Talk:Yamaha DX7

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[edit] FM7

Can anyone tell me why the search for FM7 gets redirected here?

Obviously, that's a mistake and should be corrected. They are completely different instruments.

Accepted that they are completely different instruments, but the FM7 is basically a virtual recreation of the original DX7, with added modern bells and whistles. The FM7 is able to read original DX7 patches, for example. And then there's the name! Until someone writes a great FM7 article, this isn't a bad place to redirect to. Electricdruid 11:30, 13 January 2006 (UTC)

[edit] FM or PM?

A lecturer informed me the other day that the FM7 actually uses Phase Modulation and not Frequency Modulation. Can anyone verify this? It would be good to note in the article. Magic Window 15:16, May 12, 2005 (UTC)

The DX7 uses what would now be called DDS oscillators (http://en.wikipedia.org/wiki/Direct_Digital_Synthesis). These do indeed work by keeping track of the phase of the wave rather than its value. This is done since all waveshapes have a linear relationship between phase and time, and linear relationships make the maths much simpler. The crucial part of the DDS oscillator scheme is a binary counter called the 'phase accumulator'. It is the rate of increment of this counter that determines the frequency of the oscillator. The DX7 produces frequency modulation by using the output from another DDS oscillator to modify this phase increment. Whether this is FM or PM is a subject of some discussion over at http://en.wikipedia.org/wiki/Talk:Phase_modulation. Having had a look at the maths, it seems to boil down to whether the modulation is multiplied with the increment (true FM) or added to it (PM). Since the DX7 adds it, it does use PM, not strictly FM. Electricdruid 11:27, 13 January 2006 (UTC)

The DX7 indeed used phase modulation; however, this is no "upgrade" of FM, hence I removed that part of the sentence; I leave it to the EEs to discuss why FM and PM are basically two faces of the same coin and will spare the math for now. 87.177.143.13 22:08, 22 May 2007 (UTC)Rainer Buchty

[edit] Image: of white space?

What gives? The image and the thumbnail both show as a big fat nothing! Did somebody go and peel a copyrighted image from another source and get squealed on?

2005 dec 15th image now seems to be someone's grandad. he looks like a nice fellow though

What's going on with the image for this page? I'm new to Wikipedia but I did my degree using this synthesiser and have a decent, self-made picture I'd like to upload. There seems to already be a picture in Wikipedia Commons though. I'd like to contribute but I don't want to go messing things up. I don't think I have the skills to fix the article with the existing picture, if that's suitable! JammyB 13:42, 23 April 2006 (UTC)

Yes, that picture even comes from http://www.vintagesynth.org. And it might be safe to use (if it's on Wikipedia Common, then it means something). But anyway, I saw that image removed so I tried to upload one again. I'm not sure if I did well, but I found it here: http://digitalmedia.oreilly.com/2004/12/29/flow_1204.html I don't know if it's copyrighted or not but as it was a nice and decent picture, I uploaded it. If you don't agree, you can freely delete it and replace it with something more adequate. Dioxaz 21:09, 29 April 2006 (UTC)

OK, it's been nearly a week and nobody went to change the copyright status of the image I uploaded. So, what should I do? I also saw that same exact image on Synth Mania. So, I'm assuming this image to be "public domain"... or, must I ask the maintainer of Synth Mania before doing so? Dioxaz 12:58, 4 May 2006 (UTC)

[edit] Factory patches

"The tone generation algorithms used were highly programmable, but it is said that 90% of all DX7 owners simply used the 32 factory default patches, and never tried to program their own patches. " This sort of statement has been said for years but it doesn't belong here. It's just a vague guess with no hard evidence. fataltourist 22:40, 17 December 2005 (UTC)

[edit] Notable musicians that have used the DX7

I am deleting this section. If any of these musicians are actually known for using the DX7 or created some classic, memorable song/hook with it, then they should be mentioned. This list is more suited towards a fan site than encyclopedia.--fataltourist 14:49, 27 January 2006 (UTC)

I don't understand your comment at all. No one makes songs with just one synthesizer, and Yamaha DX7 is surely one of the most successful synthesizers in history, so many many musicians were using it at least for some parts of some of their songs. What are you suggesting here - to make a list of 'notable' songs where a DX7 was 'actually' used? It makes little sense to me, this list would have been far longer than a previous one. --DmitryKo 01:10, 30 January 2006 (UTC)
Ok, I'll try again. I was speaking hypothetically. If there was a particular song/hook that is noted for its DX7 use than that would be worth mentioning in the article (like The Who and the ARP 2600). That's my suggestion to someone who would be upset about me deleting that list. Basically, I don't like these interminible lists that add little content and end up making the page very long. Plus it's hard to prove/disprove that any of those artists used it, though I guess with a synth as popular as the DX7 it's safe to assume that everyone in the universe has used it.--fataltourist 21:45, 31 January 2006 (UTC)

[edit] Um, people

The DX7 did use FM, in particular an algorithm developed by Julius Smith from CCRMA and patented. It was the Casio CZ synths that used PM (because of the patent). Yes, perhaps it was implemented in a weird way (maybe that's it could be patented, since radio stations were already using FM) but most historians (those I've read) agree that it was FM. Zyxoas (talk to me - I'll listen) 08:35, 17 June 2006 (UTC)

I just goofed this up somehow. I was editing and for some reason lost the link under synthesis type. I tried going back and forth between frequency modulation and phase modulation and gave up after a half hour. Hopefully someone can fix this.

The DX7 does use Phase Modulation, which in sound can be considered the same as FM (though PM have some advantages, more details can be found on the Phase Modulation page). I think many of you mistake Phase Modulation for Phase Distortion, which is used in Casio CZ synths and is something completely different. Phase Modulation (Yamaha DX) != Phase Distortion (Casio CZ). Dioxaz 23:23, 31 October 2006 (UTC)

Just a note to agree with Dioxaz. PM and FM are often considered the same thing in synthesis, and there is much confusion between PM and PD. It was John Chowning at Stanford university who developed the FM/PM algorithm, and Stanford who patented it, and later licensed it to Yamaha.Electricdruid 23:57, 31 October 2006 (UTC)

  • I have changed the synthesis type to FM (Phase modulation). This should make both sides happy. --fataltourist 15:26, 6 November 2006 (UTC)

Dioxas/Electricdruid, there is just no mathematical difference between phase modulation and phase distortion. The only thing is that with phase modulation you use a saw (ramp) curve as the "distortion" function (i.e. you don't get any distortion but read out the sine as-is) whereas with PD you apply a more complex (complex as in nature, not the complex number space) function to the phase pointer, hence the sine gets distorted into the desired shape. 87.177.143.13 22:12, 22 May 2007 (UTC) Rainer Buchty

Yes, I agree, Rainer. PD and PM are indeed basically the same thing. Adding a sine modulator to a ramp phase value (PM) and adding a distortion function to a ramp phase value (PD) are obviously so close as to be virtually identical. However, although the maths is the same, the implementation on the Casio CZ and Yamaha DX7 show considerable differences. Still, it makes you wonder how Casio got away with it, especially on the later VZ synths (using "iPD" synthesis) which blurred the line still further.Electricdruid 13:50, 7 August 2007 (UTC)

[edit] Incomplete MIDI Specification

Does anybody agree that it might be worthwhile to discuss the Yamaha DX7's midi implementation, since it's non-standard, primarily the points where it strays? (for example velocity only goes up to ??? instead of 127) --Thor Andersen 08:42, 16 February 2007 (UTC)

[edit] Yamaha DX5

Need an article on the Yamaha DX5, which has been used by Relâche (musical group) and Kitaro. Badagnani (talk) 09:22, 2 January 2008 (UTC)

[edit] FM Synthesis

While there may be some technical correctness in calling it PM, the current summary dismissal is a big mistake IMHO. Historically, unless you can prove otherwise, the Yamaha FM synths used Chowning's work which for whatever reason was called FM synthesis. Other products, along with countless books, articles and online sources call it FM synthesis.

I strongly feel that sentence needs further exposition. And it's not important whether it's technically PM or not as almost EVERYONE calls it FM synthesis. Wikipedia should not go about trying to rewrite history here. A casual reader on the topic is going to be really confused by that sentence.

I think calling it FM synthesis should be sufficient clarification, shouldn't it ? The reader than then refer to the article on FM synthesis (which should explain why it's PM synthesis not FM synthesis in detail). That article can afford to be more technical than an article on a specific synthesizer.

—Preceding unsigned comment added by 75.71.201.149 (talk) 06:16, 5 May 2008 (UTC)