Sunday, September 25, 2016

Inside the R4 3DS cart

Recently picked up a Nintendo DS Lite from eBay - wanting to play some Powder (all time favourite game - and most time played on both the gameboy advance, and PSP) I had to of course get a flash cart.

Actually buying one of these is a real pain - Aliexpress, eBay, etc don't list them.  
From what I read apparently PayPal does not allow the sale of what they consider 'modchips'. Thus finding a reputable site is a bit of work and many recommendations from forums lead to broken links.  (I guess stores have a hard time staying up?) I was shocked that nothing had changed from the 2000s when I last went looking for a flashcard for my gameboy micro.


I was of course curious to what the PCB looked like. Sadly it looks like the brains is a 'Chip On Board' (COB)

Apparently you can use the wifi to load files to the SD Card. Considering the DS Lite only supports WEP and the software is some sketchy windows only thing it's unlikely i'll ever try it out.

"Truth Inquiry" Uh okay. 

I believe the top left chip is KH25L1606EM2C-12G - a spi-flash chip.
The bottom right chip is 95010WP - which is a ST micro SPI eeprom

As I don't have a magnifying glass at the moment reading the text was a bit difficult. 

Bottom of the board. 

Video of the very ghetto UI. 

Saturday, July 23, 2016

ELAN Z630 guts

One of the most difficult things I have found with doing electronics and especially audio stuff is finding a appropriate case. Many times the price is is higher than the actual components! Not to mention the mechanical side of things is not my forte. Without a drill press and the proper tools it's very difficult and time consuming to work with metal. 

Recently I found a seller on eBay that had some crazy prices on various server equipment and miscellaneous audio equipment. The catch was shipping ($20-$30) with FedEx ground as the only option. 

However for most stuff, even with shipping the price was still cheaper than buying a rackmount enclosure! 

I picked up this preamp / input selector for $4.50 (and $32 shipping) $36.5 total for a 1U rackmount case with all the holes I need for my input selector! Device is a ELAN Z630.

Inside the case were some useful components I can salvage (specifically the transformer!) 

Sunday, May 31, 2015

Two years or so ago I embarked on building a amplifier. I never got around to doing a proper write up so here it is! (minus the proper part)
I saw a kit on eBay and read some reviews about the LM3886, all of which were good. Decided this would be my first amplifier project.
As usual I ended up spending far more money than I had intended. It started out partly as a money saving venture, a good quality amp is expensive but DIY is cheap.
Well it's cheap when you know what you're doing.

In the end I was happy, it sounded great and I learned a lot in the process.

I had built a small tube buffer amplifier (another kit from China) which exposed me a bit to transformer/mains voltage, I asked a coworker to give me a hand wiring up the transformer which gave me a bit more confidence dealing with mains voltage.
This project however I did myself and helped increase my comfort with mains - no shocks!
Looking back at this work I am somewhat unhappy about the wiring which is pretty sloppy. I'm pretty sure I covered up the mains connectors, and I'm pretty sure I
connected a chassis ground. I know however I checked for continuity to earth ground.

In the end this amplifier ended up in the hands of my friend. I had purchased another kit to build one for
him, and well it didn't happen and I ended up giving this one away.
This was the kick I needed, my old amplifier (A $2 acquirement at a garage sale - worked great
but came no where close to the great clean sound the LM3886 produced.
I'll eventually get the photos of that new amp I built which I'm much happier build wise with.

One thing I still have not been able to figure out is the volume control.
With a loud input source the pot works great, however
it's difficult to drive the amp to it's limits as from my computer the sound-card clips before the
amp does.
I believe I need a preamp in there and as of 2015-05-29 I have ordered a few other kits to try and fill in this gap.
I highly suggest this amplifier, other than the caps I did not switch out any of the components.
Folks on have many suggestions for components to swap out.
At some point I may give it a go, but I think my speakers are now the weak link and I have no complaints
about the sound!.

I bought the transformer from the same eBay seller and s/he had shipped it all together.
So in transit one of the Capacitors was damaged. The seller was happy to replace it but being in a rush to get things underway I ordered some caps from digikey - Nichicon UFW1H103MRD - $8 a pop!
Damaged cap!
Nichicon UFW1H103MRD
Pot, I believe this is a ALPS 100k
Step attenuator I ordered - I never build it
some progress on the amp pcb
bottom of psu pcb
Bottom of the amp pcb
Power-supply PCB almost populated
All done!
Basic test using a scrap heatsink
Messy workbench!
Speaker protection board
The testing setup.
Small device that has some RCA plugs and is wired to the pot. Useful for the testing process
Getting the heat sinks mounted was a exercise in frustration Drilling the holes in took way too much effort. If only I had a drill press.
I tried to drill the other way, it sorta worked.
It all worked out in the end.
Starting to figure out how to lay everything out
IEC Connector with the integrated fuse holder
Hey not bad!
Starting to wire up everything
The embarrassing layout
Sitting open while I do tests
Close up of the IEC connector, you can see how much of a struggle I had cutting that hole. It wasn't perfect but it's on the back, so hey no one will notice!
close up of the power button
Power button switch
Speaker binding posts installed
All the components laid out on the bottom plate of the chassis
It's a mess in there....
Back of the amp with stuff connected
Turned on, look at that pretty power glow!
Hey you can see ole reliable still on the shelf!