Highly Liquid Forum facebook twitter google plus rss feed

Go Back   Highly Liquid Forum > Discontinued Products > MD24

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-14-2011, 03:21 PM
John's Avatar
John John is offline
Moderator
 
Join Date: Jan 2009
Posts: 3,007
Default Ace Tone Rhythm Ace Drum Machine MIDI Retrofit

R. writes:

Quote:
I noticed on your site you link to a Video of Kerry Bradley and his midi-fied Rhythm Ace. I also notice you mention that "the new MD24 is a better choice for this type of project". I was about to embark on this mod myself and wondered what the difference or advantage would be to choosing the MD24 over the previous 2600 controller?
Here's a direct link to the Youtube video of the Rhythm Ace retrofit:

http://www.youtube.com/watch?v=ZxMTwfx1sjo

The MIDI2600 is a device made to work specifically with the Atari 2600. For the purposes of retrofitting the drum machine, the MD24 will do the exact same thing, and in a less-confusing, more flexible way. (I think Kerry used the MIDI2600 only because he happened to have one on hand.)

The way the retrofit works is that the trigger input circuits are "grounded" in order to trigger drum sounds. This will be easier to set up with the MD24 than with any other device.

Hope this helps--please let me know if I can provide more information.

Last edited by John; 05-20-2013 at 01:19 PM.
Reply With Quote
  #2  
Old 06-16-2011, 01:16 PM
captofchaos captofchaos is offline
Junior Member
 
Join Date: Nov 2009
Posts: 27
Default

John,
How do you set up the MD-24 for the negative note trigger?? I went through a lot of trouble reversing the polarity on my relay output cards, to use the 5V positive trigger.
DANA
Reply With Quote
  #3  
Old 06-20-2011, 08:59 PM
John's Avatar
John John is offline
Moderator
 
Join Date: Jan 2009
Posts: 3,007
Default

Hi Dana,

If you take a look at the MD24 1.x firmware user manual, you'll find an output mode called "Note Trigger" and another called "Inverted Note Trigger". The inverted mode has identical functionality, except that the 0V and 5V states are reversed.

Let me know if this helps.
Reply With Quote
  #4  
Old 04-21-2013, 06:33 AM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Question Rhythm Ace Fr-8L TR77 MIDI sync

Hi Guys
My first time here I wanted some help with Midi-fing my Rythm Ace analog drum machine. I need help with two parts the 1st is a basic midi triggering (there is a
lot of blogs with info on this areound the web i will post a list of link i found specific to the BRA Fr8L or ROLAND TR77 (essentially the same box rebadged with minor diffrences in rythm patterns.

Three cool things about this machine 1; the anolouge voice circuits which are very simular to most retro ROLAND drum machine sequencers.

2.) the fact that it was Rolands 1st product.
3.) and the rather arcane circuitry which created a subtle timing variation of the 1/4 note over two bars resulting in an almost imperceivable slight swing in the "groove " mimicking a natural player giving the timing clock a natural feel which is lacking in modern digital sequencers that sound rigidly mechanical.
I read that the timing of the patterns is genated via a circuit board and that the swing variation was programmed (permanantly) via a discreet anolog circuit.


Ok so i ordered a MD24 planing on following basically this http://www.makerspace.org.nz/content...-midi-retrofit

http://www.burnkit2600.com/tr-77/ This is another project tr77 midi mod . This page has scematices of the circuitry that we will be triggering.

Here is link to The TR77 SERVICE MANUAL http://manuals.fdiskc.com/flat/Rolan...e%20Manual.pdf

http://www.circuitbenders.co.uk/newsarchive/BRA.html

From "circuit benders page on TR77 mod ; ( they had used a diffrenet MIDI Box)
The next step is to convert the +5v triggers from the midi interface into something usable by the BRA. In order to do this we've built a circuit for every sound that uses a transistor inverter switch to amplify and invert the +5v input trigger so that its output swings from +12v to 0v when an input pulse is received. We then fed this into an exact copy of the edge detector circuit that can be found in the BRA to turn this into the required -12v spike. Remember, on the internal setup the edge detector triggers on the downward slope of its input trigger, so feeding a negative going pulse into the edge detector will give a tighter result than using a positive pulse. If you used a positive going pulse the actual sound would be triggered on its downward slope, which would be the width of the trigger pulse after when you actually pressed the midi note. In this case about 10ms

On the link http://www.circuitbenders.co.uk/newsarchive/BRA.html
You will see a scematic of a circuit they designed for this task will that same circuit suit this BRA MB24 mod project?
Basically the Ryhthm ace require -12v trigger inputs and as far as i can tell the MD24 will produce a negative trigger at -5v. How can i resolve this problem?
Reply With Quote
  #5  
Old 04-21-2013, 06:41 AM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

You will have to excuse me; for those who dont know; Fromhttp://www.forgottenkeys.co.uk/5_tr77.php The TR-77 drum machine was the first product launched under the Roland brand name in 1972. It is essentially an updated Ace Tone FR7L. The wooden case and music rest are tell-tale signs that this was primarily designed to sit on top of a home organ. Being top-of-the-range, it has a few bells and whistles like the sliders that allow you to control the volume of some of the instruments, namely: Bass, Snare, Guiro and (combined into one slider): Maracas, Cymbal and High-Hat. There’s a fade-out control with variable fade time and a Metronome. An unusual feature is Up-Tempo which literally doubles the tempo!

The rhythms are divided into four groups: Latin, what’s described in the manual as Jazz, 2-Beat and 4-Beat. As is often the case with these old machines, rhythms can be combined.

and i wish to add a midi sync to the triggers to create a sequencable via MIDI drum voice unit.

More ambitiously i would like to discuss the "pattern Matrix Circuits" and the possibilty for analog shuffle .. somehow if you will .

Thanks
Reply With Quote
  #6  
Old 04-21-2013, 06:49 AM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

FROM http://www.burnkit2600.com/tr-77/ Photos on Link. ??? is DIN sync diffrent to MIDI???
External Clock Sync

This is a mod i haven’t tried yet. From page 20:

D. Checking the wave form of collector of Master oscillator- Seeing the wave form on the collectors of Q1 and Q2, and check the wave forms whether they are as Fig.B undesirable wave form including unsaturated territory. …… This circuit constant is set as following mention, and adjust it by changing the capacitor C1 or C2.

I’m not sure i understood all that, but it seems that the master clock is made up of transistors Q1 and Q2, and possibly capacitors C1 and C2, also. You should be able to probe this area with a scope, and figure out what kind of clock pulses are going thru. Then it’s most likely a matter of building some kind of circuit that will convert DIN sync pulses or MIDI clock pulses to whatever this machine wants.

UPDATE: December 2008
Trouby writes in with an astonishingly simple Din-sync mod!
“Connect din-sync to R4: 5V, 4 or 8 ppq”

Simply connect the din sync line to the TR-77 resistor R4. You may want to de-solder R4 and connect it to a switch so you can switch between internal/external clock. It should sync best at 4 or 8 ppqn. Most devices that output DIN-sync use 24ppqn. So a divider circuit might help bring this down to a usable rate (see comments below). For start/stop, you can use the connections going to the TR-77′s start/stop jack, but put a transistor between the DIN cable and the 1/4″ jack:

TR-77 R4 -> DIN CLOCK pin
Transistor Emitter -> GROUND
Transistor Collector -> TR-77 start/stop jack TIP
Transistor Base- > 200 ohm resistor -> DIN start/stop pin
Reply With Quote
  #7  
Old 04-21-2013, 11:28 AM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

" From The lively discussion of this Mod at
http://www.burnkit2600.com/tr-77/

"The MD24 may be able to do negative going triggers, but as far as i know it can’t do 12v negative going triggers. Nothing that currently available can, so you are going to need extra circuitry. You may as well use +5v triggers and use transistor inverters to invert them and boost them to a 12v swing at the same time.
You don’t need a negative power supply. A negative going trigger just switches from a steady positive level to 0v, as opposed to a positive going trigger which sits on 0v and gives you a positive pulse. The edge detector circuit takes care of producing the negative spike pulse that triggers the sound.
You are going to have to build another power supply circuit to power the MD24 from the 24v rail if you want to mount it internally, but i’d probably mount it in an external box if you wanted to drive both machines using one interface."
Reply With Quote
  #8  
Old 04-23-2013, 04:58 PM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

Hi, i started another thread on this topic, i apologize if that is inappropriate. I believe the Tr77/ Rhythm Ace require a -12v trigger, how can the MD24 be modified to achieve the negative 12 volts?

Thanks
Reply With Quote
  #9  
Old 04-30-2013, 04:51 PM
John's Avatar
John John is offline
Moderator
 
Join Date: Jan 2009
Posts: 3,007
Default

Quote:
Originally Posted by Blaize View Post
Hi, i started another thread on this topic, i apologize if that is inappropriate. I believe the Tr77/ Rhythm Ace require a -12v trigger, how can the MD24 be modified to achieve the negative 12 volts?

Thanks
Hi Blaize,

Your thread has been merged into this one.

This is one approach that can be used to get a -12V pulse from the MD24 using an NPN transistor:


Last edited by John; 04-30-2013 at 04:53 PM.
Reply With Quote
  #10  
Old 04-30-2013, 05:03 PM
John's Avatar
John John is offline
Moderator
 
Join Date: Jan 2009
Posts: 3,007
Default

Blaize also wrote:

Quote:
But I really need assistance with the FIRMWARE??. Where is it? how do i use it? i have read the firmware user pdf and the hardware one. and i am very confused. i Understand that it is essentially a operating system.? right?' but how do i interface with it?
Firmware is already loaded onto your MD24. The MD24 you have is loaded with version 1.3. If you want to have the fixed-length output pulse functionality, you can upgrade to version 1.4. Instructions for that are here.

Quote:
Q) Will i need to program the device- or will it "learm" once wired correctly ? ?

if i need to program it. -How does this work??
The MD24 has a "factory default" configuration that is described in the firmware manual. It responds to MIDI notes 60-83 and generates corresponding pulses on output terminals 0-23.

If you want to change this, you must send it a configuration sysex message as defined in the firmware user manual. If you'd like help formulating your sysex message, let me know. Instructions for sending a sysex message from your computer can be found here. (the thread is written for the MIDI CPU but also applies to the MD24.)

Quote:
Q) What other parts (aside from wires) am I likely to need to connect to the MD24 for this project?
I haven't personally performed the Ace Tone retrofit, so I can't provide a parts list. However, I recommend doing some basic MIDI i/o with the MD24 to get started. Can you trigger MD24 output #0 using MIDI note #60?

Once we confirm that you've got the basics working, I can try to help out with the finer points of the retrofit project.
Reply With Quote
  #11  
Old 05-01-2013, 11:41 AM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

Thanks John. Ok I am going to lay out my planned project and ask that you can let me know of any faults or anything I'm missing for this;

I will build a series of this trigger circuit from http://www.circuitbenders.co.uk/newsarchive/BRA.html



"I will build a circuit for every sound that uses a transistor inverter switch to amplify and invert the +5v input trigger so that its output swings from +12v to 0v when an input pulse is received. then feed this into an exact copy of the edge detector circuit to get the -12v spike"
This is essentially a copy of the Rythhm Ace trigger circuit (same cap; resistor. ect)
There are total of 12 drum voices. 11 will use this trigger circuit. The 1 Guiro will use this circuit for the guiro. Ther is an un-used trigger input on the BRA i would like to wire this up as well with the -12v trigger. Total of 13 triggers.

Guiro Trigger circuit


the BRA doesnt have a 12v rail so i will add a 12v voltage regulator to the 24v rail in the BRA .

I will wire the circuit triggers to the midi trigger outs on the MD24 assigning each voice a number from 1-13 0r 60-73 ??"

Ok . so far so good i hope.

I plan on mounting the md24 internally in the BRA. and utilise the MIDI THRU and MIDI out connections. will this require any other consideration..?

I presume that the MD24 is pre proggrammed to send +5v logic triggers which my circuit will convert .and that i can simply assign individual voice triggers to MIDI channel numbers and will not need to program a sysex data thingamajig.?? Correct??
Reply With Quote
  #12  
Old 05-01-2013, 11:56 AM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

" oh; and can the MD24 be powered via the same 12v voltage adapter from the 24v rail in the BRA?

Thanks
Reply With Quote
  #13  
Old 05-02-2013, 03:29 PM
John's Avatar
John John is offline
Moderator
 
Join Date: Jan 2009
Posts: 3,007
Default

Hi Blaize,

I don't have hands-on experience with the Ace Tone or those particular trigger circuits, so I'm not able to provide any info about how well they will work together.

Quote:
Originally Posted by Blaize View Post
I plan on mounting the md24 internally in the BRA. and utilise the MIDI THRU and MIDI out connections. will this require any other consideration..?
Sounds good.

Quote:
I presume that the MD24 is pre proggrammed to send +5v logic triggers which my circuit will convert .and that i can simply assign individual voice triggers to MIDI channel numbers and will not need to program a sysex data thingamajig.?? Correct??
The MD24 is pre-programmed to send a +5V pulse for MIDI notes. Notes 60-83 correspond to MD24 outputs 0-23. The length of the output pulse will be the same as the length of the MIDI note.

If you want to change any of the above, then you'll have to send a sysex message to the MD24 to change the config. (It's not that hard. I can help you out with the process.)

Quote:
Originally Posted by Blaize View Post
" oh; and can the MD24 be powered via the same 12v voltage adapter from the 24v rail in the BRA?
Yes. The MD24 can be powered by a 12VDC supply. Check the MD24 hardware information about the MD24 electrical specifications.
Reply With Quote
  #14  
Old 06-02-2013, 12:04 PM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

Hi' aploagies for the delay John.

Iv'e been waiting for parts and doing research on this i am on a steep steep learning curve.

Trying to prototype the trigger circuit i posted above. cant get it too work.

So many dumb newb questions (I teaching my self Electronics using this project idea and GOOGLE.!) I realise that this isnt really the place but Im stuck!!

How do i wire a voltage regulator to the 24v rail?

Is a "ground wire" diffrent to the "negitive lead of the power rail"?

How do i have 12 of these circuits operating "next to" each other? off the same power rail?.. .. .. .. Would that describe a "Parrallel Circuit"..???

Hey John' Perhaps I should try the circuit you posted above. it looks heaps easier for a newbie like me .

.. and just to confirm that the origional reason for the "swing to ground type" negative trigger circuit for the drum voices is that ;

When a drum voice is triggerd by a +5v trigger. The drum voice sounds at the end of the +5v decay. which creates a millisecond delay in souning the voice after the initial trigger pulse!
Which of course is unsuitable for a drum machine unit!

Reply With Quote
  #15  
Old 06-04-2013, 02:10 PM
John's Avatar
John John is offline
Moderator
 
Join Date: Jan 2009
Posts: 3,007
Default

Hi Blaize,

Quote:
Originally Posted by Blaize View Post
So many dumb newb questions (I teaching my self Electronics using this project idea and GOOGLE.!) I realise that this isnt really the place but Im stuck!!
It can be frustrating. This is where people often get discouraged and quit. It might help to take a step back and do some background reading. Check the first link in this thread:

http://forum.highlyliquid.com/showthread.php?t=14

If you spend some time on the freeuk site, it might help you a great deal.

Quote:
How do i wire a voltage regulator to the 24v rail?
Search the web for voltage regulator information. There are lots of examples out there. (the freeuk site above, included)

[quote]Is a "ground wire" diffrent to the "negitive lead of the power rail"? [quote]

Sometimes yes, sometimes no. Voltage is relative. So sometimes ground (or 0V) is the "most negative" voltage in the circuit. Sometimes, a circuit will include negative voltages, in which case there can be rails for both positive and negative voltages with respect to ground. Again, some more background electronics info can help you here.

Quote:
How do i have 12 of these circuits operating "next to" each other? off the same power rail?.. .. .. .. Would that describe a "Parrallel Circuit"..???
Yes. But don't worry about that until you get just one working. Keep it simple to start.

Quote:
Hey John' Perhaps I should try the circuit you posted above. it looks heaps easier for a newbie like me .

.. and just to confirm that the origional reason for the "swing to ground type" negative trigger circuit for the drum voices is that ;

When a drum voice is triggerd by a +5v trigger. The drum voice sounds at the end of the +5v decay. which creates a millisecond delay in souning the voice after the initial trigger pulse!
Which of course is unsuitable for a drum machine unit!
You can invert the output from the MD24 so that the correct signal edge happens at the beginning of the note, not the end.
Reply With Quote
  #16  
Old 06-05-2013, 10:04 AM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

Hey John, Thanks again,

I have it all connected; Midi keyboard (M Audio), MD24, the trigger circuit and the old analog drum voice boards. i have the md24 AND trigger circuit on 1 x 9v battery

Its not sounding the drum circuits.

Should the ACT indicator light flash when receiving a MiDi note? its not.

I can kinda get the sound to play v softly when bumping wires . but its otherwise not working,

Q1} The MD24 is pre programmed to receive midi notes and send +5v signals on some sort of standard midi mapping which should work "plug and play" as I described. correct??

Or can you assist me to write the code i need .
Reply With Quote
  #17  
Old 06-05-2013, 12:47 PM
John's Avatar
John John is offline
Moderator
 
Join Date: Jan 2009
Posts: 3,007
Default

Quote:
Originally Posted by Blaize View Post
Hey John, Thanks again,

I have it all connected; Midi keyboard (M Audio), MD24, the trigger circuit and the old analog drum voice boards. i have the md24 AND trigger circuit on 1 x 9v battery

Its not sounding the drum circuits.

Should the ACT indicator light flash when receiving a MiDi note? its not.
Ok. The MD24 is not receiving the correct MIDI notes to cause output activity. This can be either:

- a MIDI wiring problem
- a MIDI channel mismatch
- a MIDI note number mismatch (by default, notes 60-83)

Quote:
I can kinda get the sound to play v softly when bumping wires . but its otherwise not working,

Q1} The MD24 is pre programmed to receive midi notes and send +5v signals on some sort of standard midi mapping which should work "plug and play" as I described. correct??
Yes. It responds to MIDI notes 60-83. If all MD24 dip switch positions are set to "off", use MIDI channel 1.

Last edited by John; 07-08-2015 at 02:55 AM.
Reply With Quote
  #18  
Old 06-12-2013, 03:10 PM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Question Act light

What does ACT in Act light stand for?

Should the light flash / flicker with incoming noteshttp://forum.highlyliquid.com/images/icons/icon5.gif
Reply With Quote
  #19  
Old 06-12-2013, 03:11 PM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

Should the ACT light flicker with incoming notes??
Reply With Quote
  #20  
Old 06-14-2013, 07:03 AM
Blaize Blaize is offline
Junior Member
 
Join Date: Apr 2013
Posts: 12
Default

ok, i got the ACT light to work, (kinda feel like im talking to a wall here, is it so hard to answer such a simple question simply!!??

I'm sure i may seem like a goose to you guys but i actually really value your assistance. especiallly with such simple Q's as what does ACT mean?

3rd time i have asked. please tell me what the ACT light means.


How do i get the md24 to send inverted triggers?

no luck with other circuits converting the +5v which the MD24 sends by default.


Thanks and kind regards.
Reply With Quote
Reply

Tags
rhythmace tr77

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 10:24 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.