Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Yamaha DX7 Technical Analysis

ajxs.me

Post reply on HN
Print view View original

61–70 of 130 posts

Re: Yamaha DX7 Technical Analysis

#61

Post by weatherlight »

I was under the impression that, despite the name, the Yamaha FM synths didn't actually use frequency Modulation but rather phase modulation. With Frequency modulation you can't have an operator feed back on its self.

If you take a DX7 patch and implement it on something like the PreenFM2 or PreenFM3 (which uses actual FM), any algorithm with more than a few operators is going to sound quite different.

I still love the old Yamaha FM synths though, the lo-fi-ness of the DACs are so musical/magical.

Here's a IDM track I made with just the Yamaha TX81z 4op FM synth. https://soundcloud.com/cassilda_and_carcosa/ontologies-tape-...

Re: Yamaha DX7 Technical Analysis

#63

Post by klodolph »

weatherlight wrote: post #61

I was under the impression that, despite the name, the Yamaha FM synths didn't actually use frequency Modulation but rather phase modulation. With Frequency modulation you can't have an operator feed back on its self. If you take a DX7 patch and implement it on something like the PreenFM2 or PreenFM3 (which uses actual FM), any algorithm with more than a few operators is going to sound quite different. I still love t…

> I was under the impression that, despite the name, the Yamaha FM synths didn't actually use frequency Modulation but rather phase modulation. With Frequency modulation you can't have an operator feed back on its self.

It’s true that it’s phase modulation, but phase is just the derivative of frequency, and the derivative is a linear operator (essentially a 6dB/oct EQ). So I don’t think it’s an especially important piece of terminology to get correct.

The statement about feedback is actually backwards. You cannot directly incorporate feedback into a phase modulation system. In the Yamaha system, the feedback is delayed by a sample to make it work. In an FM synth, this would not be necessary, and you could just directly feed the output back into the input.

Re: Yamaha DX7 Technical Analysis

#64

Post by klodolph »

boondaburrah wrote: post #53
joeberon wrote: post #29

Earlier quoted context omitted.

Yeah it's a shame, on the other chips you can get amazingly air-y textures by setting the LFO to noise and then putting the frequency all the way up. See this video for example: https://youtu.be/_xL3qr-9-ZE

Would sacrificing an operator and setting it to constant mode instead of mult work for this? You'd have to use the feedback operator if you wanted something noisy though.

The operators actually contribute phase, not frequency, and there are very limited ways that they can be routed.

Re: Yamaha DX7 Technical Analysis

#65

Post by weatherlight »

klodolph wrote: post #63
weatherlight wrote: post #61

I was under the impression that, despite the name, the Yamaha FM synths didn't actually use frequency Modulation but rather phase modulation. With Frequency modulation you can't have an operator feed back on its self. If you take a DX7 patch and implement it on something like the PreenFM2 or PreenFM3 (which uses actual FM), any algorithm with more than a few operators is going to sound quite different. I still love t…

> I was under the impression that, despite the name, the Yamaha FM synths didn't actually use frequency Modulation but rather phase modulation. With Frequency modulation you can't have an operator feed back on its self. It’s true that it’s phase modulation, but phase is just the derivative of frequency, and the derivative is a linear operator (essentially a 6dB/oct EQ). So I don’t think it’s an especially important p…

One thing that is different in the preenfm2 compared to the Yamahas stuff is, that it uses linear FM and therefore will not do operator feedback.

The guy behind the preenfm2 says, that feedback is not that important, when you have a variety of waveforms for modulation. Linear FM also has the advantage of being a bit "friendlier/warmer" when using complex waveforms as modulators (Higher harmonics of the modulator will have a smaller effect than in phase modulation).

One thing you loose when not having feedback: The normal feedback happens after the amplification/envelope if I remember correctly Therefore the amount of feedback scales with the amplitude. With feedback you therefore get less harmonics and therefore a "softer" sound at lower amplitudes. This is quite useful, because it mirrors the behavior of most natural sound sources. It is the same idea as using a lowpass gate or using the same envelope for the amp and the filter in subtractive synthesis. Of course FM synths give you enough options to get this effect in another way. I still like the yamaha style feedback though....

Re: Yamaha DX7 Technical Analysis

#66

Post by speed_spread »

ajxs wrote: post #35
mdp2021 wrote: post #20

Waiting now for the SY99 ;)

Author here: I wish! I own a TG77, and it's an absolutely amazing synth. While I don't have any direct experience with the SY99, the 77 was so far ahead of its time. The sheer amount of features packed into the synth alone is an engineering feat.

I have an SY77 that I'm scared of. It's my second oldest synth and yet the deepest, craziest machine of all the studio. I can't fathom the engineering process that went behind it.

Re: Yamaha DX7 Technical Analysis

#67

Post by pea »

ajxs wrote: post #35
mdp2021 wrote: post #20

Waiting now for the SY99 ;)

Author here: I wish! I own a TG77, and it's an absolutely amazing synth. While I don't have any direct experience with the SY99, the 77 was so far ahead of its time. The sheer amount of features packed into the synth alone is an engineering feat.

I've got a 99 and, outside of the dated fx and sequencing abilities, I think the only real difference is that you can load your own waves for the RCM modulation? I think you can hack the 77s to do that too.

Oh, and it's even more unbelievably massive and heavy. I will never part with it - they are the most criminally underrated synths, and it's crazy they are still often priced lower than the DX series.

It would be great if someone would built a better live editor for them though.

Re: Yamaha DX7 Technical Analysis

#68

Post by jacquesm »

l33tbro wrote: post #60
jacquesm wrote: post #50

Earlier quoted context omitted.

The cap? Or the actual slider? If you have the specs of the slider I can dig around for a suitable substitute, alternatively I can go on the lookout for a donor synth.

Will email you picture ;)

Ok! jacques@modularcompany.com

Re: Yamaha DX7 Technical Analysis

#69

Post by jacquesm »

weatherlight wrote: post #61

I was under the impression that, despite the name, the Yamaha FM synths didn't actually use frequency Modulation but rather phase modulation. With Frequency modulation you can't have an operator feed back on its self. If you take a DX7 patch and implement it on something like the PreenFM2 or PreenFM3 (which uses actual FM), any algorithm with more than a few operators is going to sound quite different. I still love t…

Wow, that transported me right back to my first experience listening to Kraftwerk. Thank you, keep it up, very well done!

Re: Yamaha DX7 Technical Analysis

#70

Post by [deleted] »

weatherlight wrote: post #61

I was under the impression that, despite the name, the Yamaha FM synths didn't actually use frequency Modulation but rather phase modulation. With Frequency modulation you can't have an operator feed back on its self. If you take a DX7 patch and implement it on something like the PreenFM2 or PreenFM3 (which uses actual FM), any algorithm with more than a few operators is going to sound quite different. I still love t…

[deleted]
Post reply on HN