Modifying the Roland A-80 to make aftertouch more responsive

The Roland A-80 keyboard controller is one of the few keyboards that supports polyphonic aftertouch. This makes it quite desirable for those who care about such things, and indeed, is one of the reasons I tracked down a unit on ebay.

Out of the box it is a fine 88-key 'board with a respected weighted action (it's not "hammer action" but it has a very nice response all the same), with sophisticated zone and tweakable response curves for things like velocity and the afore-mentioned key pressure.

On the down-side, it weighs a ton, and the aftertouch requires the keyboard technique of the Incredible Hulk. Seriously. In order to register any aftertouch messages emitting from the MIDI out socket, I needed to use force unattainable from mere human fingers.

What Good Luck: Fortunately, this is a known problem. See... there's this resistor on one of the circuit boards called "R43". Originally, it came from the factory with a value of 5.6k ohms, but when customers started complaining to Roland, the tech folks recommended changing it to 10k ohms. Later releases of the A-80 came from the factory with a 10k ohm resistor installed.

What Bad Luck: It seems that 10k is not enough. Other enterprising keyboard techs have Done The Research and found that higher-values give better results. Like, say, 51k ohms.

I knew about this issue when I sought for and purchased the A-80, fully intending to apply some DIY-love to the unit and make the mod. Two years later, I finally got around to it.

The first issue is figuring out how to open it up. I knew from some pictures on the web that the sides and panel opened up on a hinge (I could see the two hinges just by looking at the back panel of the keyboard) but knowing which screws to take out is a challenge. Future generations can save time by knowing that the screws you need to remove are all on the bottom of the keyboard. From the A-80 service notes:

The screw locations (I) are shown above high-lighted in yellow. Once you've removed those 15 screws (5 short, 10 long), the top panel will be loose, so carefully re-position the unit and lift the panel. It will hinge up on the back edge:

On my unit, there was a ground wire preventing the case from opening completely, but be warned! There are other connections to the circuit boards that may take up the tension if you unscrew the ground wire and haven't braced the top panel to prevent it from swinging open. (This is unlikely to happen because on a flat surface, the back panel rests on the table top.)

I had the unit mounted on supports that meant that the table top was actually lower than the underside of the unit - so the panel could free-swing further back from the unit. You're actually going to need to do something similar in order to get enough room to work on the unit.

There's a wide copper sheet linking the circuit board to the main chassis that will take up tension as the panel opens. The way I handled this was to unscrew the three screws attaching it to the chassis, then folding it back over the top panel and taping it down out of the way.

We can now see the circuit board that interests us:

Our resistor, R43, is on the left side. I've highlighted it with a red ellipse. 

There's really no escaping it: in order to replace the resistor, we need to detach this circuit board from the chassis. There are three connections you'll need to remove:

1. The ribbon cable on the top left (see the grey and black connector). This requires some care. It is basically just a slot that clamps down on the end of the ribbon cable. I actually detached it by accident and had a moment's panic when i thought I'd made a mistake. The picture above shows the cable already disconnected (sorry) but it is a simple operation to "open" the clamp by pulling the grey part of the connector away from the black part. MAKE SURE YOU NOTE WHICH WAY THE RIBBON CABLE IS ORIENTED. Then the ribbon cable just falls out. (It's trickier to reconnect it but if you're careful, there isn't much risk of getting it wrong. Just make sure the cable is fully into the slot on both sides before re-clamping.)

2. The other two connectors are highlighted by another red ellipse in the picture above. Much safer to remove but require more force than the ribbon cable. The plugs are grooved in a way that makes it impossible to reconnect them wrong.

There are six screws around the perimeter of the board that attach it to the chassis via separator posts. Two of the screws are holding cable retainers - make sure you remember where they are located before removing them.

Now the board folds back easily, allowing us access to the components from the reverse side:

There's a red arrow in the picture above (somewhat hard to see) that points out the location of R43. Make sure you know which it is! It is not labeled on the back side.

I don't have pictures of the solder removal process or the replacement resistor. If you don't know how to handle that part of the process comfortably, you should not be doing this operation yourself. I'm not going to write a tutorial on circuit repair techniques here.

The actually resistor replacement operation took about 15 minutes, after which I re-assembled the unit and screwed the panel back in place.

Bottom line: The mod works. Replacing R43 with a 51k resistor makes the aftertouch feature work as expected. Mission accomplished!

Special thanks to Plink Floyd (http://computermusicguide.com/forum/viewtopic.php?f=11&t=340) for the excellent pics and entertaining rant. 

February 9, 2014 13:46 by colin


The album gets a web site all of its own

"Fruit of the Steel Tree" now has its own web site, complete with track listing, mp3s, lyrics, production notes, photos, and demos.

See:

   www.prodigalsounds.com/steeltree

This is actually the same place you'll get to if you click on the SONGS link in the menu above.

December 8, 2013 22:15 by colin


It's here

November 14, 2013 15:07 by colin


Telling V-Vocal what default parameter values to use

V-Vocal is a monophonic audio editing plugin developed using Roland technology, integrated into the SONAR product. It was packaged with Cakewalk SONAR from about version 5 or 6. The last version that included it was SONAR X2.

V-Vocal has been compared unfavorably to other "vocal editor" software such as the better known Melodyne or Antares Autotune, but it is actually a very capable tool when used judiciously.

V-Vocal still works in SONAR X3, although due to a change in company ownership, it is no longer part of the SONAR installation. However, if you have previous versions of SONAR installed, V-Vocal will be available. In fact, in my opinion, ironically V-Vocal works better in X3 than in any previous version of SONAR.

However, some quirks remain, and one of them is the default values used for several of the editing parameters. I'm always having to remember to adjust the FORMANT parameter in particular, every time the V-Vocal window is launched.

These default values can be changed, though, through some careful editing of an arcane .INI file. All credit for this hack goes to Tom Parker for this post on the SONAR user forum in December 2006.

I'm going to copy the instructions here for quick access, and in case the post is removed from the forum or lost in the cloud:

1. First, make a backup copy of the file C:\Program Files\Cakewalk\Shared Dxi\Vvocal\Skin\VVocal.INI

2. Then edit the original VVocal.INI file

3. Starting at line 130 you'll see a section "Display 8 ( Formant Control )".
   There are 3 values (on 2 lines) that need to be changed.
   Recommended: Change them all from 100 to 0:

   a) Ctrl181 3rd value (Value if you double click in the "PITCH FOLLOW" graphic dial center)
   b) Ctrl181 17th value (Initial value for the graphic dial)
   c) Ctrl183 17th value (The critical Initial value; this will be displayed in the box below the dial)

4. Save the changes, and re-start SONAR.

November 13, 2013 07:46 by colin


October Rumblings

October's To-Do List:

  • [X] Finish Album #1
  • [X] Refresh blog theme
  • [X] Establish facebook and youtube presence
  • [  ] Send CD master to manufacturing
  • [  ] Prepare album-specific web site pages

...the month is only half over. There's still time.

October 20, 2013 11:39 by colin


Something's Coming

October 11, 2013 10:55 by colin


August Blues

Mastering on all tracks finished so far is going well. I've identified a few problems with the mixes - not many - and addressed them, so that's good.

Slaying the Dragon is almost completed, instrumentally, but the lyrics are giving me pause. So I'm currently playing a kaoroke mix in my car and singing along and it's taking me somewhere slightly different than from where I started. So, there's some on-going work to do here.

I've completed the album cover artwork. It's getting really close!

August 31, 2013 12:22 by colin


July Update

I've finished the instrument tracking for Slaying the Dragon, including figuring out the solo section. Downside: I currently hate this tune, I'm hearing it in my sleep for crying out loud. I need an earworm pill.

I've decided to re-do the vocals, the guide vox just ain't good enough, and I have some ideas for tweaking the lyrics.

This means that the August deadline probably isn't going to be achieved. Oh well. It won't be the first time I've blown a deadline.

July 14, 2013 18:44 by colin


June Tunes

Work continues on Slaying The Dragon. In the last month I've:

  • re-recorded all of the acoustic guitar, and added some strummed chords in selected sections;
  • re-recorded the Chapman Stick bass line
  • re-recorded the drums
  • laid down a new E-Piano track

Still to do:

  • I have to decide whether the "guide" vocals are O.K. as they stand, or whether I should re-record. I'm leaning towards re-doing them.
  • Re-record parts of the Hammond organ track (some parts of the guide track are perfect as-is).
  • Figure out what the solo/bridge is doing

Over the last week I've mostly been tweaking the Chapman Stick track, and reworking some of the drum fills to get a nice, tight rhythm section.

Not perfect yet

As a break, I went back to Future Imperfect and decided that most of the L6-S lead guitar needs to be benched in favor of the BlueShifter, so that basically all of the guitar is performed on the same instrument. I've retained the L6-S on the outro, which is fine because it seques into the Finale which is all L6-S anyway.

I know: No-one but me cares about these things. It's all just guitar, right? Wrong. These different instruments have character - even if it is only in my own head - which instruct the performances that end up in the track. 

It is easy for me to be infatuated with the sound of the L6-S, but on reflection I could tell that there were two "characters" of guitar in the song when really there should only have been one.

And since the BlueShifter only shows up on one track on this album, it should have that track mostly to itself, I think.

June 23, 2013 12:50 by colin


May 2013

Since finishing up "Future Imperfect" in February, I've been going back over the other components in the "Strange But True Steel Tree" suite and tidying up a few loose ends in the Prologue, Interludes, and Finale sections.

The song "Strange but True" became a problem, because I want to re-write the lyrics and re-title it "The Steel Tree". In the process of doing that, I decided I needed to re-record the drums, guitar, and bass. Now it's just waiting for me to finish up the lyrics and get the vocal re-recorded.

I also decided "Head in the Game" needed a third go-over, with some tweaks to the drums and a more aggressive bass. Then I went crazy and re-recorded all the guitars, using the Ibanez 540s instead of the telecaster. It's sounding better, I think.

Now it's time to return to the last remaining song on the album: Slaying The Dragon. I'm currently in the middle of re-recording the Chapman Stick and acoustic guitar.

I really think I have a shot at finishing this project up this year. (I mean the album, not the song, cheeky!)

May 5, 2013 12:22 by colin


The Prodigal Sounds: Fruit of the Steel Tree

About

Our debut collection of songs is now available on CD Baby!

Melodic progressive rock songs and instrumental interludes, a touch of 70's influence but a product of the dystopian Now.

 

"Very smooth, hi-tech sounding delivery..."
- Chris Jemmett, alt.music.yes

"This guy is awesome."
- Dazed, on the Carvin Forum.

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