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DIY MP3 decoder / DAC project
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Author:  tjolle62 [ 23 Oct 2009, 09:41 ]
Post subject:  DIY MP3 decoder / DAC project

Hi Guys,
Got this gadget up and running today and just wanna post a few pics on this little player,

Image

went in to carpenter shop at work and traded me a piece of mahogny and they did a cut out on'it

Image

did a jackass try to simulate a brushed finish on rear panel :(

Image

scrunched up some parts from my bin's and made a power supply but only had a 9V - 1.2VA
tranny so sound level was just too low so now i got a 9V - 8.2 VA so :sing:
tried with my lab PS and with little more juice the sound level was perfect,
i didn't get cover panel in this shoot because the paint wasn't dry enough so to next week :up:

Regards,

Kjell

Author:  Geek [ 23 Oct 2009, 16:37 ]
Post subject:  Re: DIY MP3 decoder / DAC project

Niiiiiice! really like the wood on there :D

Quote:
did a jackass try to simulate a brushed finish on rear panel :(


That takes some practise and is best done with a power sander or steel wool and a LOT of elbow grease.

Still looks good ;)

Cheers!

Author:  tjolle62 [ 23 Oct 2009, 17:17 ]
Post subject:  Re: DIY MP3 decoder / DAC project

Alright ! thnx very much for your most valuable opinion :)
wheni't comes to woodwork then i'm totaly :censored:
when it comes to mechanical and machining then they call me ,
metal no problem , wood NO go .
Got from a work buddy a type of oil called Rylard and to get a super finish it will take as you wrote
a lot of soak time and a wheel barrow full of elbow grease and to finish touch a 000 or even 0000
brass wool to get that "Glass " finish on mahogny for example,
with any luck they are going to start manufacturing these models in silver , black and gold :up:
"Keep your mind wide open and never let your soldering iron to cool off",

Regards,
Kjell.

Author:  tjolle62 [ 23 Oct 2009, 18:13 ]
Post subject:  Re: DIY MP3 decoder / DAC project

Hi Gio,
of course i understood that take a lot to master that know how to make " brushed aluminum " look,
It's as easy to get a super finish on wood surfaces for a steel worker / mechanic :bawling:

Regards,
Kjell.

Author:  Gio [ 23 Oct 2009, 18:42 ]
Post subject:  Re: DIY MP3 decoder / DAC project

Hi Kjell, I think you meant to address Gregg, not me. :blush:

Nice work with the enclosure. I have plenty of those RCA jacks and what I do is paint the white plastic red with a tiny brush. I find it looks better and is much easier to see than the thin red stripe.
Cheers

Author:  tjolle62 [ 23 Oct 2009, 19:40 ]
Post subject:  Re: DIY MP3 decoder / DAC project

Oouupsss ! sorry Gio.
Is kind of late over here close to 2.30 in the morning :alien:
yeah that bright white annoys me too and it would be much better if they took black plastic ,
on my next Mp3 project the whole box will be in mahogny and for that i will use fiber washer ;)
they have almost the same color as the wood itself.
but that tiny stripe is still small so :confused:
another thing that strikes me is that i have some black plastic at my workshop in form of round
stock in different sizes and for sure i have Ertalon ( PTFE ) in 20mm ( about 3/4" ) so monday i
stick that piece in my lathe and cut a bunch of nice black washers :idea:
let me know if u want some of those then i'll make some for u.
also tonight i ordered a bunch of LM1875T's for some smaller amp's to build in to these projects
maybe to have a cd rom and this Mp3 player in a small box unit with a tiny amp ,
Maybe an idea for christmas gift's to the small people ( kid's ),

Regards,
Kjell.

Author:  Gio [ 24 Oct 2009, 13:10 ]
Post subject:  Re: DIY MP3 decoder / DAC project

I'm good with painting mine. But thank you for offering.
Cheers

Author:  tjolle62 [ 26 Oct 2009, 10:56 ]
Post subject:  MP3 decoder project is humming !

Noticed a thing today with this project that after a while i have slight humming sound from it and if i
touch the back end of the voltage regulator (7805 ) that the hum got stronger even when
i didn't touch anything else on player :confused:
On the main is no ground and i haven't ground neg line on power board to chassis,
could that be the problem ?
Image
Regards,
Kjell.

Author:  Geek [ 26 Oct 2009, 16:26 ]
Post subject:  Re: MP3 decoder project is humming !

The back of the voltage regulator on a TO-220 case is the output I believe... the regulator should have low enough impedance to take care of hum pickup there :confused:

Your case, is it grounded through the power ground and the power ground seperated from it by a 100R/2W resistor or something?

How about ground loops... ?

Cheers!

Author:  tjolle62 [ 26 Oct 2009, 16:53 ]
Post subject:  Re: MP3 decoder project is humming !

Well i guess this problem is where you described thou i don't have any ground to chassi and no
power resistor either :blush: ,
picture is not quite right becouse now it's a slighter larger trafo ( 4.5 VA ) and the first one was
at 1.2 VA and that was not enough.
then i founded a 8.4 i think trafo :confused: but it was no good so in went a 4.5VA but now when i
see'it i didn't upgrade the e-cap it's still 470uF so might as well put in a second 470uF to it
when i had that small tranny i didn't have any humming so ?
power board is maybe too easy thou is contains of from AC to DC
Murata 100nF X2 - Trafo 9V/4.5VA - W02 bridge Rectifier - 100nF Wima - E-cap Panasonic FC 470uF/25V - 100nF Wima - 7805 - 330nF Wima

Regards,
Kjell.

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