Saturday, April 30, 2016

Phono Preamp

I know that all this electronic stuff and pictures of circuit boards is kind of boring for those of you who like cars and motorcycles.  But I like it.

The latest project is a phono preamp that uses vacuum tubes.  Why vacuum tubes you ask?  Isn't that old fashion?  Well, I'm new to it too, but the designer says that vacuum tubes have certain advantages like a wide dynamic range and, besides, he likes the way they look.  OK.  Good enough for me.

If you are curious why it's on a piece of plywood,  I hope to build a DIY turntable and stand in the future.  That may turn out to have a triangle shape.  Since the preamp should "fit" with the turntable and stand, I'm waiting until all that gets decided before designing the preamp enclosure.  What do you think, a big triangle with the points cut off?  Or maybe a trapezoid?

One of the unusual things about vacuum tubes is that they essentially need 3 power supplies and those are often in a separate enclosure to keep the tubes quiet.  In other words, there was lots to learn on this project and an extra dollop of complexity.

Tubes also take time to warm up and turn on.  Maybe 30 seconds before there is a little glow in the top of each tube.  No music comes out before that.  Kind of strange for our normal "instant on" solid state life.

Speaking of the separate power supply enclosure, I tried something a little unusual in the paint job.  I was going for "old leather", but I don't quite get there.  Oh well.  The power supply will sit in back on a bottom shelf, so no one will really see it.

The good thing is that it sounds great!  Background noise as good as a CD and a very dynamic presentation.  I guess I need to buy a few new records.

Friday, March 4, 2016

My father's version of steampunk

They say that you should always spend time with your parents and every question you can think of while they are still here.  Of course, my father passed away last year, so when I find something unusual in his stuff, I can no longer ask him what it was for or how it worked.  I guess what they say is true.

My father had a bunch of electronic projects, mostly things that he wanted to explore and made something that allowed him to do it.  Naturally, all that stuff came home with me when we cleaned out his house.  Now, he never expected or intended for anyone else to be interested it his little projects, so there is no documentation and almost no labeling.  Imagine my surprise when I open up an electronics test box and find this funky looking electro-mechanical device.

As for me, I have no idea what it was for.  I've studied it for a while and I think I can describe some of it's function, but why you would do this is a mystery.  I am open to suggestions.

In the meantime, I just love the way it looks.  I guess all the brass got me thinking steam punk.  But it's also got a combination of Rube Goldberg and something hand made early in the 19th century.

Anyway, here is what I see happening.  To start with, there is a DC motor that drives a gear reduction and a shaft mounted in oil-light bearings.  I don't have any idea where the motor is from.  The gears and shaft are likely left over from our slot car days.

Then there are two commutators mounted on the shaft with home-made brush holders on each commutator.  Don't you just love the brass tube with one end folded over as a brush holder?  One one end, the commutator makes a circuit with several resistors that seem to step down (up?) in resistance as the brush connects with each part of the commutator.  The whole thing connects to the opposite commutator in only one place.

I'm stumped.  But it does look cool!

Tuesday, February 23, 2016

Where did the winter go?

 This is one of those winters when I keep waiting for it to begin.  It's the end of February and it hasn't really started yet.  With a little luck, we will get a few inches of snow tomorrow, but it is too late to make up for the real winter I was hoping for.  You see, for the last 38 years of my life, I have spent the majority of winter on test trips in Arizona or California, etc.  I thought, now that I'm retired, I will get to enjoy a real, full time winter.  Not this year.

But that doesn't mean that I don't have pictures of snow to cheer me up.  Actually, this post was inspired by my friend, Doug, who is a native of the southwest ( a no snow kind of guy), but who has given winter and snow the old college try for the sake of some good friends.  So Doug, think positive thoughts.  Snow is wonderful.  Snow is beautiful.  You can always hire somebody to shovel.

My favorite breakfast restaurant.

 Anybody for hoops?

And easy parking.

Forgive me if I am reusing photos that you have already seen.  It's just that they are my favorites and make me want to get out and play.

Tuesday, January 12, 2016

Guido's Smile

Guido has been out playing in the snow.  Can't you see the smile on his face?

This weekend, it was sloppy, but Monday turned cold and Tuesday morning we woke to cold, powdery snow, the kind with good grip. ;-)

This naturally got me thinking about time spent with my friend, Guido.  He recently outran his extended warranty and is pushing 5 years.  Hmmmn.  Normally, I should be thinking about a new car.  Yet strangely, I'm not.

Two recent experiences came to mind.

Out in New York state, we pulled into a toll plaza and the guy in the window calls out, "Fiat Sighting!"  It was like he was playing "red car, blue car" and seeing a Fiat was something special.  I guess I was the red car.

Around Detroit, I mainly expect to see cars from the Big 3.  Even though the Fiat is technically a "Big 3" car, it really isn't main stream.  Plus, if you see another Fiat, you can bet it's an employee lease car.

I spent time with family in Chicago over the holidays.  There, you barely see a car from the Big 3.  Most everything is a Honda, Toyota, or a Hyundai.  I found it interesting that there were even fewer Fiats than in Detroit.  They certainly weren't as common as Mini's and other affordable but different cars.  I'm coming to the conclusion that the Fiat is really a rather unique and special car.  Not for everyone, but for those who understand and appreciate it...........

It reminds me of the story that my friend Doug told about riding his Aprilia motorcycle.  Someone unfamiliar with the brand asked what it was.  Paraphrasing, he told him that the Aprilia was an exotic Italian performance motorcycle.  Kind of like a Ducati, but far more exclusive.

That's Guido for you in a nutshell.  Different, special (to those who appreciate it), tons of personality, and great fun to drive.  Not expensive, but exclusive and individualistic in spite of a low price.  How could I turn my back on that?

Sunday, January 3, 2016

Hand-me-down Parts and Pieces from Family and Friends

What do you know, I finally finished a project!

I have this tendency to work at a project until I have solved all the questions/problems in my mind, and then set it aside.  Or, I will get the project working, but not put the finishing touches on it.  For example, I built some speakers in 1998 that have been my main living room speakers since then.  In the meantime, I have rewired them inside and created an updated crossover, but I never got around to finishing them.  They are still surfaced in raw MDF and the maple veneer is sitting in my basement.

This time, I had to finish the project because it was a Christmas gift for my niece who recently purchased a house.  The project was a small stereo (music always warms a house, in my opinion).  The idea was to use as many parts as possible that were leftover from friends and family.  Personally, I like the idea of knowing that something in my life has a history thru people that I know, especially from those that have passed.  I guess it's an engineer's way of remember those people.

10 or more years ago, I made a little amplifier for my friend, Bob.  When he passed away a few years ago, his ex-wife sent it back to me.  When we moved my father out of his house, I collected his DIY speakers.

Those components were the key ingredients of this project, but along the way, I was able to use parts from my brother-in-law's disassembled electronics, electronic parts from my parts bin, my father's parts bin, even the metal for the amplifier enclosure and the wood for the speaker boxes were already in my house.

The result was an 40 Watt per Channel integrated amplifier with 3 inputs (2 RCA rear and 1 for plugging in a smartphone on the front) and a volume control with an old volume knob of the 40's era.  Key components in the sound path were upgraded to provide cleaner sound and the coupling capacitor was chosen to match the sound of the speakers.  I got the word that lighter color and less shiny surface were preferred, so a satin, off-white paint finished the aluminum box, along with wood accents.

The speaker drivers are about 30 years old and came from a project that my father built when he first retired.  He had built them to go with a subwoofer, but we didn't have room for that in this system, so new boxes were designed and built to provide full range performance to the old tweeter and woofer.  The tweeter is a Dynaudio D-28AF from Denmark and was first class 30 years ago.  It still sounds and measures as if it were new.  The woofer is a Focal 5N401 from France.  30 years had aged the rubber surround so that it was cracked and in need of replacement.  Happily, I found new surrounds built to matching specs in the Netherlands.  The pair was put in a damped, bass reflex design with a bass cutoff of 55 Hz and a crossover specific to these drivers.

A little 2D CAD of the speaker box design.  Magnets from an old iMac to hold on the grille cover

 My niece already had her father's excellent turntable, but no way to play it because they lacked a phono preamp.  I brought along a DB-8 phono preamp built by a guy in NH.  Not handmade by me, but close enough.

Combine that with a Grace Primo to bring in music from the internet and the system was complete.  I have to say that I am please with the resulting sound.  In my niece's small living room, the speakers do a great job of filling the room without any strain.  The end result was clear, dynamic, and detailed.

Now, if I could just finish one of my own projects.

Thursday, December 10, 2015

West Virginia and LightZone

Just so you don't think that I have turned into a hermit in my dotage, I did manage to get out on a motorcycle ride at the end of September.  This is the first time I have been able to edit the photos, since my photo editor has been locking up.  In this case, for you camera nuts, I am trying a new photo editing software, LightZone.  I like it because it is one of these open source, community supported, and free software packages.  I have a lot to learn, but so far it works very well.  I will drop a screen shot of the program at the end of this post and recommend that you consider it, if you like taking and editing photos.

Now, on to W. Virgina.

In most of West Virginia and Virginia, the mountains run in long ridges with wide valleys between.  The exception is an area in the north eastern part of W. Virginia where the mountains look like they have been stirred up by a giant spoon.  Valleys and ridges twist and turn with rivers and streams in the valleys doing the same.  If you are looking on Google maps, turn on "terrain" and check out the area east and north of Elkins.

There are very few paved roads in this area.  Most are one lane, hard packed gravel.  In 2009, I explored the area a little bit, but ran out of time and wanted to go back.  This year, I got the chance.

I don't make much speed on this kind of trip.  I like to just putt along and enjoy the scenery.  Of course, I stop at the drop of a hat to take a picture.

On most of the W. Virginia state highways, there are so many trees that you really have a hard time seeing what the land is doing.

 These little roads seem to follow either the top of the ridge or the stream in the valley and there are a lot more views.  Funny how I always take pictures from the top of the ridge.  I also notice that I never seem to have other people in my photos.  It seems, when I am with other people, I am usually too busy to take pictures.

 Lots of lovely sunshine on this trip.  After 5 days of riding down on the backroads and playing in these mountains, I headed south to meet up with the MSTA motorcycle club for a group ride.  Unfortunately, that was the beginning of the rain and flooding that hit the East Coast.  I abandoned the group and headed for home, safe in the knowledge that I had already had a good time exploring.

And as promised, here is the screen shot of the LightZone program.  Lots of editing tools on the right and "styles" on the left.  One of the best things about this program is that they have taken time to make some very useful YouTube videos to teach you how to use the program.  Very nice.

Wednesday, November 25, 2015

Happy Thanksgiving

 The last time I posted was January and here it is Thanksgiving.  To be honest, I assumed that no one was interested and I had kind of run out of energy, so I've been just letting the blog sit.

Recently, I have gotten a couple of complaints that I haven't been posting from friends that I don't see very often.  So, I thought I would take this moment to run down a short list of things that have been happening with a promise to post once in a while.  I will give more detail in future posts.

About this time last year, I was frustrated with the job.  The normal thing to do is wait for better times.  This time, however, I looked over my finances and realized that I could retire.  Hey!  That's cool!  Why wait?

I hung around for through most of the winter test season, so I wouldn't leave my coworkers  in a pinch, and officially retired April 1.  It turns out that I could have left earlier because those coworkers both left the job, part of an exodus from my department in particular.

My first couple of months were spent rebuilding the KLR engine.  Smooth.

But then family issues called.  Both my brother-in-law and my father (94 years old) got sick. In the end, both passed away with 2 weeks of each other.

In the months following, I don't seem to have accomplished very much, but I guess that isn't surprising.

To answer the question that all not-yet-retired people ask, I do like retirement.  It seems that there are two kinds of people.  Folks that live through their work and don't have significant outside interests.  It seems that they get bored in retirement. 

Then there are those folks like me.  When I retired, I had a list of projects a mile long.  Since I retired, the list has gotten even longer.  I was even dreaming up new projects when sitting at my father's bedside in the hospital.  So, although I will never get them all done, I haven't had a moments boredom since I retired.  In fact, it feels like I am busier than ever.  I have to discipline myself to attend social events and otherwise take care of myself.  Otherwise, it would be just none stop projects.

So there is the update.  I'll try to be good and keep posting.