Monday, August 30, 2010

Eleven Mile Canyon with the Whole Family

We set out to head up to a nice little river about an hour from our house but due to a  summer festival going on literally in the middle of the road,  the road was closed and the detour would have taken hours.  So we made lemonade.  We kept on going to one of our favorite rivers on the front range, Eleven Mile Canyon of the South Platte River.
We set up camp in the catch and release section on what is usually a great little fishing hole with a nice quiet, slow moving pool only for whatever reason the flows were way up and the water was really moving.  That was ok with us as we had fun coloring and of course looking for bugs.  Elizabeth had a collection of bugs that I've never seen in my life.  She will be very good at determining what to use for flies someday!  

The entire day we could not keep Elizabeth out of the water even though to us it was frigid cold.  She loved it.  

Andrew was as happy as a clam fishing with Daddy.  He sat in the back pack, would fuss a little bit when he wanted a bottle and Jan would just fish over where I was standing so I could feed him a bottle and then they were back out fishing again.  
As usual, Elizabeth was thrilled with the catch of the day!  

We could not resist including this picture of our day camp.  Elizabeth is not very efficient nor effective at going potty in the woods.  Therefore, the potty comes with us when we go on family outings!  When I was taking this picture, Elizabeth kept asking, mommy, what are you taking a picture of?  Oh, just the woods, Elizabeth!

Sunday, August 29, 2010

Vacuum Tube Headphone Amplifier

So what does an engineer do to stay up on their electrical engineering and earn a little respect with his coworkers?  Take on a little electrical engineering project of course.  So what project could I take on that I could show off at work on my desk that looks cool and has a practical application?  The most interesting thing that I found was a vacuum tube headphone amplifier - basically something that takes the output from your CD player or iPOD and makes it louder.  Yes, both such devices already have a circuit in them to power your headphones however they usually aren't of the best quality and generally only work well with cheaper headphones that don't sound all that great to begin with.  This thing should make a huge difference.

So after quite a bit of research I settled on the SOHA II headphone amp which utilizes a vacuum tube input stage and solid state output stage.   All of the info including schematics and building instructions can be found here at and PC boards can be purchased from

This is a pretty clever little design utilizing inexpensive and easy to find 12au7 preamp tubes, the schematic is shown below (this is the schematic for one channel).  The beauty of this design is that these tubes only require 60-90 volts to run properly as opposed most tubes requiring 200+ volts to work so it is much safer for a first time builder such as myself.

Here is the power supply schematic as well:

While the schematic looks pretty complex at first look it is really quite an elegant design making use of relatively inexpensive parts and is a rather robust design allowing for easy tube swapping.

Once I did all of my homework I ordered up most of the parts including the circuit boards from and purchased in the rest from Mouser, Digikey, and some scraps I was able to scrounge up at work.

Step 1:  Design the Amplifier Housing
I started out with plans to use a commercially available metal enclosure but I decided something a little more unique would be more interesting.  So I sketched up a little design:
Then a quick CAD model - Google Sketch is very cool!

Step 2: Build up the Circuit Board

From a box of parts to the nearly completed board
Step 3:  Build the case and and put it all together

The corners and top piece are Bocote while the main body of the amp is Zebrawood

I put LEDs under the tubes to get them to glow

Listening Impressions:
Now that I have had this for a while I find this amp is quite incredible, its almost like switching to a high def TV from std def.  The bass has a lot more punch, the midrange/vocals are amazingly smooth and the highs shimmer and are exceptionally clean.  Another  observation is that the music takes on an almost 3D quality. With such clarity your ear can roam to single out individual instruments in a way that I had never experienced before.  Bottom line - I love this little amp!

I'm thinking maybe this coming winter I may just have to try another one of these!

Sunday, August 15, 2010

Flats 2010

This year our trip was a little different than usual - now for the first time since my brother and I were little kids there we little  kids running around the cottage which significantly changed the dynamic on the island.  Having kids there brings out the best in the place - there is so much beauty and so much life at the flats but having spent so much time there throughout my life i find that so much of it can easily be taken for granted.  Having the kids around, particularly Elizabeth who is so in tune with nature brings the mystery back and illuminates all of God's magnificent creation for us all to enjoy.  She is so inquisitive and interested in all of the new things she sees and is so excited by it all.

Having two kids there to look after really changes things in other ways too.  This year for the first time I didn't get a Michigan fishing license, not because I was willing to risk it but because we just never had much of a chance to fish.  Elizabeth did a little fishing from the dock on the island and a wonderful time catching a few perch.  I'm not sure what was more fun for her, playing with the fish or the worms?

This year Kate wanted to try to go to the Riverside every day while we were there.  Last year Kate was pregnant and was craving the pizza, "Boat Knots", and ice cream every day as well but on several occasions we were unable to make the trip due to weather conditions and the boats available to get her there.  As it turns out the best way is by jet ski, or wave runner, or personal watercraft, whatever they are calling them these days - due to the shallow cuts through the marsh which often give outboards problems, but we didn't think pregnant Kate on a jet ski was such a good idea.  We then used the second best mode of transportation, the jet boat - a slightly more seaworthy vessel - or at least the term 'boat" implies a little more safety and confidence to grandparents than "jet ski"!  This year - Kate isn't pregnant but never kicked the craving so off to riverside we went, some days twice!

Casey, Jennifer, and Abe made it down for a couple of nights with us and were there to celebrate Elizabeth's 3rd birthday.  We also had a chance for a quick waterski one evening right as the sun was setting making for some great photos.

Towards the end of our trip we decided to take Elizabeth over to Freighter Beach to play.  Freighter beach is neat little sandy beach right off of one of the main shipping channels in the Great Lakes.  Its a bit of a hike for us but it makes for a great boat ride and offers one of the few sandy beaches around and a great place for Elizabeth to play.

We got Lucky in two regards, one, we get to see a freighter and two, we had the whole place to ourselves.

We even has some foxes this year running around the island, I was fortunate to get a couple fun shots of them!
Elizabeth hasn't started sailing yet but she has already figured out that relaxing at the dock is half the fun.  It won't be long before she is out sailing with her daddy!  I can't wait!

Aunt Carla made it down for a few days and we had a great time visiting with her!

Uncle Casey had a great time playing with Andrew and Elizabeth!

We had a wonderful time once again this year and are looking forward to getting back again soon.  Each year brings a new adventure as the kids grow so much from each year to the next, I can't wait to see what next year brings!  

Saturday, August 14, 2010

East Coast Visit (Part II)

After visiting Cathy and her family in VA we headed up to Pennsylvania to visit my Grandmom and have a little family reunion.  On the way, we stopped at the Baltimore Aquarium and had lunch at one of our favorite seafood resturants of all times, Mamma's on the Half Shell.  Visiting with  Fred, Ellen and Freddy for lunch made the stop extra special.

Elizabeth loved the aquarium.  Her favorites were the endless collection of turtles, sting rays and the amazing shark tanks.

Unfortnuatley, after we had lunch, my mom called ad we found out that my Grandmom Bunny was in the hospital after falling in her garden the day before.  He shattered her shoulder and broke her thumb.  She is still in rehad and we are praying for a speedy recovery so that she can get back home to St Marys and her garden and gift shop.  We had the opprotunity to visit her in the hospital a few times and she just loved meeting Andrew and talking with Elizabeth. Andrew and Grandmom played peek a boo and tug of war and Elizabeth liked showing grandmom her angel ( that Grandmom Bunny gave to her).  She loves the angel and sleeps with her every evening.

Despite Grandmom's health, we did have a nice time in PA.  My Aunt Carol came up from VA,  my Aunt Jane from CT, Mr. and Mrs. T from Allentown, mom and dad from TX, Cathy from VA,  my Aunt My and Uncle John who live close to Grandmom and the lovely sisters at St Marys.

The highlight of the trip for Elizabeth were the bugs and horses.  Aunt Myra has a butterfly bush that had at least 25 butterflies on it at any one time.  The butterflies entertained Elizabeth for hours.  We didn't think that she would be able to catch one but she surprised us!  She carried the poor butterfly around for a day in her bug box (and we chalked it up to a budding scientist).  In Elizabeth fashion, she of course didn't limit her search to butterflies but found lots of ants, fire flies, worms, gnats etc.  She finds bugs that I wouldn't have a clue where to even look to determine what it is!

In Grandmom Bunny's garden

Chasing and catching butterflies at Aunt My and Uncle John's house

Like Grandpa like Granddaughter