Messages

1561

preenfm2 and preenfm3 / Re: Patches...

« on: October 12, 2014, 08:56:31 AM »

Oh yeah..... 
Thanks a lot... Will try them today.

I love when you write "To start"... 

Xavier

1562

preenfm2 and preenfm3 / Re: [SOLVED] display issue

« on: October 10, 2014, 09:10:44 PM »

Awesome 
Thanks for the quick update.

1563

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite? [workaround found]

« on: October 09, 2014, 09:46:54 PM »

I ordered the first Blue OLED one on December 23rd 2013.
It had a problem (persistent line).... So i first thought the noise it introduces was because of that.

The other one was shipped in January 31st  2014...
It worked great except the noise was exactly the same.

I don't know if mine or Martin's one are the exception.

1564

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite? [workaround found]

« on: October 09, 2014, 09:24:50 PM »

Thanks for sharing.... 

What surprised me was the drop in the digital noise when the output volume drops 5-10%. 

Yes that's the biggest drawback of the "R4" black PCB...
The pot does set the reference voltage of the DAC.. And at full volume the reference is too close from VCC and the DACs are noisy.  So leave it  at 95% when background noise is low.
The other drawback was that it makes noise when touching the limit max and min.

The new PCB "r5" (white) has a standard dual pot for volume in the output stage.

Your blue OLED noise spectrum looks good... Maybe a newer version of the 2 i had.
Is it the one you orderde :
http://www.mouser.fr/ProductDetail/Newhaven-Display/NHD-0420DZW-AB5/?qs=%2fha2pyFadugsZRC%2fBKGy2mkdx2%252bOYcqbfPjKTcQxEB12QUIUlVR6Ww%3d%3d
?

1565

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite? [workaround found]

« on: October 08, 2014, 09:25:18 PM »

Clément, beautifull !! 
Thanks a lot for sharing these pictures.

So, the noise is a proximity issue.  Interesting.

The 15.65Khz peak of the yellow OLED is a proximity issue. Unhearable for me but visible on the spectrum and can be anoying for some people (clément proved it ).
The background noise of the blue OLED is not linked at all with proximity. Noise in the GND or 5V or both ! So loud it makes my blue OLED unusable.

See attached spectrum pictures. The yellow one is before any modification such as the one above.

Martin, let me know if your blue OLED has the same background spectrum.

Xavier

1566

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?

« on: October 08, 2014, 10:47:57 AM »

Great news,
Thanks for the update.
If one day you open your preenfm one more time and if you have the occasion to take a picture, don't hesitate 

I'll change this thread title adding that there is a workaround.

1567

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?

« on: October 07, 2014, 11:51:33 PM »

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.

Yes that's what i think too.
And i just tried to insert  a flat piece of metal wrapped in a plastic bag, between the OLED and the PCB.
The peak diminishes (-8db / -10db)
Maybe that's the way to investigate.

1568

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?

« on: October 07, 2014, 09:25:12 PM »

That's very interesting but the noise  with the OLED on the shruthi does not seem to be the same.

There's no "white" noise added in the preen, what shows up in voxengo SPAN and that Clément hears is a 15.6Khz sin.
I don't know if this peak is louder on clément's preenFM2 or if he's particularely sensitive at this frequency.

1569

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?

« on: October 06, 2014, 09:58:59 PM »

Are the volume the same on both output when you center the sound ?

I noticed that after removing the 2 buttom screws of the OLED, if i push the OLED closer to the PCB the high frequency peak is increased, if i pull it it decrease.

Do you have any pins you didn't cut that would come close to the OLED and capture the noise ?

1570

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?

« on: October 05, 2014, 10:07:18 PM »

If you actually can use your BLUE oled display, i would answer yes.

But from my experience, my 2 blue displays are unusable.
The 5 or 6 yellow ones i tried were all silent.

Xavier

1571

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?

« on: October 05, 2014, 12:05:25 PM »

Hi Clément,

There's no LCD screen compatible with this OLED one.
LCD are much thicker.

But read your PM

Xavier

1572

preenfm2 and preenfm3 / Re: Scrolling through programs and combos

« on: October 05, 2014, 11:10:24 AM »

You cannot do that directly from the preenfm2.

Don't know if that's doable with your live configuration but you can send midi information:
Use CC #0 (=1) and #32 (=combo bank number) to select the combo bank.

Then program change CC will load your combo preset.
http://ixox.fr/preenfm2/manual/midi/

Xavier
 

1573

preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite?

« on: October 04, 2014, 10:22:48 AM »

Hmm.  I have an ugly blue Newhaven one.

  And it's usable ?
My 2 newhaven blue OLEDs add a huge background noise and not only in the high frequencies.

And right, i just noticed voxengo SPAN shows a peak at around 17Khz with the yellow one. But i can't hear it. My hears must be too old 
I can lower it a little (-3db) by adding a big electrolyte capacitor between GND and 5V at the bottom left of the PCB.

Let me know if you find something better,

Xavier

1574

preenfm2 and preenfm3 / Re: Last firmware 1.05 : randomizer

« on: October 04, 2014, 09:50:27 AM »

3. Ah OK.. Cannot try right now but this should work. You should be able to move down the cutoff frequency with the envloppe when using a negative matrix multiplier.

Xavier

1575

preenfm2 and preenfm3 / Re: Last firmware 1.05 : randomizer

« on: October 03, 2014, 11:10:52 PM »

Hi Martin,

1. Yes.. I think that's what we call paraphonique.
    You feed the filter frequency with one of the free enveloppe ?
    I agree it would be better to wait for the last note to finish... Not sure it's easily doable. I'll have look.

2. I think the general rule is that cannot go higher or lower than what is authorized directly in the UI.

3. What would you expect exactly with the filter. I'm not sure i understand.

4. Algo 1 to 9 comes from the preenfm. And greater than 10 from the DX7 for patch compatibility. So there maybe some duplicate..

Looking forward for you patches

Xavier