chadblinman

I've been developing a wired desktop remote for the excellent Sound Skulptor MC624 (original thread about that here https://groupdiy.com/index.php?topic=56723.0).  Seen here is my version 3 prototype––in cardboard, but fully functional and already in use.  :D

This runs on an Arduino Mega with the Arduinix shield to drive Nixie IN-2 tubes.  Commands are transmitted to the MC624 over RS485 serial (via the Link connection).

This is a one-off for myself (not a product) but I'm freely sharing my Arduino code and other design details on Github:  https://github.com/chadblinman/MC624_remote


ruairioflaherty

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #1 on: June 18, 2017, 08:16:59 PM »
hey Chad,

We have a mutual friend in John Whynot and he was telling me all about your remote, it looks awesome, well done!  I've recommended that unit to a lot of people, John included.  It really is very well thought out and sounds fantastic, in my case I sold my Cranesong Avocet when I built mine, the MC624 sounds significantly better.

Mine is with a friend now as I use a different solution in the studio I work in, otherwise I'd be building your remote.

ruairioflaherty

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #2 on: June 18, 2017, 09:47:43 PM »
Me again,

I've had a quick look at your Github, thanks for the effort in documenting what you'e done. 

Can I ask why you've gone with a linear pot with endstops rather than the endless rotary encoder used on the original design?  I'm guessing feeding a varying voltage to the A/D on the Arduino was easier to implement?

 

chadblinman

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #3 on: June 19, 2017, 04:03:42 PM »
Can I ask why you've gone with a linear pot with endstops rather than the endless rotary encoder used on the original design?  I'm guessing feeding a varying voltage to the A/D on the Arduino was easier to implement?

That's a very good question.  (And thanks for your kind words!) 

I initially thought to use a standard rotary encoder, but I wanted some (admittedly frivolous) things that it wouldn't do.  I wanted a smooth-turning control with a luxurious high-torque feel, and I wanted to use a knob with a pointer, for the additional visual indication (and because I like the look).  For a while I investigated using an absolute rotary encoder, which is feasible.   But I was concerned about the feel and reliability––encoders, especially cheaper ones, tend to be a bit flimsy and flaky.  Finally it seemed simpler (and less expensive) to read a normal pot on one of the Arduino's analog input pins.

The Bourns pot I'm using has a great feel and is inexpensive.  The only problem was eliminating noise and jitter.  I can't have the remote flickering on its own between two adjacent volume values...click-click, click-click.  I tried filter caps and a couple of different smoothing methods in the code, but the thing that really did the trick is Damien Clarke's ResponsiveAnalogRead library.   There's a great post about it here, if you're interested in the problems and how he solved them:  http://damienclarke.me/code/posts/writing-a-better-noise-reducing-analogread  It's perfect!

Brizco

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #4 on: June 22, 2017, 09:40:29 AM »
WOW! And thanks very much for sharing!

I'm coming from the analog side of electronics, still have some experience in C++ and Java... but absolutely no experience with all this arduino stuff :(

I'm very interested in building a remote for my MC624... do you have some more Information on how wiring is done and code for other Display modules other than nixies?

Now i have to read more about arduino...

thank you
regards
Martin

chadblinman

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #5 on: June 22, 2017, 10:00:11 AM »
I'm coming from the analog side of electronics, still have some experience in C++ and Java... but absolutely no experience with all this arduino stuff :(

I'm very interested in building a remote for my MC624... do you have some more Information on how wiring is done and code for other Display modules other than nixies?

Thanks!

I'm no expert––this is my first project building anything like this, and my first foray into Arduino programming.  I had to learn a lot of things.  But I was able to find everything I needed in the existing work of others and the whole experience has been deeply rewarding.  I highly recommend it.

Using a modern display instead of Nixies would actually be much simpler!  There are off-the-shelf displays, interfaces and code that can be put together easily and cheaply.  Look here and let your imagination wander:  https://www.adafruit.com/category/63

Rochey

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #6 on: June 22, 2017, 10:17:37 AM »
Bravo. Excellent Work!
Expat Audio Home: http://www.expataudio.com

ruairioflaherty

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #7 on: June 23, 2017, 12:37:27 AM »
Chad,

Another question if I may.  How do you deal with things like setting input or output offsets if the volume knobs is in a low position? 

chadblinman

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #8 on: June 23, 2017, 04:09:39 PM »
Another question if I may.  How do you deal with things like setting input or output offsets if the volume knobs is in a low position?

I'm not sure what you mean.  Can you clarify?

ruairioflaherty

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #9 on: June 24, 2017, 10:51:59 PM »
Sure.  When I set an offset on an input or output I turn the rotary encoder to select anywhere from -10 to +10dB of offset (to balance speaker levels for example).  If I was using your controller and the volume knob was at say 8 o clock, when I go to set my offset I'll hit the endstop of the pot before I get to the setting I want.

I guess the easy solution is to turn up the volume before going into the offset menu?

Cheers,
Ruairi


chadblinman

Re: Desktop remote for Sound Skulptor MC624 monitor controller
« Reply #10 on: June 25, 2017, 01:25:47 PM »
Sure.  When I set an offset on an input or output I turn the rotary encoder to select anywhere from -10 to +10dB of offset (to balance speaker levels for example).  If I was using your controller and the volume knob was at say 8 o clock, when I go to set my offset I'll hit the endstop of the pot before I get to the setting I want.

I guess the easy solution is to turn up the volume before going into the offset menu?

Ah, I see what you mean.  Well, the remote is not set up to access or adjust any of the system setup functions.  I simply use the main unit's front panel controls for all of that.  (Even in slave mode, all front panel control works normally.)

I'm not even sure what would happen if the remote's volume control were adjusted while the main unit was in setup mode.  If anything, I think it would only continue to adjust master volume (not adjusting the offset value or whatever is happening in setup).

It's an interesting thing to consider making the remote useful for system setup.  But I think it's a non-starter.  Although it is feasible to program the remote code to respond to button combinations and long-presses, as far as I know there are no serial commands to enter setup modes.  Jean-Pierre would need to write them into the main unit's programming.  But then there are immediately other problems, not least that the remote's Nixie display can't indicate everything that the main unit's display can.   And since the serial connection is one-way only, the remote can't "know" what's going on in the main unit––it cannot access stored settings to display them (unless the remote "remembers" the settings from previous sessions by writing them to EEPROM...but those would not be in parity if anything were changed at the main unit).  Finally, as you've pointed out, there are setup adjustments that by their nature require the function of an incremental encoder, while the volume control on my remote can only transmit absolute values.  I can think of work-arounds for a couple of these problems, but they'd be wonky...

My intention has always been to leave system setup control at the main unit, and use the remote for the everyday stuff.  But you've got me thinking:  Are there offsets or other setup functions that you change often enough that you'd want to control them with the remote?