Nelson Pass Aleph X clone build log

This is the biggest amp build so far and I doubt I will ever build anything bigger. Again, I went with a clone from the father-figure of DIY amps, Nelson Pass. Again, I got lots of help from the diyaudio.com community. And also got a ton of help from this particular website.

I won’t bore you with the details. If you’re interested in the nitty gritty, read through the diyaudio thread. Instead, here are a few photos from the build.

That is a lot of heat sinks and a lot of power transformer. Being class A comes at a cost.
Antek

These are the power supply boards half populated with big capacitors. Almost 300,000uF of capacitance could hurt you. A lot.
Aleph X

These are the boards for one channel. The main board and the daughter boards that parallel the MOSFETs to handle the extra power.
Aleph x

Here’s the basic layout on the heat sinks:
Aleph
Bottom view showing the 1/4″ aluminum tie pieces:
Aleph

I mounted the PSU board on one of the heat sinks:
Aleph X

Here they are completed and in testing position:
Aleph x

Like I said, they’re big. I think 20″ deep, 14″ wide, and probably about 50 lbs each. I’ll put them on a scale to find out for sure, but they’re really heavy.

Still breaking in, but so far, they sound really good. And act as space heaters as well.

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Starting the year with some culture

We got a season pass to the exploratorium as a gift this year and took full advantage on this New Year Day. As an uber-geek, I enjoy the hands on exhibits and do my best to explain things to the kids without going too far over their heads. I usually fail miserably, but they seem to like playing with all the various items despite my pontificating. Before I lose you as well, here are some photos of the day.

3 out of 4 isn’t bad:
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Xylophone band:
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A corner reflector display Ashley liked:
http://en.wikipedia.org/wiki/Corner_reflector
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She also liked this light refracting piece:
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At the dynamic rings funnel:
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This is the tornado display but reminds me of a Superman scene:
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Superman

This penrose triangle is a real thing… but is not possible as it appears. See the link for how they did it:
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A few more pics from our way out:
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Hello again

While putting together the annual calendar, Bonnie mentioned that some months are pretty sparse in the photo department. So here’s to rectifying that for 2013. No better time than the present to start so here we go.

Alissa’s School Christmas Concert:
Amazingly, Alissa got up with her class and sang a few Christmas songs for their holiday concert. I wasn’t able to get much of a photo so this will have to do:
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Here are a few of some friends as well:
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And in the pews proudly wearing her tree hat:
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Alissa’s birthday:
It was also Alissa’s birthday recently so we had a party at build-a-bear along with a few folks over for dinner on her actual birthday.
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And of course, it’s Christmas Eve so Santa will be here shortly. It was a nice day though so we spent some time outside:
Amanda is in the Christmas spirit:
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We had some pre-Santa activities earlier in the day resulting in this:
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Followed by the girls putting out cookies and milk right before bedtime:
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Along with a few other poses:
No idea why Alissa is posing like Superman:
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In this one, Alissa looks like she has to pee and Ashley has a crick in her neck:
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At a loss for words:
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With Grandma:
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With some dude who really, really needs a haircut:
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Twin swim!

Ashley and Amanda started swim lessons a few weeks ago. Amanda loved it from the first minute as expected. Ashley cried through the first day but has been good ever since. At today’s lesson, they were legitimately swimming about 6 feet from the instructor to the steps.

Here are a few photos.

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Going old school – Restoring an AR XA Turntable

As if I don’t have enough audio stuff already, I got curious about trying old school records and asked my father in law for his old one(s). The first he gave me was a reasonably modern Technics. Works fine. Kinda boring though.

The next one though… probably a 60’s era Acoustic Research turntable. Didn’t work, a little water damaged, and in need of some TLC for sure.

You can see it’s a pretty basic unit:
AR turntable

A little research showed a bit of a cult following though with a number of folks showing how they had restored their own turntables. So parts are available and upgrades ripe for the picking. Yay! Project!

Here’s the bottom:
AR turntable

The T-Frame is a stamped steel unit that makes up the sprung portion of the turntable. (The platter bearing and tone arm bearing as well as the motor assemblies are suspended by foam-damped springs.

You can see two motors actually. The left one is actually a starter motor that helps get the platter up to speed from zero rpm. It also makes sure the primary motor spins in the correct direction as it doesn’t necessarily do that on its on. Other things to note are that the really rudimentary shielding on the motors as well as the wire nuts. Did not expect to see those outside of a wall outlet.

AR turntable

Here you can see there’s some water damage (or maybe just humidity) on the bottom plate thing. It’s really just some dense cardboard.
AR turntable

Here you can see that there are actually two platters. An outer one that simply sits on top of the inner one that is driven by a belt.
AR turntable

This is the inner platter with the drive belts as well as the starter motor belt.
AR turntable

And the inner platter upside down to show the bearing and the shaft. Notice the spherical ball bearing at the end of the shaft. The bearing and shaft just needed a little cleaning/buffing plus a few drops of oil to spin smoothly again.
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You might have noticed that the plates were both fairly pitted and not exactly smooth. I actually ended up using a headlight polishing kit with pretty good results:

Pieces strewn apart but with the top plate painted black.
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Top plate stripped and ready for priming and painting.
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Solid walnut! Sanded and tung oiled. And here you can see some pretty intricate joinery.
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Here’s the tonearm after I had already polished up several of the pieces:
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This is the pivot bearing for the tonearm. It’s a nicely machined brass piece:
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This is the really cheapy and shot head shell and cartridge:
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This is my favorite piece (dorky, I know.) It’s a stepped aluminum pulley for the drive motor. The steps are for either 33 or 45 rpm. Also, the steps are crowned.
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Here’t the original (totally shot) RCA cable directly soldered to the tonearm wires:
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As a result, I ended up drilling recessed holes for RCA jacks:
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I also ended up ripping part, cleaning, and reassembling the on/off switch. It’s pretty crappy but I wanted to keep it as close to original as I reasonable could.
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I bought a new Shure M97x cartridge along with new tone arm wire to finish off that part of it. Also, I milled a hole for an IEC so it would be easier to plug in and out. Also, the power cable was pretty old and ratty anyway.

Unfortunately, I messed up one of the pogo pins in the tonearm while soldering in one of the new wires so had to order a new one. Once that comes in though, it should be quick work to get this thing working and playing music! Now… just need to find some records to actually play!

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More speakers!? A high-end two-way bookshelf

I wanted to try a speaker with super high-end drivers so I found some used for a pretty good deal and also found a pair of cabinets that someone didn’t want anymore. As such, I was able to go high-end without a high-end price. Brand new, the drivers and crossover plus a from scratch cabinet would have easily exceeded $1000. As is, I spent about half that.

Here is the cabinet that I started with:

And I turned them into these:


I still have quite a big of material left over of course, but it was nice to be able to spend zero dollars on the cabinet and just a few bucks on some rattle can satin spray paint.

The crossover is a Madisound design that came with the drivers (The Scan Speak 5″ Revelator and D6600 tweeter). They turned out fine… but I’m not convinced the price premium is worth it. I haven’t done a lot of listening yet so I might change my mind, but I doubt it. Even if I can hear a difference compared to my various Dayton speakers, for sure it will not be very significant.

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Pre-school Graduation Photos

Here are a few photos of Alissa’s graduation. The full set is here. She had a bit of stage fright for the performance but it was cute nonetheless. I’ll get the performance video up one of these days.

The cake Bonnie made:
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Stage fright:
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A little better:
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And worse again:
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Hula hooping like a champ but not looking at the crowd:
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Graduation ceremony:
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Done:
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Pre-school graduation video

The school asked uss to help with the end of year video this year so Bonnie and I put this (16 min) montage together:

Bumblebee Class of 2012 from Jason Wang on Vimeo.

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Our old cars

I’m still a huge car guy but haven’t had much interesting stuff going on in the car arena in quite a while. But I did get a chance to give the Pilot and Lexus overdue car washes yesterday. The Pilot is almost 6 years old with a little more than 40,000 miles and still looks brand new (a couple minor run ins with our garage door but not bad considering there’s literally a fraction of an inch clearance). Just change the fluids and keep the tires inflated.

Cars

The Lexus is also running like a champ. It’s more than 10 years old now (I’ve had it for about 5) has about 127,000 miles and has not needed anything of note after the water pump and timing belt change I did myself shortly after I bought it. It has needed new tires for quite a while now and I finally found a set of almost brand new tires on a set of Honda s2000 wheels. The wheels aren’t perfect, but I got the set plus a pair of Kosei wheels and Nitto tires for cheaper than a set of new tires would have cost! I love CL.

Before:
Cars

After:
Cars

The new wheels are 16″ vs. 17″ so they look a little small to me, but no big deal. Also, I’m missing a pair of center caps. Finally, these wheels are lug centric where as the Lexus ones are hub centric so I needed a new set of conical lug nuts too. Who knows… maybe I’ll own an s2000 again someday and these will be my track wheels. 🙂

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