[Done] Salami's 1st GBZ Modded-HDMI UART Shift-Buttons Brightness Control

Show off your completed Game Boy Zero, or post your build logs here!
User avatar
YaYa
Posts: 1719
Joined: Mon Jun 26, 2017 12:42 pm
Location: brittany - France
Has thanked: 871 times
Been thanked: 688 times
Contact:

Re: [WIP] Salami's 1st GBZ Modded-HDMI UART Shift-Buttons Brightness Control

Post by YaYa » Sat Oct 06, 2018 9:55 am

Merlin wrote:
Sat Oct 06, 2018 6:45 am
I like your solution.
I don't know why most people can live with mono audio and so lost part of music and sound effect.
(Original game boy is stereo and even if has only one speaker,it's output sound is the sum of L and R without losses)
What you stated is a complete heresy as the fake advertising done by Nintendo at the time... taken from wiki

Stereophonic sound or, more commonly, stereo, is a method of sound reproduction that creates an illusion of multi-directional audible perspective. This is usually achieved by using two or more independent audio channels through a configuration of two or more loudspeakers (or stereo headphones) in such a way as to create the impression of sound heard from various directions, as in natural hearing

So where and how could you ever say that a single loudspeaker can output stereo ?

Nintendo lied at the time to the consumers. The sound board may produce stereo sound aka two different channels but as they are mixed, the produced sound is monaural and you could not create multidirectional sound with one speaker.
Follow me on instagram Image

User avatar
YaYa
Posts: 1719
Joined: Mon Jun 26, 2017 12:42 pm
Location: brittany - France
Has thanked: 871 times
Been thanked: 688 times
Contact:

Re: [WIP] Salami's 1st GBZ Modded-HDMI UART Shift-Buttons Brightness Control

Post by YaYa » Sat Oct 06, 2018 9:59 am

To further develop, when a produced sound is stereo, droping it to a mono speaker without mixing can, i insist on can, produce missing sound if one of the stereo channels does not contain same information as the other.

So taking one would lead to missing information.

Mixing sound will “flatten” it but the information would be complete but falsely reproduced.

My 3 cents of an almost complete life working with sound, producing music and djing :lol:
Follow me on instagram Image

User avatar
Merlin
Posts: 60
Joined: Thu Feb 22, 2018 12:32 pm
Has thanked: 44 times
Been thanked: 28 times

Re: [WIP] Salami's 1st GBZ Modded-HDMI UART Shift-Buttons Brightness Control

Post by Merlin » Sat Oct 06, 2018 12:32 pm

So where and how could you ever say that a single loudspeaker can output stereo ?
I didn't say this!
Single speaker can't output stereo.This is obviously!

Maybe I explained it wrong.

Audio on headphones can be STEREO because we have 2 speakers! (Left and Right)
Audio on Speaker is for sure MONO because we have 1 speaker! (Mono)

So, If we have only 1 speaker and an audio signal with 2 different channel (left and right)...why use only one channel (left) and lose the other (right)?
I mean that I prefer to mix both channels togheter and have a MONO L+R output (like Wermy's Mintypi build)
In many builds only left channel is connected to speaker so audio information in right channel were lost.

About original Game Boy...obviously that it isn't stereo when using speaker but it can be stereo when headphones are used!
It depends from game to game,many games are stereo with two idendical sound information on each channel,so like a dual mono setup...
but some other games have a real stereo sound,with two different sound information on each channel.
For example in Super Mario Land or Castlevania Adventure with headphones you can clearly hear the alternance of sounds between left and right channel!

User avatar
YaYa
Posts: 1719
Joined: Mon Jun 26, 2017 12:42 pm
Location: brittany - France
Has thanked: 871 times
Been thanked: 688 times
Contact:

Re: [WIP] Salami's 1st GBZ Modded-HDMI UART Shift-Buttons Brightness Control

Post by YaYa » Sat Oct 06, 2018 1:28 pm

That’s more clear yeah !
So we are all agree :D
Follow me on instagram Image

salami738
Posts: 128
Joined: Sat Sep 09, 2017 6:06 am
Location: Germany
Has thanked: 60 times
Been thanked: 36 times

Re: [WIP] Salami's 1st GBZ Modded-HDMI UART Shift-Buttons Brightness Control

Post by salami738 » Mon Oct 08, 2018 3:09 am

Merlin wrote:
Sat Oct 06, 2018 6:45 am
I like your solution.
I don't know why most people can live with mono audio and so lost part of music and sound effect.
(Original game boy is stereo and even if has only one speaker,it's output sound is the sum of L and R without losses)

My setup is: USB SOUND CARD>POTENTIOMETER>HEADPHONE JACK(Stereo)>SPEAKER(with L and R mixed toghether without resistors like Wermy's mintypi build)
Audio is very clear,volume level on headphone is excellent and volume level on speaker is acceptable.
SpoilerShow
Image
In the past I tried to add a PAM8403 amplifier before speaker but sound was very loud and distorted.Maybe because input on ampli was too high!
Now I have to try to add the amplifier and adding resistors to mix L and R and then connect R input to ground like your build!
Nice and clean diagram!
As far as i know, the PAM8403 will distort if any of the following conditions are met
  • too high input levels (can be corrected by putting a resistor divider between source and PAM inputs - a resistor in series won't solve this)
  • DC input (can be corrected by using capacitors in series with the inputs. A audio amplifier should only have AC at the inputs. This can lead to speaker damage)
  • PAM8403 output GND connected together (e.g. GND connected. This is a BTL amp, you shouldn't connect the outputs together. Because of that you shouldn't drive headphones with this amp, because they use a common GND)
  • PAM8403 output connected together (soldering issue, ...)
Feel free to ask further questions, if you like!

greetings from germany


salami738
Posts: 128
Joined: Sat Sep 09, 2017 6:06 am
Location: Germany
Has thanked: 60 times
Been thanked: 36 times

Re: [WIP] Salami's 1st GBZ Modded-HDMI UART Shift-Buttons Brightness Control

Post by salami738 » Mon Oct 08, 2018 1:06 pm

Project is finished. I enjoyed building it, but it will be sold soon. Because I don't have the time to play with it.

Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image
Image


Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest