#1

There are three things that are currently concerning me about my module:

  • There is a very high pitched ringing sound coming from the module itself. If you just put your ear to it it’s audible but I can hear it from about two feet away too.
  • There is a considerable amount of noise/ringing coming from the outputs as well.
  • The module goes into distortion on playback even when I auto adjust the volume before recording.

Has anyone out there had similar issues? Could this be a problem with my power? I’m using the uZues and I’ve had a lot of problems with these things so I’m wondering if that could be the problem and not the module itself.

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#2

Have you tried removing any other modules on the same power supply and seeing if there is still an issue?

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#3

No not yet. I considered it but wasn’t convinced it would change anything. Will definitely try that this weekend though.

#4

re: the high pitched sound — there was some discussion about this on MW when the module was first released. i don’t remember all the details per se, but i remember there being something about the high pitched noise being a byproduct of the nature of that kind of module in a euro environment and that it was ‘acoustic’ or, not in the signal path. not sure about the noise/ringing coming from the outputs…that could be something else entirely.

the only distortion i got was when i first racked it and didn’t really grasp how the auto level worked…once i did, it solved it. don’t have any whine coming from mine either (on intellijel power supplies)

#5

Oh nice I will definitely go check that MW thread. Thank you for that.

#6

OK yes… from Make Noise on MW:

“The noise you complain of is acoustic only. It is not in the audio signal path. This is the nature of running a powerful DSP within an open frame modular synthesizer system. Especially if you have openings in your system that are not covered by metal blanking panels you will hear this noise. Additionally power supplies which have poor line/ load regulation will exhibit greater acoustic noise while running a module like the Morphagene.”

I think it’s finally time for a power upgrade. Someone on another thread about this same problem linked to this:

http://www.genusmodu.com/products/libb.html

I might have to go this route and also buy one of their suggested power supplies to avoid any further power issues in the future.

Thank you @jwm for pointing me towards MW.

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#7

I’m genuinely curious about how a DSP causes “acoustic noise”?

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#8

I own one other thing that does this actually and it’s a cheap iPhone charger. When my phone gets to above 90% the adapter starts to ring. It’s really high pitched and similar to the “whine” I’m hearing from the Morphagene. I’ve also heard this in cheap dimmer switches and other kinds of lights. These things can also leak into audio signals.

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#9

It’s also fairly common in mobile video cards. The moment you push the GPU on most nvidia mobile cards, you start to hear a coil whine.

#10

Update:

Unplugging all other modules didn’t solve the issue. Will have to experiment with other power sources next.

#11

The switching noises coming from all that CPU/FPGA logic are quite audible. Intel CPUs are quite audible - Edit: ancillary board components such as coils and capacitors near the chip are much more likely a source of switching noise than the chip itself. Switching power supplies are also very audible, some especially when idle. iPhone chargers are quite audible, especially when idle. I can totally imagine a switching PSU giving out a high-pitched whine as a module’s DSP does various things causing subtle changes in power draw at audio rates.
My small case came with a giant AC→AC transformer and an old-school rectifier inside the box, large electrolytic capacitors and all. Beginner-friendly : )

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#12

Interesting. I found this Reddit thread which suggests audible noise sometimes comes from parasitic capacitance and the piezoelectric effect: https://www.reddit.com/r/electronics/comments/1m2hr3/why_do_transistors_make_noise_ie_why_do_they
I’d be curious to hear for myself just how loud this is.

#13

Did some more testing on this and I can definitively say that the whining sound is coming out of the Morphagene’s output. Not only that but it’s also coming out of all over outputs along the same power supply. Once I get a new power supply I’m expecting this problem to go away completely.

My plan is to get the Genusmodu low impedance bus board with an L-1 Synth PSU kit. I’m going to power all digital modules and anything within my audio’s signal path with it. (as much as will fit). Hopefully this will take care of any noise issues.

#15

I’ve been having some troubles with this aswell, but I think it’s just part of how the module work. When turned all the way to the left you have to adjust the input gain. To me, your issue sounds like it’s because the last time you adjusted this the input/sound source needed a lot of gain from the input, so this level is very high which also brings your noise level higher.

Does this make any sense? I always reduce the noise from the input with adjusting the gain level anyways, so this works pretty well for me. That being said, Morphagene can get a little noisy…

Hope this helps. Curious to hear others experiences with this.

#16

Set input gain level by pressing REC and SHIFT and hold.

#17

The thing is when doing this it usually gets worse, and when it doesn’t it’s still there.

If it’s a normal thing for the module… idk, it sounds really extreme at times (I mean, have you heard that sample above?).

If that’s the case, it’s quite a deal breaker as I was trying to build my skiff around the MG, and for a module of that price i wasn’t expecting noise issues. :cloud_with_rain:

#18

Gonna have to listen to your sound example later, but if it’s really extreme there may be something wrong. Have you tried updating the firmware? Idk why that would make a difference, but worth a try…

#19

(merged some posts and edited title to reflect the specific issue being discussed)

#20

I’m curious, does anyone know that the ‘powerful DSP’ used in a Morphagene is?

#21

Are you recording a line level signal, like from your computer or phone? If so, it might be the amplification that the morphagene uses, which is digital and, IMO, pretty noisy and gross. I skip that amplification entirely and use other modules that use analog amplifiers to get the signal up to modular levels.

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