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First Budgie SE (Single-ended EL84 amp)

PostPosted: Sat Aug 11, 2012 10:22 am
by Shannon Parks
Just got my Budgie SE boards in this past week. The top plate was a prototype board but I went with production amp boards. After some tweaks, it all should be a go. I love this little amp! The chassis is 6x10x2, so its got a tiny footprint.

Shannon

Image

Image

PostPosted: Sat Aug 11, 2012 10:43 am
by TerrySmith
I'm interested! That's a nice layout, any more details?

PS: Don't forget to pick it up before you mow the grass! ;)

PostPosted: Sat Aug 11, 2012 11:25 am
by Ty_Bower
I really like that layout too! It reminds me of an amp I once started building...

http://www.diytube.com/phpBB2/viewtopic ... c&start=50

Wish I had finished that amp. Sigh. Anyway, is there an ETA on when the Budgie SE boards will be available?

PostPosted: Sat Aug 11, 2012 11:43 am
by Shannon Parks
I actually have the boards, but I probably need another week to finalize things (BOM and stuff). I'll order top plates at that time, but you needn't wait if you don't want one. The top plates will be gloss black with gold stenciling like my commercial Budgie. This one was a green PCB that I spray painted black along with the Edcor bells. It was tough cramming everything in there, but was doable. Unhappy with a couple items that are fixable (hate the Neutrik headphone jack - switching to an 1/8" jack). But overall, I think it's a contender. I'll have to post some "under the hood" shots later.

Here's a peek at the schematic, but I see a couple small things I haven't fixed yet (went to a 22uF final stage cap, 100k pot, heaters lift to the EL84 cathode voltage, and a couple other things):
http://www.diytube.com/forumpix/budgiese.pdf

It's kind of a Clem ULtra with AC-coupled inputs, headphone jack with my 20/20 scheme and volume pot standard. A perfect amp for the shop, work or school with 3W output from 500mV source, like a smartphone.

Shannon

PostPosted: Sat Aug 11, 2012 12:16 pm
by EWBrown
Lovin' it! that is so cool (love) [:) (love) [:) (love) [:) O:)

And, no hummmm or buzzz, either [:) ;) (lol)

Image

/ed B

PostPosted: Sat Aug 11, 2012 2:24 pm
by Geek
Looks gorgeous! :))

(not the bees =:o )

PostPosted: Sat Aug 11, 2012 3:59 pm
by Shannon Parks
Here's of close-up shot of inside.

Shannon

Image

PostPosted: Sat Aug 11, 2012 4:11 pm
by Shannon Parks
Ty_Bower wrote:I really like that layout too! It reminds me of an amp I once started building...

http://www.diytube.com/phpBB2/viewtopic ... c&start=50

Wish I had finished that amp. Sigh. Anyway, is there an ETA on when the Budgie SE boards will be available?


Cool amp, Ty. You still have the spice file handy? I presume you used LTspice?

Shannon

PostPosted: Sat Aug 11, 2012 7:05 pm
by Ty_Bower
separks wrote:You still have the spice file handy?


You've got mail...

PostPosted: Sat Aug 11, 2012 7:22 pm
by 20to20
Ty_Bower wrote:I really like that layout too! It reminds me of an amp I once started building...

http://www.diytube.com/phpBB2/viewtopic ... c&start=50

Wish I had finished that amp. Sigh. Anyway, is there an ETA on when the Budgie SE boards will be available?


Ty that is one fat Biaaach of a PT. Optical illusion or did it come out of a TV?

PostPosted: Sat Aug 11, 2012 7:48 pm
by Ty_Bower
20to20 wrote:Ty that is one fat Biaaach of a PT. Optical illusion?


No illusion. The PT is way oversized for the application, but the price was right. eBay surplus from a couple years back, they weigh roughly ten pounds.

PostPosted: Sun Aug 12, 2012 6:12 am
by Ty_Bower
separks wrote:Here's of close-up shot of inside.


Close-up shots can be tricky sometimes. My usual technique is to use the macro mode, and make sure the zoom lever is all the way over to wide-angle. If you start using the camera zoom, it loses its ability to focus up close.

Only problem is with a shot like this, the barrel distortion becomes pretty obvious. Sometimes the fix is to use just a little bit of zoom, say maybe zoom up to 2X then back off just a hair. If the camera can still focus up close, it should get rid of the curved lines at the edges of the frame. You may have to back the camera away from the subject, either to properly focus or to get the subject to fit in frame. If it's the first reason, just crop the part you want from the final photo.

PostPosted: Sun Aug 12, 2012 8:54 am
by soundbrigade
When I am finished with the heap of projects I have lying around, I surely will add this one to the heap. =:o

PostPosted: Sun Aug 12, 2012 9:59 am
by kku
Now that is one cute lil amp. At first glance the pot knob looked like small motor run cap to me. [:)

PostPosted: Sun Aug 12, 2012 4:02 pm
by TomMcNally
Very nice little amp. Can't wait to build one, or two, or three ...

... tom