cool, thanks y’all!
DMGs are soldered using lead solder, as mentioned use a higher heat to see if that makes it easier, I use a solder station and since buying one about 5 years ago my soldering got a lot easier, well worth investing if you do not already have one.
yeah I upgraded to a temperature controlled iron about a year ago and my soldering quality improved.
@masterofstuff124 good advice/insight! I didn’t even think of using sandpaper on stubborn surfaces. I usually just heat the crap out of them until the solder sticks. Probably not the best idea on a gameboy where some components can be damaged, but it works when making cables 
hey just wanted to say that i used some contact cleaner (deoxit) on a qtip
and rubbed it over/around the solder joints on the gb board before i soldered and it made a big difference!
much easier now
thanks again for the tips!
just did this “bass boost” mod for the pro sound output.
was totally worth it if you’re not using mono or the direct out. sounds a lot fuller now
it works! internal clock in mod synced up to the op1.
also the pinout diagram i found for the link port in case anybody wants to give it a go.
i double checked it w/ a multimeter just to be safe.
pin 2 is for sync out, pin 3 sync in. connect to tip of your jack.
pin 6 is gnd, but i just connected the jack sleeve to closer gnd point.
the fiio is for amplifying the sync signal from the op1.
i’ve got a second DMG that i’m going to try sync in and out.
@docshermsticks — that’s awesome man!
sorry to be a bit obtuse, but i’m afraid my modding experience with the GB includes opening it one time and looking at it… and that’s it.
the pic of the GB has extra ports added, one of which is for the sync i assume…
but the pic on the write has the sync points next to the DMG link port… so…
how’d you do that? what’d you do exactly? and what’s the easiest way to replicate the success you had… ?
simplified for ham-fisted chump who lives in Viet Nam where the link cables are rare as, and bricking DMG’s is basically throwing gold in the bin.
i mean… if you have a minute 
you can do it man! i didn't know much either about a week ago.
lots of info & good tips for modding gb's on the internet.
just go slow at each step and you should be alright. i think the major thing is to worry about messing up the screen, but what we are doing here is far away from the screen so no worries there.
pin 2 for sync out, pin 3 for sync in on the diagram i posted above
(ignore the top part of the pic w/ the red usb adapter. its someone else's pic i found w/ the pinouts)
so you have to run a wire from the link port pin to the tip of your jack, which is what i did.
then also run a wire from the sleeve of your jack to one of the many ground points on the gb board.
the one on the battery contact is one option, or the one on the original headphone jack another
space is limited on the inside so the bottom left corner on the top half of the gb is a nice spot to place your jack.
if you remove the headphone board on the DMG, you can fit 3 jacks there like i did.
otherwise i think you can only fit one. there's other spots, but this one was the easiest for me.
removing the headphone board is only necessary if you need the extra space
also doesn't necessarily mean that you will lose sound there. i just hooked up the original headphone jack w/ the pro sound mod and then reconnected the 2 extras pins on the headphone jack to restore the speaker to its normal operation (speaker on and off when you plug something in or out).
so to sum up:
1. connect wire to pin 2 (out) or pin 3 (in) of link port
2. connect other side of wire to TIP of your jack
3. connect SLEEVE of jack to ground point on GB w/ a second wire
4. check to see if it works
5. drill hole for jack (take your time here, make sure it fits!), then put everything back together.
6. sync up your buddies and have some fun!
i'll try to remember to take a pic of the inside when i do this to my other DMG
awesome! thanks for the detailed response
Has anyone tried the direct out mod on a gameboy color? I’m assuming NL Mono would sound just as good on a color or pocket as it would on a DMG if using the direct out mod, correct? Thanks
@psychickcv yea u are bypassing the gb amp and sound w/ the direct out. i don’t have another GB besides DMG but it should sound the same on any model.
i think somebody did it earlier in the thread (edit: or at least mentioned it)
on a side note, my b button stopped working on my 2nd DMG as i’ve been modding it up. after a lot of head scratching and cursing, i noticed the smallest of small chip on the corner of the button/lcd pcb on the bottom near select.
follow the trace, yup its the b button.
never scraped & resoldered a trace before but am now happy to say that the b button is back in action!
really relieved i didn’t permanently damage it.
also have been experimenting w/ RC Lowpass filters on the pro sound output (hum) and the direct output (white noise).
2 poles gives pretty decent filtering w/o killing the highs. went around 7.2kHz for the pro sound and 9kHz for the direct out.
like how the filtering smooths out the sound. esp snares and hats.
i havent done it. waiting for a sale or something. a bit strapped with all the projects I got going on. plus holidays. Ill get one eventually hopefully during a sale. and will mod it with the direct out, sync, etc for my gameboy pocket.
a little slice of how the dmg w/ nanoloop mono and 1.7 is working in my setup… op-1 too, just for relevance.
Not sure it’ll this is the right thread, but 2xaa on Instagram has some nice work integrating nanoloop and op1
we dont have a Nanoloop thread. so this has sorta become the defacto! But everytime it gets bumped up I have to resist so hard not to order the nanoloop mono. Something about it I yearn for. Its like a tiny analog 4 octatrack. that instagram channel is awesome!
must resist. thinkof the OPZ…
FUCK FUCK FUCK
if the mono runs on this. good lord…
Hmm, somehow I doubt it’d work. Depends on the attention to detail regarding full compatibility… if it has the audio pin enabled, then it may work… having said that though, nanoloop is a bit temperamental in general (for example, nl2.x doesn’t work on this awesome looking GBA clone).
In any case, there’s really nothing like running nanoloop on the original handhelds. I really need to get around to modding my silver gameboy pocket 
I'm finally getting the time to play with this a bit more.. plus I just got a volca kick and they sound very nice together:
https://www.youtube.com/watch?v=-vqSVrMfWVg
Hey @Darenager is there any way you could share where you soldered to bypass in internal amp for this? Or anyone else who knows? Already have one DMG with RCA out but this would be nice also!
the answer is on page 4
second pin from the left on the game cartridge connector
D’oh! Thank you, I thought I had seen it but I keep checking and never saw it again for some reason. Thank you! Time to order a second DMG!
I can link two together for clock just with a standard gameboy cable? Or will I need to make a converter?
D'oh! Thank you, I thought I had seen it but I keep checking and never saw it again for some reason. Thank you! Time to order a second DMG!I can link two together for clock just with a standard gameboy cable? Or will I need to make a converter?
Yeah, the standard link cable works.