synth-part-2.html

*************************************************

This is the first part in a series covering how to make a MIDI controlled synthesizer using an Arduino Uno and the Mozzi library.  By the end of Part 1 we'll have a midi controlled synth that you can select between two waveforms, Square & Saw.

Stella Synth

This is one of the projects in the amazing book 'Arduino For Musicians' by Brent Edstrom.  I had a bit of trouble with it occasionally breaking/crashing into white noise, but with the help of some nice people over on the Mozzie Arduino synth forums we managed to get it to work.  I think the books errata has since been updated, so check that out before you upload the sketch.

02 Drum Machine Update 2 (?!)

OK, so I've had ten finished drum machine sitting in boxes for well over a year, but I've been exceptionally busy, so I've not had time to put them up for sale :-)  I will do soon I promise, plus I'll email all the people that requested one.  Here's a bit of an update of what happened between that time;

Awaiting finishing

DIY Volca Mixer Schematic

I've not had time to get the PCBs made yet, but here's a more clear schematic for the Vixer Volca Mixer.  Not confirmed working (the previous hand-drawn schematic certainly does), but I've tripled checked it, so fingers crossed it should do.  Will confirm once the PCBs are made up, or let me know if you make it  Just right click and save.   Enjoy & have happy new year!

Jasper Synth Wasp Clone

Jasper Wasp Clone has now been finished, check out some gratuitous build photos below;

The finished Synth

DIY Volca Mixer Prototype

This has taken FAR longer than expected to complete, but finally the prototype of the Volca Mixer is ready.  I've settled on the following features;

3 Inputs
Aux effects send/return, with each channel having an amount pot, plus an overall amount pot
Switchable Global Delay
Switchable Headphone Amp
The mixer has the ability to run without batteries (bypassing Delay and Amp)

Here's a quick video of it in action;

Keep reading for full schematic;

DIY mini Volca Mixer Development

Brief

Make a small mixer for use with things like the Korg Volcas and other tiny synths.  I wanted something I could just grab and use on the sofa with minimal hassle setting up.  Ideally it should contain;

Spec

A compact mixer with between 3 to 6 inputs
Fits in a 1590BB guitar pedal enclosure
Possible Effects section
Not be too expensive

Keep reading to see the prototypes...

Simple PT2399 Plate Reverb / Surround circuit

I'm working on a mixer at the moment with built in delay and possibly reverb.  The PT2399 datasheet example 'surround / delay' circuit has been changed around to create this plate style reverb.  It still needs a bit of work as it's quite noisy, but as a start I guess it's getting there...

Hear it for yourself;

Easy DIY Roland Boutique Wood Side Panels

Made from a Lidl Prawn Packet

Being a massively picky individual I found the colour scheme on the SH01a with the keyboard attachment didn't quite look correct, so decided to build some new wooden side panels for it.  

Luckily an old box from a Lidl packet of frozen prawns managed to fit perfectly = a Lidl & Roland collaboration perhaps?  If you ever read any youtube comments about the Boutiques you might think the whole range was already co-designed by Lidl.  I really like them for what it's worth!

Watch the video for the full guide;

Or find the instructable here

****UPDATE**** SIMPLIFIED SCHEMATICS FOR MAKING THE STRING SYNTH

Below is a simplified schematic for the string synth...  Sorry it's not the best quality I'll try and take a better picture later, but hopefully this should be of help those of you new to schematics that want to try and build this synth. 

The connections where it says 'goes to keyboard', you can see elsewhere in this blog for another detailed diagram of where and how these can be wired up to the keys.   As for the potentiometers, I *think* I've drawn them the correct way (if you make this and the pots are working the opposite as you'd expect, swap around the ground and 5v connections on each pot).  If the drawing is incorrect, let me know and I'll re-do it. Even if this version is wrong, nothing will break & it'll still work OK (just the pots will work in reverse). 

You can see where the pots 5volt and ground connections need to go in the diagram, I didn't join them in the picture because the wires would start overlapping and become confusing.  It's pretty obvious what to do though.

Also drawn is the audio out headphone socket, with the positive voltage/audio signal coming from the output D11, which then goes through the resister/capacitor (which acts as a filter to reduce some of the noise from the Arduino).  The other side of the audio goes to the ground signal.  If you don't know how to wire up a audio jack, maybe google 'audio jack pin-out' or 'audio socket wiring diagram'.

If you plan on adding the analogue filter, you'd leave off the audio jack and have the previously mention positive wire go into the input of the filter.  You'll have to learn to read the schematic for that I'm afraid, as I couldn't really simplify it without it becoming more complicated than a normal schematic.  Give me a shout if you get stuck though.

Good luck! 

P.S

I'll draw a simplified schematic for the Arduino drum machine soon.

****UPDATE PART 2******

Below is a wiring diagram to add a bypass switch to the filter;

...And if you were struggling to figure out how to wire up the Pots for the filter, I've drawn out a simple picture showing how (I've had to do this whilst away traveling, so it's partly drawn from memory but I'm pretty certain it's correct)...

Obviously the drawing only shows how the pots are wired and not the full schematic.  Go look at the proper schematic for the rest of the plans, but this will give you a good idea of how to wire up the pots.

Powering the filter from a 9v Battery will give it it a bit more 'oomph', so if you'd like to do that, the below illustration will give you an idea.  Further, should you want an LED indicator showing if the filter is switched on or not, see the chequered box;

I only had SPDT switches available when I built the synth, so that's why there's separate switches for both the on/off & bypass, but you could easily just use one 2PDT to save space.  You could even add an audio in jack at the start of the filter to process other audio.

Good luck!