Radium wrote:> Randy Yates <yates@ieee.org> wrote in message news:<ADZkb.6720$Uz6.297@newsread1.news.atl.earthlink.net>... > >>Radium wrote: >> > [...] >> >>>In an analog FM synth the signals >>>smoothly vary by their frequency. In a digital FM synth the signals >>>vary by their frequency in discete steps. >> >>An "analog FM" synth? Never heard of such a thing. > > > Exactly. Neither have I. > > I have no idea what Les Cargill means about FM being differen from > digital. FM synths are digital, like it or not. I don't see why they > shouldn't be. Most analog systems have poor SNRs, are bulky, and need > physical precision to play decently. > > Samplers are different from FM synths even though both groups are > digital.I agree so far.> Samplers have a stale cut-off at high frequencies. Samplers > are suckers for synth sounds. Synth pads, synth FX, synth lead, synth > bass are a torture to listen to when played through sample-based > synths. After all, these "synth" sounds were generated on an FM synth > to begin with. Record them into samples and of course they will rot.No opinion here.>>The old >>popular analog synths like the Minimoog and Arp Odyssey used >>plain old "subtractive" synthesis, i.e., they'd generate a >>waveform (sawtooth, square wave, sin-ish, etc.), then remove >>part of it with a lowpass filter (a VCF). Of course you could >>modulate the filter cutoff with the ADSR generator and/or the >>LFO. Same with the VCA. > > Low-pass filter was necessary to cut-off the unpleasant hiss. This is > definitely not a problem in FM synths.I disagree here. I never remember hearing hiss out of the Moog. And even if there were, the filter was not for the hiss, but rather was a significant part of the instrument's sound. Especially when you cranked the Q so that you could hear the cutoff frequency as a whistle. Re: the end of ELP's "Lucky Man" where he holds that low, low synth note and tweaks the LP filter. -- % Randy Yates % "...the answer lies within your soul %% Fuquay-Varina, NC % 'cause no one knows which side %%% 919-577-9882 % the coin will fall." %%%% <yates@ieee.org> % 'Big Wheels', *Out of the Blue*, ELO http://home.earthlink.net/~yatescr
Sick of sample-based "synthesis"!
Started by ●October 16, 2003
Reply by ●October 20, 20032003-10-20
Reply by ●October 21, 20032003-10-21
"Eric C. Weaver" wrote:> > Les Cargill wrote: > > > Digital isn't FM and vice versa. DX-7s and later revisions of > > DX-7s are not hard to find. > > Beg yer pardon, but FM and digital are not mutually exclusive at all. > > I impelemented FM sythesis on an LSI-11 micro in assembler back in 1983 or so, > and it worked as well as any single-operator FM synthesizer could.So this process was purely in the digital domain? -- Les Cargill
Reply by ●October 21, 20032003-10-21
Les Cargill wrote:> "Eric C. Weaver" wrote: > >>Les Cargill wrote: >> >> >>>Digital isn't FM and vice versa. DX-7s and later revisions of >>>DX-7s are not hard to find. >> >>Beg yer pardon, but FM and digital are not mutually exclusive at all. >> >>I impelemented FM sythesis on an LSI-11 micro in assembler back in 1983 or so, >>and it worked as well as any single-operator FM synthesizer could. > > > So this process was purely in the digital domain?Yes. Digital oscillators with numerically-controlled frequencies are used. The outputs of the digital oscillators are PCM streams that are summed into a composite PCM stream, which can then be converted to analog in the usual fashion. -- % Randy Yates % "...the answer lies within your soul %% Fuquay-Varina, NC % 'cause no one knows which side %%% 919-577-9882 % the coin will fall." %%%% <yates@ieee.org> % 'Big Wheels', *Out of the Blue*, ELO http://home.earthlink.net/~yatescr
Reply by ●October 21, 20032003-10-21
In article ADZkb.6720$Uz6.297@newsread1.news.atl.earthlink.net, Randy Yates at yates@ieee.org wrote on 10/20/2003 18:49:> Radium wrote: >> [...] >> In an analog FM synth the signals >> smoothly vary by their frequency. In a digital FM synth the signals >> vary by their frequency in discete steps. > > An "analog FM" synth? Never heard of such a thing. The old > popular analog synths like the Minimoog and Arp Odyssey used > plain old "subtractive" synthesis, i.e., they'd generate a > waveform (sawtooth, square wave, sin-ish, etc.), then remove > part of it with a lowpass filter (a VCF). Of course you could > modulate the filter cutoff with the ADSR generator and/or the > LFO. Same with the VCA.the even older patchbard Moog synths (or Serge, or maybe the ARP2600) could be *exponentially* FM modulated. the Moog deliberately had identical 1/4" phone jacks for both the audio signals and the modulation signals. one guy did a Computer Music Journal article of what the FM spectra would be. not suggesting anything big came of it.> And yes, they were horrid. Especially when you get them up on > stage in front of hot lights where the temperature was changing.but they have a (sorta fat, at least the MiniMoog) sound that is, even today, hard to emulate. there is a real market for good ol' analog synths in good shape as well as old tube preamps or guitar amps. the good news is that Bob Moog i think finally got his trademark (R A Moog or Moog) back. r b-j
Reply by ●October 21, 20032003-10-21
"robert bristow-johnson" <rbj@surfglobal.net> wrote in message news:BBBAD466.4AE2%rbj@surfglobal.net...> the even older patchbard Moog synths (or Serge, or maybe the ARP2600)could> be *exponentially* FM modulated. the Moog deliberately had identical 1/4" > phone jacks for both the audio signals and the modulation signals. oneguy> did a Computer Music Journal article of what the FM spectra would be.The Moog modular 921B oscillator had linear control inputs as well as the usual exponential. To quote the users manual these could be used for "... frequency modulation at audio rates ..." see http://moogarchives.com/ for a great set of moog-related material regards, Kevin
Reply by ●October 21, 20032003-10-21
Randy Yates wrote:> > Les Cargill wrote: > > "Eric C. Weaver" wrote: > > > >>Les Cargill wrote: > >> > >> > >>>Digital isn't FM and vice versa. DX-7s and later revisions of > >>>DX-7s are not hard to find. > >> > >>Beg yer pardon, but FM and digital are not mutually exclusive at all. > >> > >>I impelemented FM sythesis on an LSI-11 micro in assembler back in 1983 or so, > >>and it worked as well as any single-operator FM synthesizer could. > > > > > > So this process was purely in the digital domain? > > Yes. Digital oscillators with numerically-controlled frequencies > are used. The outputs of the digital oscillators are PCM streams > that are summed into a composite PCM stream, which can then be > converted to analog in the usual fashion.Randy, thanks. You've disabused me of yet another badly gathered hunk of malinformation. This shows why we should teach synthesis in the schools, rather than letting children learn about it on the playground.> -- > % Randy Yates % "...the answer lies within your soul > %% Fuquay-Varina, NC % 'cause no one knows which side > %%% 919-577-9882 % the coin will fall." > %%%% <yates@ieee.org> % 'Big Wheels', *Out of the Blue*, ELO > http://home.earthlink.net/~yatescr-- Les Cargill
Reply by ●October 21, 20032003-10-21
"Radium" <glucegen@excite.com> wrote in message news:464c821f.0310201733.e1544c8@posting.google.com...> Randy Yates <yates@ieee.org> wrote in messagenews:<ADZkb.6720$Uz6.297@newsread1.news.atl.earthlink.net>...> Most analog systems have poor SNRs, are bulky, and need > physical precision to play decently. >bulky - mostly,yes poor SNR - early FM synths like the DX7 had truely horrible output stages and generated as much, if not more, noise as most analogue synths of that era. Most soundcards with OP3s didn't fair much better; remember, the DACs at that time weren't that hot and the cards were in a computer filled with nasty RFI... need physical precision to play decently - as do all real istruments...> > Samplers are different from FM synths even though both groups are > digital. Samplers have a stale cut-off at high frequencies.Both have exactly the same physical problem, they cannot produce frequencies above the nyquist cutoff. The only saving grace of the DX series was their relatively high sample frequency; >60kHz if I remember correctly> Samplers are suckers for synth sounds. Synth pads, synth FX, synth lead,synth> bass are a torture to listen to when played through sample-based > synths. After all, these "synth" sounds were generated on an FM synth > to begin with.err, no.... Some sounds may have been sampled from FM synths, but the majority have come from other sources> > > The old > > popular analog synths like the Minimoog and Arp Odyssey used > > plain old "subtractive" synthesis, i.e., they'd generate a > > waveform (sawtooth, square wave, sin-ish, etc.), then remove > > part of it with a lowpass filter (a VCF). Of course you could > > modulate the filter cutoff with the ADSR generator and/or the > > LFO. Same with the VCA. > > Low-pass filter was necessary to cut-off the unpleasant hiss. This is > definitely not a problem in FM synths.again, no. The filter was to sculpt the sound, hence 'subtractive synthesis'. The clasic waveforms of an analogue synth, namely sawtooth and square, have harmonics that extend way up past 20kHz. For most sounds, they are too 'bright'. To be pedantic the DX series and the OLP3 didn't perform FM, they were actually Phase Modulation. But since the oscillators were sinusiod, the difference is moot. regards, Kevin
Reply by ●October 21, 20032003-10-21
Randy Yates <yates@ieee.org> wrote in message news:<4_0lb.7011$Uz6.103@newsread1.news.atl.earthlink.net>...> Radium wrote: > > Randy Yates <yates@ieee.org> wrote in message news:<ADZkb.6720$Uz6.297@newsread1.news.atl.earthlink.net>... > > > >>Radium wrote: > > >>The old > >>popular analog synths like the Minimoog and Arp Odyssey used > >>plain old "subtractive" synthesis, i.e., they'd generate a > >>waveform (sawtooth, square wave, sin-ish, etc.), then remove > >>part of it with a lowpass filter (a VCF). Of course you could > >>modulate the filter cutoff with the ADSR generator and/or the > >>LFO. Same with the VCA. > > > > Low-pass filter was necessary to cut-off the unpleasant hiss. This is > > definitely not a problem in FM synths. > > I disagree here. I never remember hearing hiss out of the Moog. And > even if there were, the filter was not for the hiss, but rather was > a significant part of the instrument's sound. Especially when you > cranked the Q so that you could hear the cutoff frequency as a > whistle. Re: the end of ELP's "Lucky Man" where he holds that > low, low synth note and tweaks the LP filter.You're correct.
Reply by ●October 21, 20032003-10-21
glucegen@excite.com (Radium) wrote in message news:<464c821f.0310201733.e1544c8@posting.google.com>...> Randy Yates <yates@ieee.org> wrote in message news:<ADZkb.6720$Uz6.297@newsread1.news.atl.earthlink.net>... > > Radium wrote: > > > [...] > > > In an analog FM synth the signals > > > smoothly vary by their frequency. In a digital FM synth the signals > > > vary by their frequency in discete steps. > > > > An "analog FM" synth? Never heard of such a thing. > > Exactly. Neither have I. > > I have no idea what Les Cargill means about FM being differen from > digital. FM synths are digital, like it or not. I don't see why they > shouldn't be. Most analog systems have poor SNRs, are bulky, and need > physical precision to play decently.FM synthesis is a digital method. Anyone who thinks different need to read more about FM synthesis.> > Samplers are different from FM synths even though both groups are > digital. Samplers have a stale cut-off at high frequencies. Samplers > are suckers for synth sounds. Synth pads, synth FX, synth lead, synth > bass are a torture to listen to when played through sample-based > synths. After all, these "synth" sounds were generated on an FM synth > to begin with.I find so many comments from newsgroups saying that sample synths are better than FM synths. How so?? All "synth" type of instruments (e.g. pads) sound horrible when sampled. The tone of synth pads was generated on a FM synth. Sampling this type of sound only makes it less realistic.
Reply by ●October 21, 20032003-10-21
Radium wrote:> [...] > I find so many comments from newsgroups saying that sample synths are > better than FM synths. How so??I think that when you say "sample synths," what you really mean is "wavetable synthesis." They're just more realistic. The timbres produced by FM sound "nice" (i.e., clear, good high-frequency content, etc.), but just aren't as realistic as wavetable synthesis. At least in my opinion.> All "synth" type of instruments (e.g. pads) sound horrible when > sampled. The tone of synth pads was generated on a FM synth. Sampling > this type of sound only makes it less realistic.It's business. If you look into the software development effort, it's much easier to spend all your time and effort getting the wavetable synthesis working rather than having to build both a wavetable synthesis and FM synthesis engine (so that FM sounds could be generated instead of reproduced through the wavetable). -- % Randy Yates % "...the answer lies within your soul %% Fuquay-Varina, NC % 'cause no one knows which side %%% 919-577-9882 % the coin will fall." %%%% <yates@ieee.org> % 'Big Wheels', *Out of the Blue*, ELO http://home.earthlink.net/~yatescr
