DMG Deep Bass Prosound à la noizeInaBox

After looking at the DMG schematics, i got the idea to bypass the whole audio path of the gameboy and recreate my own output to see if we can get a better sound.

The idea behind this is to get better "pro-sound" output whit more BASS, because the DMG 1uF coupling caps will kill all deep bass.

I saw somewhere that a trick was to short the 1uF caps, but was a quite strange way of doing this because you will get the DC offset directly in the phone amp.

So my way of doing a prosound is connect directly at the CPU output (easier to solder directly before the 1uf caps) and add another circuit for DC coupling and High Z output leaving the original circuitry for headphone and speaker intact.

Schematics will come soon ..

Results : As expected, we get a much better bass response, for bass i mean sub bass(20-50Hz)

Some audio examples from LSDJ with associated the frequency analysis
I've tested with the same "song" each time with the classic prosound (pre-pot) and with my new pro-sound version using different caps value.
Prosound output directly connectin to my Mac internal input and saved without any compression (PCM 16bit ). No sound post processing.
 Sorry for the "song" but  is only a Bass test, not a full track as i don't know LSDJ that  much

Sound example Original Prosound

Using Pre-Pot Classic Prosound on DMG-01
Original Prosound Spectrum analysis : 

                                        Peak 36 Hz = -21.2dB




Sound example noizeInaBox Prosound using 2u2 Cap
noizeInaBox Prosound 2u2 Cap
Prosound using 2u2 Spectrum analysis :

                Peak 36Hz = -17.9dB ...  +3.3dB  than orignal prosound  .. yeah .. i like sub bass



Sound example noizeInaBox Prosound using 10u Cap :
noizeInaBox Prosound 10u Cap
Prosound using 10u Spectrum analysis :

 Peak 36Hz = -17.6dB ...  +3.6dB  than orignal prosound  .. yeah .. will buy a subwoofer :)


Sound example noizeInaBox Prosound using 100u Cap
noizeInaBox Prosound 100u
Prosound using 100u Spectrum analysis :

         Peak 36Hz = -17.8dB ...  +3.4dB than orignal prosound  .. nothing more ..


I know the  spectrum analysis look quite identical,but look closer at the lower frequencies (20-50Hz) and remember that 3dB more is like double power.

In order to do some better testing, i needed to use white noise, luckily the Gameboy got a noise channel so i tried the same spectrum analysis using the Gameboy white noise (white noise normally is all frequencies in the same time at same level) :

Original Prosound using white noise Spectrum analysis:

                                         50Hz = -44dB  ... look at 20Hz ..


noizeInaBox Prosound 10u cap using white noise Spectrum analysis:

                     50 Hz = -41dB  +3dB  than orignal prosound  and re look at 20 Hz..

noizeInaBox Prosound 100u cap using white noise Spectrum analysis:

                                          50 Hz = -41dB   +3.dB  than orignal prosound

My Conclusion :
Will build my nexts prosounds using my circuit because i like deep bass. i think the selected cap value will be 10u because you don't gain anything more with a bigger cap.
Another remark.if there is some low freq. noise, they will not be filtered with this prosound.
This method need  more testing because it is only the first tests, but look good .
Didn't tested yet if this affect in any way the headphone or speaker output.
And remember that is is only for "enhance" sub bass 

As it need more components, i will do a SMT PCB with some Oxicaps.
If it works fine, you will see soon on the market the noizeinabox prosound pcbmount 

Finished DMG-01

I just finished my Game boy DMG-01

It doensn't have much funky mod, only the classic

• Promod sound mod
• Green 3 Led backlight
• Black screen protector
• custom painting
• Super Gameboy CPU

Game Boy Super Game boy CPU Transplant tutorial

I just finished my CPU transplant between my DMG-01 and a Super Gameboy cartridge.

For Info :With this mod you wont' get more cpu power, or anything similar, it will only change the boot delay, so each time you power-up  the GB, it will boot very fast into the game and you won't get the Nintendo boot sound.

Don't try this if you don't have good soldering skills.

I decided to make a little tutorial, well 2 tutorial in fact. so here is the fast tutorial

1. Desolder your Super Gameboy CPU

2. Desolder your Gameboy CPU (DMG-01)

3 Solder you SGB cpu in place of the GameBoy cpu

That's it.

As I've done some picture of the process, so I did a longer tutorial with pictures.

Super Game BOY CPU transplant Tutorial 

So you want to transplant your super gameboy cpu in your gameboy ? 

Warning: if it’s the first time you desolder or solder SMT components, don't try on your SGB and GB use a old motherboard you don’t need anymore or similar to train you a bit..

This mod need good soldering skills. (normally if you have the skill to do this, you should not need any tutorial )

Tools needed  :

• Gameboy DMG-01
• Super Gameboy cartridge.
• Gameboy game or lsdj (to test afterward)
• The special tools to open SGB and Gameboy
• Solder iron with fine tip (and some solder)
• Flux
• Ideally a rework station or some chipquick (everything that you want to remove smt component)
• Time and patience.

Step 1

Before doing everything check if GB and SGB are working fine.

Open your game boy and your super gameboy to make them ready for the transplant.

Step 2 

Desolder the Super gameboy CPU using the rework station or with your preferred method.

(I will not explain how to do it because there is several tutorials on how to desolder SMT component on internet. Just use Google)

 Try to not over heating the CPU during the desoldering process.

Clean the pins of your desoldered SGB cpu with the solder iron

Step 3

Desolder the gameboy CPU using the rework station or with your preferred method.

Do not heat to much the board, CPU or other component. You can lift up a little bit the capacitors near the GB CPU to be sure you don’t touch them with your rework station.

Once removed, check to board to see if everything looks ok. 

 

Step 4

Clean PCB pads after desoldering.

You can use solder wick  to clean or you can put flux on the pads and using the solder iron go across each pad QUICKLY to  melt the solder and clean the pads ,after that clean the flux.

If you use solder wick method, it may be easier to put in place the SGB chip after because all solder will be removed and pads are flat but I don’t like this method because it heat a lot more the PCB than using the solder iron and flux.

Do not apply too much heat because the pads could lift up and it will be very difficult to repair (or impossible).

 

Step 5

 Place the super Game boy CPU precisely to match the pads (check the orientation notch)

Put a little bit of solder on your iron tip.

Hold it in place and using the iron with fine tip, solder one CPU pin in the corner.

Recheck the chip placement and if it’s fine solder one opposite CPU pin

It is easier if you add some flux on the pin you want to solder before soldering.

 After that your CPU should not move anymore

Step 6 

Put more flux on all pins.

Solder all remaining CPU pins, there are several technique to solder them, check video on internet on  how to solder SMT chip. (solder each pin individually or with a little bit of solder on the iron tip move across the pads)

If you make a join between 2 pins, don’t worry you can remove them using some solder wick

Step 7

Inspect attentively all your work, especially  joins between pins or if a pin is not correctly soldered (a magnifier would help). this is a crucial step.

Step 8

Clean the Flux.

Don’t forget this step because depending the flux you use, it can be conductive, and if it’s the case your Game boy will not work or could even destroy your GB.

It happen to me, I didn’t clean the flux  (sparkfun Flux #2331-zx) and the GB didn’t want to boot. After cleaning the flux everything was working fine

If you lifted up the capacitor near the CPU, it is a good time to put them in place again.(before mounting the board in the case)

Solder job is done. :) 

Step 9

Test your Gameboy and enjoy the fast boot (don’t forget to put a game or LSDJ)

If it doesn’t work (nothing appear on the screen and contrast not working) double check your CPU orientation and all soldered pins . (try to resolder all pins and check solder joins)

That's it ... job finished.

Quick video to see the Super Game boy fast boot. :

(sorry for the high compression of the video due to upload on blogger, we don't see anymore the marking on the chips) .

Disclaimer: I am not liable for any damage caused to you, your GameBoy or Super Game Boy due to human error.

Special Thanks to NeX for the idea and the help.