Category Archives: Music

Performance styles for PSR-E443

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The PSR-E443 folks don’t get enough love, so here is a collection of performance styles for the E443 and the E433.

So, what is a “performance style?”

The Yamaha Motif/MOX series of synthesizer workstations have hundreds of factory “Performances” to to help a composer get started with a new song. A Performance has up to four independent voices (drum, bass, guitar, etc.) and up to six sets of related musical phrases — “arpeggios” in Motif-speak. The arpeggios are drawn from a built-in library of several thousand musical phrases in a slew of contemporary genres. Each set of phrases has a role (main section, fill, break) and the composer switches between sets while playing in order to lay down a basic arrangement or backing track. Even if you’re not a songwriter, the Motif Performances are just plain fun for jamming or practice.

I recorded and translated 22 of my favorite Motif/MOX Performances to PSR/Tyros styles — Performance styles. They play just like regular styles (follow chords in the left hand, play fill-ins when changing main sections, etc.) The styles are stripped down and are meant to be played. A few of the styles have only bass and drum, so there isn’t a lot of elaborate orchestration to get in the way. The introductions and endings are very simple.

This first collection targets the PSR-E443 and E433. The styles are SFF1 and should work on other arrangers supporting SFF1 although you may need to substitute different drum kits. The styles in this collection do not use Mega Voices. A more advanced collection with SFF GE and Mega Voices is being developed.

Since these are my favorite performances, the styles come from a funky, jazzy, fusion kind of place.

For more information, check out the README page. Then, download the ZIP file and have fun!

MOX interview: Follow up

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Here’s a quick follow up after my interview with Yamaha marketing.

First, the word “conversation” is a better description than “interview.” I had a really enjoyable, high-bandwidth conversation with fellow gear-heads. What could be better than that? The Yamaha team members are friendly, extremely knowledgeable and open. They are also good listeners and had read my pre-interview MOX retrospective.

So, thanks to Yamaha for listening!

I also learned some things that I intend to put into practice going forward. We discussed how I created the voices that I use on my church gig and the issue of sound dropping across voice changes in MOX Voice Mode. One way to avoid sound cut-off is to use Song Mode instead of Voice Mode. Assign a voice to each part in Song Mode and then select parts on the fly. I’ll have to give this a try. I also want to experiment with the assignable knobs for drawbar control and Song Mode may be part of this solution, too.

Since the conversation was relatively short — about 25 minutes with my MacBook Air crashing due to a thermal overload part way through (Yikes!) — I went blank on some of the reasons and history for my work style. For example, I created the voices for the church gig through the front panel and didn’t use either the PC- or iPad-based editors. I since reconstructed my mind-set from way-back-when. I’m sure that I was sooooo anxious to use the MOX at the gig that I just dove into the front panel. I had programmed a TG-500 back in the day and the Yamaha voice architecture was still familiar to me. (The Motif/MOX effects structure is way easier to understand than the old TG, thankfully.) The last thing I needed was a software editor to get between me and the gig!

I didn’t have an iPad when I bought the MOX6 and wasn’t aware of the Yamaha apps for Motif/MOX. The apps — once I learned about them — motivated me to budget for and to buy the iPad. Aside from Web-browsing and e-mail, my iPad is almost entirely devoted to music-making tools (no cat videos). I have both Cubasis and Mobile Music Sequencer (MMS) installed. MMS gets used; Cubasis not so much. Cubase is one of those tools that I want to learn — kind of like my current explorations in Ableton Live.

Starting today, I would use the iPad apps. Heck, I should (would) check out the Yamaha PC-based editor and the fine Motif/MOX tools by John Melas.

Well, there you have it. A positive experience all the way around!

If you’re curious about how I use the MOX for content creation, please check out the following posts and pages:

Yamaha Reface (No, I haven’t played it)

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It’s Internet de rigueur to comment on the new Yamaha Reface keyboards — whether you’ve played them or not! So, here goes…

I’m in fat city with an original AN-200 (Prophet-5 plus beat machine in a box), a P-50m (pianos in a box), a CS-01 (monophonic analog synthesizer) and a Nord Electro 2. Although a few of these pieces are gathering dust, they pretty much cover the sonic territory of Reface. DX-wise, I had more than enough FM in the 80’s, thank you, and could always get my old CE-20 repaired, if the urge to frequency modulate should ever overcome me again. Overall, I’m unlikely to take the plunge and buy a Reface keyboard just out of necessity.

First off, I genuinely wish Yamaha all the success in the world with these products. This is the first time that Yamaha have strayed from the AWM2 mainstream in some years. I would hate to see this innovative product line tank and make Yamaha risk-averse. The Reface product line started out as an after-hours skunk works engineering project. The fact that Yamaha committed to manufacturing and marketing Reface is significant and shows real effort to shift their corporate culture. Further, if Reface makes scads of money for Yamaha, then its profits will lift other boats within Yamaha.

Sonically, Reface sounds pretty darned good. The CP and YC are my favorites because they fit with the musical genres that I work in. I hope that some of this technology will migrate into future synthesizer and arranger workstation products. Spectral Component Modeling (which includes Virtual Circuit Modeling) grew from VL technology. The VCM effects in the MOX/Motif are quite good, so please give me more of that! I am pleased to see Yamaha work on organ emulation and would like to see the drawbar control, vibrato/chorus and rotary speaker effects in a new workstation. Both the Motif/MOX and higher-end arrangers are missing the Hammond “vibrato scanner” effect — a significant omission.

So, why am I not buying? Apparently, “mini” keyboard sales are making money for Novation and others, and Yamaha wants a piece of this market. The decision to use mini-keys strongly bifurcates the marketplace — you either like (accept, tolerate) mini-keys or you don’t. I’m a “don’t.” I have tried mini-keys in the past and, well, no thanks. This is not an “anti-Yamaha” position — I lost all interest in the Korg Odyssey, for example, when I learned that it had mini-keys.

The Reface is touted as a portable, take-it-anywhere keyboard. If you’ve been reading this blog, then you know that I’ve put together a portable rig based on the Korg Triton Taktile (TT.) The TT has 49 full-size keys and is not much bigger or heavier than a Reface. The TT key bed is excellent and four octaves is enough room to roam. Although the TT is missing the up-to-date tone generation and effects technology in Reface, it’s a very playable alternative to Reface.

Finally, there is the issue of the $500 street price. I suspect that Yamaha is looking to make a few extra bucks from the early adopters. Korg may have pursued the same strategy with the TT. They brought the TT out at a higher street price and then eventually reduced the price to the current $350 USD. The TT comes with a superb bundle of software plug-ins and offers, making it a terrific bargain. Unfortunately, for Yamaha, this is the competition facing Reface (pun intended) and a $500 street price looks mighty steep for an ax with mini-keys and no free software incentives.

Internet reaction from Reface detractors has been vehement — far over the top, in my opinion. It seems like some people have taken Reface as a personal affront! Please, settle down. Yamaha is a big company and they will surely roll out new products for the rest of us. The Motif refresh is overdue, for example, and must be in the works. It’s good to see Yamaha releasing new products that are out of its mainstream offerings. All the best!

Footloose and fancy free

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Maybe you would like to play your music in the great outdoors at a family picnic. Or, like me, you would like an extremely light, battery-powered rig for quick set-up at rehearsals.

Modern battery technology to the rescue! More musical instruments and portable speakers than ever run on battery power. Many of these devices sport an integrated rechargeable battery and a USB-based charge or power outlet. You can have that light battery-powered portable rig by combining a battery- or USB-powered keyboard with one of the many available portable speakers.

Here’s how I designed my portable rig.

I started with the KORG TRITON Taktile 49 USB-powered MIDI controller and synthesizer. The TRITON Taktile (TT) has 49 keys and is very light-weight (less than 8.5 pounds). The TT incorporates the Triton Classic sound engine and programs which are under the control of eight front panel knobs and sliders. I reviewed the TT here and here , so I won’t go into more detail about its sonic capabilities.

The TT does not have built-in battery power. However, it runs quite well on a rechargeable USB battery pack. USB battery packs are readily available and are usually intended to power or recharge personal electronic devices such as MP3 music players, phones, tablets and so forth. Fortunately, electricity is electricity and the TT is happy to operate on power supplied by a USB battery pack. As long as a battery pack can supply the necessary current (usually stated in milli-amperes or “mA”), the pack should be able to power any compatible musical instrument keyboard.

Let’s explore power requirements a little bit more, using the TT as the example. KORG claim that the TT draws 550mA of power through the 5 Volt DC USB-B port. I purchased an Incase Portable Power 5400 recharging “brick.” The Incase brick can supply up to 2.1 Amps (2100 mA) of current, more than enough to power the TT. The “5400” in the product name refers to the battery capacity: 5,400 mAH. In theory, the Incase 5400 brick should be able to power the TT for nearly 10 hours. (God helps us if we ever rehearse that long!) I have been using the TT/Incase combination during practice for the last few days under light use and haven’t burned off 20% of total capacity yet.

So far, so good. But, what about a portable speaker? Unfortunately, you can’t expect to drag your keyboard into Target or Best Buy and audition portable speakers. Most of the speakers on display in box stores are wired into a point-of-sale demonstration system which plays back canned demo tracks. You won’t be able to disconnect from the demo system and connect a synth to the back of the portable speakers on display. Thus, you should audition as many speakers as possible with the canned tracks and try to find the one with the best overall reproduction without “boxiness” and weak low end.

I tried out portable speakers in-store rather obsessively and exhaustively. I eventually settled on the JBL Charge 2 Bluetooth speaker. The JBL Charge 2 has reasonably flat response and good low end without the boxiness of many small speakers (such as the higher priced Jambox Mini). The Charge 2 is a little bit chunky weighing about 0.5 pounds. It specs out pretty well: 2×7.5 Watts and 75Hz – 20kHz frequency response. Two passive radiators provide solid bottom end; bass notes are distinct with recognizable pitch.

Sonically, I’m quite happy with the TRITON Taktile and JBL Charge 2 combination. The JBL handles high energy sounds like organ and French horn without distortion and flappy speakers. The headphone output from the TT is a little too low, however, and I must turn the volume all the way up on the JBL in order to get to rehearsal-level volume. Our church group rehearsals are “unplugged” (except for me, of course), so I don’t anticipate any problems on the job. However, I’m considering the addition of a battery-powered gain stage between the TT and the JBL. The following candidates for gain stage look viable:

  • Boostaroo R234 Revolution Headphone Amplifier
  • Rolls MX56C Minimix A/V Battery Powered Mixer
  • MCM Custom Audio Compact Headphone Amplifier

The Rolls MX56C is attractive because, hey, who couldn’t use a battery powered utility mixer for other production applications? The MCM headphone amplifier has a Micro USB-B power input in addition to a 9V barrel connector. The MCM can be powered from a USB-A port just like the one on the Incase power brick.

Potentially, a fourth alternative is a guitar boost pedal. The pedal solution is viable as long as the pedal is flat and does not color the sound of the acoustic voices. I tried a Danelectro D-2 FAB Overdrive pedal with the jazz/pop voices and the overdrive does a great job of dirtying up the voices while adding gain. The TT voices are exceptionally clean and the added grit on electric pianos and guitars is especially welcome. As Moe the Bartender would say, “He ain’t pretty no more.”

There are two other aspects of the JBL Charge 2 that are worth mentioning. First, the JBL is such a chunk because it incorporates a 6000 mAh Lithium-ion Polymer battery and a 2.0 Amp USB-A charging/power port. Originally, I intended to power the TT using the JBL Charge 2. Unfortunately, there is too much digital noise on the USB power line when the TT is connected and is drawing power. One can clearly hear undesirable synthesis artifacts and noise at a completely unacceptable level when the JBL both powers and amplifies the TT. Now, I run the TT on the Incase power brick separately. I am thinking that the JBL could power the MCM headphone amplifier, hopefully without the digital noise.

Second off, the JBL is a Bluetooth speaker. (It works quite well in this capacity having tried the JBL with an iPad.) It seems like a no-brainer to send audio from the TT to the JBL over Bluetooth assuming that a Bluetooth audio transmitter is attached to the 3.5mm stereo output of the TT. This is a loser for live play, however. The transmitter must encode and compress the audio which imposes an unacceptable delay between playing a note and actually hearing the note through the JBL. I’ll stick to good ole latency-free audio cable.

The picture below shows the whole rig: the gray Incase power brick, the TRITON Taktile, and the JBL speaker resting on top of the TT. The TT does not have much clear room on top. Most of the top is taken by buttons, switches, sliders, pads, etc. The JBL’s perch is rather precarious. I would feel better having the JBL on the floor or a stable resting place nearby.

TT_and_Charge2

The entire rig fits into a Kaces 49-key gig bag and weighs 12 pounds. Finally, a self-powered rig that is as easy to handle and move as an acoustic guitar!

Triton Taktile: A few more thoughts

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A quick follow-up to my earlier snap review about the Korg Triton Taktile.

I’ve spent more time playing the Triton Taktile and generally remain pleased with many of the on-board preset sounds and the keyboard feel. The only major disappointment is a way to toggle the rotary speaker speed for B-3 organ sounds. Speed changes are an important part of B-3 playing style and I sorely miss this capability. I hope that Korg can find a way to add speed change in a future update. Unfortunately, the Leslie effect seems to be sampled into many of the sounds, so an update of this kind may not be possible technically.

I wanted to register my favorite patches, so I decided to download and install the Korg Kontrol Editor. The front panel procedure for registering favorites is not particularly fiddly, but the Kontrol Editor allows entry in one go and presents a WYSIWYG view on the contents of favorites Set A and Set B. I like to see how the patches are laid out across the buttons and to juggle their order. The Kontrol Editor does the business as you can see in the screen below. The Kontrol Editor leaves tool/keyboard synchronization up to you. When you have something worth writing then you click a button to transfer the edits to the keyboard. When you want to read something back from the keyboard into the editor, then click the appropriate button.

KontrolEditor

The screenshot shows my favorite sixteen patches. Set A is my “church” group consisting of voices that I am most likely to use at rehearsals with the music ministry. Set B is my “jazz/pop” group of voices that are fun for jamming with MP3 backing tracks or even PSR-S950 styles.

If you ever go to use Korg Kontrol Editor on Windows, please note that you must install the Korg USB-MIDI driver first. The install documentation has a small hiccup and doesn’t mention the need for the driver right up front. No biggee, but you will need the driver.

The Korg part of the installation is smooth. The Windows part, however, became a learning experience. A-hem. I had plugged the Triton Taktile (TT) into a USB port before installing the Korg driver. Windows installed some default driver of its own. This is not surprising. However, the Kontrol Editor did not recognize the TT after installing the Korg USB-MIDI driver. The editor has a means of manually selecting MIDI ports and the TT did not appear in the editor’s list of available (connected) ports.

Time for the usual Windows driver-Hell troubleshooting. Before doing anything else, I uninstalled the Korg driver and rebooted.

While searching the Web for a solution, I found several references to the notorious Windows XP MIDI limit. Windows installs a separate driver for not only each different MIDI device (keyboard), but each unique combination of device and physical USB port. Yep, this means that you get two instances of the same driver if you plug your TT (or whatever) into physical USB port A today and into physical USB port B tomorrow! Windows XP remembers up to ten MIDI drivers and if you tend to move your MIDI devices around USB ports, the ten slots get filled up. Then, no more.

There is some debate as to whether this limitation is present in Windows 7 or not. (I’m using Windows 7.) One solution to the problem is to manually remove registry entries for unused (inactive) MIDI devices. Tromping around inside the Windows registry, however, is not a particularly safe or fun activity.

There are two better and safer methods for removing inactive MIDI drivers:

  1. A method suggested by Craig Anderton on Harmony Central. (Search on “windows midi limit”.
  2. The Korg USB driver uninstall utility.

Craig’s method is clear, but requires a little Device Manager knowledge. Basically, you need to execute these two commands as Administrator:

    set devmgr\_show\_nonpresent\_devices=1
    start Devmgmt.msc

Windows launches the Device Manager where you can navigate to the “Sound, video and game controllers” part of the device tree. There, inactive drivers are shown with a greyed out speaker. Right click on each unwanted inactive driver and select “Uninstall” from the contextual menu. Once slots are freed up, you should be good to go.

Or, better yet, try the Korg USB driver utility. This utility program is installed along with the Korg USB driver itself. The uninstall utility displays the unconnected (inactive) MIDI devices and lets you uninstall the associated driver. I installed the Korg USB driver (leaving the TT unattached) and ran this utility on my machine. I selected and removed all of the inactive devices/drivers. Then, I plugged in the TT and voila, the KORG driver and editor recognized the Triton Taktile. All was then good with the world.

Even if you don’t own or use a Korg keyboard, I recommend this utility as a way to work around the Windows MIDI driver divot. Korg really should be commended for writing this utility and making it freely available. As to Windows, I really don’t need any more learning experiences of this type…

Another minor issue is dealing with the 3.5mm (1/8″) stereo output. This output is fine when connecting in stereo to either a 3.5mm or 1/4″ stereo phone input or connecting to two 3.5mm or 1/4″ phone mono inputs — just use the appropriate cable (i.e., TRS to TRS or an insert cable). Connecting from 3.5mm stereo to 1/4″ mono is more troublesome as the right and left channels need to mix down to mono. I received the following reply from Korg USA product support:

You should be ok to connect the Triton Taktile to a mono input by using an 1/8” stereo to a (1/4” or 1/8”) mono cable. I don’t think there are any programs that have sounds panned hard right so all the programs should sound fine.

The HOSA (Livewire) CMP-105 is such a cable. Properly, one should mix down the right and left signals, passing each side through a 1K ohm resistor into a common electrical node (the mono output). You might also want to check out the advice and circuits at Why not wye?

I’m happy to use the CMP-105 as long as there aren’t any long term reliability issues on the Triton Taktile side. The stereo to mono cable does work as suggested by Korg. I will mainly use this solution when driving a mono-only effect like a guitar pedal. Otherwise, there are usually enough available inputs to do a more proper mix down.

Finally, I was curious about the MIDI bank select and program change messages that are needed to select Triton Taktile programs. The TT follows the typical Korg convention: Bank Select MSB is 121 (decimal) for regular voices and Bank select MSB is 120 for drum kits.

The program layout is somewhat schizoid. Korg did not collect all of the drum kits at the end of program list (as Mr. Spock would expect). The drum kits are interspersed with regular voices in the final quartile. Normal voices are assigned banks and program change numbers in the expected fashion up to program number 399, which is the first drum kit. Program number 1 has bank select MSB 121, bank select LSB 0 and program change 0. The program change numbers increase to 127 when the bank select LSB increases to 1 and the program change number rolls over to 0. This continues in an orderly fashion until program number 299 and the first drum kit. After that, the assignment is difficult to enumerate. (Please see the table below.)

I determined the bank select and program change values by monitoring the TT’s MIDI OUT while changing programs through the front panel. If you want to fill out the rest of the table, grab a copy of MIDI OX and monitor the MIDI OUT. Yeah, I’m lazy. 🙂

Program# MSB LSB PC# Program name
1 121 000 000 A. Piano
… … … … …
127 121 000 126 F.Horn Ens
128 121 000 127 Flute
129 121 001 000 Sax Ens
… … … … …
255 121 001 126 Hybrid Brass
256 121 001 127 Blind Brass
257 121 002 000 Reso Brass
… … … … …
383 121 002 126 Brass/Lead
384 121 002 127 PWM Lead
385 121 003 000 Glide Lead
… … … … …
415 121 003 030 Monster
… … … … …
399 120 000 007 Std Kit 1
400 120 000 011 House Kit
401 120 000 015 Psycho Kit
402 120 000 017 Orch&Ethno
403 121 003 018 Velo Hit
404 121 003 019 Gtr Hit
… … … … …
416 120 000 120 Std Kit 2
417 120 000 010 Brush Kit
418 120 000 009 Power Kit
… … … … …

Korg Triton Taktile: Snap Review

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The Korg Triton Taktile has a double personality. On one hand, the Triton Taktile (TT) is a MIDI controller with eight knobs, eight sliders, eight buttons, sixteen pads and a set of DAW function buttons. (These are the specs for the 49-key model, the model that I’m using.) On the other hand, it is a synthesizer with the Korg Triton classic sound engine. Right now, I’m playing the TT as a synth and I will be concentrating on the synth features.

The Sound On Sound review of the Korg Taktile controller (the model without the sound engine) is very well-written and I recommend reading the SoS article for more information about the TT’s control capabilities. I will say that Korg hit my major checkmarks for a controller: a 49-key keyboard with a good action, expression pedal input, sustain pedal input, and TA-DA, a 5-pin MIDI output in addition to the USB-B connector for power and computer/tablet communications. The TT will operate on a portable, rechargeable USB power pack (minimum 5V 1A output) and that is in fact how I’m using it in the studio. The picture below shows the Triton Taktile under battery power. The TT weighs just a little bit over 8 pounds (3.8kg) and is easy on the eyes as well as the back.

TT_with_battery

The TT connects to either headphones or external amp through a 3.5mm stereo jack. All of the connections are made through a panel on the right side of the TT. The output level is sufficient for comfortable listening on Roland RH-A7 headphones, my current choice for head gear.

As you might be aware already, you don’t get a full Triton classic. The TT is not multi-timbral and it does not have combinations (“combis” or layers) and insert effects. However, you can bring up one of 512 classic programs (voices) and play your heart out! There are two system-level master effects (MFX1 and MFX2) that are appropriate for the preset voice, e.g., chorus and reverb on electric piano. The TT is strictly a preset machine as program edits cannot be stored. This hasn’t cramped my act so far, but like any of the TT’s limitations, it could be a deal-breaker. You can save your favorite preset programs into two sets of favorites (set A and set B, each set with eight slots) for quick patch selection.

Hit the dedicated SOUND button to leave controller mode and go to synth mode. The current patch number and name are shown on the nice bright OLED display. Even though the OLED display is small, it is very readable. There are three ways to select a program:

  1. Press one of the program category buttons (assignable buttons F1 to F8). The TT selects the first program in the category or the last selected program in the category. It remembers the last selected program until power-off.
  2. Use the value slider (ribbon) to scroll through the programs. Tap the “+” or “-” at either end of the slider to increment/decrement, or slide your finger along the ribbon to move quickly to a new patch.
  3. Select one of your favorite programs from either set A or set B.

It takes a little practice to get the hang of the slider. Do not take this ax to a gig and expect to select patches on the fly! I recommend setting up favorites and getting the general layout of the patches before hand. Otherwise, an embarrassing epic fail will ensue.

The keyboard feels very good for a controller in this price range. It has a little more resistance than the Yamaha MOX series, for example. I find it quite comfortable to play — it does not feel like a toy. Korg claim that it is the same action as the Krome and I have no reason to doubt them. The pitch bend and modulation wheel also have a satisfying feel. The knobs and sliders are a little bit “light” to me. I don’t have an opinion on the pads as yet.

I enjoy playing this instrument! The knobs and sliders control eight parameters: volume, cutoff, resonance, attack, delay, release, MFX1 and MFX2. Cranking the cutoff and resonance is a real visceral thrill. The two master effects, unfortunately, are very subtle and understated. The TT cries out for a multi-effects unit with distortion and other sonic manglers.

My favorite sounds are the electric pianos, drawbar organs, church organs (!), strings, and acoustic guitar. Korg strings have always had a wonderfully expressive depth and these patches do not disappoint. The electric pianos are very clean. I threw a cheap Danelectro overdrive on the output in order to realize the EP’s full funked-up potential. Oh, for a multi-effects unit, Korg!

The brass isn’t too bad, especially the horns, cornet and flugelhorn. The TT’s woodwinds are pretty naff — yuck. My musical personality is split between liturgical church music and jazz/funk/60s rock. On the church side, I’m disappointed with the oboe, clarinet and other reeds. On the pop side, I don’t often venture into synth territory. However, the HipHopLead patch is great when you feel the urge for Herbie. There are a lot of lead and pad sounds to explore and I’m sure that I’ll find a few other useful patches.

The handbook in the box is helpful, but not sufficient. Be sure to download the parameter guide and the Triton Taktile-specific MIDI implementation chart. Korg could be a little more forthcoming about the MIDI implementation considering that the Taktile series are MIDI controllers for heaven’s sake. The full list of programs is at the absolute end of the parameter guide. I always look through the list of patches for a synth/workstation when considering a purchase and this list is somewhat hidden away at the end of the parameter guide.

Bottom line, I’m happy with the Triton Taktile even when its limitations are taken into consideration. It could be the heart of a light-weight, portable, battery-powered rig and I’m exploring that potential right now.

Polyphonic Arduino synthesizer

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If you’re interested in building an Arduino-based ROM-pler, this next project is for you!

One of my long term dreams is to build a low-cost 60s-style combo organ. My latest project uses an Arduino UNO as a sample playback, sound synthesis engine. Although the waveforms are taken from the old VOX Continental and Farfisa Mini Compact organs, the design and code could easily use single cycle waveforms from a vintage synth, a string machine, your first born child, whatever! The 60s combo organ project is essentially a software ROM-pler that plays back up to five waveforms at a 22,050Hz sampling rate.

The project hardware consists of an Arduino UNO and a Narbotic Instruments MidiVOX shield. The MidiVOX shield has a Microchip Technologies MCP4921 12-bit digital to analog converter (DAC) and an opto-isolated MIDI input. Although the MidiVOX is no longer in production, it’s basic circuitry is easy to recreate; several other popular audio shields use the MCP4921.

Waveforms are stored in the Arduino’s program memory (PROGMEM), just like code. Program memory is non-volatile and the waveforms are ready to go just like a pre-loaded sketch. The combo organ sketch sets up TIMER1 to generate interrupts at a 22,050Hz sample playback rate. The interrupt handler reads the next sample for each of five virtual tone generators, sums the samples together, and writes the next aggregate sample to the DAC.

MIDI communication is performed through the standard Arduino MIDI library (version 4.2). The sketch registers two callback functions via the library: a note ON handler and a note OFF handler. The MIDI note handlers configure the five virtual tone generators. The sketch’s loop() function is trivial — it merely calls the MIDI library read() function and checks a reset button on the MidiVOX shield.

We all know that Direct Digital Synthesis (DDS) — the usual approach for sample playback — is a compute intensive technique for sound synthesis. DDS dynamically shifts the pitch of a stored waveform from its root pitch (the frequency of the sampled note) to the target pitch (the frequency of the MIDI note played by the musician). DDS performs waveform pitch-shifting through phase accumulation and interpolation. Floating point arithmetic is too slow and most DDS implementations use fixed point arithmetic. Even then, the computational load is heavy.

So, how did I achieve five note polyphony? Instead of storing a single waveform at a single root pitch, my approach stores twelve waveforms — one waveform for each basic pitch in the chromatic scale. The algorithm uses integer phase increments, thereby eliminating floating or fixed point arithmetic and interpolation entirely. The approach requires more space, but is quite fast. Each sampled instrument occupies 20% of program memory, allowing up to four different instruments before running out of PROGMEM.

Here are two quick MP3 demo files: a Farfisa-type sound and a and a VOX-type sound. I created the vibrato by routing the audio signal through an inexpensive Behringer UV300 vibrato pedal.

As usual, we always publish code. Need a cheap ROM-pler? Now you’ve got one!

Update 22 July 2016: If you’re into retro, be sure to check out the Arduino lo-fi beat box project. Filled with lo-fi TR-808 goodness!

MidiVOX: An appreciation and review

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They just don’t make ’em like they used to. In the case, of the Narbotic Instruments MidiVOX shield for Arduino, I really mean it!

The MidiVox is a bit of a blast from the past as Narbotic no longer manufacture and sell the MidiVOX shield kit. Major bummer. Luckily, I purchased one of these little gems from the MakerShed when the shields were available a few years ago. Narbotic kindly maintain the design information and code on their Web site.

To me, the MidiVox is a most logical combination of a MIDI IN port and a 12-bit digital-to-analog converter (DAC). The MIDI port incorporates a 6N138 optocoupler for electrical isolation and a 5-pin DIN connector. The port is connected through a “PGM/MIDI” switch to Arduino digital pin D0, also known as the serial receive (RX) pin. The PGM position connects the serial pin the usual way in order to download to the Arduino. The MIDI position connects the Arduino serial RX pin to the MIDI IN circuitry. The switch component is robust and is easily accessible when the MidiVOX is on top of the Arduino and/or other shields.

The 12-bit DAC is a Microchip Technology MCP4921. This DAC is used in several other audio shield designs including the Adafruit Wave Shield and the Nootropic Design Audio Hacker Kit. The MCP4921 connects to the Arduino SPI port through digital pins D13 (SCK), D11 (MOSI), and D9 (chip select/slave select). Conventional practice recommends using D10 as slave select (SS), but it isn’t a big deal to use D9 instead as this is mainly a software issue. Slave Select (called “chip select” in the MCP4921) chooses and enables communication with the slave device. This capability is essential when more than one device is connected to the same SPI interface as in the case of the Nootropic Audio Hacker shield.

Although it seems like a no-brainer to connect all SPI devices to the Arduino SPI pins, the Adafruit Wave Shield does not follow this approach. It connects the SD card interface to the SPI pins, but connects its MCP4921 to three ordinary digital pins. The Wave shield software bit-bangs the digital pins to transfer data to its DAC. I’m not a fan of this approach, preferring to use standard libraries instead of possibly buggy, poorly documented bit twiddling code.

The MidiVOX shield implements a 2-stage, passive filter following the DAC output. The MidiVOX sends a mono signal through an on-board trim pot into a 3.5mm audio output jack. Trim pots are usually rated for a relatively small number of operating cycles, so it’s best to set this level once and make volume adjusts at an external mixer, preamp, or whatever.

The MidiVOX shield provides a DATA LED controlled by digital pin D7. The shield also has a RESET button (momentary contact switch) connected to digital pin D6. This button is ACTIVE LOW, meaning that the button pulls D6 to ground when it is pressed. Therefore, the pin mode should be configured as INPUT_PULLUP such that D6 is pulled up internally when the button is not pressed (i.e., the momentary contact switch is open).

Construction was easy. The resistors have five color bands, but don’t let this throw you off. The construction directions give the correct color code and you can (and should!) always check resistor values with a meter before insertion and soldering. I replaced the basic header pins with “stackable headers” (two 8-pin and two 6-pin). Stackable headers provide a way to make easy external connections to the shield stack from a breadboard, etc.

The completed board is shown in the photo below. The MidiVOX is stacked on an Arduino UNO with the USB, audio and MIDI cables, and is ready to go.

MidiVox

I wrote a diagnostic sketch to check out the different parts of the MidiVOX. I wish manufacturers would provide check-out sketches instead of relying on somebody’s possibly flaky application sketch for smoke testing. If something is busted, it’s important to find it early through a directed test that isolates the failure. Fortunately, everything checked out OK the first time!

The MidiVOX diagnostic program is an Arduino sketch to check out parts of a Narbotic Instruments MidiVOX shield. Rename the “loop” functions and rebuild in order to test a particular section of the shield.

Since the MidiVOX is discontinued, we’re all out of luck if we want to get (another) one. However, I strongly recommend studying the MidiVOX design. When I first got started with Arduino and MIDI, I borrowed the MIDI IN circuitry and the low pass filter design. These are simple, solid circuits and are good basic building blocks for other designs and applications.

Where to next? My dream is to build a low-cost 60s combo organ with the era-appropriate look and sound. The organ would look like a Vox Continental with a Z-shaped chrome stand and bright red Tolex covering. It would sound like either a Farfisa or a Vox — nothing too nuanced with all of the drawbars or tabs turned on. I’d like to use a cheap and lightweight MIDI controller as the keyboard. The controller would drive a low-cost (Arduino-based?) sound generator. I’m hacking out a prototype using an Arduino UNO and the MidiVOX shield. More to come…

Make music with MMS on a PSR

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Yamaha Mobile Music Sequencer includes features for Motif, MOX and Tyros5, but did you know that you can create music using MMS on your PSR arranger? Yes, you can!

I’m using MMS with both the Yamaha PSR-E443 and PSR-S950 and I have written up a tutorial on making music with MMS on PSR/Tyros. This article concentrates on set-up, MIDI voice selection and MIDI file export which are aspects not covered by the MMS manual. The tutorial complements the many on-line videos that demonstrate composition and mix down. In particular, I show how to use the full 128 voice General MIDI voice set in the PSR, thereby expanding your sonic palette beyond the limited range of voices built into MMS.

Enjoy and keep on keepin’ on!

Scat voice expansion pack

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I’m pleased to release version 1 of my jazz scat voice expansion pack for Yamaha PSR-S950 and PSR-S750 arranger workstations. The expansion pack has five PSR voices which let you create “Take 6” style, a cappella arrangements and other kinds of jazz voice performances. Give the MP3 demo a try!

Four of the PSR voices are individual syllables: DOO, DOT, BOP and DOW. The DOO syllable is looped and let’s you create sustained chords for backing. The DOT, BOP and DOW syllables are short and provide scat-like expression. All four syllables are combined into a velocity-switched voice where you select and play one of the syllables based on how hard you strike the keys (i.e., MIDI note velocity). You will need to adjust touch response (and practice!) to get the most playable and musical result.

Here is a link to the expansion pack file. You need to download and UNZIP this file, then install the YEP file by following the directions in the Yamaha PSR-S950/PSR-S750 Owner’s Manual. See the section titled “Expanding Voices”.

I am also releasing the multi-samples that I used to create the expansion pack in case you would like to create a scat voice for your own synthesizer or software instrument. If you are curious about how I created the expansion pack voices and the samples, please see this blog post.

Both the scat voice expansion pack and the scat voice samples are released under a Creative Commons Attribution 4.0 International License.

Creative Commons License
ScatVoices and ScatVoice samples by Paul J. Drongowski are licensed under a Creative Commons Attribution 4.0 International License.

You are free to use the expansion pack voice or samples (even for commercial purposes) as long as you provide a link to http://sandsoftwaresound.net from your own web site AND/OR explicitly credit me in your creative work, e.g., “Scat samples/voice by Paul J. Drongowski”.