Less simple I/V for TDA1543

[rbroer]

Some pictures and schematics first:

[rbroer]

[rbroer]

[rbroer]

Sorry for rotation,
There is a 800 pixel width limitation and when I resize it becomes unreadable.

[rbroer]

Basically the same I/V stage as for the TDA1541 posted earlier, just some adjusted values,
Like 2 LED's for setting the output on the TDA1543 output to aprox. 2.4V

This time it's a one board solution containing:

TDA1543 with REG101-5 smd LDO regulator,
Tent XO with REG101-5 smd LDO regulator,
74VHC374 for reclocking all I2S lines; note the double reclocking which even allows one to hook up an external asynchronous clock
3 legged pre-regulator (one choosen for lowest noise, thanks Guido)
Of course lots of RC filtering, smd bypass caps (not shown on schematic, many 220u/10V Oscon's.
The TDA1543 has a combo of 1000u/10V Rubycon ZL (best bass), 220u/10V Oscon (HF filtering, creates "peace" in sound).

The I/V part uses DALE/RIKEN for Riv, and Philips KP for Riv.
The caps for filtering the TL431 references are 10u/10V Oscon this time.

The board only needs unregulated power supplies and I2S as inputs and outputs a clock signal for my cd player and the DC coupled analog outputs.

Sound:

Well, the same improvements as with the TDA1541 folded cascode I/V; there is more depth, width, microdetail in the sound.
This sounds incredibly transparent;
I recently compared this player to the passive I/V player and the cd player with single ended common base I/V and this is another level.

It's a matter of music now whether I use this TDA1543 player or the TDA1541A-S2. The latter is great for jazz and easy listening, the TDA1543 I really prefer when things have to rock.

One happy chap

PS
I took the pictures just before I finished the boards, so I could take 'm outside in daylight. So some parts are not there yet (like the integrator cap)

PPS
Peter Daniel, how far are u with these boards

[Peter Daniel]

I finished the output board and I'm half way done with this board. I have a feeling that this will be the first one I'll try.

What can I use for Tent clock (if I don't have one)? I have a pretty good Raltron VCXO running at 24,704 Hz; would it work here? The other choice could be Kwak Clock, I guess, as I have one too. What are you using for smd regulators?

I see a small cap installed on servo chip. What's it for?

PS: I would've finish much earlier, but I was too busy with the amps.

[Elso Kwak]

Originally posted by rbroer
Basically the same I/V stage as for the TDA1541 posted earlier, just some adjusted values,
Like 2 LED's for setting the output on the TDA1543 output to aprox. 2.4V

This time it's a one board solution containing:

TDA1543 with REG101-5 smd LDO regulator,
Tent XO with REG101-5 smd LDO regulator,
74VHC374 for reclocking all I2S lines; note the double reclocking which even allows one to hook up an external asynchronous clock
3 legged pre-regulator (one choosen for lowest noise, thanks Guido)
Of course lots of RC filtering, smd bypass caps (not shown on schematic, many 220u/10V Oscon's.
The TDA1543 has a combo of 1000u/10V Rubycon ZL (best bass), 220u/10V Oscon (HF filtering, creates "peace" in sound).

The I/V part uses DALE/RIKEN for Riv, and Philips KP for Riv.
The caps for filtering the TL431 references are 10u/10V Oscon this time.

The board only needs unregulated power supplies and I2S as inputs and outputs a clock signal for my cd player and the DC coupled analog outputs.

Hi Rudolf,
Looks nice this PCB.
Any reason why you don't use the CFB (Skizlai) in the input?
I don't see any use for current sink T5. It may present a high impedance to T6 but the IV resistor is parallel to it and is only 1k3.
In the same way I don't see any use for T11. The T6 circuit is a common base amplifier and thus presents a low input impedance.
T6 is a current source in itself. The current through T11 is already the sum of currents determined by T1 & T6. You can get a conflict of current sources and sinks in your circuit.
I don't like servos and preregulators, you already know.
You use two flip-flops in series but if you use the same clock as for the player only one is needed, as the clock is not asynchronous. Also I doubt if there is any use for reclocking in a one-box player as you don't have any data related jitter and no PLL recovered clock. My research has shown that you gain very little by using an 11.2896 MHz clock for reclocking just as reclocking the SPDIF output does not bring anything. Kusunoki the originator of the reclocking idea was using a 50 MHz clock. Still on my schedule is trying the 125 MHz clock from Vite. Sonically results are very dependent on the clock used. In my current set-up with I2S Direct I don't use any reclocker.

[tschrama]

Hi,

Looks very nice indeed! But I think that a CFP for the input can give a improvement. It lowers input impedance 10x.

As for the servo.. why a OPA627? You would need it's speed, it is not very quiet. Maybe the DC/drift spec are the reason? That's a very expensive servo.......

Greeting,
Thijs

[rbroer]

Originally posted by Peter Daniel
I see a small cap installed on servo chip. What's it for?

It's just a socket with integrated decoupling cap between 8 and 4, here it won't do anything since power is on 7 and 4, but I just happened to have only these ones

Originally posted by Elso Kwak

T6 is NOT a current source Elso
I suggest studying the circuit a bit better Elso, you're mixing up constant current sources with (folded) cascodes.

In fact, the board is layed out for CFP everywhere, but I had oscillations. Also Terry pointed out, they wouldn't sound natural. In the end I got it working with CFP, but must concur with him, somehow it doesn't sound right, natural.
About reclocking in a cd player, my experiences are quite different, it does quite a lot IMHO, especially when using a very low jitter clock like the Guido Tent XO. My preference goes to his oscillator, least veiled sound IMO, but YMMV of course
It does make sense of course, a clock feeding a decoder chip will propagate through many internal gates, not improving jitter performance at all.
I've implemented synchronous reclocking in cd players 3 times now, and each time there was a very noticable improvement, tighter bass, better PRAT
Servo works in current mode; simulations indicate no THD effect, just for the sake of it I used good resistors. I've listened with and without the servo opamp, there's no difference I can notice.
The servo is there for safety, there is some drift due to temperature changes.


I had several requests for boards for the TDA1541 output stage, and told y'all to wait till I finished fine-tuning the TDA1543 board. This has finished now, so I'll probably order some new boards soon. I'll implement a few changes and make provisions for the "super-pair" this time, replacing the CFP.
Y'all got my email, closing time two weeks from now (both pcb's).

[Elso Kwak]

Originally posted by rbroer



T6 is NOT a current source Elso
I suggest studying the circuit a bit better Elso, you're mixing up constant current sources with (folded) cascodes.

In fact, the board is layed out for CFP everywhere, but I had oscillations. Also Terry pointed out, they wouldn't sound natural. In the end I got it working with CFP, but must concur with him, somehow it doesn't sound right, natural.
About reclocking in a cd player, my experiences are quite different, it does quite a lot IMHO, especially when using a very low jitter clock like the Guido Tent XO. My preference goes to his oscillator, least veiled sound IMO, but YMMV of course
It does make sense of course, a clock feeding a decoder chip will propagate through many internal gates, not improving jitter performance at all.
I've implemented synchronous reclocking in cd players 3 times now, and each time there was a very noticable improvement, tighter bass, better PRAT
Servo works in current mode; simulations indicate no THD effect, just for the sake of it I used good resistors. I've listened with and without the servo opamp, there's no difference I can notice.
The servo is there for safety, there is some drift due to temperature changes.


I had several requests for boards for the TDA1541 output stage, and told y'all to wait till I finished fine-tuning the TDA1543 board. This has finished now, so I'll probably order some new boards soon. I'll implement a few changes and make provisions for the "super-pair" this time, replacing the CFP.
Y'all got my email, closing time two weeks from now (both pcb's).

I beg your pardon, Rudolf, you take me for dumb?
I posted even a similar circuit with CFB input on 07-05-2003:
http://www.diyaudio.com/forums/showt...512#post201512