[sdiy] tr 606 heavy modularization, pictures and questions (4:37 am)

[Seb Francis]

Hi Anthony,

I have a 606 that I modified to accept external triggers so I will share 
what I did, although it's not exactly what you want ...

With the 606 (and other Roland drum machines) you have a common trigger 
pulse that runs continuously at a speed depending on the tempo.  This 
trigger pulse is the correct length (approx 1ms) to make each drum sound 
right, and it varies in level to give the accent.  Then for each drum 
there is an 'enable' pulse which is ANDed with the trigger pulse to 
trigger each drum circuit.  This 'enable' pulse is not necessarily the 
right length or level, just a signal to be ANDed with the trigger pulse.

The ANDing is done with 2 transistors .. using the Cymbal as an example: 
Q28 & Q29.  What I did was cut the track between the collector of Q29 
and R141.  I then applied my external trigger to R141.  My external 
trigger is the correct 1ms wide and the voltage level varies with MIDI 
velocity so I have velocity sensitive accent control, and the 
possibility to have a different accent level even for drums triggered at 
the same time.

I also added individual outputs by tapping off the top of each volume 
pot .. so you can still mix the drums together by turning up the 
volumes, but when turned down the drums come only from individual outs.  
This is a really worthwhile mod as some of the drums (e.g. the toms) 
sound great with loads of distortion and other processing, whereas 
others (e.g. the hats) sound much better clean.

Hope this helps a bit.
Seb



Anthony Bisset wrote:

>http://www.dspaudio.com/~abisset/606/606.html
>
>Hi All,
>
>I'm integrating my 606 with serge/fenix modular and could use a bit of
>help.  Check the pictures to see something a bit out of control...
>
>What I'm trying to accomplish:
>
>in the example below, my 606 has no internal signal path for triggers,
>they must be patched externally (loopback), giving us the ability to take
>triggers out repeat, delay and/or drop them based on external cv
>processing then send them into the appropriate trigger input.
>
>The sequencer should be decoupled from the instrument triggers.
>if someone wants to use the 606 in standalone mode, then the trig outs
>need to be looped back to their respective trig ins:
>here we have the bassdrum trig connect through our external cable:
>
>
>   ____patch cable from bd trig out->in___
> /                                        \
>|                                          |
>| | | | | | |                              | | | | | | |
>trig ins------------------606--------------trig outs
>
>
>Now we put some modular cv processing in the middle
>
>
>
>  __________modular_neg_slew_gen__________
> /                                        \
>|                                          |
>| | | | | | |                              | | | | | | |
>trig ins------------------606--------------trig outs
>
>
>now the bass drum is triggered based on the neg slew generator repeating,
>lagging, or whatever after processing the 606 sequenced bass drum
>trigger.
>
>this sorts the 606's lack of swing and lets you do rushes, flams, delays,
>whatever.
>
>What i'm thinking to do is:
>
>1.) isolate the trigger outs by cutting the traces directly after the cpu
>and giving them their own banana jacks.  Does anyone know the appropriate
>pins?.  I've read every post on AH with 606 in the message body and I've
>emailed tons of folks, no one seems to know or be willing to tell me.
>I have a scope here and I'm looking at the pins and decoding the
>schematic, but some confirmation of what I'm seeing would be very
>encouraging as I'm new to electronics.
>
>I'm looking at PE and PF (pins 12-15 and 16-19) on the CPU. I'm also
>looking at 32 (which looks like a constant pulse that will need to be
>replicated when a trigger comes in and probably reflect the voltage we
>want (since this is the 606's accent).  Are PD doing anything, the bass
>drum seems to be on pin 10 (PD,2)
>
>2.) build trigger inputs that correctly take external cv/gate signals
>and translate them back into 606 trigger messages (maybe with better
>velocity control)...
>
>Can anyone suggest how to do this...  Would it be simpler to hijack the
>post logic instrument trigger pulse's themselves rather than worry about summing
>trig and accent together?  If I went this route, then i'd have to add some
>circuitry on the trigger in points (which would be direct to the
>instruments) to scale the voltage appropriately.
>
>any suggestions, roadmaps, tourguides...
>
>Your help would be warmly recieved and my experience will be posted on a
>web page for others to read and utilize in their own projects.
>
>
>-Anthony
>
>
>
>  
>