UGS-muse preamp GB

Ok all is done, I removed the manual saving and cleaned up few things + found another minor little display bug on the VFD.
I have been played with both the VFD and the OLED and it looks nice now, better than before indeed.

I will look at the complains regarding the double click (and text editing) on the encoder with my UGSD as I don't have the dual encoder on my UGS Muse.
I believe this is the only minor remaining things to improve, let me know otherwise.

I'll send this binary this weekend to one OLED and one VFD owner for validation.

BTW VFD is really nice, wondering if I am not preferring now VFD over OLED

check also the output volume setting in menu.
when you associate a certain output volume (i mean the "default" you pre-load at the startup) is not consitent, for example, if i set at the minimum, when i save it jump to like +19db).
 
Volume Issue & noise

I finally finished soldering and connected all the cards. Powering was not issue, everything went smooth and also I did not have any difficulty with the firmware upload. When power on there is sound in the selected input. However I have two major issue now:

1) The volume is not working. I am using optical encoder and when I turn up/down the volume knob, I can see the display is working (db up/down) but no actual change in volume. I realised that when I change the input and back again, the volume actually changes, totally strange.

2) There is cracking noise in one channel, sometimes left and sometimes on right side. I took of all the input cables but the parasite sound is still there.

I first installed v. 2.9.7 of the software. After erasing all the settings tried to install v. 2.9.3 but the problem remains the same :cuss:. I really need help, does anybody have any idea?

Regards,

Umit
 
Hi Umit,
Your problem should lie around the muse device.
If its power rails are all OK, looks like more a digital communication problem with the SPI interface.
One thing to understand with the Muse 72730 is that the serial i/f allows just to write the programmed value (there is no read back possibility) hence the reason why you see a disconnect between display and sound experience behavior.
 
I believe this is the only minor remaining things to improve, let me know otherwise.

Alex - one more tweak which would be perhaps useful. With the current version of FW assigning of the name for an input or change power off message etc is really panful and time consuming as all ASCII codes are available (including very strange special symbols etc) so in case that you have to scroll to find a character you want to select it may take some time. Maybe you can limit this to useable character set (upper and lower case, numbers and perhaps hyphen, underscore, space etc).
I know - you do this once in some time only while you setup this feature but maybe it is worth to consider to make this task easier...

Regards,
-jacek
 
I finally finished soldering and connected all the cards. Powering was not issue, everything went smooth and also I did not have any difficulty with the firmware upload. When power on there is sound in the selected input. However I have two major issue now:

1) The volume is not working. I am using optical encoder and when I turn up/down the volume knob, I can see the display is working (db up/down) but no actual change in volume. I realised that when I change the input and back again, the volume actually changes, totally strange.

2) There is cracking noise in one channel, sometimes left and sometimes on right side. I took of all the input cables but the parasite sound is still there.

I first installed v. 2.9.7 of the software. After erasing all the settings tried to install v. 2.9.3 but the problem remains the same :cuss:. I really need help, does anybody have any idea?

Regards,

Umit

On top of what Eric is proposing, did you setup correctly the resistors to define the Muse chip address?
 
Alex - one more tweak which would be perhaps useful. With the current version of FW assigning of the name for an input or change power off message etc is really panful and time consuming as all ASCII codes are available (including very strange special symbols etc) so in case that you have to scroll to find a character you want to select it may take some time. Maybe you can limit this to useable character set (upper and lower case, numbers and perhaps hyphen, underscore, space etc).
I know - you do this once in some time only while you setup this feature but maybe it is worth to consider to make this task easier...

Regards,
-jacek

Ok just done, you have now a reduced font set.
If you want to have the name setup faster I can also remove the blinking function.
 
Hi Umit,
Your problem should lie around the muse device.
If its power rails are all OK, looks like more a digital communication problem with the SPI interface.
One thing to understand with the Muse 72730 is that the serial i/f allows just to write the programmed value (there is no read back possibility) hence the reason why you see a disconnect between display and sound experience behavior.



Thank you Eric, I could narrow down the possibilities and finally solved the volume issue by changing U5. Now volume is working perfect.

But the cracking noise is still there, I’m investigating the source. Any suggestions?
 
Ok just done, you have now a reduced font set.
If you want to have the name setup faster I can also remove the blinking function.

remove the blinking is better.
also, i am already implementing a character selector like that :

Char_sel.png

U8g2 setColorMode(2) and then fill a box around the char selected.
a monospace font is useful there :)

just an idea
 
Thank you Eric, I could narrow down the possibilities and finally solved the volume issue by changing U5. Now volume is working perfect.

But the cracking noise is still there, I’m investigating the source. Any suggestions?

Does it happen also without any external source connected?
If yes, I would be inclined to think it is somehow power supply related or at least, this is the first thing I would have checked myself.
Do you have an oscilloscope to probe the power rails (digital and analog)?
 
remove the blinking is better.
also, i am already implementing a character selector like that :

View attachment 910257

U8g2 setColorMode(2) and then fill a box around the char selected.
a monospace font is useful there :)

just an idea

Yes this is exactly what I had in mind to replace the blinking but the problem is that I need to check also if this is compatible with the VFD...
 
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Does it happen also without any external source connected?
If yes, I would be inclined to think it is somehow power supply related or at least, this is the first thing I would have checked myself.
Do you have an oscilloscope to probe the power rails (digital and analog)?

Yes Eric, the noise is there without any source connected. I will borrow my friends' scope tonight to check the power rails as you suggested and will inform the results shortly. Thanks for now...
 
@redjr - did you find your problem? I am having somewhat similar observations.

Sorry I missed your post. I have not. I tested everything I knew to test, replaced almost all of the parts and still can't get the output voltage to the correct value on the negative rail. It's been a couple month now since I've messed with the project.

I do have some other options for powering the boards, including a very nice PSU from Hicoco. However, all those parts adds another $200USD to the project. So at the moment, the project is in limbo and there's little motivation.

Do let us know if you come across, or find your issue and how you solved it.

I have a couple other projects I'm working on now.