Suspect TDA1541As?
Hi,
Well, after some advice, last night I got the scope out on the 'modern' TDA1541A, played a sine wave through it and then snipped the leg of the 470pF cap again. Upon doing this, it was really clear that a sort of crossover distortion could be seen on the output signal.
So, the 470pF cap is needed, or corruption occurs, so this is a legitimate 1541A (from what I can tell).
Hurray! I am happy again.
Cheers,
Phil
Hi,
Well, after some advice, last night I got the scope out on the 'modern' TDA1541A, played a sine wave through it and then snipped the leg of the 470pF cap again. Upon doing this, it was really clear that a sort of crossover distortion could be seen on the output signal.
So, the 470pF cap is needed, or corruption occurs, so this is a legitimate 1541A (from what I can tell).
Hurray! I am happy again.
Cheers,
Phil
Oh that schem, i allready thought of it when you mentioned the sk170 fet. The schematic is from Pedja Rogic, have build and tried. Without fet part i hooked it on a PCM56, this dac doesn't need an offset.
My advise is to build it, turn put pot in middle, run dac and measure offset on dac-output. If you use a socket for the dac push a cheapo 1541A in it, and no S1 or S2 or other expensive selected dacs to reduce money waste when a first setting was not at best. Then set pot for minimal offset, and reset it after 30 min warmup.
Maybe Pedja himself can give some other/better tips.
My advise is to build it, turn put pot in middle, run dac and measure offset on dac-output. If you use a socket for the dac push a cheapo 1541A in it, and no S1 or S2 or other expensive selected dacs to reduce money waste when a first setting was not at best. Then set pot for minimal offset, and reset it after 30 min warmup.
Maybe Pedja himself can give some other/better tips.
Just shows how useful a schematic is - I was suspecting it was a discrete common gate/base amplifier.
Tubee, having used this circuit, how would you rate it?
I am looking for potential successors to my opamp IV stage.
I think I might try Jocko's IV stage first (or, simpler still, a textbook common base stage with good PS regulation).
Cheers,
Phil
Tubee, having used this circuit, how would you rate it?
I am looking for potential successors to my opamp IV stage.
I think I might try Jocko's IV stage first (or, simpler still, a textbook common base stage with good PS regulation).
Cheers,
Phil
If you think of jocko's stage, try pedja's first, and if you like it stay with it. Jocko's (but then a derivate of it from r.broertjes) have i tried too, liked it first but after a while discovered a sort of distorsion on the sound i didn't like.
The AD844 stage is way better then a regular opamp 5532 output, but when you pick a good opamp (i tried a THS bla bla opamp) the simple cdp opamps stage can be rather good. My all day cdp is a modded cd304mk2 with original opamp stage,(THS)
The 844 stage is fast, and emphasises rithmic music, but hooked it on a pcm56 nonos. Jocko's stage emphasises the more continous tones, maybe better for classic? (but hooked it on a 1541 nonos.) All matter of taste.
I still want to revive my pasive 6922 tube stage for my PCM56 non-os, and have a four paralled 1541 dac in mind, and new speakers, and...... time for a big sleep........
The AD844 stage is way better then a regular opamp 5532 output, but when you pick a good opamp (i tried a THS bla bla opamp) the simple cdp opamps stage can be rather good. My all day cdp is a modded cd304mk2 with original opamp stage,(THS)
The 844 stage is fast, and emphasises rithmic music, but hooked it on a pcm56 nonos. Jocko's stage emphasises the more continous tones, maybe better for classic? (but hooked it on a 1541 nonos.) All matter of taste.
I still want to revive my pasive 6922 tube stage for my PCM56 non-os, and have a four paralled 1541 dac in mind, and new speakers, and...... time for a big sleep........
Hi!
First of all - a great thread! Thank you all for all the data and ideas!!
I will ask you in advance to excuse me for the dumb questions I will most likely ask as I am not yet experienced in reclocking and many other DAC-related things...
I am thinking about building an external (or embedded in the power amp) DAC with both SPDIF (=> CS8412) and I2S inputs available (maybe I will use 74ACTQ574SC with the 3-state control to select one input or the other, I even expect that it will be easy to use the VERF pin of the CS8412 to automatically select the input).
I am very interested in the large info siu sin man tho talked about ( http://www.diyaudio.com/forums/showthread.php?postid=368406#post368406 ). I tried writing him a mail, but I got my mail back undelivered :-( I would be very grateful if anybody has it and would send it to me. Is there such a person??
It is strange for me that I can't find a schematic with TDA1541(A) used with external clock. It would be interesting for me if somebody would like to share such schematics with me.
Is it enough to (TDA1541): tie -OB/TWC pin 27 to ground and provide 12.288 MHz clock on SCK pin 4? Do I need to somehow synchronize (reclock?) I2S with that clock? Why the data sheet says "Maximum clock frequency at clock input (pin 4) min 12 MHz"?
Does the TDA1541A have the option of using external clock? I think it doesn't, right?
Further, when used with CS8412 can I divide the 12.288MHz clock (external for TDA1541) by 2 and fed it to CS8412?
For I/V converter: I am thinking of passing the TDA1541 outputs through a filter like NFM21 and the E pin of OPA861 in a common-B connection. Further, to pass the C pin through another NFM and develop the output voltage over a resistor. (I will also have to force about 2 mA into TDA1541's output, right? A JFET sounds to me relevant here...) I would like to hope that I can get up to 8Vp-p that way... Well, for SS amplifier I will need further filtering, maybe for a tube amp too, but I am far from that point at the moment.
Best regards,
Andrey
First of all - a great thread! Thank you all for all the data and ideas!!
I will ask you in advance to excuse me for the dumb questions I will most likely ask as I am not yet experienced in reclocking and many other DAC-related things...
I am thinking about building an external (or embedded in the power amp) DAC with both SPDIF (=> CS8412) and I2S inputs available (maybe I will use 74ACTQ574SC with the 3-state control to select one input or the other, I even expect that it will be easy to use the VERF pin of the CS8412 to automatically select the input).
I am very interested in the large info siu sin man tho talked about ( http://www.diyaudio.com/forums/showthread.php?postid=368406#post368406 ). I tried writing him a mail, but I got my mail back undelivered :-( I would be very grateful if anybody has it and would send it to me. Is there such a person??
It is strange for me that I can't find a schematic with TDA1541(A) used with external clock. It would be interesting for me if somebody would like to share such schematics with me.
Is it enough to (TDA1541): tie -OB/TWC pin 27 to ground and provide 12.288 MHz clock on SCK pin 4? Do I need to somehow synchronize (reclock?) I2S with that clock? Why the data sheet says "Maximum clock frequency at clock input (pin 4) min 12 MHz"?
Does the TDA1541A have the option of using external clock? I think it doesn't, right?
Further, when used with CS8412 can I divide the 12.288MHz clock (external for TDA1541) by 2 and fed it to CS8412?
For I/V converter: I am thinking of passing the TDA1541 outputs through a filter like NFM21 and the E pin of OPA861 in a common-B connection. Further, to pass the C pin through another NFM and develop the output voltage over a resistor. (I will also have to force about 2 mA into TDA1541's output, right? A JFET sounds to me relevant here...) I would like to hope that I can get up to 8Vp-p that way... Well, for SS amplifier I will need further filtering, maybe for a tube amp too, but I am far from that point at the moment.
Best regards,
Andrey
tubee said:
Thanks... How could I tell that? :-(
So... for CD 44.1 kHz I need 11.2896 MHz. Sounds like I need different frequency for different sample rate (256xfs?). Hmmm... how does the TDA1541 handles that without external clock?!??
Never?!!?
Does anybody knows the jitter of the internal oscillator of TDA1541??
Best regards,
Andrey
Thank you!
I admit I got the http://audio.peufeu.com/node/45 data when I read the thread, I thought there are some 60 pages or something ;-) Nevertheless - thank you!
BCL - this is pin 2. Right? Sure, I imagine it shifts the I2S serial data stream into the input shift register. I've been thinking of providing clock on pin 4 (system clock input). I think it has already been quoted from the data sheet here "A separate system clock input (SCK) is provided
for accurate, jitter-free timing of the analogue outputs AOL and AOR.". This is what I am interested in. Any details are certainly welcome!!
Best regards,
Andrey
I admit I got the http://audio.peufeu.com/node/45 data when I read the thread, I thought there are some 60 pages or something ;-) Nevertheless - thank you!
BCL - this is pin 2. Right? Sure, I imagine it shifts the I2S serial data stream into the input shift register. I've been thinking of providing clock on pin 4 (system clock input). I think it has already been quoted from the data sheet here "A separate system clock input (SCK) is provided
for accurate, jitter-free timing of the analogue outputs AOL and AOR.". This is what I am interested in. Any details are certainly welcome!!
Best regards,
Andrey
http://www.diyaudio.com/forums/showthread.php?threadid=79452 ,
"Building the ultimate NOS DAC using TDA1541A" ?
OK, I will, thank you! Indeed, there is more to read than the current thread...
Best regards,
Andrey
"Building the ultimate NOS DAC using TDA1541A" ?
OK, I will, thank you! Indeed, there is more to read than the current thread...
Best regards,
Andrey
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.