1321
preenfm2 and preenfm3 / Re: It's alive, but weird behavior with an Yamaha KX25 ...
« on: April 07, 2016, 08:22:37 AM »
Thanks for sharing, very nice 
What are those knobs ?
What are those knobs ?
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1322
preenfm2 and preenfm3 / Re: Yellow OLED : high frequency solution
« on: April 05, 2016, 09:28:52 AM »
From my experience, with the shield only I could decrease the parasite by 10dB at best.
With the full modification i achieved a 35dB improvement.
You can check easily check with voxengo SPAN.
You should place your shield with SPAN active because a 3mm position move can easily lead to a difference of 6dB or more.
Xavier
With the full modification i achieved a 35dB improvement.
You can check easily check with voxengo SPAN.
You should place your shield with SPAN active because a 3mm position move can easily lead to a difference of 6dB or more.
Xavier
1323
preenfm2 and preenfm3 / Re: Yellow OLED : high frequency solution
« on: April 04, 2016, 11:35:14 PM »
The 22 ohms resistor alone does not change anything.
You have to cut the pin 2 of the OLED header then link pins 2 and 15... See the red wire on the picture above and the missing pin between the OLED and the preenfm PCB.
I remove the whole pin but simply cutting it on the OLED side will work.
Then yes it's really worth it...
You have to cut the pin 2 of the OLED header then link pins 2 and 15... See the red wire on the picture above and the missing pin between the OLED and the preenfm PCB.
I remove the whole pin but simply cutting it on the OLED side will work.
Then yes it's really worth it...
1324
preenfm2 and preenfm3 / Re: Hello, new to the board :) / High frequency parasite? [workaround found]
« on: April 04, 2016, 11:43:15 AM »1325
preenfm2 and preenfm3 / Re: It's alive, but weird behavior with an Yamaha KX25 ...
« on: April 03, 2016, 09:53:20 PM »There must be something weird with the KX25. Maybe regarding the timing.
Recording and playing it back, or routing through MidiOX probably fixes that which make it work.
Sorry, I cannot do anything without trying a KX25.
The only thing i can say is to use the Preenfm2 arpegiator instead
1326
preenfm2 and preenfm3 / Re: Yellow OLED : high frequency solution
« on: April 03, 2016, 02:06:39 PM »
Details screenshots....
1327
preenfm2 and preenfm3 / pfm2 with yellow OLED : high frequency solution
« on: April 03, 2016, 02:05:52 PM »
Situation : Yellow OLED display have a big inductor that sends a 13.5Khz sin wave in the preenfm2 audio path.
Yellow OLED solution
I spent some time trying to find a solution to this problem, and i have somthing really efficient.
Look at the After and Before screenshot.
If you have a PCB R5d (or +) : solder a 22ohm at the "oled" position and go to step 4 directly... DON't do step 1,2,3.
If you have a PCB R5c (or -) : step 1,2 and 3 is for you.
The idea is to put a resistor 22 (ohm) between the LCD and the preenfm2 5V.
As there's no direct possibility, we'll use the Led+ pins (pin 15 of the LCD) that is not used with OLED display and where we can insert a resistor.
Step 1 : put a 22 ohm in the 68 ohm slot... this resistor is between the 5v and the pin 15 of the display.
Step 2 : cut the pin 2 of the OLED so that it's disconnected from the preenfm2 5V.
Step 3 : Link the pin 2 and 15 on the Display. Now the Oled is powered throught the 22 ohm resistor and get around 4v.
Step 1 to 3 makes the parasit frequency much more sensitive to shield. I think it removes almost totally the electronic noise but the magnetic noise is still there.
Step 4 : build a shield with many alumnium sheets that you use for food. you may have that in your kitchen.
The more you put the more efficient it is.
Take a 22cm x 22cm, fold 1 time then 2 times horizontaly, same thing vertically. You get 16 layers.
Do that with 4 sheets to get at least 64 layers.
Put that in a plastic bag (antistatic may not hurt) and add some tape. Be sure no aluminium will touch the contact.
Step 5 : put your shield under the screen.
Step 6 : Let me know
Xavier
Yellow OLED solution
I spent some time trying to find a solution to this problem, and i have somthing really efficient.
Look at the After and Before screenshot.
If you have a PCB R5d (or +) : solder a 22ohm at the "oled" position and go to step 4 directly... DON't do step 1,2,3.
If you have a PCB R5c (or -) : step 1,2 and 3 is for you.
The idea is to put a resistor 22 (ohm) between the LCD and the preenfm2 5V.
As there's no direct possibility, we'll use the Led+ pins (pin 15 of the LCD) that is not used with OLED display and where we can insert a resistor.
Step 1 : put a 22 ohm in the 68 ohm slot... this resistor is between the 5v and the pin 15 of the display.
Step 2 : cut the pin 2 of the OLED so that it's disconnected from the preenfm2 5V.
Step 3 : Link the pin 2 and 15 on the Display. Now the Oled is powered throught the 22 ohm resistor and get around 4v.
Step 1 to 3 makes the parasit frequency much more sensitive to shield. I think it removes almost totally the electronic noise but the magnetic noise is still there.
Step 4 : build a shield with many alumnium sheets that you use for food. you may have that in your kitchen.
The more you put the more efficient it is.
Take a 22cm x 22cm, fold 1 time then 2 times horizontaly, same thing vertically. You get 16 layers.
Do that with 4 sheets to get at least 64 layers.
Put that in a plastic bag (antistatic may not hurt) and add some tape. Be sure no aluminium will touch the contact.
Step 5 : put your shield under the screen.
Step 6 : Let me know
Xavier
1328
preenfm2 and preenfm3 / Re: It's alive, but weird behavior with an Yamaha KX25 ...
« on: March 28, 2016, 09:02:15 PM »Congrats for the preenfm
If you save a midi file from the KX25 and plays it to the preenfm, does it freeze the preenfm ?
If yes can you send me the midi file ?
1329
preenfm2 and preenfm3 / Re: Voice allocation / keyboard management
« on: March 22, 2016, 12:05:04 PM »
Hi,
Yes it would be better to initialise member variables. Even if the compiler clear them to 0.
Answer to your second question. Yes there is a problem every 4000000000 notes.
If you play 10 notes per seconds without stopping, that will take 12 years so that a younger notes is cut instead of a older one.
That's acceptable
Best,
Xavie
Yes it would be better to initialise member variables. Even if the compiler clear them to 0.
Answer to your second question. Yes there is a problem every 4000000000 notes.
If you play 10 notes per seconds without stopping, that will take 12 years so that a younger notes is cut instead of a older one.
That's acceptable
Best,
Xavie
1330
preenfm2 and preenfm3 / Re: Newbie questions
« on: March 22, 2016, 09:28:33 AM »Yes sin^2 seems to be useless.
All the sin variant are not great and take some memory. I only keep them for preset compatibility since the first versions of the preenfm1.
But now you have user waveforms....
1331
preenfm2 and preenfm3 / Re: Wil PCB's and MCU ever be available here?
« on: March 21, 2016, 10:08:30 AM »Yes they will.
I'll order them this week. Should be available in one month.
Xavier
1332
preenfm2 and preenfm3 / Re: Faceplate drill pattern/ template
« on: March 08, 2016, 06:32:30 PM »
Hi Trimix,
Take a look here :
http://ixox.fr/preenfm2/download/
You should find what you're looking for in the "case" part.
Let me know,
Xavier
Take a look here :
http://ixox.fr/preenfm2/download/
You should find what you're looking for in the "case" part.
Let me know,
Xavier
1333
preenfm2 and preenfm3 / Re: Issue when gliding fixed frequency operator
« on: March 07, 2016, 10:57:37 AM »
Thanks a lot, I never realized that.
Xavier
Xavier
1334
preenfm2 and preenfm3 / Re: Usb File Directory Structure
« on: March 05, 2016, 10:16:14 AM »
I don't have plan to modify the PCB.
It's not perfect, but i don't see any potential problem such as the one you describe.
Which pads are you talking about ?
I'm not aware of anybody that did not sucessfully build his preenfm2
Best,
Xavier
It's not perfect, but i don't see any potential problem such as the one you describe.
Which pads are you talking about ?
I'm not aware of anybody that did not sucessfully build his preenfm2
Best,
Xavier
1335
preenfm2 and preenfm3 / Re: more CC control
« on: March 01, 2016, 12:06:06 PM »Seems like it's a common request.
I don't have much free time for the moment, but if any dev wants to take a look, this is very simple to add any CC.
Xavier