"Super-Pair" I/V for TDA1543

[rbroer]

Here's the latest incarnation of the folded cascode, common base I/V converter.
Just finished it, and it's up and running

The TDA1543 part of this pcb,
with synchronous reclocking of I2S signals,
Tent XO and the digital supplies can be found here,
Less simple I/V for TDA1543

It's basically unaltered, using VHC logic for synchronous reclocking, several 220u/10V Sanyo Oscon's for bypassing, mixed with 805 SMD combo's of 100n & 10n per Pete Goudreau
Again I settled on 1000u/10V Rubycon ZL with 220u/10V Sanyo Oscon for the TDA1543 supply.
Each chip gets its' own very tiny and very low noise REG101-5 regulator, 805 smd 100n+10n for the BYPASS pin.

I left the DC servo out this time, since my amplifier has one of its own already. Peter Daniel reported some negative influence, even though my simulator THD measurements indicate no ill-effect.

The jfet cascode on the 2nd current sink does improve things, again the THD measurement in the simulator tell me it shouldn't make a difference

Implementing the super-pair brought a small improvement, now the simulator promissed a large improvement

Important lesson learned: DO NOT TRUST SIMULATORS, sorry Jocko, needed to find out for myself...

Riv is a mix of Riken (1.5k), Tantalum (10k) and DALE RN65C (40.2k), Civ is a Philips 1.0n KP

Q2N is 2SC2547E
Q2P is 2SA1085E
all other bjt's are BC549C and BC557B

100u/25V and 470u/25V are Rubycon ZL series

Resistors are small Beyslag series MRS16T

I'll probably leave it this way now, don't have may ideas how to improve it.
Tried the CFP, didn't like it (oscillated at first)

Happy DIY,

[Peter Daniel]

So how much better is it, comparing to a previous version? Mostly, is it worth upgrading?

[rbroer]

Here it is:

[jean-paul]

Hi Rudolf, is D3 a LED ? I don't think it is but what diode do you use there ?

[Bricolo]

What's the difference between a super pair and a CFP?

[rbroer]

Originally posted by Peter Daniel
So how much better is it, comparing to a previous version? Mostly, is it worth upgrading?

Currently I like it a lot, doesn't mean zip to you, I know
Bit hard to tell, since only yesterday I re-installed the jfet cascode on the previous I/V board.
Did you install that jfet on your board btw ?
I'll let you know in a couple of days.

Originally posted by jean-paul
Hi Rudolf, is D3 a LED ? I don't think it is but what diode do you use there ?

You could use a 4148 diode, but I used a green LED...think like Christmas trees

[jean-paul]

I only see 4 LED's on the PCB, that's why I ask. In your schematic I see 5 LED's ( 3 green ones and 2 red ones ).

BTW since the servo is omitted maybe it is better to use an output cap + resistor to ground after it ? Could you repeat the adjustment procedure in this thread for those that don't know the Search function ? The Iref resistor for TDA1543 will be 1k2 ?

Did you change your design for TDA5141A like this one as well ?

Many questions but not meant negatively.

Regards,

Jean-Paul

edit: I checked again and I now see that there are 2 LED's D3 in the schematic ...

[Bricolo]

Originally posted by Bricolo
What's the difference between a super pair and a CFP?

[Pedja]

...

[Bricolo]

Thank you


Where can I learn more about them?