"Reference" TDA1541A DAC with I2S-BUS architecture

[studiostevus]

Hi antonioo, have you done a sq comparison?


---
I am here: http://maps.google.com/maps?ll=58.921215,5.597375

 

[antonioo]

I have not finished the red baron, i had a hard time finding
Hitachi SK''s.
Previous i had 2 dac''s (green pcb), one wonders off to a friend,
To try out some combination''s need''s a lot off time.

 

[antonioo]

Question to oliver.

The RIV resistors bother me, if i use 2x redbaron, i use 4x 250 ohm.
Is that right??
On your pictures there none.!!
The little ground module- i toke 5v and gnd from dac pcb. on the
output side i have 2 gnd''s??.
My gues is to use audio out-ref , where to put it?
What to do with adjust R''s on Dac and on the small pcb??
Is that double?

Ihope you can help me.
Greetings Ton

 

[dvb projekt]

Question to oliver.

The RIV resistors bother me, if i use 2x redbaron, i use 4x 250 ohm.
Is that right??
On your pictures there none.!!
The little ground module- i toke 5v and gnd from dac pcb. on the
output side i have 2 gnd''s??.
My gues is to use audio out-ref , where to put it?
What to do with adjust R''s on Dac and on the small pcb??
Is that double?

Ihope you can help me.
Greetings Ton

Hi Ton,

if you want to use two Red Baron DAC´s parallel with the onboard I/V stage, you must connect it like this:

1st - Every DAC module needs all parts of the I/V stage, expect the I/V resistors. Adjust the DAC output to 0V (DC-offset of the TDA1541A).

An externally hosted image should be here but it was not working when we last tested it.

Don´t forget to make the small modification and switch the source and drain of the MOSFET like in this picture !!!

An externally hosted image should be here but it was not working when we last tested it.

2nd - The output of the current buffers on each DAC module (inner four-sided point of the I/V resistor) must be connected together (parallel).

An externally hosted image should be here but it was not working when we last tested it.

3rd - You need only one pair of I/V resistors with 250R value on one DAC module (four-sided / round point).

4th - You connect the DC-Reference Module as followed:

From DAC module

Ref. (Audio out) --> Ref. +5V
GND (DC Digital) --> GND

From DC Ref. Module

GND Ref. Left --> GND RCA Left
GND Ref. Right --> GND RAC Right

You could see it on this photo

An externally hosted image should be here but it was not working when we last tested it.

5th - Trimm the RCA GND to 0V

An externally hosted image should be here but it was not working when we last tested it.

That´s it.

Cheers

 

[noizas]

1st - Every DAC module needs all parts of the I/V stage, expect the I/V resistors. Adjust the DAC output to 0V (DC-offset of the TDA1541A).

Hi Oliver,

I cannot catch idea, how it is possible to adjust AOR and AOL outputs to 0 VDC (to GND/A) without I/V resistors?
If R1 and R2 are missing there are no pull up circuits with DC source "above" GND/A to compensate -2mA drain, IMHO.

Maybe I'm missed something, can you explain?

Saulius

 

[dvb projekt]

Hi Oliver,

I cannot catch idea, how it is possible to adjust AOR and AOL outputs to 0 VDC (to GND/A) without I/V resistors?
If R1 and R2 are missing there are no pull up circuits with DC source "above" GND/A to compensate -2mA drain, IMHO.

Maybe I'm missed something, can you explain?

Saulius

Hi Saulius,

all measurements must be done with the I/V resistors, correct.

 

[antonioo]

I have 1 red baron playing, with a sp/dif entree , made of the CS8414 chip.
The same (old) problem occours: BCK wont accept the 68R and 220R.
It dont need''s a buffer.
What is at this moment the best ( buy??) thing to do.

Anton

 

[studiostevus]

The same (old) problem occours: BCK wont accept the 68R and 220R.

Anton

What do you mean? If it plays without the attenuation resistors, i'd opt to just leaving them out. I tried using the buffer stage made by Oliver, but there is significant jitter introduced...

 

[antonioo]

Hi Studiostevus

I disconnect both resistor''s at the point where they meet with BCK, else
no sound, with Dac v2.3 te same.
anton

 

[studiostevus]

May be due to the level of the bck signal. You can fix this by:
- connecting bck directly without the resistors
- using a buffer to increase the bck signal, and then the resistors to decrease them again. This doesnt have my preference

- Check ecdesign's thread on the latest circuit for i2s attenuation (using diodes) and devise a circuit that fits your bck-source

On the other hand, the cs84xx is a widely used receiver. Maybe someone who has used this one can reply on how to get it working

 

[antonioo]

Hello Oliver
The red baron will not go working well, distorted sound.
My suspicion goes to 2SK216, are there other sk''s useble?
Since i got 2 V2.3 playing it''s , wonder about red baron, the adjustible resistors seem, to do not a lot.
anton

 

[dvb projekt]

Hello Oliver
The red baron will not go working well, distorted sound.
My suspicion goes to 2SK216, are there other sk''s useble?
Since i got 2 V2.3 playing it''s , wonder about red baron, the adjustible resistors seem, to do not a lot.
anton

Hi Anton,

please make some detail photos of the pcb´s. That will help to get rid of your problem.

Best,
Oliver

 

[antonioo]

Hi Oliver
After intensiv search, i found a sort of corrosion under a soldering.
Sone after i get it playing. There is one mistery left : from the two ground''s on the
small pcb only is working as a gnd,
Groet anton

 

[antonioo]

Hi Oliver
After intensiv search, i found a sort of corrosion under a soldering.
Sone after i get it playing. There is one mistery left : from the two ground''s on the
small pcb only is working as a gnd,

Groet anton[

/QUOT
Correction of some typing misstake: Question to : Only the left channel of
the smaall pcb work""s as a gnd.
Anton

 

[dvb projekt]

Correction of some typing misstake: Question to : Only the left channel of
the smaall pcb work""s as a gnd.
Anton

Still a few detail photos will help

 

[antonioo]

Oliver in the coming day''s i will try to
make some picture''s,
I am also busy with house renovation so time is scares

Anton

 

[UV101]

Could be flux build up that wasn't cleaned after soldering.

If anyone is interested in some fully built salas shunt regs on olivers pcbs, I have a few that are surplus here. Pm if interested ;-)

http://www.diyaudio.com/forums/showthread.php?t=200881

 

[AndrewGM]

If anyone is intersted in the group buy for Hexfred diodes HFA04TB60PBF, here are the details:-

per set of 8 £5.90

Per order £2 donation to the forum (only required once per order)
postage to UK £1 (1st class), postage to europe £2 (std airmail)

The price per diode is already incredibly low, but if there is enough interest, I can possibly reduce the price further.

Please PM me with you paypal email address, details of how many you require and delivery address if you are interested.

Alon, please can you do the same.

Thanks guys, Ian

*edit - i'll be looking to dispatch orders around 10th August

Blimey that was a good price !!
Can you still get these Ian ?

Andrew

 

[Mayday]

Are these PCB's still available? Might be interested in a complete kit w all PCB's.

 

[studiostevus]

You got PM...

For others as well: I have several modules that I am not using anymore, some are new and unused, some are complete with component. PM me.

-TDA1541a modules (complete with components, except tda1541a chip)
-Salas shunt pcb's
-DDNF pcb's + psu pcb's
-Teralink X2
-DDDac SPDIF to i2s module
-more...