Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th February 2004, 07:05 PM   #1
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Default Flying higher and higher with the Doede Dac

Many people have already built a Doede Dac with 8 TDA 1543's.
I would suggest to share experiences on building and finetuning this DAC in this thread...

There are already a couple of other threads concerning aspects of the Doede DAC. One of them deals with the question to reclock or not: Doede DAC..reclocked or not?

On his site, Fabian has a lot of interesting information: http://www.geocities.com/tdac1543/

And there is of course Doede own excellent site: http://www.dddac.de/

I hope many will post their findings on modding and finetuning the DAC.
  Reply With Quote
Old 16th February 2004, 07:10 PM   #2
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
After building the DAC in an enclosure, using better cabling and connections, I started to finetune the Vref.

Using a spectrum analyzer, I found that the best setting was at 3,50 Volt DC at the left output, and 3,46 Volt DC at the right output.

I got the followong result:

The bottom level in yellow is when the DAC gets digital silence.
The upper level in red is when the DAC receives a 1 kHz sinuswave at -6dB.

This was the best attainable spectrum. I could not see a significant difference between reclocking or no reclocking.
Attached Images
File Type: jpg doedeoptimumdigitalsilenceplus1000hz.jpg (50.0 KB, 2241 views)
  Reply With Quote
Old 16th February 2004, 07:14 PM   #3
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Note in the previous picture the relatively high distortion at 44.1 kHz
For the rest I don't think this spectrum is bad at al.

Here is the frequency plot when feeding the dac with whitenoise:
Attached Images
File Type: jpg doededacoptimumwhitnoise.jpg (27.5 KB, 2170 views)
  Reply With Quote
Old 16th February 2004, 07:21 PM   #4
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
After finetuning Vref, the DAC sounds ten times better than before. It does make a huge difference!

There is a better definition of ambience and less glare.

At this moment I use a Mundorf standard MKP of 8.2 uF, bypassed with a 1 uF Wima MKP and a 0.1 uF Mundorf Supreme Cap. This gives a pleasant sounding combination, but I will order some Blackgate NP's to try them as well.

I removed the 50k resistors at the output. I found them making the sound much duller. I hope I will not run into oscillation.

The Dac is very dynamic indeed, and it has a nice detailed midrange. What is still missing is a more refined treble. I hope this will improve with Blackgates...

Regards,

Lucas
  Reply With Quote
Old 16th February 2004, 08:28 PM   #5
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
As a comparison, here is the same spectrum for my Philips DVD 963 SA player:

The line in yellow is when playing digital silence.
The line in blue is when playing a 1000 Hz sinuswave without upsampling.
The line in red is when playing a 1000 Hz sinuswave with upsampling to 24 bit 96 kHz by the AD 1895A.

Funny to see those differences between upsampling or not
Attached Images
File Type: jpg philipsdvd963sadigitalsilenceplus1khz.jpg (52.3 KB, 2088 views)
  Reply With Quote
Old 16th February 2004, 08:43 PM   #6
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
And here the frequencyresponse when playing white noise...

The Philips is completely flat here, where the Doede Dac has its -3 dB at 20 kHz, and a lot of rubbish in the 30 to 50 kHz region.
Attached Images
File Type: jpg philipsdvd963sawhitenoise.jpg (32.3 KB, 2030 views)
  Reply With Quote
Old 16th February 2004, 09:10 PM   #7
diyAudio Member
 
Bernhard's Avatar
 
Join Date: Apr 2002
Location: Munich
Lucas,

I can not understand why people built DACs with TDA1543.

This chip is declared by Philips as "economy" and used in their el cheapo players.

It is the very worst of all.

THD is -75dB in the data sheet, your measurements are very accurate

By comparison, the 1541 has -95dB.

Does the distortion noise floor provide tube sound ?

Had a CD614 with this chip. Sounded lower middle class.


Bernhard
Attached Images
File Type: jpg 1543crap.jpg (77.7 KB, 3167 views)
  Reply With Quote
Old 16th February 2004, 09:19 PM   #8
diyAudio Member
 
Audiofanatic's Avatar
 
Join Date: Oct 2002
Location: The Netherlands, Utrecht
Default Hi Bernhard!

Quote:
Originally posted by Bernhard
Lucas,

I can not understand why people built DACs with TDA1543.

This chip is declared by Philips as "economy" and used in their el cheapo players.

It is the very worst of all.

THD is -75dB in the data sheet, your measurements are very accurate

By comparison, the 1541 has -95dB.

Does the distortion noise floor provide tube sound ?

Had a CD614 with this chip. Sounded lower middle class.


Bernhard
Why do you trust the philips data, trust your ears, if you never listen to the TDA1543, with an active 627 output opamp, you'll forget about the philips data!

Audiofanatic
__________________
Be nice to animals.
  Reply With Quote
Old 16th February 2004, 09:25 PM   #9
diyAudio Moderator Emeritus
 
jean-paul's Avatar
 
Join Date: Sep 2002
Location: Germany
Quote:
Originally posted by Bernhard
Lucas,

I can not understand why people built DACs with TDA1543.

This chip is declared by Philips as "economy" and used in their el cheapo players.

It is the very worst of all.

THD is -75dB in the data sheet, your measurements are very accurate

By comparison, the 1541 has -95dB.

Does the distortion noise floor provide tube sound ?

Had a CD614 with this chip. Sounded lower middle class.


Bernhard
Oh oh, another spec hunter Trust the Philips data but let your ears be the judge please.

Try the TDA1543 in non os just for the heck of it. It will cost near to nothing so building one DAC with it won't hurt your wallet. Big chance you'll forget about the 4 x TDA1541A thingie.

Your CD614 had oversampling which makes quite a difference. IIRC it had an even more crappy digital filter than SAA7220 too. And the power supply could have been better too and... well you know what I mean.

To be honest I think TDA1543 is one of the better DAC chips soundwise but TDA1541A and TDA1545A I like more *when implemented right*. It is those last words that make building a DAC with 1543 so nice. Only one supply voltage and passive I/V, not much that can be screwed up except for PCB layout and a decent supply. I'll leave the comments about stacking TDA's and running them on near maximum allowable voltages to others.
__________________
It's only audio. Official member of the Norske Brillegeit Gang.
  Reply With Quote
Old 16th February 2004, 09:40 PM   #10
diyAudio Member
 
Bernhard's Avatar
 
Join Date: Apr 2002
Location: Munich
The measurements confirm the Philips specs.

I had some friends in school who had motorcycles of which the specs said 25 km/h.

My diy friends were very clever, they made it go 75 km/h.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Higher power A75. dinu Pass Labs 76 15th January 2008 06:23 PM
Higher value oil capacitors? rick57 Tubes / Valves 36 24th March 2006 07:48 PM
Is there anything higher than 8 Ohm speakers? Dominick22 Full Range 16 9th January 2006 02:27 PM
Is it true that the higher the BL of a subwoofer, the higher its lowest playable... 454Casull Subwoofers 16 19th March 2004 04:28 PM
Super-power amps - higher current better than higher voltage Circlotron Solid State 34 28th June 2002 04:01 AM


New To Site? Need Help?

All times are GMT. The time now is 11:14 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2