diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Digital Line Level (http://www.diyaudio.com/forums/digital-line-level/)
-   -   help understanding different clocking for tda1541 (http://www.diyaudio.com/forums/digital-line-level/140132-help-understanding-different-clocking-tda1541.html)

Chilli6565 9th March 2009 09:14 PM

help understanding different clocking for tda1541
 
2 Attachment(s)
Hi,
I have just built the analogmetric tda1541a dac kit...but I am not sure what type of clocking it uses, ie re-clocking, synchronous, etc.I would like to add a discrete clock as I have a surplus lc audio clock 2 (45mhz ) and was going to change the crystal on it to 11.296mhz.:confused:

Chilli6565 9th March 2009 09:16 PM

forgot
 
...I forgot to mention I am running the dac in nos mode ( no saa 7220 filter )
thanks:cool:

hotiron 10th March 2009 11:22 AM

How does it sound? What were you using before?

Chilli6565 10th March 2009 08:59 PM

sounds good
 
Hi Hotiron,
It sounds very good...but it is very sensitive to component changes such as retifier diodes and main resevoir caps. I am using mine with a fet output buffer stage, bf245a/bs170..I felt it sounds better than all the op amps I tried..ad711 was the best of them.I also tried several caps for ic decoupling..oscon, Nichicon muse, panasonic fm,blackgate standard and rubycon za..the only one I didnt like was the Rubycon za, much to stark for my liking...probably the two best I liked were the pana fm and blackgate.
I have also built the AMB dac with wolfson chip very nice too..altho in a hi end system the tda1541 would be superior.
I am using a modified sb3 as source...tho I still feel it is holding back a bit.
When it comes to clocking ..dem clocking..re clocking....etc I am a bit lost...maybe one of the clock guru's will try and explain the differences to me..
hope this helps.:D

hotiron 10th March 2009 10:04 PM

2 Attachment(s)
You don't need a clock if you are running NOS.
see photo.

Chilli6565 10th March 2009 10:55 PM

hhhhmmm
 
Thanks Hotiron.....wow, that is supposed to be a very good dac too.Is the clock then onboard the tda1541?.
Has anyone compared the sound differences between the two clocking options?.
Also what are the lpf resistors for ?

SoNic_real_one 10th March 2009 11:41 PM

You don know what are those resistors are for... but you are saying that "altho in a hi end system the tda1541 would be superior".
That's a good demonstration of how urban legends are perpetuated by people with limited (that means just "some") knowledge in the digital field.

Chilli6565 11th March 2009 01:34 AM

some people
 
SoNic_real_one...there are hundreds of different ways that a tda1541 dac can sound, some of which I have described earlier...obviously you are not smart enough to absorb that information. the tda1541 dac can sound good or bad, depending on how it is implemented. Just because I dont know what the lpf resistors are for ( low pass frequency as a guess ) dosn't mean the dac will sound good or bad... and as it states on the schematic they are optional.
Have you heard both dacs??if so, in what configuration???
So if you can't add constructive criticism...then go ahead and be a ******.:att'n:

philpoole 11th March 2009 01:41 PM

I2S has a bit clock. So the data is clocked in on that, and samples are presented on the WS signal.
A 'clock' as you put it in the normal sense usually refers to the master clock, which runs at something like 11 or 16 MHz. You need this to drive the decoder or digital filter, but not this DAC.
The resistors are used to reduce the current going into the DAC to reduce distortion. A LPF is apparently better still (I haven't tried). If you search for a thread called 'tda1541 info', you'll find a lot of info on that there.

Reclocking can be used to square up the I2S lines, basically using a bank of flip flops and a master clock to clock the data into the flip flops. The idea is to reduce jitter induced by previous stages by reclocking to a low jitter clock.
DEM reclocking: The TDA1541A uses Dynamic Element Matching (DEM) which uses an oscillator to switch between different internal current sources. DEM reclocking replaces the oscillator signal with one derived from an assumed better clock. Again more in that thread on this.

Chilli6565 11th March 2009 08:25 PM

thanks
 
thanks heaps philpoole, thats exactly the kind of input I am after:D


All times are GMT. The time now is 08:22 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