Thursday, April 17, 2014

What The Vari-Load Batman.

What are all of those secondary wires coming out of that amorphous GM-70 output for??


75TL thrown in for size



I have made it well known over the years that I don't do multiple secondaries or taps because I feel they compromise the overall design. Well I guess I need to change that particular stance and I would like to introduce you all to the Vari-Load concept.

By adding a second strategicly places winding on the secondary I am able to get three different turns ratios which all have essentially the same frequency characteristics.  When you work the speaker impedance back to the load you get a number of options to play with.  Below is a screen grab of the spreadsheet showing how the numbers work out.


The three possible connections are:
Secondary 1 alone (Sec 2 remains floating)
Sec 1 in series with Sec 2 adding
Sec 1 in series with Sec 2 subtracting

since secondary two has a small number of turns and is never referenced to ground, it doesn't introduce the capacitive issues that plague other transformers causing varied response as you adjust the impedance.

To make things even worse (and I assure you i did not draft this on 1, April.... take a gander at this.






 Sure it is a box.... Big deal...   but the next three pictures may terrorize some of you.







Sunday, March 30, 2014

Getting Loaded

Hey all...

I finally came up with a way to make custom copper wound load resistors for loading MC cartridges.


The values are best to be kept below 1K (hey we only load the cartridge directly right!) which should cover most cases.



 Above is a 120 ohm and a190 ohm to load a Zu 103R feeding a 1:20 silver SUT.



and a peek under the black shrink.  I have some clear shrink on the way to see if the peekaboo look works.

As for the measured parameters....  They are wound in a non-inductive fashion and here is the impedance plot from 10hz-100Khz of a 190 ohm unit.


Are they perfect?  Hell no!  Am I going to lose any sleep over their imperfections?  No way... I'll just put some BS marketing spin on them like 5% tolerance throughout the entire audio spectrum... or maybe just let the audio jackals have at me for this silly idea.

 

dave



Wednesday, March 26, 2014

Learning...

.

learning a new place... learning to work metal... 
learning to work alongside new friends.... 
and learning is a goal of life, so....




messing with an amp idea...




not sure what that was about, but...




you know I cannot deal with fresh brass... gotta get that patina...




and this is learning patience... I *so* want to drag this car out and get it running...

peace,
me

Friday, February 21, 2014

The shortest distance between two points...

is not through Anchorage.

I printed this label out for a package to make a 50 mile journey south to NYC.



When it didn't show up the next day as expected I was a bit concerned.  Three days later it showed up at a sort facility 4300 miles away. 




The good news is it arrived today.

Wednesday, February 12, 2014

Hummingbird....

.

because you guys (and deb) know how I love conical horns... 



psyche!

I would never do that to you guys... 

in honor of Jean-Michel Le Cleac'h:


we finally figured out how to make solid wood horns that are stiff and yet are thin enough to not crack over a century... I am excited... meet elm and walnut....


it feels good to have both the 16a and Sierra horn debacles behind me... nothing like a hard lesson to help you see the light.... woo hoo!!!

peace,
me

Tuesday, February 11, 2014

Indian Rights...

Or the most rightous indian experience in NYC.
food

Wednesday, January 29, 2014

Whale Rights....

thank you for the photograph, Barrett... I need to have my camera out more often at work...


peace,
me