Synchronizing it altogether

[multi_s]

the arduino midi stuff is pretty good but if you ever want to go further another suggestion for developing midi devices is the MIOS stuff from here:

http://www.ucapps.de/

not to knock anything MV makes but this allows you to go where they have not (yet).

another interesting device is the psoc hardware from cypress. i just started looking at it the other week and it is really easy to use. has built in dacs that can be setup graphically to read from wave tables (even ones you draw manually). there is a cheap dev board for psoc 4 that has sample midi projects so maybe that could be a good starting point.

[Glenouille]

Cool Scott, I did not know about the Cypress stuff. I have just ordered a PSoC 4 Pioneer kit to take a look at it.

[goroth]

I've said it before and I'll say it again - I'm such a Luddite when it comes to the guitar. This whole thread blows me away.

[PetZounds]

I've said it before and I'll say it again - I'm such a Luddite when it comes to the guitar. This whole thread blows me away.

I agree wholeheartedly.
It's pure insanity and awesomeness.
Very sick stuff going on in here.

[univalve]

Another great midi Tool:

[multi_s]

actually midi sounds way better if you buffer it with an NOS pentode tube pre.

just my 2 cents.

nice april fools joke i hope.

[Tristan]

Nevermind the 8Step, in the set up pictured the 8Step is only used to sequence the volume and rate of the second Warped Vinyl.

The DB-90 looks a piece of kit form the 80es but it does some pretty unique things. It can sync to a MIDI clock via MIDI and outputs an audio signal. The Goatkeeper can only sync to an Audio signal, it cannot sync to a tap tempo signal like the CTL-Sync can output, that’s why I need it on top of the rest.

Last I spoke to Molten Voltage they said building a box that could do MIDI>audio was on their to-do-list but since then I started thinking/working on something too.
Nothing as advanced as what they can do, but using Arduino you can take a MIDI Clock and output pretty much whatever you want. The Arduino can even output a simple square wave as an audio signal. I’m trying to get this to work as with an Arduino Nano, an optocoupler a 5pin din, a jack output and the right code, I could fit all this in a small enclosure like a 1590A and replace the DB-90 in my set up. I have it working but I want to add a pot with subdivisions first. (why do simple when you can do overcomplicated?! )

Hey man, I just heard that according to Austin a square wave won't work to sync the Goatkeeper, Molten Voltage will be releasing a unit that sends a 5 volt square pulse soon so William asked Austin about that before.

[Glenouille]

I did not want to get too much into details but maybe it was a bad idea! What I use here with the Arduino is called Pulse Width Modulation, or PWM, it is a technique for getting analog results with digital means. Digital control is used to create a square wave, a signal switched between on and off.
This on-off pattern can simulate voltages in between full on (5 Volts) and off (0 Volts) by changing the portion of the time the signal spends on versus the time that the signal spends off. The duration of "on time" is called the pulse width. To get varying analog values, you change, or modulate, that pulse width.

With the Tone() function you can generates a square wave of the specified frequency (and 50% duty cycle) on a pin. It goes simply like so Tone(pin, frequency, duration). In other words, the Arduino can be used as a very basic VCO.

So to verify the idea (and because after reading your post I wanted to verify the concept ), I used a tap tempo circuit I created last WE.

The circuit is just a pushbutton with a LED and the necessary resistors hooked up to an Arduino Uno.

The code detects if the button has been pressed 3 times and will always average the last 3 taps and the LED will blink in accordance. (It can also display the tempo in BPM on a LCD screen but we don’t care about that right now)

Now I just modified the circuit to add a jack output and plugged a cable from there to the Sync input of the Goatkeeper . (I even added a little pot to fine tune the volume if need be) I also modified the code so that it generates a square wave at 440Hz when the LED is on.

It works OK. There are other problems to address (Arduino does not really seem ideal for doing 2 things simultaneously like keeping on playing the master tempo while detecting if things are being pressed, but it could be my patchy knowledge of the thing, I'm still in discovery mode. Anyway I need to tackle this), but from a sync quality perspective the Goatkeeper seems to “read” the signal neatly.

I need a few extra components (that should arrive before the WE) and I should be able to get the MIDI aspect of it sorted. Well hopefully...

[Tristan]

Okay, that sounds promising, please keep us informed!
I'm probably going to pull the trigger on the Molten Voltage package (Master Control + MIDI Splitty + CTL-Sync).
By the way, there's also a unit that is developed for the Whammy which seems to be able to do tap tempo and send or receive MIDI Clock,
it's called the Whammy D2: http://smirnovelectronics.com/en/whammyd2/

[nevada]

Slight hijack: Does a tap tempo input = compatible with Volca sync output? I am in awe of the idea...

[Glenouille]

No highjack - this is the purpose of this thread!
Now I did not try it when I had the Volca Beats... Sloppy testing process!
On the Beats, The SYNC OUT jack sends a 5V pulse of 15ms at the beginning of each step. A pedal like the Boss DD5 can handle that from its TEMPO input (it should also work with the DD-7, PH-3 and others with the same Tempo input).
If it does not work straight away there are a few things that can be done to make it work. But someone should defo try this and report findings. I do not have the Volca Beats anymore so cannot try myself!

[nevada]

I might try this soon and report back. I think I need to buy the right cable.

FWIW, I'll be testing a Volca Keys into a Strymon Flint tap tempo. I think it's a different kind of input than the Boss pedals, but we shall see.

[nevada]

I gave this a shot. No luck so far, but I might have the wrong cable. I'm using the Volca sync cable with a 1/4" adapter.

[Glenouille]

Damn, not so simple then... Did you use a TRS adapter?

You are right about the Strymon Tap tempo circuit, it is different from the Boss one.

The Boss tap tempo is a single pole single throw switch. It is normally closed (NC) meaning the switch is “on” by default, it breaks contact when the button is pressed (0V) and makes contact when it is released (5V).
The Strymon tap tempo is a single pole double throw switch. By default a connection to ground (0V) is established, when you press the switch it makes a connection to the 5V source.
To trigger it remotely you need to use a TRS cable going from the remote tap tempo pedal to the main pedal (Flint, Mobius, Timeline). The main pedal expects 0V on the sleeve and 5V on the Ring.

The cable that ships with the Volca is a 3.5 TRS cable and apparently Volcas end up jittering or skipping steps if you use TS cables (It must ground something somewhere I guess).
Now I do not know if the way the connection is set up on the Volca side will match what the Flint is expecting. If the pulse is transmitted from the Volca on the tip, I would maybe use a floating ring cable; basically a TRS cable with tip on both sides connected to each other, sleeves on both sides connected to each other but the ring section is not connected to anything (left floating). This would prevent any grounding issues.

I wish I could test it on my end, I do not have any Strymon gear though. When I had the Volca Beats I was using the RH-301 as my main clock going into a Kenton thru-5, then going from one output to the Volca using MIDI and going from another output to the Molten Voltage CTL-Sync (MIDI>tap tempo converter), but that's a lot of gear compared to maybe finding the right cable...

[nevada]

I did use a TRS adapter. Actually here's the exact cable:

photo.JPG (218.04 KiB) Viewed 2369 times

I'm going to give it another shot. Your info is extremely helpful, and it makes a lot of sense to me. I think this should work... I read in the Volca manual that there' some sort of sync peak switch in the global parameters. Maybe that's equivalent to the normally closed/normally open thing?

I'm going to test this again tonight and report back. If this works... oh man.