From batzman@dove.mtx.net.au Tue Feb 13 11:51:06 1996 13 Feb 96 14:50:43 +0500 12 Feb 96 10:16:26 +0500 Date: Tue, 13 Feb 1996 01:10:46 +1030 From: "The Dark force of dance" Subject: RE: dx7 madness! Y-ellow All. Now I don't wanna hear any winging from the analogue purests here about this. I'm just gonna impart this information for the benifit of all interested parties on the list and leave it at that. At 10:20 AM 2/11/96 -0500, Roderick W. MacQuarrie wrote: >...and a computer...the closest I've come to physically "tweaking" FM is the graphical faders on the screen...it's just not the same as having physical knobs to turn and sliders to move... The DX7 has one knob. Well two if you include volume but for all practicalities it has one. Because it remembers the last thing you did with it, you can use it to tweek parameters. For example if you wish to control the speed of the LFO, Hit the LFO speed button and play with the knob. Even if you change patch it will remember that you wanted to tweek the LFO. So the Technique used to tweek parameters is to first of all "KNOW YOUR DX". Dial up the patch you want. Go into edit mode. (one Key) Start playing your sound. Hit the key of the parameter you wish to tweek and then play with your knob. (Err the one on the DX) If you wish to change various parmeters you can simply select them in turn and tweek them. This is not much different from using an analogue synth in that you only have one hand in which to do this anyway. If you know what the parameters do and you understand how the DX works, You can do this just as fast as you would on yur avarage Analogue synth. Now you might get into a situation where some sequencer or other is playing the DX and now you have two hands. This just makes it faster. You put one hand over the parameter and one hand on the knob. Another interesting way of tweeking the DX is the patch change morphing technique. This is where you hold down a key with a particular sound and then change patch to a completely different sound. This will automatically morph through the two sounds as if you have released the key. And here in lies the catch. If you tweek a DX7 MK 1 via MIDI, the MK 1 will reset the sound (All notes off) everytime you send a sysex message. However the TX7 and later models don't do this. So you can hook up yur little fader box thing and assign parameters to it. Or you can tweek it in real-time from a sequencer or other computer package. >What boxes are available that would allow the DX7 to be tweaked "physically". WOuld the PC-1600 work? (Sorry for the non-analogue content here)...I actually like my little CZ-101 more than my DX-7... Note that there were two full sized fully knobed programmers availbel for the DX. These are fairly rare however and your chances of getting hold of one are slim. I believe that jellinghus (However it's spelt) made one and Robin Whittle of devil fish fame made one. The Jellinghus one suffered from the same problem as mentioned above. But the one Robin Whittle made was somewhat different. I'm not sure if he modified code or modified the DX or both to accept it but it gave you a pannel with all 145 parameters in Knobs and switches that could be tweeked in real-time. No-one I know has ever owned one because of the expense of these things. I mean imagine a pannel with 120 or more knobs and "N" switches on it. We're talkin' modular proportions here. At current prices down here, each knob would set you back about $5.00 even if bought in bulk so that's at least $600 in knobs alone. I believe these boxes were several times the cost of the DX themselves which meant that they never became immediatly popular and never really caught on. A shame really. Another way of achieveing something similar to this is by using a Yamaha KX88 mother keyboard. This could store patches and parameters for a large number of synths. It also allowed you to assign it's control knobs and controller devices to any parameter and have a different assignment per patch. So each patch in a DX (OR chain of DXs) could have it's own set of tweeks. One final note. All yamaha DX family of synths have secret sysex codes. One code for every parameter and front pannel button in fact. By linking multiple DX7s together in a daisy chain you can hit a button or change a parameter on one synth and it will be as if you phisically did the same on another synth. This is how you edit a TX7 from another DX7. Although this data has never been published, you can make a map of the secret codes by turing your DX to Sysex-available and tweeking each parameter and hitting each button in turn. The DX will send the code and you can capture it with whatever MIDI montioring software you have. I've never fully mapped the DX but we use to amuse ourselves by tweeking the DX by remote and making the DX think it had someone standing at the keyboard. Interestingly the DX will not display any of this stuff on it's LCD as you do this. So obviously Yamaha had no clue about what Sysex was really all about in those days and went way overboard. Finally there are 4 controllers available on the DX MK 1. To get a filtersweep type sound you assign one of these controllers (Perhaps foot peddle) to what is known as EG BIAS. You can set it up such that certain operators will respond to this and others wont. You create a patch where most of the EGs are tracking together. This gives the effect of an analogue synth having only one EG. You make your base sound using only 4 operators and add top end harmonics with the other two. These two operators are also the ones that respond to the EG-BIAS. Now by varying the foot controller the DX will seem to perform a lowpass filter sweep. If one of these two operators is also the one within the feeback loop it and the operator is set to fixed frequency, it will also seem to scream like a filter. Though not quite. You can also simulate other kinds of filters such as bandpass and highpass but you have to work on the subtilty of the sound. There are some differences between the filter sweep simulation of a DX and of an Analogue synth. Most notably is the fact that the overall level doesn't drop with the loss of top-end etc. However this can be programmed in too with care. You can replace the controller for a slow LFO if you wish. My only real regret about the DX is that it only has one LFO. I'll leave it at that for you to expeiment with at your leasure. Whilst it's probably not the easyest way of producing "That sound", it is possible. You have to learn to think of the DX in the same way you'd think of CSOUND. As a canvas for your timbral creations. On that score I guess I should also mention breifly yamaha's earlyer FM products. The GS 1 and GS 2. These were FM based but the FM was rather more complex. Yamaha didn't feel that a suitable user interface could be built so they instigated a means of site programming. That is to say that the user could send a tape of the sound they wanted synthesized to a local agent who would encode that sound into FM and return it on a little bus-ticket thing not unlike that used but the CS70. These things were capable of re-synthesizing realworld sounds very convincingly. Indeed I recall an artical in one of "THOSE" magazines touting it as "The New Melotron". The DX7's archetechture is a stripped down version of this in the interests of user interface. (Ha!) Proving that the FM process isn't flawed, only the implementaion of the DX. I don't know exactly what was inside a GS1 but I guess that if you had 12 operators, each controlled by a waveform rather than an 8 parameter EG and a patch together algorithm, you'd have something able to re-synthesize just about anything. Noting here that RE-SYNTHESIS (Aditive) and FM-SYNTHESIS (Also aditive) are very similar in concept. Hope that helps. be absolutely Icebox. _ __ _ | "_ \ | | batzman@dove.mtx.net.au | |_)/ __ _| |_ ____ Batz Goodfortune | _ \ / _` | __|___ | All Electric Kitchen | |_) | (_| | |_ / / _-_|\ |_,__/ \__,_|\__|/ / / \ / ,__ \_.-*_/ |_____| South Australia Alive to Synthesize