What Are You Building Today

[luvdunhill]

I believe the old thread is gone, so starting a new one.

A retrofitted power supply for a JDM Esoteric SACD player

[mypasswordis]

Today I got my dad to breadboard his first circuit, using a GPIO pin off a Raspberry Pi 3 to blink an LED with a python script. Does that count?

Next up for him is a T2.

[spritzer]

T2 with DHT's!!   

Me I just did construction today as I finished all of the small projects I'd been neglecting for the past few weeks.

[dsavitsk]

I spent the day trying to cut a chunk of wood with a 30 degree angle. After a few tries, I am as close as 29.996. That's probably going to have to work.

[crappyjones123]

I doubt many people would have a tool to measure 30 degrees that precisely Doug

[dsavitsk]

I don't either, but I can cut 12 of them, put them in a circle, and divide the error by 12.

[luvdunhill]

(makeshift board heater)

Then there were three. Now need a jig to be able to apply the paste to the bottom side - perhaps a piece of plywood with a cutout?

As you can see, the middle pin of the transistors and the tabs wouldn't flow. These are multilayer boards with that large copper area exposed. I also had to "reheat" the boards during the process. I am not confident I really got good contact on the j-hook trimmers. I will just apply hand solder to these parts likely.

[dsavitsk]

That seems like a lot of effort for 18 parts. Have you looked into small ovens? Or hotplates?

http://dangerousprototypes.com/2013/03/14/workshop-video-59-946a-solder-reflow-hot-plate-workshop-video/

 

[luvdunhill]

Actually I will get these made for me, but need to validate a few values. It was a pretty quick job, much faster than doing it by hand.

a plate wasn't viable because there are parts on both sides.

[luvdunhill]

I failed at cutting a round hole. But it works well enough.

[Fitz]

Round is overrated anyways.

[Mister X]

Pretty clever makeshift reflow setup.

[luvdunhill]

So, if anyone is interested in some of these micro 11-turn trimmers I have decided to go with a different value and have a kings' ransom of 50 ohm left over

[Dusty Chalk]

<3 Purple circuitboard

[luvdunhill]

Burn-in

[luvdunhill]

Here is a low pass filter board, utilizing above discrete opamp

[Mister X]

Some random person from the other side of the world asked if I could fix a dead channel on his Y1.5 build.

 

 

Had a couple of other issues to sort out but the dead channel part was easy.

 

[UFN]

Fourth pin from the bottom?

//UFN

[Pars]

C8 ground doesn't appear to be soldered... 1st and 2nd pins from the bottom appear to have something bridging them as well.

[Mister X]

Picked that little thread of wire off and got sound from that channel.  

 

 

 

 

[Mister X]

Had to switch the resistors around but otherwise Ti's upgrade board for the LM78X looks promising. 

 

 

[luvdunhill]

cross-post, but in case anyone is interested:

http://www.diyaudio.com/forums/swap-meet/291234-fs-nelson-pass-vfet2-front-end-pcbs.html#post4712322

[luvdunhill]

Here is a low pass filter board, utilizing above discrete opamp

... And doing something useful. Any guesses on what?

[guzziguy]

Maybe a crossover?

[luvdunhill]

My assembly order arrived! Complete with quality stickers!