46
preenfm2 and preenfm3 / Re: Patches...
« on: October 12, 2014, 11:12:15 PM »
Nice, I will do the update and check those out 
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47
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite? [workaround found]
« on: October 09, 2014, 08:10:48 PM »
What the hell, no high pitch? I need a blue one 
By the way, for clarity, can you please precise in your post that you have a blue OLED?
It's too bad we didn't discuss before taking our measurements, so we could have tried to match the Input level of our sound cards in order not only to compare the spectrum of the background noise, but also its level.
I do have the Voxengo plug-ins as well I think.
By the way, for clarity, can you please precise in your post that you have a blue OLED?
It's too bad we didn't discuss before taking our measurements, so we could have tried to match the Input level of our sound cards in order not only to compare the spectrum of the background noise, but also its level.
I do have the Voxengo plug-ins as well I think.
48
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite? [workaround found]
« on: October 08, 2014, 09:46:19 PM »
And here is mine, after the shield. Maybe then it was mine that was extremely noisy, because my new curve looks like yours no? The 15kHz is still well above but to a range that I really have to push the volume to hear it. The funny thing is that, without speakers plugged, I can hear it from the PreenFM case itself ah ah.
Anyways, like this, I have absolutely no problem with any noise.
EDIT: I forgot to say that, with the Input volume I set in my soundcard to make this last graph, any note from the PreenFM mk2 initial preset with a velocity of 60 or more is clipping the input. So all this background noise pretty low, even the 15kHz peak, compared to the useful signal.
Anyways, like this, I have absolutely no problem with any noise.
EDIT: I forgot to say that, with the Input volume I set in my soundcard to make this last graph, any note from the PreenFM mk2 initial preset with a velocity of 60 or more is clipping the input. So all this background noise pretty low, even the 15kHz peak, compared to the useful signal.
49
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite? [workaround found]
« on: October 08, 2014, 05:40:28 PM »
Here it is, the shitty DIY Shield to protect from the coil on the OLED.
Cutting some stripboard to make a box
Soldering the first edges
Finishing and putting as much solder as I could
Testing
Adding aluminium tape and a magnet (this is pure mojo)
The results are incredible!
Edited by Xavier : I attached the pictures bellow so that they never disapear.
Cutting some stripboard to make a box
Soldering the first edges
Finishing and putting as much solder as I could
Testing
Adding aluminium tape and a magnet (this is pure mojo)
The results are incredible!
Edited by Xavier : I attached the pictures bellow so that they never disapear.
50
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite? [workaround found]
« on: October 08, 2014, 10:59:52 AM »
Well right now it's pretty ugly inside, tape everywhere, an old key to do the shielding… 
I will try to come up with an idea to make some kind of a Faraday Cage around the coil. Basically this parasite is really to be treated like a sound wave. I have the feeling that if you build a wall around it doesn't get through.
I will try to come up with an idea to make some kind of a Faraday Cage around the coil. Basically this parasite is really to be treated like a sound wave. I have the feeling that if you build a wall around it doesn't get through.
51
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?
« on: October 08, 2014, 09:47:17 AM »
Xavier! The metal ruler worked!!!
First I put some electric tape on the PCB and on the back off the screen.
Then I moved around with the ruler as I could, looking for a magic spot and as you said there's a place that is killing the problem straight. I mean it's still a bit there but so quiet.
It is, more or less, around the Positive solder points of the Right Output. Which is also the area where, what a surprise, there is the coil on the OLED
First I put some electric tape on the PCB and on the back off the screen.
Then I moved around with the ruler as I could, looking for a magic spot and as you said there's a place that is killing the problem straight. I mean it's still a bit there but so quiet.
It is, more or less, around the Positive solder points of the Right Output. Which is also the area where, what a surprise, there is the coil on the OLED
52
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?
« on: October 07, 2014, 10:48:10 PM »
Yes I found several topics on the MI forums, but the problems seem to differ from one persone to the other (some talk about a general noise, others about a high freq like mine).
I updated my post above with a picture of the spectrum of my background noise (I thought I had attached it before but I'm not sure if it was successfully embed from Dropbox).
The safest solution might be going back to LCD, it's a pity because it looks great and, who knows, maybe it's my precise OLED that is acting in this way and an other one would not… On the MI forum, most people who had issues or who are more sensitive to those issues on the MI forums went with this solution.
The thing I'm completely sure now is that it's mainly a proximity thing: I breadboarded the screen outside of the PCB and the issue is almost 100% gone.
I updated my post above with a picture of the spectrum of my background noise (I thought I had attached it before but I'm not sure if it was successfully embed from Dropbox).
The safest solution might be going back to LCD, it's a pity because it looks great and, who knows, maybe it's my precise OLED that is acting in this way and an other one would not… On the MI forum, most people who had issues or who are more sensitive to those issues on the MI forums went with this solution.
The thing I'm completely sure now is that it's mainly a proximity thing: I breadboarded the screen outside of the PCB and the issue is almost 100% gone.
53
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?
« on: October 06, 2014, 10:04:20 PM »
This is actually my next step! I didn't cut really short the legs of the components so next time I open it I'll make it as short as possible and see if this might not be an electro-magnetic / proximity perturbation.
By the way I did my first rehearsal today with the PreenFM, it was such a pleasure, I think some of my bandmates will be tempted as well
By the way I did my first rehearsal today with the PreenFM, it was such a pleasure, I think some of my bandmates will be tempted as well
54
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?
« on: October 06, 2014, 01:51:58 PM »
I think I'm getting closer… i noticed that the sound on the Left and Right output is different.
- Right output has the high frequency but is also sort of distorted
- Left output gives cleaner sound, less distortion, but more high frequency parasite
Could it be a problem around one of the DACs then? Or the filter with the last chip?
- Right output has the high frequency but is also sort of distorted
- Left output gives cleaner sound, less distortion, but more high frequency parasite
Could it be a problem around one of the DACs then? Or the filter with the last chip?
55
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?
« on: October 06, 2014, 09:52:10 AM »
Ah nice! Thanks for the example. It's indeed really different compared to mine, not sure which one I prefer though
I just did the same test (a few tones then the noise louder):
https://www.dropbox.com/s/i60emmqf7vzya1f/PreenFM2%20OLED%2015.5kHz.wav?dl=0
As I said earlier, I absolutely don't mind about the general background noise which is absolutely more than fine. The problem I have here is the peak at around 15.5 kHz that is driving me nuts. Each time I open the channel on my mixer I hear this "whistle" first. I suppose I'm a bit over-sensitive there…
EDIT: a link to a picture from Ableton's Spectrum Analyzer
https://www.dropbox.com/s/f7mr6ejufo7i5x4/15.5kHz%20peak.tiff?dl=0
I just did the same test (a few tones then the noise louder):
https://www.dropbox.com/s/i60emmqf7vzya1f/PreenFM2%20OLED%2015.5kHz.wav?dl=0
As I said earlier, I absolutely don't mind about the general background noise which is absolutely more than fine. The problem I have here is the peak at around 15.5 kHz that is driving me nuts. Each time I open the channel on my mixer I hear this "whistle" first. I suppose I'm a bit over-sensitive there…
EDIT: a link to a picture from Ableton's Spectrum Analyzer
https://www.dropbox.com/s/f7mr6ejufo7i5x4/15.5kHz%20peak.tiff?dl=0
56
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?
« on: October 05, 2014, 03:15:14 PM »
Hey Xavier, thanks for the reply, I'll go to my PMs
57
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?
« on: October 04, 2014, 12:12:28 PM »
Hello everyone,
First of all thanks a lot for taking the time to reply!
Unfortunately so far my research wasn't very successful… I tried to put a big electrolytic cap across the spot you talked about Xavier but the reduction is not enough for me I'm afraid. Didn't get great success around the 220uF neither.
Mmarsh: indeed I found a topic in the Mutable community, the idea was to put a cap at the spot Xavier was referring to, but straight on the OLED pins, which I tried also.
Martin: I suppose I'm a bit over-sensitive in this frequency range, but I'm sure my synth is somehow faulty, I'm going to double check again the soldering because I'm usually not really difficult with background noise.
I did find one solution that works 100%: plug the PreenFM through a passive D.I. with GND Lift. Like this I have a regular background noise, there might be this frequency a bit stronger (when you know it), but it's more than reasonably quiet!
EDIT: I forgot, does anyone know of a compatible non-OLED screen?
First of all thanks a lot for taking the time to reply!
Unfortunately so far my research wasn't very successful… I tried to put a big electrolytic cap across the spot you talked about Xavier but the reduction is not enough for me I'm afraid. Didn't get great success around the 220uF neither.
Mmarsh: indeed I found a topic in the Mutable community, the idea was to put a cap at the spot Xavier was referring to, but straight on the OLED pins, which I tried also.
Martin: I suppose I'm a bit over-sensitive in this frequency range, but I'm sure my synth is somehow faulty, I'm going to double check again the soldering because I'm usually not really difficult with background noise.
I did find one solution that works 100%: plug the PreenFM through a passive D.I. with GND Lift. Like this I have a regular background noise, there might be this frequency a bit stronger (when you know it), but it's more than reasonably quiet!
EDIT: I forgot, does anyone know of a compatible non-OLED screen?
58
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?
« on: October 03, 2014, 08:17:27 PM »
Thanks Martin, I think the OLED seems to be exactly the problem. I just checked on google and the first answer is from… the Shruthi community! I have never noticed this on mine because I don't have an OLED screen it seems (I have to say the screen of the PreenFM looks so nice!). Anyways, some people have been struggling with the same issue, there's even someone who measured it around 15kHz so I guess I'm getting close. I can confirm that in the last 5% of the Volume course it gets worse, but still, to me it's not usable like this on a long term. 
Although I was sure of my soldering I soldered again everything with no result. If I'm patient enough I might take the screen off and take a listen…
To be continued!
EDIT:
OLED removed => no more noise!
Now I have to find a way get rid of it because I do need the screen
Although I was sure of my soldering I soldered again everything with no result. If I'm patient enough I might take the screen off and take a listen…
To be continued!
EDIT:
OLED removed => no more noise!
Now I have to find a way get rid of it because I do need the screen
59
preenfm2 and preenfm3 / Hello, new to the board :) / High frequency parasite? [workaround found]
« on: October 03, 2014, 06:27:29 PM »
Hello everyone,
My name is Clément, I'm from France but relocated for a few years in Brussels.
I put my PreenFM2 (got the metal box kit) yesterday and could not stop playing with it since! I can not say how much I am pleased and impressed by everything. The design of the case if wonderful it's amazing to have such a nice piece of equipment kinda half DIY. The sound is great, the navigation easy and the program on the computer makes it even easier to create sounds, even for a total FM noob like me
Since I completely fell in love after such a short time of using it, I also have to report something that is bugging me, and I haven't seen this problem reported so far…
I have a high frequency parasite, kinda like this more or less 15kHz old TVs were producing. It's not that loud, be enough to drive me crazy and not to use it on stage.
I tried all kinds of plugging, with & without USB, power adapter, and even a 9V battery, so I'm 99% sure it comes from the PreenFM.
It's here always at the same volume wether I turn the Vol knob up or down, so I would guess it's not exactly on the signal path, but more in the Ground?
Has anyone experienced this? Any idea what could be the source of this parasite?
And here's a picture of my build, just for the pleasure
My name is Clément, I'm from France but relocated for a few years in Brussels.
I put my PreenFM2 (got the metal box kit) yesterday and could not stop playing with it since! I can not say how much I am pleased and impressed by everything. The design of the case if wonderful it's amazing to have such a nice piece of equipment kinda half DIY. The sound is great, the navigation easy and the program on the computer makes it even easier to create sounds, even for a total FM noob like me
Since I completely fell in love after such a short time of using it, I also have to report something that is bugging me, and I haven't seen this problem reported so far…
I have a high frequency parasite, kinda like this more or less 15kHz old TVs were producing. It's not that loud, be enough to drive me crazy and not to use it on stage.
I tried all kinds of plugging, with & without USB, power adapter, and even a 9V battery, so I'm 99% sure it comes from the PreenFM.
It's here always at the same volume wether I turn the Vol knob up or down, so I would guess it's not exactly on the signal path, but more in the Ground?
Has anyone experienced this? Any idea what could be the source of this parasite?
And here's a picture of my build, just for the pleasure