FM Synth Noise.. normal or just old gear? (answered)

[part12studios]

Hi there,

So I'm doing an audit of patchings from MIDI Quest.. 2500 or so for my FB-01.. however I also have a TX-7 and a TX-81z.. and i while i don't have them all here in front of me this moment to A/B/C compare.. i recall that they all tended to have this kind of static / artifacting in the lower range of sounds..

i guess I just wonder if this is normal for yamaha FM synths in general or maybe this is something that comes from age? it's not terrible, but it definitely is part of the sound and i guess i just wonder how engineers maybe mitigate the sound in recordings because it seems like if i tried to record this in a song i'd hear that noise.. but can't think of songs i've heard with DX sounds.. then again.. i guess the DX sounds I recall from songs tend to not be super low end.. so maybe it was just a matter of playing to the FM synth's strengths..

I'm having a local electronic repair guy work on a Tama DS200 right now, but if he can succeed fixing that I am going to explore the mods this guy talks about http://llamamusic.com/fb01/#freq one of them fixes the noise issue some.. and i must say the comparisons of before and after + the very inexpensive cost of parts make those mods pretty appealing.

Thanks,
Caleb

[commodorejohn]

The FB-01 and TX81Z are fairly clean overall, but all the Yamaha FM chips are characteristically a bit noisy at very low levels. Is it something you notice mostly on the release phase of notes, or is it persistent even when nothing's playing?

[part12studios]

@commodorejohn no the units are all perfectly quiet when no sound is played.. it's just the lowest of lows that the artifacting comes through and noisy stuff.. i don't believe either unit is actually "Bad" or sounds like a chip or something is off.. I know there are frequency / phase things that go on with fm synthesis and when they happen at higher ranges Like the weird "radio tuning" things that happen.. but in the lower range.. some patches that are little more than sine waves can have these overtones that kinda overshadow the low end sound being produced by the patch that is intended..

[commodorejohn]

Yeah, that's common with Yamaha FM chips. I don't know what causes it, but it's definitely normal behavior for them.

[part12studios]

just interesting how popular the dx7 was.. you'd think they would have managed to clean it up but again i think it's just FM synthesis wasn't really made for low end.. those noises are not there in the mid / higher ranges.. i'm excited to see about those fb-01 mods which do seem to brighten / noise reduce / boost output for those units.

[madtheory]

Try loading your SysEx into FM7 instead. It will usually interpret it the same as the Yamaha only without the noise.

[part12studios]

cool that FM7 can load those patches. I'm not using any software besides Digital Performer 3 and other OS9 software at this time. But that is good to know. I had a version FM7 at one point years ago, but it was before I really appreciated FM synths.

[Mooger5]

just interesting how popular the dx7 was.. you'd think they would have managed to clean it up but again i think it's just FM synthesis wasn't really made for low end.. those noises are not there in the mid / higher ranges.. i'm excited to see about those fb-01 mods which do seem to brighten / noise reduce / boost output for those units.

Music wasn´t so bass heavy in 1983 and recording and PA equipment wasn´t as clean sounding as today´s. I listened to a live demo of a DX7 back then and never noticed any noisy artifacts. I wouldn´t give them a second thought if I had though, as the novelty of the sounds was so mesmerizing.