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-   -   DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...) (https://talk.maemo.org/showthread.php?t=74341)

dr_frost_dk 2013-03-26 19:44

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
Just want to show off my newest project (besides the 1000' others hehe)


You don't have to have a facebook account, this is a public album :)

http://www.facebook.com/media/set/?s...1&l=0b484a5e9d

https://dl.dropbox.com/u/29047266/20130323_007.jpg

Estel 2013-03-27 17:30

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
Nice, but what is it?

handaxe 2013-03-27 18:24

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
DIY smart TV/multimedia centre?

dr_frost_dk 2013-03-27 19:22

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
look at the link...

But it is a B&O avant 28" OLD (15+year) TV, a TV that cost's 10,000$ at the time, but now that flat screen's are so cheap NOBODY want's an old tube TV.

Now the project:
Compleately stripped it down, put in my AOC 27" LED-LCD, my computer witch is almost silent, not finished with the last things

Things to do:
put in better 4" then stock.
Build a dual 4th order subwoofer box with 4x 8" in isobarik config.
Build a 4 channel amp
Make LPT port control of the motor that controls the turning mechanism


TO conclude, yes a Smart TV/Multimedia Centre = Full HD, Awesome design (B&O not mine hehe), POWERFULL HiFi (Stereo) system we are talking 250/500W (rms/max)
An All in one, only 1x power cord

dr_frost_dk 2014-03-26 18:41

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
for those who are interested in the TDA7293/4 with power transistors then besides the forum we have a group on facebook
https://www.facebook.com/groups/760434413975466/

dr_frost_dk 2019-10-01 14:13

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
Good old thread...
Doing more nice audio stuff now like these im working on now
https://www.youtube.com/watch?v=2-qvH7Uq_K8




Some stuff here:
https://www.thingiverse.com/dr_frost_dk/about

Trzyzet 2019-12-25 03:08

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
Maybe not the listening equipment, finally I received my PCBs for hardware SID chip replacement. Over 10 years ago, on my first year of electronic technical school I started dreaming about built own synthesizer based on C64 SID chips and I almost finished it this summer.
https://i.postimg.cc/kRdvzc8T/20191225-025623.jpghttps://i.postimg.cc/ygRTL5JJ/20191225-025648.jpg

In the background of second picture you can see soldering station. This one is also built from scratch by myself. It uses Arduino as driver and temperature controller and only one encoder for all user interface. Tips of my choice was very good Hakko T12.
I know it is possible to buy ready drivers for T12 but guys who make it mistakenly founded / researched the thermocouple used in tips for measuring themperature is type K. But it really is something between type C and D so on cheap driver when you will set 350 Celsius degrees you will have over 550 on the tip. This motivated me to build my own station :D

Trzyzet 2020-09-08 19:54

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
Well, I received package with N900 boards so its time to be a bit more active on the forum :)

At the start some background:
Creative Audigy 2 ZS Platinum Pro from 2004. Last produced soundcard with the hardware MIDI synthesizer. In the sound quality this 24bit/192Khz soundcard is an absolute killer and for me it sounds better than most newer constructions, even USB and audiophile ones. In the November 2019 I changed PC and I had no more PCI slots, simple PCI->PCIe adapter make it work like a charm again. That card had its studio twin - E-MU interface with exactly same DSP and all of the ICs inside; to make Creative card for use for the civils they designed headphone opamp with very low gain.

Because I'm using Fostex T40rp as my daily headphones for many years, now MK3 (much sturdier MK2 has been stolen a month ago) I was living with a fact this great soundcard can't drive better headphones. Until now.
At the Friday, right before midnight, I was listening the music and I've got the idea - what if I can make this card compatible with more demanding headphones?

I was looking for the pictures of the board of SB0290 unit (frontpanel) but there was no pictures at all so I think mine are first ever sent. Opening is simple, just unscrew everything, remove potentiometers caps and remove screws also from there. There is also one screw under the casing in the middle.

On the top is a huge shield soldered to the bottom of the PCB
https://i.postimg.cc/fRKP7Rvv/IMG-20200905-024101.jpg

After removing it we can finally see the top side
https://i.postimg.cc/CxYtfqb1/IMG-20200905-010015.jpg

Okay, now zoom on the headphone amp
https://i.postimg.cc/5tKkGKTY/IMG-20200905-011255.jpg

Yes, that's Japanese NJM4556A opamp which amplifies signal from CS4392 24bit/192kHz DAC. It's DAMN good, but to secure users with 32Ohm and less headphones, and of course, separate this construction from proper E-MU solution, opamp gain has been set to less than 2. Just by adding 1kOhm resistors parallel to the R151 and R121 I set the gain to almost 8, because opamp is powered from the 9V regulator and maximum output voltage from DAC is 1.05V that's highest safe value for opamp, and I think my ears too.
https://i.postimg.cc/N0jzdvJv/IMG-20200905-022029.jpg

With those two guys there I made this soundcard compatible with almost any pair of headphones. The last thing to do is to replace encoder which change volume in the windows to the standard potentiometer right after opamp. Also encoder can be pressed and it will act as mute button, I found ALPS potentiometer with a proper switch so I will still have mute functionality.
https://i.postimg.cc/B6SbhByz/IMG-20200908-195932.jpg

If you can see, its already lying with the knob inserted but I'm still waiting for second potentiometer, microphone one because it becomes not enough reliable. That's everything :D

dr_frost_dk 2020-10-17 16:58

Re: DIY Audio thread, show you DIY audio 'equipment' (Amps, BT etc...)
 
Finally got the time and resources to finish the RGB system :)

RGB System - Release Video


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