Another D1 clone with CCS

[Klaus]

Hi,

my D1 stage clone launched… The sound is just incredible. Extreme stability, neutrality and silence in the sound – maybe caused by the consequent CCS using.

The schematic is a transfer from the P1.7 CCS into the pure D1 stage – thanks to the one and only! I have chosen the double JFET 2SK389 as converter. The sound is changing strongly with the bias current, find your own choice! Use for tests trimming resistors in the CCSs.

I am still feeding this stage with just 0,1mA from my TDA1547 using 6,5k work resistor R_L and 680pF Filter cap parallel. But soon a pack of PCM1704 will feed this converter sweetie pie…

Am I just to stupid or is there no way to upload attached files to the diyaudio server?! I have no web space installed so I can not refer to a personal www adress to lay down my pics somewhere. So please check the attached two links to see pics of the monster and the schematics…

http://www.audiomap.de/forum/index.php?az=show_mesg&forum=116&topic_id=15097&mesg_id=15097&page=
http://www.audiomap.de/forum/index.php?az=show_mesg&forum=116&topic_id=15097&mesg_id=15147&page=


Tweaky regards

Klaus

 

[Peter Daniel]

I'll do it for you. You should save the drawing as a picture and attach it here.

 

[zygibajt]

I'm planning to try D1 stage with TDA1541A DAC.
Do you think using just the half of orignial (balanced) circuit without any changes to parts values would work ok?

Bartek

 

[Peter Daniel]

It should work fine as it's not an X circuit.

 

[Asen]

zygibajt,

I was thinking of doing the same but using 2 TDA1541 the way D1 works. Do you have any special reasons to use just 1 DAC chip?

Regards

 

[Peter Daniel]

I have: it's a stereo DAC.

How do you plan to seperate into L & R channels?

 

[zygibajt]

I have one reason ,too.

I'm playing with CD player,not separate DAC.
By the way,I'm not quite sure I want to complicate things too much!

All best

Bartek

 

[Asen]

Peter,

I mean the second chip could be used to invert the phase. My idea was not splitting the channels. Do you think it's not possible with 1541?

 

[Peter Daniel]

I believe you can invert the phase in I2S signal, so the second chip is not required. You can of course do it with another chip as well you can use separate chips for L and R channels (guido was working on it), but such setups might sound different than doing it with a single chip.

 

[rfbrw]

If one wants to recreate the Pass D1 with the TDA1541A a second chip will be necessary.

 

[Peter Daniel]

If you need balanced output, but not for single ended?

 

[rfbrw]

If a single-ended output is all that is required, why the need to invert phase as referred to in your last post but one.

 

[Peter Daniel]

I was refering to inverting the phase as an additional feature (polarity switch) as the first post doesn't seem to be dealing with a balanced signal.

 

[Asen]

What I had in mind was a balanced output. I mentioned it - "the way D1 works". I'm sure a balanced output could be achieved with only 1 TDA chip using the same or similar (Aleph P like) output circuit but I think Nelson's DAC solution with 2 chips is much more brilliant...

Regards

 

[Peter Daniel]

But it would also be elegant to have one chip handle left channel and the other chip to handle the right channel. How you take care of that?

 

[rah]

Using 2 x TDA1541A for balanced D1 o/p

Using 2 x TDA1541A for balanced D1 o/p is exactly what I plan to do (once I get time). The idea is to split the I2S into L/R and feed it into the TDA1541As in simultaneous mode. 1 TDA1541A chip will output L+ and L- (on one supply), and the other R+ and R- on another supply. The output going straight in a D1 o/p stage.

Some ideas that that I had discussed with others:

* Because both + and - are on the same chip and share the same supply, any garbage on the supply would be common to both + and -

* The active divider is shared by + and - so that problem of loosing clarity in the high-end, described by many that have paralleled TDA1541As would possibly not exist.


So, the question is how do you split the L/R data off into 2 x TDA1541As in a balanced configuration, with discreet logic?

Well, I believe it can be done easily if you use the simultaneous input mode in the TDA1541As. I’ve posed the circuit I designed here:

http://www.diyaudio.com/forums/showthread.php?postid=299718#post299718

I have not had a chance to try it out, but looks fine in theory/simulation…

 

[Asen]

My idea is 1 TDA1541 to output both L and R channels, and the other the same signal but with inverted phase. It should work, I hope...

 

[rah]

Yup, that will be *much* easier to do...

Looks like not many have tried balanced TDA1541As (in any configuration). Would be nice to hear what they found, in
terms of subjective differences between, single TDA1541A , 2 x TDA1541A paralleled, 2 x TDA1541A balanced. Especially with the D1 o/p stage ...

 

[guido]

I believe you can invert the phase in I2S signal, so the second chip is not required. You can of course do it with another chip as well you can use separate chips for L and R channels (guido was working on it), but such setups might sound different than doing it with a single chip.

That's GuidoB.

Anyway, it works. If you simplify some stuff (no mute, no choice diff/non diff etc) you can simplify the equasions. Then you can create the equasions from the GAL with normal logic in hardware.

http://www.diyaudio.com/forums/showthread.php?threadid=8614&highlight=

Greetings,

GuidoB