Super Breadboard Front Panel

Welcome to Part 2 of my ‘Super Breadboard’ post.

In the previous post I showed you the basic layout of the main baseboard which holds the Arduino Development board, the FV-1 development board, the voltage booster, the breadboards and the Input/Output/Bypass box.

For the front panel, I used a piece of 0.9mm thick aluminium measuring 100mm x 250mm which I bought from Bitsbox. After drilling the holes for the pots, switches and MIDI connectors (see below), I bent along one of the long edges to form a 15mm ‘flange’ and drilled three 3mm holes in this and in the baseboard which I could then attach it to using M3 bolts, washers and nuts.DSC00384

Any guitar pedal will usually have one or more potentiometers (pots) to allow the guitarist to adjust aspects of the pedal’s performance: think of the Drive, Level, Bass, Treble, Delay etc. etc. that you see on typical pedals. I’ve allowed for up to six pots on the front panel and, since different circuits require various different pot resistance values, I wanted to be able to easily swap out the pots. Fortunately, I found that the lugs on the 16mm pots were a perfect fit for the JYK crimp connectors I frequently use for off-board connectors:

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This will allow me to easily try different pot values without having to do any soldering to the pots – I can just unplug one pot and plug in another one. The other end of the pot wires have male Dupont connectors to plug straight in to the breaboard:

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You’ll notice on the front panel that there are standard 5-pin MIDI IN and OUT connectors – I added these in case I want to experiment with MIDI control – for example, the Blue Nebula pedal has a MIDI IN that allows you to change the patch using a MIDI controller or sequencer. In the earlier eTap2hw development phase I built a couple of echo boxes with MIDI inputs and I had some tiny little (30mm x 20mm) MIDI interface PCBs made up to house the MIDI In and Out circuits so I was able to use one of these in this project. It’s the small red PCB below:

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The 4-way Dupont connector carries the +5V and GND wires plus the MIDI TX (transmit or ‘MIDI out’) and MIDI RX (receive or ‘MIDI in’). These would normally be controlled by software running on the Arduino Nano.

So that just about completes the ‘super breadboard’ – now all I have to do is get cracking on designing some exciting new guitar circuit stuff!

My ‘Super Breadboard’

Most developers use a simple breadboard (see picture) at some stage as they are working out a new electronic circuit design.

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The trouble with using these for developing guitar effects is when it comes time to connect your input and output jacks and maybe you want to have a bypass switch so you can compare the dry guitar sound with the sound coming out of your brand new effect. Then there’s the need to wire up pots for the effect controls and perhaps you’ll need to swap them out to try different values. And what about toggle switches? Many effects have one or more toggle switches to select options such as tone shaping or extra gain or whatever.

There’s nothing more annoying and frustrating than the jack sockets falling off the breadboard every time you pick up the guitar to try out the new gizmo you’ve been working on or the pots disconnecting themselves when you try to turn a knob.

I finally gave in and, with a lot of those thoughts floating in my brain, the idea of a breadboard dedicated to the task of developing guitar effects began to emerge.

As you will know if you’ve spent any time reading this blog of mine, I enjoy finding ways to include some sort of microcontroller in my projects, usually an Arduino Nano because of its small size. The final push I needed to get the bits together for my new ‘super breadboard’ came when I found and bought an ‘Arduino Nano Development Board’ on eBay. This was a very good idea that I wish I had thought of myself!

It’s the large green pcb on the left in the photo below. It has a number of buttons and LEDs and a couple of trim pots prewired to connectors on the board. There’s also a LM7805 5V regulator if things need a bit more power than the Nano’s own 5V output can provide, for instance, to power up servos, up to 12 of which can be connected to the standard servo connectors in the middle of the board. The board’s designer, Mike Hawkins, also included provision for a 0.96″ OLED display and a small breadboard for any extra circuitry you might want for the digital side of things.

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I found a suitable piece of MDF in my garage and gave it a couple of coats of white car primer before starting to figure out how to fit in everything that I wanted to include. I added a couple of the larger 830 tie point breadboards to the centre of the board and I wired up a sort of dummy stomp box in a Hammond 1590B enclosure which houses the In and Out jack sockets, a 3PDT bypass switch and ‘effect on’ LED plus some DC power jacks and a four-way terminal block on the top.

The + and – terminals take flying leads from the 9V supply to the power rails on the breadboards and the S and R terminals (S)end and (R)eturn the signal to the effect circuitry on the breadboards.

Just between the large breadboards and the in/out box is a small module that can boost the input voltage up to 45V. For circuits that require more than the 9V you get from a  ‘standard’ stomp box BOSS-style PSU, this handy module can be set using the multi-turn trim pot to whatever voltage you need – I have mine set to put out +18V which is a common value in some circuits used to give them extra headroom.xl60009-dc-dc-step-up-boost-converter

This DC-DC boost/step-up converter module (£3 from Hobby Components part # HCMODU0091) is based on the XL Semi XL6009 DC-DC converter and is capable of boosting a wide range of input voltages up to a maximum of 45V. Its output can supply up to 2.5A out current (dependent on input voltage and operating environment) and has built in thermal limiting protection circuitry. An on-board multi-turn potentiometer allows for adjustment of the output voltage which can set anywhere from Vin up to its maximum output voltage.

Just above the stomp box is an FV-1 development board carrying a Spin Semiconductors SKRM module. This was the module that started it all off for me as it formed the heart of Piet Verbruggen’s, by now famous, eTap2HW project. That led eventually to the development of the Blue Nebula pedal.

The FV-1 is the DSP chip that makes all the ‘magic’ work in those and many other guitar effects and amplifiers.

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Since the photo was taken I have completed the module by adding the 8-way rotary switch that selects one of the 8 effects that can be programmed into the EEPROM on the module, using a PICkit2 programmer that connects to the socket on the right-hand end of the small motherboard into which the SKRM module is plugged. This also holds the three pots that are used to adjust the effect parameters, just as the P1, P2 and P3 knobs do in the Blue Nebula.

The front panel

To be continued …

MemBuilder Technical Document

I’ve just added a short ‘Technical Document’ to explain how to create your own ‘effect’ files for MemBuilder. You will need to be able to write Spin DSP code for your own effects and use the SpinASM IDE to compile that as a hex file. NB: If this is all gibberish to you then you don’t need this document and you won’t be able to do anything with it so please don’t ask me to explain how to write Spin code!

If you’ve got this far there is also a “Builder Header” file that you need to download so you can add your hex code to it. It’s all explained in the document 🙂

Both the Technical Document and the Builder Header file are available on the Latest Updates Here page (link in the menu bar above) – just scroll down until you see the MemBuilder section.

 

Blue Nebula Review

US-based guitarist Mark Sorenson (aka ‘Synchro’) has posted a very comprehensive review of the Blue Nebula on the gretsch-talk.com forum which, if you are possibly considering a purchase, would be well-worth your while to read.

Gretsch Talk Review

The Blue Nebula can be ordered direct from Stanley FX. Price is £249.99 plus £15 worldwide shipping.

New MemBuilder Effect Files

By popular request I’ve just uploaded two new effect files for use with my MemBuilder app.

  • Reverb / Tremolo is the standard effect pre-installed in MEM 2 slot 6
  • E-MATIC 1 F Spec is the ‘special’ version of the Meazzi Echomatic 1F based on the details supplied by Alan Jackson of the settings implemented at Abbey Road by Dick Denney and of a “FAST” speed setting. (See Appendices 1 & 3 in the Blue Nebula User Manual for more information). This is factory installed in Slot 5 of MEM 2.

These two effects complete the full set of eight MEM 2 effects as supplied with the Blue Nebula by StanleyFX and this will enable you to use MemBuilder to assemble your own MEM 2 set of effects, retaining any of the original ones you wish to keep and replacing others you don’t want with an alternative effect from the list here.

 

Translating the MemBuilder User Manual

First off, thanks to Tonnie for his Dutch translation of the MemBuilder User Manual. Tonnie provided this translation quite a while back but due to my extended holiday over Christmas and the New Year I’m only getting around to uploading it now. As usual the links to all software and manuals are on the LATEST UPDATES HERE link in the navigation bar at the top of each page.

Earlier this week I got an email from Microsoft explaining a new document translation feature in Word for Office 365. With this I can translate a Word document into almost any language with a couple of clicks of the mouse!

After a wee bit of editing to ‘untranslate’ things like the names of buttons and changing la Nebulosa azul back to Blue Nebula for example, it seems to produce a fairly readable translation.

So, I’ve now ‘autotranslated’ the MemBuilder manual into French and Spanish and added these to the updates page.

I’d be interested to read any comments of my French and Spanish readers if this has turned out good enough to be useful. It’s certainly much less labour-intensive than translating a whole manual by hand!