non-profit ver.3 TDA1541a DAC for limited budget diyers

[Stevox]

These are the settings I try, and wich are working.

Jumper: JP1 short, JP3 2-3 short, JP2 short


NOS mode
S2 - on off on on - JP4 close - JP5 close all - Clock out - SA7220 - out

NOS mode*
S2 - on off on on - JP4 open* - JP5 close all - Clock out - SA7220 out

NOS+SA7220
S2 - on off on on - JP4 close - JP5 open - Clock out - SA7220 in

NOS+Clock
S2 - off off on on - JP4 open - JP5 close all - Clock in - SA7220 out

NOS+Clock+SA7220
S2 - off off on on - JP4 open - JP5 1-close 2-3-4 open - Clock in - SA7220 in

NOS+Clock+SA7220*
S2 - off off on on - JP4 open - JP5 All open * - Clock in - SA7220 in

As you can see there are 2 mode for NOS and NOS+Clock+SA7220, but what are real ones...

Peter.

[fedde]

Yes, that was my guess. The filter chip uses a lot of energy then... :-)
My experiences with the clock PCB are better now. Do you like to use the clock PCB?

Fedde

[Kip]

Hi Thomas,
As Idefixes pointed out, it is not the same cd rom contrller that you sent me. My buttons are on a separate pc board. I am having other problems with the cd rom controller besides the output to the dac question. It will play then that is all. No responce after that.

[Idefixes]

Originally posted by Kip
Hi Thomas,
As Idefixes pointed out, it is not the same cd rom contrller that you sent me. My buttons are on a separate pc board. I am having other problems with the cd rom controller besides the output to the dac question. It will play then that is all. No responce after that.

On my ASUS on CDROM drive I have an extra spdif output. I will use this to connect to the Dac.

Marc

[Jean-Charles]

Hi Thomas,
Thank you for the reply.
No, I am not absolutely sure the noise comes from the 5 Volt rail of the clock board. This is an assumption from my part. What I can tell is that if I put the clock board in operation we have noise generated.
I will hook an oscilloscope on it today and I will report to you.
I have tried a few things like changing the audio opamps, used good thin film caps at the output, the changes where not significant enough to report. It is already very good.

The sound is very similar to the equipment of reference, but it needs to be a little more transparent, not by much.

Do not worry about the sound, it is very good. I am impressed because I compared it with an YBA DAC and will do later against Sonic Frontier, Audio Research and Goldmund. All the above DACs cost many, many thousands of dollars and your DAC compares very well with them.

I know the differences between the YBA and other DACs, so I know in advance what to expect.

I suspected the noise to veil the sound a little, but that remains to be seen, no proof of that, yet.
With the 30db+ of gain in the op amps stage, any residual noise will be amplfied to audible levels easily.

I am happy to collaborate with you and report my observations to help in tweaking this DAC. It is real fun to see an equipment of this price almost equal the big expensive machines.

If it is easy to implement, I will try a 5V 5W zener ahead of U4 to reduce power dissipation and I will report to you if it does the job good enough.

Jean-Charles

[Kip]

Thank you Marc,
I may need another cd rom and I am up for suggestions. This may also be some of the issues I am having (older cd rom drive). I will try to lay low to see if anyone else has any of the same problems and what their solution and cd rom is.

[Idefixes]

Work on DIY DAC chassis go foward







Black heathink will be scewed on the cahssis bottom to deal with U4 tempature. I will do the same chassis for the Drive base on CDROM+CDROM controler.

Marc

[ashok]

Here is the updated settings chart with Stevox's inputs.
The asterix is for settings which work but need some explanation ( does it ? ).
The diagram shows JP5 as seen on the board. Left of the JP5 print is pin 1 and right of JP5 print is pin 5.
That should clear up any doubts.
Cheers.

[rtd]

Originally posted by tube-lover
hi RTD,

no no..... I send to france already in reg.mail RA18485047hk.

sorry I made a mistake that U also in USA.

thx

thomas

Hi Thomas,

Is this reg.mail reference Ok ? I cannot see it on mail tracking on Hong Kong Post website ?

Thx,
RTD

[tube-lover]

hi rtd,

post to U already by small airmailparcel. U will collect within ten days. small parcel wiull not tracy, but looks will safe.


hi kip,

my computor was repair already.

pls see the photos of the connection of the cd-rom.

thx

thomas