I'am sorry if i'am not able to explain well this stuff but i have some problems with the english language.
Anyway referring to schematic attached in the first post if you want try it without reclocking (74HC4040 and Crystal Oscillator removed) i wrote: "you have to change the 8414 from mode 3 (M0=1, M1=1, M2=0, M3=0) to mode 2 (M0=0, M1=1, M2=0, M3=0)" that means change pin 23 from +5V to GND, pin 13 could be also floating (not connected to anything - as it is when you remove the 74HC4040).
If you would like to understand better the various modes of functioning of the CS8414 you can read page 21 of the datasheet, it's enough to google for "cs8414 datasheet" or click here:
http://freenet-homepage.de/kxdev/docs/codecs/8413-4.pdf
Ciao
Andrea
Anyway referring to schematic attached in the first post if you want try it without reclocking (74HC4040 and Crystal Oscillator removed) i wrote: "you have to change the 8414 from mode 3 (M0=1, M1=1, M2=0, M3=0) to mode 2 (M0=0, M1=1, M2=0, M3=0)" that means change pin 23 from +5V to GND, pin 13 could be also floating (not connected to anything - as it is when you remove the 74HC4040).
If you would like to understand better the various modes of functioning of the CS8414 you can read page 21 of the datasheet, it's enough to google for "cs8414 datasheet" or click here:
http://freenet-homepage.de/kxdev/docs/codecs/8413-4.pdf
Ciao
Andrea
is that smoke
.....I tied pins 23 and 13 to ground (no 74hc4040 or crystal ), but when I powered it up the power on led was dim then a couple of seconds later it started smoking from the rectifier diodes!...anyway I got to it in time ..changed back to original circuit and was ok.
When I looked at the original cct in the first post ( analogmetric dac kit )...it shows 5vdc to pin 23...so I was creting a dead short !.....tell you what those lm317 regs are pretty tough!....did you mean to float the 5vdc to pin 23 then short pin 23 to gnd??
.....I tied pins 23 and 13 to ground (no 74hc4040 or crystal ), but when I powered it up the power on led was dim then a couple of seconds later it started smoking from the rectifier diodes!...anyway I got to it in time ..changed back to original circuit and was ok.
When I looked at the original cct in the first post ( analogmetric dac kit )...it shows 5vdc to pin 23...so I was creting a dead short !.....tell you what those lm317 regs are pretty tough!....did you mean to float the 5vdc to pin 23 then short pin 23 to gnd??
Re: is that smoke
You have to disconnect pin 23 from +5V and connect it to GND, maybe you can bend the leg of the adapter corresponding to pin 23 (is 8414 mounted on an adapter?) to go out of his socket and connect it (the leg) to GND.
Ciao
Andrea
Chilli6565 said:.....I tied pins 23 and 13 to ground (no 74hc4040 or crystal ), but when I powered it up the power on led was dim then a couple of seconds later it started smoking from the rectifier diodes!...anyway I got to it in time ..changed back to original circuit and was ok.
When I looked at the original cct in the first post ( analogmetric dac kit )...it shows 5vdc to pin 23...so I was creting a dead short !.....tell you what those lm317 regs are pretty tough!....did you mean to float the 5vdc to pin 23 then short pin 23 to gnd??
You have to disconnect pin 23 from +5V and connect it to GND, maybe you can bend the leg of the adapter corresponding to pin 23 (is 8414 mounted on an adapter?) to go out of his socket and connect it (the leg) to GND.
Ciao
Andrea
You're welcome,
anyway i explained you how to set your DAC without reclocking because it seemed to me that it was what you want to try and not because i think it's better, simply try and let us know your impressions.
The kind of reclocking implemented in your DAC has pros and cons, it lower the jitter but you have some samples slipped or repeated every now and then (this comes from the fact that you have two asynchronous clock with frequency very close to each other but not equal, one in the transport and one in the DAC).
Someone says that this effect is unnoticeable and you have only the pros of low jitter, other says that with NOS DAC, that are more tolerant to jitter, you don't need to reclock.
As i said try and choose the solution you like more.
Ciao
Andrea
anyway i explained you how to set your DAC without reclocking because it seemed to me that it was what you want to try and not because i think it's better, simply try and let us know your impressions.
The kind of reclocking implemented in your DAC has pros and cons, it lower the jitter but you have some samples slipped or repeated every now and then (this comes from the fact that you have two asynchronous clock with frequency very close to each other but not equal, one in the transport and one in the DAC).
Someone says that this effect is unnoticeable and you have only the pros of low jitter, other says that with NOS DAC, that are more tolerant to jitter, you don't need to reclock.
As i said try and choose the solution you like more.
Ciao
Andrea
I can only apologize chilli6565 I stupidly assumed you would know that these pins were tied to VDD!!!!! I now feel very bad and look like a knob.
You need to look at the two schematics this is common sense>
What ye thinkin about?
I am listening to ZZTop El Rancho right now .super modded rotel 855 tda 1541
and it is kicking ***> I would offer to fix yours if you were not at the other side of the planet.
You need to look at the two schematics this is common sense>
What ye thinkin about?
I am listening to ZZTop El Rancho right now .super modded rotel 855 tda 1541
and it is kicking ***> I would offer to fix yours if you were not at the other side of the planet.
working
ok guy's...I have the dac operating without the 74hc40404 and crystal.
Ok, now to the subjective sound!!!well, I dont know if anyone here will agree with me but I definately prefer it WITH the 74hc4040 and crystal in the circuit. Without it the sound was some what "hashy" and the soundstage suffered as well...but the bass was fast and tight.
thanks again hotiron,anbello and others
Now, I have two spare clocks here a Burson and a lc audio clock two....how hard would it be to implement one of those to see if sound quality would be superior??.
ok guy's...I have the dac operating without the 74hc40404 and crystal.
Ok, now to the subjective sound!!!well, I dont know if anyone here will agree with me but I definately prefer it WITH the 74hc4040 and crystal in the circuit. Without it the sound was some what "hashy" and the soundstage suffered as well...but the bass was fast and tight.
thanks again hotiron,anbello and others
Now, I have two spare clocks here a Burson and a lc audio clock two....how hard would it be to implement one of those to see if sound quality would be superior??.
I have this DAC kit also, I have never tried the reclocking, I agree with your above statement, but there is a fix for this "hashy" sound.
Looking at the schematic for this DAC, Change R25 to 470 Ohms and Change C33 to 220nF.
This is the loop filter for the CS8412 coming off pin 20.
This in itself will totally get rid of the hashy sound....
Also omit: C20, C39, R15,R16, these do the high frequency filtering and are totally unneccesary and negatively affect the sound and once you remove them you will know what im talking about! , although I did leave in in C41 and C44.
Replace C74 and C75 with Nichicon Muse 100uF or any of your favourite coupling capacitors. The 10uF Wima caps included with this kit sound nasty!!
If you do this then the sound smoothes out and sounds fantastic.
This kit is REALLY GOOD in NOS once these few mods have been done to it! HIGHLY RECOMENDED!!!!
Hi Chilli6565
I also have just purchased this DAC kit with a view to trying to get this DAC behaving as best I can. I already have heavily modded TDA1541 based player and have learned some interesting facts along the way.
In std form (not NOS) the master clock is on the SAA7220. This will inturn clock other places (on my CDP not the DAC) this "daisy chanining" and has a disasterous effect on sound quality. I have now sorted the clean master clock distribution and it has raised the bar.
In this circuit, the clock goes to the divider chip which then distributes but there is still some "daisy chaining"
In addition, DEM reclock (which I've not yet tried) is supposed to be another massive improvement.
Attached is the re designed clock layout i'll be using. In recent testing a couple of us found significant improvement by adding the system clock onto pin 4 of the 1541. This was a sys clock input on the non A version (supposedly deleted for the A version) but if is believed that although not all datasheets for later chips show it as still being sysclock, it still is!?!?
You should see the clock being connected directly to all 4 chips and then /2, /4 and /256 connected as required.
In addition, for the DEM reclock, you'll need /4 of the sysclock to pin 17 and inverted /4 to pin 16 (or vise versa, i'll need to check!!). Hopefully the fonts aren't too small!
From what I've read, if you sort out the supplies and the clock distribution from a decent source, you get the benifits of the NOS mode with the benifits of OS mode! Its a bit of effort but its definately worth it!
I've also done some work on the PSU if you're interested!
Most of this info can be found on the CD650 and the 1541 ultimate threads.
hope you find the info usefull!
Ian
I also have just purchased this DAC kit with a view to trying to get this DAC behaving as best I can. I already have heavily modded TDA1541 based player and have learned some interesting facts along the way.
In std form (not NOS) the master clock is on the SAA7220. This will inturn clock other places (on my CDP not the DAC) this "daisy chanining" and has a disasterous effect on sound quality. I have now sorted the clean master clock distribution and it has raised the bar.
In this circuit, the clock goes to the divider chip which then distributes but there is still some "daisy chaining"
In addition, DEM reclock (which I've not yet tried) is supposed to be another massive improvement.
Attached is the re designed clock layout i'll be using. In recent testing a couple of us found significant improvement by adding the system clock onto pin 4 of the 1541. This was a sys clock input on the non A version (supposedly deleted for the A version) but if is believed that although not all datasheets for later chips show it as still being sysclock, it still is!?!?
You should see the clock being connected directly to all 4 chips and then /2, /4 and /256 connected as required.
In addition, for the DEM reclock, you'll need /4 of the sysclock to pin 17 and inverted /4 to pin 16 (or vise versa, i'll need to check!!). Hopefully the fonts aren't too small!
From what I've read, if you sort out the supplies and the clock distribution from a decent source, you get the benifits of the NOS mode with the benifits of OS mode! Its a bit of effort but its definately worth it!
I've also done some work on the PSU if you're interested!
Most of this info can be found on the CD650 and the 1541 ultimate threads.
hope you find the info usefull!
Ian
ccschua said:
It is best to distribute the clock directly. Each chip that receives the clock and passes it on, adds its own noise. The divider should do a reasonable job at dividing and passing on as that is its only function. There has been some debate over the connection of pin4 to the system clock. This was a published function of the nonA version. It is not published as included on the A version but having researched it and then tested, I have concluded that it will take a clean system clock (dependant on mode of operation) and improve the audio as a result.
There is a mistake in my diagram! In the original diagram at the start of this thread, this pin should be connected to /2 clock on pin 9 on the 74hc. My appologies!
I'm will definately implement this mod very soon on my cdp! The theory is posted on the unltimate NOS 1542A thread.
Ian
Will do!
I've not looked much at this area yet. I've just copied the original configuration and sorted seperate clock supplies as required. I'm also considering using a 9001 chip with an adapter.
Looking at the data sheet, the std mode for the cs8412 is I2S.
What will grounding pin 13 achieve (obviously iso;ating the clock 1st!)?
Ian
I've not looked much at this area yet. I've just copied the original configuration and sorted seperate clock supplies as required. I'm also considering using a 9001 chip with an adapter.
Looking at the data sheet, the std mode for the cs8412 is I2S.
What will grounding pin 13 achieve (obviously iso;ating the clock 1st!)?
Ian
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.