I understand what you are getting at. The TDA1541 is an ancient DAC and not capable of much.
But I do like the sound of it, infact I like it so much I am in love with it.
A PCM1704 dac would be better, but, this is TDA1541 territory...
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Well, I'm not worry and I'am not talking about the dac chip but all the things around it. Nore I want to discourage you, I'm just sharing, caps are not lost even if you buy many of them (have a little collection also, unfornatully not enough BG...🙁)
Agree with you that the caps are important also but unluckily don't sucess to tell you that you wiil find limitations due to the layout of this kit : regulator (maybe you can fix with old used cap with high Z at the output and low Z at the base filtering), spidf CS chip (jitter you can NOT fix with caps), bad output I/V oap stage, bad gnd trace, bad rf layout, etc... and here this is not the territorry of the dac chips or Philips engineer but the developper (copyst?😀) of the pcb!
Well sterile discussion after all I made this path already but will follow your thread with pleasure 🙂
cheers
Agree with you that the caps are important also but unluckily don't sucess to tell you that you wiil find limitations due to the layout of this kit : regulator (maybe you can fix with old used cap with high Z at the output and low Z at the base filtering), spidf CS chip (jitter you can NOT fix with caps), bad output I/V oap stage, bad gnd trace, bad rf layout, etc... and here this is not the territorry of the dac chips or Philips engineer but the developper (copyst?😀) of the pcb!
Well sterile discussion after all I made this path already but will follow your thread with pleasure 🙂
cheers
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I have not had the opportunity to listen to BG but if they are anything like Elna Cerafines then I'm sure they are amazing.
Well the caps weren't that expensive so its no loss, this is a pretty low cost setup.
I have also never heard AD797's but want to buy some so I can listen to them.
The Elna Cerafines that I've ordered were 27 GBP all up including postage. Not much for so many capacitors.
I like to think it is OUR thread. I am in the market to buy many components and try to get the best possible performance out of this PCB with modifications. When the components have been used in this DAC I can use them elsewhere. I will listen to the caps and components and modifications that you and others recommend.
I will stand on the shoulders of giants (knowledge and experience for what works) but only until I have experienced the reasons behind this for myself.
Only a small part of it is genuinely mine, the Germanium diodes selection is mine, the use of Elna Cerafines is mine, the use of such huge chokes is my choice, the use of the K73-15's and K73-16's is mine (they are really cheap capacitors by the way).
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Member
Joined 2006
Brave young man, you will become a Jedi too, someday...and be the force with you…
Right*Wookiee? 🙂
Right*Wookiee? 🙂
Yes, yes Right... If wookies can be Jedi with coat, young men can be also 🙂 ! Where did you get this photograph of me ?
have almost finished my first AYA 2 2014 with the SURE Electronic spidf Wolfson hardware mode pcb as the price of the CS8014 was near the same !
The distinction-1541 is looking at me and say 'tubes, tubes, tubes' !
With the advise of Oliver (Stixx fellow) have sourced some good SP OSCON as the one bought at HK were fake and from the bad value ! Rubycon ZA are breakin on the Subbu before going to the AYA 2 2014 but have a little doubt if they are genuine or not ! They will be benchmarked with my genuine BG standard 50 uF on the analog stage for the OPA861 !
Wait also for the Wave I/O to swap the spidf... hop ! And just received good PS board from Mravica fellow ! Just need a good Shunt regulator also for an analog stage in a AD1862... and will play to star Wars with my toys at Christmass ! 45 years old but always a Child with audio !
Total OFF Topic like the last Star Wars which is total Walt Disney with Avengers in it now !
have almost finished my first AYA 2 2014 with the SURE Electronic spidf Wolfson hardware mode pcb as the price of the CS8014 was near the same !
The distinction-1541 is looking at me and say 'tubes, tubes, tubes' !
With the advise of Oliver (Stixx fellow) have sourced some good SP OSCON as the one bought at HK were fake and from the bad value ! Rubycon ZA are breakin on the Subbu before going to the AYA 2 2014 but have a little doubt if they are genuine or not ! They will be benchmarked with my genuine BG standard 50 uF on the analog stage for the OPA861 !
Wait also for the Wave I/O to swap the spidf... hop ! And just received good PS board from Mravica fellow ! Just need a good Shunt regulator also for an analog stage in a AD1862... and will play to star Wars with my toys at Christmass ! 45 years old but always a Child with audio !
Total OFF Topic like the last Star Wars which is total Walt Disney with Avengers in it now !
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Eldam, did you do something different with your hair lately?. 😀
If you're looking for shunt reg for AD1862, maybe replicate what Pedja did in AYA tda1541 stage (and not so much the OPA stage).. really hard to beat, no feedback.
Thanks for accommodating the post, Freax.. and best of all for your adventures!
Regards,
Shane
If you're looking for shunt reg for AD1862, maybe replicate what Pedja did in AYA tda1541 stage (and not so much the OPA stage).. really hard to beat, no feedback.
Thanks for accommodating the post, Freax.. and best of all for your adventures!
Regards,
Shane
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I just realized that this schematic doesn't have anything on FILT Pin 20 of the CS8412.
Can't remember if its a good thing to leave this lifted or not.
Reading:
http://www.diyaudio.com/forums/digital-source/192056-need-help-analogmetric-tda1541-dac.html
Answer:
http://www.diyaudio.com/forums/digi...elp-analogmetric-tda1541-dac.html#post2629695
Here we go, turns out the schematic is wrong. Checking the PCB now...
Yep this is R25 & C33, C35 is completely optional and bypasses both the resistor R25 and C33.
Can't remember if its a good thing to leave this lifted or not.
Reading:
http://www.diyaudio.com/forums/digital-source/192056-need-help-analogmetric-tda1541-dac.html
Answer:
http://www.diyaudio.com/forums/digi...elp-analogmetric-tda1541-dac.html#post2629695
Here we go, turns out the schematic is wrong. Checking the PCB now...
Yep this is R25 & C33, C35 is completely optional and bypasses both the resistor R25 and C33.
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What makes things even worse is this goes directly to the large earth feeding the analog output coupling capacitors/AOR & AOL.
May have to disconnect those and isolate the ground a bit. (Not sure how sucessful I'll be.)
I've checked the PCB and it looks like that the error appears to only affect the Schematic picture, and NOT the actual PCB.
On the PCB itself R25 connects to Pin 20/FILT of the CS8412, so all is fine in this part.
I might disconnect that gnd connection coming from R25/C33 and reroute it to another grounding.
This seems to me like a very strange place to be dumping large amounts of digital noise.. Straight onto the low voltage analog OUTPUT ground! eek... I've checked where the nearest ground is for the CS8412 and it appears that Pin 21 (CS8412 AGND) connects directly to a top-side ground trace, this to me seems like the most logical place to connect the butt-end of R25 to, after breaking the trace going to the analog ground.
It boggles my mind as to why they didn't do this...
Sigh.. More research into this descision is in order. A job for tomorrow perhaps.
EDIT:
Even more bad news, the ground at C64 connects to the same analog ground that Pin 20 does...
Basically they've got the same ground sharing between 4x opamps and the output stage with a CS8412.....
Thats like listening to a phone conversation in a tornado.
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EDIT2:
C37 & C38 do too.. I may have to leave these holes empty and simply make up some kind of alternate ground which ultimatley ties in the other two caps for the FILT output and all four go to Pin 21 on the CS8412...
EDIT3:
What a mess...
Maybe I can isolate each section with chokes. Would be easier this way than having to recreate new grounds for each chips ground.
https://www.sigcon.com/Pubs/news/7_02.htm
C37 & C38 do too.. I may have to leave these holes empty and simply make up some kind of alternate ground which ultimatley ties in the other two caps for the FILT output and all four go to Pin 21 on the CS8412...
EDIT3:
What a mess...
Maybe I can isolate each section with chokes. Would be easier this way than having to recreate new grounds for each chips ground.
https://www.sigcon.com/Pubs/news/7_02.htm
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May also need to cut the earth or better off calling it a "shield" on the top layer at where it says "R24", this is what looks like nothing more than an artifact of a badly drawn ground layer/filled plane/ground plane which is actually going to end up coupling digital noise from the SAA7220 chip directly to the TDA1541 chip ground/decoupling section...
Might be a good idea to rejoin this and mate it with the ground plane which surrounds the 74HC4040 and the CS8412.
On second thoughts I think the designer deliberatley tried to make this circuit sound bad. I'm utterly convinced of this.
Might be a good idea to rejoin this and mate it with the ground plane which surrounds the 74HC4040 and the CS8412.
On second thoughts I think the designer deliberatley tried to make this circuit sound bad. I'm utterly convinced of this.
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Ok... If I cut traces on the left hand side of the SAA7220 down the side that R24 is on, and seperate the TDA1541 ground and the SAA7220 ground I can hopefully create two seperate grounds one for the digital side and the other for the analog/TDA1541 side, I can then join whatever grounds are needed to make digital I2S between the SAA7220 and TDA1541 work. But this time through a common mode choke.
THEN Components C65/C66/C34 and R17 can then be placed directly onto the pins of the SAA7220 and this way I can avoid having to join them up with the new TDA1541 ground.
R18 can stay where it is.
Then I can place a common mode choke inbetween and rejoin the ground and data lines from the SAA7220 back to the TDA1541. Using 4 wires wrapped around a Toroid, one wire around a toroid for each data line and another for the ground joining the SAA7220/TDA1541 together.
Then cut the Positive bus trace coming from Q7 which is going to the SAA7220 and get it away from the sensitive TDA1541 region with a jumper wire.
Or I could just use capacitors to couple each stage together..
THEN Components C65/C66/C34 and R17 can then be placed directly onto the pins of the SAA7220 and this way I can avoid having to join them up with the new TDA1541 ground.
R18 can stay where it is.
Then I can place a common mode choke inbetween and rejoin the ground and data lines from the SAA7220 back to the TDA1541. Using 4 wires wrapped around a Toroid, one wire around a toroid for each data line and another for the ground joining the SAA7220/TDA1541 together.
Then cut the Positive bus trace coming from Q7 which is going to the SAA7220 and get it away from the sensitive TDA1541 region with a jumper wire.
Or I could just use capacitors to couple each stage together..
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Found another error on the schematic.
SAA7220:
Pins 4, 6, 7 & 12 are not all connected together, instead Pins 4, 6 & 12 are connected and then earthed. they are earthed to the Digital side of TDA1541, Pin 14 DGND of TDA1541.
SAA7220:
Pins 4, 6, 7 & 12 are not all connected together, instead Pins 4, 6 & 12 are connected and then earthed. they are earthed to the Digital side of TDA1541, Pin 14 DGND of TDA1541.
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Hi Shane,
Yes this photograph was shoted few days ago after the fear of my life : I was in the middle of trafficjam on a motorway inside my Falcon-Millenium and just saw a HUGE tiger near WaltDysney France... and After saw a Roseta sattelite in Kanguru suit jumping from rocks to rocks... pills maybe ?!
I'm afraid with such hair Loreal cosmetics would not want of a model like me anymore 😀... have to launch my own brand for Wookies : LowReal Cosmos Ethic ?
... natural wax for string and so on ! Freax, sorry for those little disgressions 🙂. you will find some usefull informations about the tda1541 grounding in some threads : of course ECDESIGNS ultimate TDA1541 one, also the pcb drawing RyanJ printed and called Distinction-1541... this is a quest, see the thread "Any good TDA1541 kit ?"... A lot of works will help you. And of course the oldest Jedi have maid it already : http://www.audialonline.com/online-topics/
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Only problem is no matter where I look I can see very sparse boards and designs which require massive cases.
At least my TDA1543 Anarchist dac could fit in the side panel of a 3U rackmount project case, leaving the rest of the case bare for transformer/filter cap/diode bridge.
These TDA1541 dac that you find for sale on here need massive banks of capacitors on multiple boards, etc.
But on the Analog Metric DAC it is all on one PCB, I only need to drill 4 holes and then it is done.
I also have a power budget to consider, It must draw 10 watts and no more, so no tubes allowed as an I/V buffer stage.
So only Passive I/V or OPAMPs.'
So I must undo what has been done here as is described by ThorstenL:
http://www.diyaudio.com/forums/digital-line-level/203511-any-good-tda1541a-dac-kit.html#post2853067
This is also a budget dac, where most money is spent on the components and not the PCB, I don't have the guts to go and spend $40 or more on a PCB board when that money could be spent on components.
AD797's are even by themselves only $25 each. Sure I could probably get better results from I/V Passive conversion but............ I do want to try out 4x OS and Digital Filtering and OPAMPs... To see what I'm missing out on.
But then i've heard that AD797's "always" oscillate, which I don't think is true, which is why they're still on my list of parts to obtain. Not everything on this site is gospel...
And lastly, I hate SMD components, I hate handling them, I hate buying them, I even hate installing them, Not for a lack of a proper soldering iron but because I just hate the damn things. Yet they are good apparently for the DEM reclocking stages because lead length impacts how well they will perform with high frequencies, which makes COMPLETE SENSE to me, yet I'm still willing to use Discrete components...
I don't think any novice reading this thread would ever be able to follow along with what I've done if they had to solder SMD components either.. So for entry-level modifications this is out of the hands of the novices. I don't want that, ever. I want to be able to understand what I've done, not be confused by some alien "experts" expertiese working on my project. Basically if I can't understand it then I won't do it.
And lastly, shunt regulation, what!? That would completely blow my power budget right out of the water... Okay yeah sure it has low noise, but... I have to keep the 3 pin volt regulators for the sake of power consumption.
And last but not least, all of my components need to be easy to obtain, Elna Cerafine is kinda almost out of reach but you can still get them from the UK, anyone can, but I'm not going to hunt down super-expensive fast rectifying diodes which cost $34 a pop! or specially-craft my own ultra-low-noise voltage regulator.
And the dac should be able to operate in all conditions, 45 degree weather, severe dust storm, high humidity, it should also be able to take a good hard knock and be thrown around but still work for a decade or more without hiccup. This PCB has attracted me because of this. I live a hard life so therefore my equipment does too, I don't want any of this super-soft gooey easy to break things which need constant support from parts suppliers, or even worse operates components at their thermal or voltage limits.
To sum it all down, this is the dac for the common diy'er, not someone who is pulling down 6 figures a year.
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Those threads above are just given for inspiration 😉. And all the projects in its are for all, it was the first goal: a "good enough" TDA kit for all 🙂 instead of speaking off the shelf toys on a parking between fools 😀 . Btw, you can't go wrong following T. advices, The TDA1541 Yoda ! yes a 3D DIY if you need.
I understood with all those threads the layout and pcb design is not a "plastic ****" but a piece of art which has to be appreciate as much as the dac chips and others components 🙂.
I bet you like it already to see all the mods you are doing on your pcb. it will finish maybe with your own maid with a 15 usd veroaboard with continuous gnd plane (Mouser, etc...) and point to point connection on the top of it !
I don't remember if it is the AD797 or the OPA627(?).. , one of the two is not unity gain stable... the 797 is easier : just a big decoupling caps near it helps if I remember some threads. look for the Sen converter also for I/V... you will appreciate it's simplicity. parts needs to be Ids Matched and I believe you can find it in the Diya store. And why not after in buffer position the oap Molly, fellow like, the AD4562 (?for the ref... have some dyslexia as a wookie : big hammer, small brain... but like Falcon Millenium🙂 )
cheers
I understood with all those threads the layout and pcb design is not a "plastic ****" but a piece of art which has to be appreciate as much as the dac chips and others components 🙂.
I bet you like it already to see all the mods you are doing on your pcb. it will finish maybe with your own maid with a 15 usd veroaboard with continuous gnd plane (Mouser, etc...) and point to point connection on the top of it !
I don't remember if it is the AD797 or the OPA627(?).. , one of the two is not unity gain stable... the 797 is easier : just a big decoupling caps near it helps if I remember some threads. look for the Sen converter also for I/V... you will appreciate it's simplicity. parts needs to be Ids Matched and I believe you can find it in the Diya store. And why not after in buffer position the oap Molly, fellow like, the AD4562 (?for the ref... have some dyslexia as a wookie : big hammer, small brain... but like Falcon Millenium🙂 )
cheers
And I thank you considerably, however copying from them would be duplicating any errors which they've produced and it wouldn't be very original either. I need hard data on what I'm doing and at the moment I'm blind, what I need is an oscilloscope and spectrum analyzer.
My trusty old BWD 511 has blown its CRT filament so I'm in the market for a new one.
May have to pickup a USB based one soon. I'm thinking of a Hantek 6022BL
Thanks for that information. I knew that decoupling caps would help. I was brainstorming while in bed about how an opamp would oscillate and the only way I could think of it doing it is if it was picking up RF from either the TDA1541 output or the SAA7220/CS8412 or its ground traces.
I've come up with a few ways to mitigate this interference but I need an o'scope to measure the results/before & after.
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I suggest we play tic tac toe while we wait for parts to arrive.
http://www.calculatorcat.com/games/tic_tac_toe.phtml
http://www.calculatorcat.com/games/tic_tac_toe.phtml
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