ShintarouMusic wrote:
CarrieStronggrog wrote:

Could I just resolder the points R & L onto the pre-pot points you showed in your pictures and then just add the 4.7UF capacitors to my 1/8" / mini-jack and it would be the same thing?
- I prefer the compact look of the 1/8" jack over the big RCA outputs...

Hi yes you could, that's what I did

Thanks a lot for confirming this!

I'm just gonna purchase the right capacitors and give the mod a go!

katsumbhong wrote:

Thanks my, dude

I'm the one to thank YOU for your great tutorial! smile

Although I have a small question for you...

I have a GBC with a 'classic' plain prosound mod (post-pot) that is connected to a small female mini jack (1/8") which doesn't sound very good.

Could I just resolder the points R & L onto the pre-pot points you showed in your pictures and then just add the 4.7UF capacitors to my 1/8" / mini-jack and it would be the same thing?
- I prefer the compact look of the 1/8" jack over the big RCA outputs...

Thanks again for this great step-by-step tutorial!

Would these capacitors be a correct choice? I've heard that panasonic makes some of the best capacitors with very low ESR.


I just re-uploaded all the images.

Bass Mod and Noise Filtering Mod for the GBC... 56K Death!!!
by Katsumbhong

The purpose of performing these mods is to help give the GBC a clean line-out signal with a bump up in bass frequencies.

Difficulty: Intermediate

This mod requires steady hands to solder very small gauge wires onto SMT components.

Parts Needed:

+ (2) Female Chassis Mounted RCAs
+ (2) 4.7UF 16V non-polar (bipolar) electrolytic capacitors
+ (1) 470UF 6.3V polarized electrolytic capacitor
+ 30-gauge wire
+ Wire strippers for 30-gauge wire

I purchased the capacitors from Digikey. The following are their parts numbers and pricing at the time of writing this tutorial.

4.7uf Capacitors

470uf Capacitors

Tools that I used:

+ Soldering iron with a very fine tip
+ Solder
+ Drill w/ drill bits
+ Dremel w/ grinding bit
+ Headphone Amplifier
+ Small diagonal cutters or nail clippers
+ Needle nose pliers
+ Shrink wrap
+ Small screwdrivers, flat tip and philips-head

Here we go!

This is the area that we will be focused on for the bass mod.

This is tricky. For the left and right output, we will have prep the left side of the SMT components with a small dab of solder. If you remove or damage the connection of these SMT components, you will disconnect the bridge to the speakers and headphones. We will also prep the top tab of the volume potentiometer for ground. You may also alternatively choose to use a different grounding point as you see fit. Make sure to take your time with this step.

This is the area you will be working with for the noise filtering mod.

Take your 470UF capacitor and bend the legs and test fit in this area. The positive leg of the capacitor will go on the top post on the left while the negative leg will get soldered to the ground pad on the right side. You will have to heat up and add solder to the ground pad. After you are finished soldering, snip off the excess capacitor legs with diagonal cutters or nail clippers.

Cut three lengths of 30-gauge wire, roughly the length of the GBC, or a little longer than the length of the GBC.

We will then need to strip the ends of the 30-gauge wire and solder them to the points we prepped on the GBC board for the bass mod.

A close up of the wires soldered into place.

Next we will routing the wires through the right side of the cartridge connector in the gap between the cartridge connector clip and pcb.

Another shot of how the wires were routed.

At this time we will prep the battery tabs. We will be needing to remove battery tab from the rear case. You should be able to slip a small flat tip screw driver to push a tab to remove the battery tab.

You will want to heat up the underside of the spring portion of the tab and flow solder through the gap. I do this mod to all the gameboys I mod. Whenever there are issues with batteries not making good contact in the battery compartments of gameboys, to what I have found, it is the contact between the spring and the battery tab. They are two separate pieces and the spring is crimped onto the tab. Corrosion tends to get between the tab and the spring, causing no continuity for current to flow.

This is what the battery tab should look like after flowing solder through the gap under the spring tab. Reinstall the battery tab into the rear case of the GBC.

Do the same with the battery tab on the pcb.

We will then trim away this plastic section from the rear case of the GBC using diagonal cutters.

This is what it should look like after you have removed the plastic section.

In this photo, I have the different parts of the RCA separated. I source internal star washers from a local hardware store, which I then use to help center where I want to drill holes into the case.

This is the area that we will be wanting to drill for the RCAs.

We want to place the star washer under the battery cover ledge molding and to the outside of the battery cover clip molding. Take a small drill bit and make a small pilot mark for where you will be drilling.

Working your way up, starting with small drill bits, use the smallest drill bit to drill out where you made your pilot holes in the inside of the rear case, then flip the case over and continue drilling with incrementally larger drill bits until [in my case] you finish off with a 1/4” diameter drill bit. This is what the case should look like when you are done. Please make sure to test fit your RCAs. Your RCAs may have a different diameter and may require a hole of a different diameter drilled.

Before we install the RCAs, we will need to shave off the tips.

Using a dremel with a grinding bit, you will want to shave off the ends of the RCAs to help give extra clearance from the PCB.

This is what the RCAs should look like, for the most part, once you are done shaving off the tips. Make sure to de-burr the RCAs with a razor blade if there are any shavings left on them.

Install the RCAs with the RCA itself, the grounding tabs, star washers, and nut. Have the grounding tabs face each other and have the “crescent” portion of the RCAs facing outward, as shown in this photo. You don’t have to tighten the RCAs down all the way as we will be doing so in a few steps.

Strip a section of 30-gauge wire, snip it off, loop and wrap the wire in the grounding tabs.

Flow solder between the two grounding tabs and wires. At this time, making sure that the RCAs are placed correctly, tighten the nuts down with needle nose pliers.

Strip the ends of the three wires that we soldered to the pcb earlier.

Next we will prepare the 4.7UF capacitors.

Bend the capacitor legs in an “L” shape.

Using the wire that is soldered to the left output on the pcb, wrap the exposed end of the wire onto the bent leg of the capacitor near its base.

Apply solder where the wire and capacitor leg meet. Snip off the excess material off the capacitor leg past the solder joint.

Bend the other leg of the capacitor around toward the top of the capacitor as pictured.

Cut two sections of shrink wrap that is long enough to both cover the soldered end of the capacitor and over the top of the capacitor itself. Slide it over the capacitor.

Apply the flame of a lighter, match or other heat source to the shrink wrap. Wait for it to cool down and slide over another section of shrink wrap over the same area and repeat the process of heating the shrink wrap. It should look similar to this after you are done. Repeat the same steps to prepare the second capacitor with the wire that is soldered to the right output on the pcb.

Once you are done preparing the capacitors, take the capacitor which is soldered to the wire for the right output, loop the exposed leg from the outside of the right RCA and wrap the leg over the top and to the outside of the RCA.

Solder the leg of the capacitor to the RCA as shown in this photo.

Repeat the previous steps to solder the capacitor which is soldered to the left output to the left RCA. At this time, solder the ground wire to the grounding tabs. Snip off any extra material from the legs of the capacitors at this time.

Close the Gameboy Color back up and you should be ready to rock! It will be a snug fit, but there shouldn't be any excessive resistance or pressure from the components to close the case securely. To test out the mod, I used my altoid tin headphone amp.

The output will be pre-potentiometer so if you want to adjust levels you will have to do so through a mixer or to whatever you are plugging your GBC into. There will be a definite boost in bass frequencies.

This mod will make the GBC a well desired gameboy unit for LSDJ. The GBC processor will be able to handle high tempos, handle complicated table commands and reproduce accurate samples in the WAV channel. The bass mod will bring up the bass frequencies and the noise filtering will take care of any hum or white noise. You will also use half the batteries as you would in a DMG.

I apologize for the quality of the photos. I used my iPhone 4s and edited the images in Photoshop. Hopefully this tutorial was informative and had enough photos to document the process accurately enough to be followed through.

A big shout out goes to Scannerboy who to my understanding was the first person to list this mod on this site.

You can bass mod with 1/4” stereo and 1/8” stereo as well. After sending Nonfinite photos of this tutorial he sent back photos of doing the bass mod with a 1/8” stereo jack using SMD/SMT capacitors.

If you have any questions, please feel free to message me or post in this thread.

Corrected typo on capacitor value.

Thanks a lot @shitbird! Now I remember that I actually briefly browsed through that thread a loong while ago!
So judging from that thread, there are two very sensitive resistors you'd have to solder to... R30 for left channel and R31 for right channel. There's supposed to be a picture shared by @tenshun that shows this but it seems like the link is dead unfortunately. Oliver suggests to add yet another capacitor to remove excessive HUM, but he then also says that his so called 'noise mod' is mor or less obsolete in this thread.

I still have some questions regarding this mod and I hope some experienced people could perhaps answer them.
• Should olivers noise mod be considered to do when breaking out this line out source ?
• To what point should ground be soldered?
• Do anyone have any recommendations for a successful result? Cause it seems to me that it's rather tricky compared to the standard DMG and GBC ones.

I'd be happy to hear from anyone with this mod that could share their experience with it... smile

› Show Spoiler

So as the topic says, where do you original GBA musicians tap off your Line Out signal / ProSound -mod?
It seems like this is something that people are very secret about.

And yeah, you lucky ones that happen to have a Line Out on your original GBA with backlight mod (AGS 101 screen)... Does that affect the sound?

I don't know if this was the correct subcategory to post this in or whether it should be in the Tutorials, Mod section ?

Have a great evening chtuners! smile


(14 replies, posted in Nintendo Handhelds)

Looks neat!


(2 replies, posted in Nintendo Handhelds)

That's completely normal! The signal coming through your pro-sound 3,5mm jack is a Line level signal which is made for connecting to an external amplifier, such as the one connected to your speakers or the pre-amps in your mixer. The headphone jack uses the internal gameboy amplifier to amplify the signal to be able to drive your headphones. Essentially what a prosound mod does is bypassing that internal amplifier to allow external amplifiers to amplify the raw line level signal and do so much better.
I hope it makes more sense for you now smile


(3 replies, posted in Nintendo Handhelds)

I know that my GBA flashcart has support for both video, music and photos but the quality isn't any good..
I'm curious though, how come you would want this as a photoviewer ? Like, do you wanna stroll around with it and show your friends your photos on this device. No judgement, just curious because I really like any kind of game boy solution.. smile

Cool! I'd be happy to participate and start composing once the guidlines are all set wink

unexpectedbowtie wrote:

Can anybody point out the power LED solder points to use to avoid the heating up problem? I'm not 100% sure on what ones are correct, and it'd be good to sort out a few of my DMGs that get pretty hot before I fry anything. (!)

Hey, I'm sorry to bump this. But did you get an answer on which points to use?
I'm enjoying some time off to look over my trusty old DMG.

catskull wrote:

If you do use unregulated power, just be aware that the backlight brightness will go down as your batteries die. That may or may not be an issue for you. We used to desolder the power indicator LED for the backlight, but we switched to the regulated power source.

BennVenn claims to have a drop in replacement power regulator ready to go. So it's possible that you could simply upgrade your regulator if/when he finishes it. Until then, yeah I'd probably go with the unregulated power.

I also have some questions for you catskull, would you mind sharing the 'regulated' points of the DMG you switched to ?
Also, do you have any news regarding that replacement regulator board you were talking about? I was just thinking, could I maybe just replace some capacitors on the regulator board with some caps with higher capacitance to lower the heat coming from the regulator board and reduce the stress on the DMG hardware?


(3 replies, posted in Atari)

Thanks a lot @Matej and @fedepede04 for your help ! The PSU was the problem ! I don't know if I'm gonna try to recap it with new capacitors or buy a new one from exxo

Hi fellow chiptuners,
so I just bought a lot of two Ataris on a flee market. These are my first ever 16bit computers. One  of them is the STe 1040 and other STf 520 but unfortunately the STe 1040 doesn't seem to turn on.
So basically nothing happens when flipping the switch to turn on the STe, the two lights on the keyboard don't light up.. So I decided to open it up to see what was going on and to my great surprise I saw that there where no RF shields what so ever under the hood, could that really be why the STe wasn't starting ?
Then I checked the power supply board but nothing seemed really weird there after a first glans. What's your suggestions?

Could I maybe take the powersupply board from the STf and put it in the STe ?

Apeshit wrote:

That's connected to regulated 5v source. Connecting to the unregulated power source is not bad for the console, it bypasses everything. Putting strain on the regulator with the high current draw from an EMS cart and a backlight is damaging to the console.

Ah damn, thank you for pointing this out! I'm a bit noob on all these different solder points, which ones are considered the best to drive my nonelectronics V5 without having to add resistors etc. ?

I used these solderpoints:

And my backlight dims slightly when playing a song in LSDJ effectively or when the battery get low. Is it connected to an unregulated source ? Is that bad for the console ?

I'm sorry catskull I didn't quite understand what you ment by "a drop in replacement power regulator", is Benn Venn planning to release replacement boards of this kind ?
I just checked my DMG through the little hole of the battery cover and I have CPU-06, which I guess means that I have the old revision and therefore the heating would be seen as something 'normal' ?

Is this destroying the components internally ?

I'm also under the impression that the heat wasn't as bad like 1-2 years ago.. But I really don't know.

Judging from your photo, I could only imagine that it would be that little guy underneath the two capacitors(?) in the very corner that's causing the heat..

My DMG is labeled G261... on the back, does that min that it's the newer revision ? Around the power adaptor port it's marked "USE ONLY DMG 03 - 05"

Is this heat actually damaging my gameboy ?

Apeshit wrote:

Sounds like the regulator is overheating. Unrelated to the pro sound jack.

I'm guessing your gameboy is backlit. What kind of backlight/cart are you using if so?

Ah, ok I use the EMS cart with nonfinites V5 backlight, according to what he wrote on his website when I bought it there was no need for resistors or any other components.. The backlight is soldered onto two points on the same board as the screen, just below it.

irony7 wrote:

Power regulator heating up, perhaps?

If the Prosound jack is located in the corner on the bottom of the upper shell to the left of the headphone jack, it's right next to the DC converter board. I understand there are heat issues, especially with early revisions of that board.

That's exactly it, I never use any AC adaptor though, only batteries.. Is that DC converter situated on the same small chip that holds the headphone output ?
Edit: After further investigation I found that the heat seems to come more from the lower shell around the curved left corner facing the ground when it's laying flat on its' back.