You can read up on the PHILIPS DAC960 D/A converter, which featured the TDA1541A.
You can also download the original PHILIPS DAC960 service manual from here.
I often enjoy reading what you have to say. It is nice to be able to read a schematic, rather fun much of the time unless you are hunting down a problem and just can't quite get to that bug.
I suggest you read the next post where I clearly already acknowledged the 7220 as strictly an input filter and thanked for the correction. Seems I'm the only poster on headfi that will acknowledge an error. LOL I couldn't recall it's if it worked on both ends of the 1541 or not and put a ? next to it in the original post for that reason. Lots of the best gear of it's day used a 7220 so it couldn't have been that crappy. What does a DF1704 have to do with anything? We were discussing the PCM1704 DAC.
Again, the input filter was never important to the point (why in parentheses with a ? in the first place) and trust me, no one has more tude and TRIES to look more technically savvy in the forum than you do. If I had looked it up, it would have been obvious to me as well as was that the dac used in the Altman is 16 bit which I noted here. This isn't about winning but supplying good info though it sure doesn't seem that way most of the time and I readily admit that I am no engineer. Neither one of us made this unit or could have done it as well so I will accept that it can sound quite good as it seems all that use it think so.
I have taken time off from HeadFi because of threads like this where somebody absolutely refuses to admit the obvious and then some know it all spouts off for no good reason to get even about being caught out by something else. I just had another poster claim "you got me banned", like that's even possible. It's juvenile and does get old after a while.
http://www.altmann.haan.de/tera_player/default.htm Check this out. I don't get exactly what's going on in front of the DAC here. Maybe you can help us and we can get back on track.
p.s. I didn't start the hardware nonsense in this exchange.
Lots of mistakes here qusp, hard to know where to start TDA1541A not an R2R ladder, rather segmented current source. SAA7220 not particularly crappy as a digital filter, what makes it crappy is the power draw, puts crud all over a decent power supply. The reason I'm not winning here is I'm playing for the fun of the game not to win. Appearance to me counts for zilch. Rather ironic that you'd lecture me about reading stuff which isn't on forums, after all I do have a degree (BSc, 1st class, Russell Group U) in this EE stuff
Yeah we've already met over in another place, well spotted. Very pleased to see you're up for learning. I think Thorsten managed to tame the SAA7220 in terms of power supply, so it can be done but its a bit of a dog, admitted. Just the digital filtering part isn't too bad - players with decent attention to the PSU issues and feeding a TDA1541A can sound pretty good I believe.
Current sources, as far as I'm aware are created with common-emitter transistors - the output of current being the collector of the transistor. This has advantages over R2R in terms of gltich which translates to way better dynamics. That's why the distinction between segmented current source and R2R is important, because if the design's done right you can hear the improvement. Charles' design is using an NXP chip and that will be current-source based - though in the case of a CMOS DAC its the drain of the transistor doing the current outputting.