Power DAC (like Wadia) full digital amp - Page 2

KOON3876 · 19th October 2007, 06:02 AM

Now I implemented 5 bit, then try to listen some music.
S/N ratio by theory is 36dB, yes I can listen music and some quantization noize.
10 bits more...

KOON3876 · 21st October 2007, 05:12 PM

Loop back by Edirol UA-1 EX, digital out - Analog in at speaker terminal.
THD+N 2.2% is pretty bad, but anyway it's working.

with magnified view of received wav, I can see some gritch around negative peak. maybe one of lower current sink has trouble...

Eva · 21st October 2007, 05:53 PM

Interesting, but, how did you manage to get those DIY-looking prototype PCBs with thru-hole plating? Are they really DIY?

KOON3876 · 21st October 2007, 07:22 PM

Of course not a DIY board..
made by ExpressPCB.

torzsok · 24th October 2007, 07:29 PM

How is it going?

Strange that there is no interest from others here. I can't offer any serious advice either being a newbie, but I like the idea and I would love to see how it develops. Keep it up!

torzsok

KOON3876 · 24th October 2007, 07:36 PM

I found some 74HC08/74HC02 is out-of-order, Y pin is 5V fixed or A input goes through without gating

(maybe I shorted 5V and output while making / testing)
Now waiting delivery from Digikey. I did not ordered spare parts!

Boris_The_Blade · 24th October 2007, 07:46 PM

Quote:

Strange that there is no interest from others here. I can't offer any serious advice either being a newbie, but I like the idea and I would love to see how it develops. Keep it up!

Yea I'm interested too, though I really have nothing to add. It's a neat concept and I hope it pans out well.

I bet the PCB probably cost you big $$$ from express pcb...

nice work

BWRX · 25th October 2007, 03:23 AM

Quote:

Originally posted by Boris_The_Blade
Yea I'm interested too, though I really have nothing to add.

Likewise. It's a very interesting and complicated project.

KOON3876 · 28th October 2007, 05:37 AM

Thank you for interests.

After bit-by-bit measurement, re-soldering, bridge found! and cleaning, ... now all bit is working correct.

0.3% THD is not a fame as DAC

Now listening some musics.
nice. good at presentation of depth. musical enough.

best of the features is "interesting". only a pile of 74HCxx, 4580D, analog switch and TR/FET, C/R are driving speaker, from non tweaked PCM signal (and Reference Voltage, used for volume control).

MaxS · 28th October 2007, 06:33 AM

Hi,

First of all, nice project.

You're using so many 74s than, to my mind, you can think to use CPLD.

21st October 2007, 05:53 PM	#13
Eva diyAudio Member Join Date: Oct 2003 Location: Near the sea	Interesting, but, how did you manage to get those DIY-looking prototype PCBs with thru-hole plating? Are they really DIY? __________________ I use to feel like the small child in The Emperor's New Clothes tale

28th October 2007, 06:33 AM	#20
MaxS diyAudio Member Join Date: Mar 2006 Location: France	CPLD could became your friend ! Hi, First of all, nice project. You're using so many 74s than, to my mind, you can think to use CPLD. __________________ Ca marche pas ! Tu ne l' as pas branché non plus ....

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19th October 2007, 06:02 AM	#11
KOON3876 diyAudio Member Join Date: Nov 2006	Now I implemented 5 bit, then try to listen some music. S/N ratio by theory is 36dB, yes I can listen music and some quantization noize. 10 bits more...

24th October 2007, 07:29 PM	#15
torzsok diyAudio Member Join Date: Apr 2005 Location: Budapest	How is it going? Strange that there is no interest from others here. I can't offer any serious advice either being a newbie, but I like the idea and I would love to see how it develops. Keep it up! torzsok

24th October 2007, 07:36 PM	#16
KOON3876 diyAudio Member Join Date: Nov 2006	I found some 74HC08/74HC02 is out-of-order, Y pin is 5V fixed or A input goes through without gating (maybe I shorted 5V and output while making / testing) Now waiting delivery from Digikey. I did not ordered spare parts!