Make it yer own Tungar Supply

Went to the "Secret Land of Walter" last weekend to have some fun with some friends.  On the agenda for the weekend were some Tungar Supplies for his 4 RCA 1428's so I brought a few boxes of parts to complete the task.

Then some basic supplies were added and we were off to the races.

The kitchen table was taken over for a short period while Carroll and his helper whipped things together and tested things out.

After all was well they went upstairs for the in system test.

Then finally things were buttoned up for some music for the distinguished guests who many of which were there in spirit only.

Mom and Dad gave me the keys to the room.

and a member of the press came in and requested some Reggae...  I begged him not to leave.

Art and Herb also did their thing for Stereophile and Art just added some more.  FWIW... the table was a 501 and the creation of Ijaz Khan.  The armwand is dymondwood (think panzerholz with parallel grain structure) and the cartridge a 103 with a line contact/boron cantilever combo and a new (much) softer suspension which tracks at 1.3g.  I promise the field coil will be done by next time around.

Capital Audiofest

some pics of the room.

Filament Boards.

Hey... where have jeffrey and dave been???  Well the answer to that is busy.  To add at least a little content to this miniscule corner of the web, here is one of the small things I have recently made.

This is a "keeper" board that attaches to a pc mount bobbin and holds a schottky bridge and a pair of caps for a choke input filament supply.  The chokes are dual bobbin and wound with flat wire for choke input duty and have split windings so one leg goes in the + side of the supply and the other in the ground.  The PC mount bobbin allows for a nice way to hold the needed parts and the whole thing is supported by the mounted choke.

The ultimate use of these boards is for providing DC to some coleman regs and here is the resulting waveform when drawing an amp and a half of current.  Yes that is a 60mv p-p 120hz sine wave

Finally a picture of what is really going on.

Shielding SUT's

One of the biggest problems with rolling your own SUT is shielding them to get them quiet.  In the very near future I plan on offering two options to help the cause of the DIY'er for shielding.  One is a Steel box that has holes for RCA jacks and a ground lug.  This can be lined with mumetal and copper foil for an effective enclosure.  The other is a deep drawn mumetal can that can be placed end to end  for a final shield.  These can then be put inside a steel box for complete shielding.

Elmaformers

It is such a task for people (including myself) to solder the $400 autoformers to a switch so I am doing a circuit board that wires them directly to an elma switch.

While not being the smallest of finished items, it fits together nicely and can stack for as many decks as needed which makes true balanced operation a breeze.

This is a simple two deck "proof of concept" on proto boards with a 24 position switch that can have any desired taper you choose.  They will wire up lust like a traditional pot with In, Out and Ground connections for each deck.  I am so happy with the results I am planning another version on the 47 position switch that can have 1dB steps.

From Russia With Love

So I receive a belated holiday present from a friend and it comes in a box with cyrillic letters on it so I get a bit excited.  When I open it, my first thought is why the hell did Fred get me an ugly red sweater?

Upon closer examination I quickly realize that there is something hiding inside that sweater.

Ahhhh,  now I feel much better but I am still really confused why this sweater used as packing has no armholes.  This naturally brings me to the conclusion that this isn't a sweater but a Soviet Era method of packing valuable tubes.  (take that eimac!) While the boys were having fun playing with the "armless sweater" their mom comes in and asks why there were playing with a skirt? We all need to go out and mow the lawn now.... or work on the car.... or something.....

Random says 10

Random picked 10 as the winner.





drop me an email with your address and they will find their way to you.

dave

Freebruary

Just got these back from a vendor and they need a new home.  They are the current modules and have a cheap pair of interconnects soldered into them for a quick audition.  I'm leaving them as is and it is up to the lucky winner to decide what to do with them.

Leave a comment below with an identifiable name and Random.Org will pick a winner in a few days.

Micro-Bomb

I finally sourced some MuMetal cans that are big enough to house the SUT's.  Two of them will fit together to house a pair and a band of adhesive backed mumetal holds them together nicely.

While not exactly small it goes a long way to getting the required shielding to package these things up.  Simply add a steel box,  some RCA's, solder and enjoy.

dave

Music Maker - Stevie K with a 16a

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so my friend steve... no, not that steve with a 16a from North Carolina... this Steve... lives in a quiet little town... nice sunsets... small farms... and he is that guy who hears the records calling his name from every Goodwill he drives past.. which was a great very many as he drove quite a bit for work... now he just feeds his cows and spins those records... so he bought a new music system for all of those records... yep, another Western Electric 16a in North Carolina... and GIP 555w drivers..... which are beyond amazing... 

and Steve is a super hardcore DIY'er.... DHT line stage... DHT amp with DHT driver... built it himself!  and it sounds great... just fabulous... and he built the "Bass Base" for the 16a... check it out!

proper way to clamp

expansion shown with bracing every eight inches - super important!

walnut ply looks good

*live* Muddy, Chester, Buddy, Sonny Boy!!

NERDS!

 how is that for documentation?

and packaging...

these things sound absolutely stunning.. and remember, I have originals... contact me if you want to hear some.. 

Hey Furby!  You look like a sheep!!

peace,

me

Drug thru the Kongeå

It is ETF time again and this year the promoters took into consideration 'Birthday Month' so Jackson and Slagle are going with mercury and nickel.  This year the competition is for a preamp power supply and 16 different designs will have at it.  Of course a little pandering to the judges always helps!

Tiny Coils

I thought things were getting a bit out of control when I was seriously considering mounting a microscope on my lathe.  Never mind that I am attempting to keep 0.01mm precision and doing other silly things like spending $16 on a 0.2mm diameter cutoff wheel for a dremel.

Seems like 1997...

Dave is testing Sovtek 6B4G's and building push pull amps.... Dear god say it ain't so.

In his defense the DHT's are replacing triode wired EL-34's and the outputs are 49% nickel (soon to be 80%)

Big (ger) Amorphous.

The old "Big Amorphous" cores have been downsized.  They were perfect for a 10W from a 300B or a 75TL but the requests for 20W at gobs of current keep coming in.  Sure I can gang up multiple cores or add an offset winding but the winding window gets small quick. 

 

 

The new option takes up a 6" cube and stay tuned to see what gets built from them.

A nice small system.

Not everybody has all kinds of room to dedicate to audio and one of our friends put this together.

I really like the way things are laid out and the use of steel and wood for the rack.

CAF

Back and recovered from the Capital Audiofest.  This year we continued to bring things that were different and had no possible chance of selling.  This time the main difference was presentability.

I'll admit it looks a bit like a late 90's projection TV but there is a reason for this look.  Once you step around back you see the 'direct drive' power amplifier neatly tucked into the base.

 For this round it was Push Pull triode wired EL34's and while this isn't technically a "direct drive" amp,  I have not come up with a better term.  The two interesting Key points are the panels are biamped through discrete step up transformers loading the EL-34's and the crossover is in the amplifier circuit allowing the transformer direct connection to the panels.

The cabinets are Walnut with some bloodwood inlay and there are a few other tricks going on inside.

The two biggest comments at the show were along the lines of 'I thought quads didn't have any bass' and 'who says quads cannot go loud'.  It was mentioned on some of the forums that we only seemed to play things that showed off these two points and neglected to play the girl on a stool with a guitar that quads are known for.  Oh well... we can change that for RMAF.  Check out what Herb has to say at the link below.

Herb on the ESL