Bonnie’s flat lying down dumplings:

My awesome standing up dumplings:

I don’t know why Alissa doesn’t look happy in this picture.

Another project in the books. This one is my first class A power amplifier build. The circuit itself is actually relatively simple. And the casework wasn’t bad either truth be told. But I’m getting ahead of myself.

The design is from one of the godfathers of the DIY HIFI community, Nelson Pass. He runs a DIY website as well as a commercial and a sort of hybrid enterprise that sells retail items but also provides schematics and articles so the enterprising DIY’er can “roll his own.” He’s also active on the diyaudio.com site and chimes in from time to time.

The specific design I chose is the F5. It’s a push-pull Class A amplifier, utilizing JFETs and MOSFETs in a very simple two stage complementary circuit. It spits out about 180W (most of it in heat) and is one of the more popular designs from Mr. Pass.

For my build, I sourced the PCB from tech-diy.com and most of the little bits from mouser. The heat sinks were from antek and the rest of the chassis was made up of scraps actually. I had spare 1/4″ aluminum for the bottom, African mahogany for the front panel, plywood for the rear, and plexiglass (from an old document holder) for the top. I did buy some 1/4-20 bolts and some new RCA jacks and speaker posts. But all in all, I think I only spent about $300 all told. Some have been known to spend that much just on the front plate!

In any case, pictures are where the fun is so here you go.

The trafo, rectifiers, and first pair of caps that make up the separate PSU enclosure. I used a 4-pole Neurtrik Speak-On connector for V+/G/V-/earth ground:

Here’s the enclosure for the PSU. Made from more scraps:

Here are the amp PCBs coming to together mounted on the heat sinks:

Here’s the view of the front/bottom with the mahogany and aluminum holding the heat sinks together:

And of the rear/bottom:

In mockup mode:

The beginnings of milling the rear:

All put together with the plexiglass top:

Shot of the front with the powdercoated aluminum letters I splurged on:

Stacked on the PSU:

It sounds great and doubles as a space heater! I got it biased up to about 580mV and the DC offset is essentially zero on both channels.

Some sketches I made on the plane on the way home from a business trip:

I got the tweeters used and the woofers aren’t that much to begin with so I just bought them.

I made the cabinet with simple birch plywood all leftover from other projects with mitered and biscuited corners. The front corners will be about a 3/8″ bevel as a design feature (I’m a sucker for the laminate look for some reason) with a basic hand rubbed tung oil finish to match many of my other builds.

The sides and back glued up:

Crossovers installed with foam and just waiting for the front baffles:

The problem with not having perfectly square cuts and positioned biscuits:

Testing out the first speaker:

Their current resting place book-ending my headphone amp and the chipamp.

So far, I’ve been very happy with them. They need a little breaking in and they don’t sound nearly as good as the full size designs, but they’re very good for what they are.

The next project will be the opposite end of the spectrum… very large with dual woofers, dual mid-ranges, and my first build with a ribbon tweeter. And of course, I still need to finish the other amps and buffer projects!

Over the weekend, we also spent some time cleaning up the backyard and took advantage of the weather to take another few random shots.

It seems the kids enjoy smiling for the camera on a tripod (I got a Gorilla one from Eric for Xmas, thanks Eric!) more than when I’m taking the picture myself. I think they mostly enjoy watching me run back and forth to trigger the timer.

First, some warm up shots at home while getting ready:

We decided to expose the kids to their first muni ride, so we made the short walk two blocks to the L-Taraval:

After our muni ride, we went to the Metreon for lunch before the movie:
A big bread bowl of soup fed us all.

After watching The Secret Life of Arietty (and a lot of popcorn), we went to the MOMA by way of the Blue Bottle Cafe on the terrace level.

The girls enjoyed their hot chocolate and we had our fancy coffee:

After a quick walk through the MOMA (it was free first Tuesday of the month) we got back on Muni and came home:

Alissa practiced her photography skills on me:

And on the West Portal station:

All in all, a successful field trip!

Of course, Bonnie had to go nuts with the decorating and favors and food.
Case in point… Scratch made cupcakes with cream cheese frosting:

Sprinkle marshmallows:

Custom inscribed and decorated sugar cookies:

Favor bags:

We also got a bunch of toys from Oriental Trading company in lieu of other entertainment. There were inflatable animals and flowers and other crafty type activities that all the kids seemed to enjoy. Even the younger ones had a good time:

Alissa was a very gracious host herself:

… and made sure even the (grand)parents had fun:

Of course, the party couldn’t be complete without the girls blowing out their birthday candles.

Once again, we treated this as a family reunion of sorts and were happy that The Paches made the trip (capitalized since Christian is so tall) as well as the Nas. Grandma was there as well as Uncle Chung who has since actually moved to a house just around the corner from my parents. As always, the other Wangs (my parents and Mike and Jen) were there to serve as our local guides.)

Anyway, without further ado, here’s the photo log of our trip:

Over the course of the week, we spent a fair amount of time at a couple parks close to my parents’ house:
Amanda looking up after a successful slide:

Chloe looking ever more the teenager:

Aidan seeing the sights:

Alissa and Chloe through the looking rock:

Ashley and Amanda flying a plane:

Car models:

Fearless Amanda:

Despite this whoopsie:

Alissa’s first time doing monkey bars:

We also went to the strip…

…to visit the holiday display at the Bellagio…

…as well as visit the M&M store.

The one grown-up night out we did was with Christian, Anna, and Jen to dinner at Nobu. Here are a few of the dishes we had:

It was very yummy but perhaps not blow your mind yummy. Especially considering the price.

Otherwise, we spent a lot of time hanging out at home and enjoying the great chilly but sunny weather:
A little tennis video I made just for fun:

Some Wii games:

Amanda getting her finger prints all over my iPad:

Ashley enjoying a seaweed snack:

Jelly faces:

Of course, we also exchanged some gifts, mostly for the kids. However, Leslie also had the great idea to have a photo quilt made for our grandma who has been dealing with Alzheimer’s. The quilt allowed for 60 images and turned out great. Here she is opening the quilt:

All in all, a great trip. Here’s to 2013?!

The funny thing is the ones we paid for are even worse. Maybe next year!