| Pedja |
Hi there,
I was thinking about how many of you would be interested for the TDA1541A non-oversampling DAC board. It would comprise the CS8412 receiver and probably the AD844 common base I/V and would be double sided board with silk screen and solder mask. So, the overall conception would be very close to that you can see in my site. However, Elso’s reclocker will not be included but I could try to make the additional mounting of the Elso’s own reclocker board as easy as possible. Eventually, reclocker driven by the canned oscillator could be included if there are more of those interested for this option, but I will not, for now at least, make both the boards with and without it. I/V could be also made using discrete transistors thus having better specs but this would also add somewhat to the overall complexity.
Price will depend on the quantity i.e. on the way the things with this thread will look in the next few days (or weeks).
Anyone interested? None? :xeye: Tens of thousands? :bigeyes: ;)
Pedja |
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| bzo |
I'd be interested in a board or two. I've been admiring your DAC on your website, and it looks like a real nice project.
I would definately want to use Elso's reclocker, so making that easy to integrate, or included on the board would be a big plus. |
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| Blitz |
| I would be certainly interested, but would like togo either with a D1-outputstage or a tube-i/v-stage. To have two 1541 would not be bad as well. |
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| Pedja |
So, I have not remained alone here, not bad…
As said, the I/V will be probably based on the AD844 as common base stage. I have found it excellent sounding and extremely simple to build. In this case one can use also any classic (single) opamp based I/V, only the I/V resistor should be soldered across the different points.
Another option is the usage of the discrete common base stage with better specifications (it will not be one of those posted by Jocko and Rudolf), but I first should be sure the sound worth more work (will have the results during next week).
As about the other I/V stages I think I can not say anything better but that the existing I/V could be anytime bypassed so you can use one of your own.
The board will be certainly intended for one TDA1541A only.
Pedja |
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| Peter Daniel |
| If you think about adding reclocker later and don't want to compromise the main board design, you could make it in such a way that the small reclocker board is mounted on stand offs, on the main board, and can be added or removed anytime. Connections could be made with any sort of headers and pin connectors and if not used, certain pins wuld be just shorted. |
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| Bricolo |
good idea
the jumpers could also be used as I2S inputs, for those who want to use it in a cd player, with the CD chip |
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| Pedja |
| quote: | Originally posted by Peter Daniel
If you think about adding reclocker later and don't want to compromise the main board design, you could make it in such a way that the small reclocker board is mounted on stand offs, on the main board, and can be added or removed anytime. Connections could be made with any sort of headers and pin connectors and if not used, certain pins wuld be just shorted. |
Yes, that is the idea, something like daughterboard above the main board. Signals paths could be short whether the reclocker is used or not. |
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| darkmoebius |
I also have been a regular to your website and DAC evolutions(not to mention all the others). I would never try to build one on my own, but with your PCB I'd do it in a heartbeat.
After watching the overwhelming success of BrianGT's Gainclone group buy, I bet we've got another winner as soon as people hear about it.. |
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| mozfet |
I'll have a couple of boards for cetain!
Mozfet:D |
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| Calimero |
I am interested in two boards. Have been looking at a good PCB-design for a TDA1541 recently and after browsing through your web-site (especially your 1541 project) I had the plan to email you about the availability of PCB-boards.
Is the board you mention in this thread a new design or the one you have already available. Is it an idea to allow for different kind of ASR's, as I think besides SPDIF or I2S, an USB type of input would be nice.
What about using Elso's design using the AD8561 before the input of the CS8412.
Henk
PS: your web-site is well documented and it is hard to imagine you do this for hobby. It has a very professional look. |
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| jean-paul |
Since I gave up designing an *excellent* pcb for TDA1541A I am in for a few boards. The board you show at your website would be good as it is ( at least it looks very good at the pictures ! ). Will your new board be totally different or will it be based on that one apart from the concept ? Please do consider the use of an input transformer with CS8412, my guess is that you'll like it as much as I do.
A second suggestion is to integrate the power supplies ( except transformers ) on the pcb avoiding wiring. Inexperienced participants sometimes have hum after putting a DAC together and integrating power supplies would be a solution for that. It's just an idea ;) ( using RCA connectors directly on the pcb for input and outputs could be a suggestion too with the same objective ).
If you need help I would be delighted to help you out with the layout as long as you do the TDA part :D |
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| Marlowe |
| I want one to three PCBs :cool: |
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| Nuuk |
Hello uncle Pedja ;)
I have been looking at the Scott Nixon 1543 kit. Is your 1541A a better sounding DAC and if so how much more complicated would it be to put together for a complete DAC novice? |
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| Pedja |
| quote: | Originally posted by Calimero
Is the board you mention in this thread a new design or the one you have already available. |
| quote: | Originally posted by jean-paul
Will your new board be totally different or will it be based on that one apart from the concept ? |
The new board will be based on the previous project and will be made in the same spirit. ;)
| quote: | Originally posted by Calimero
Is it an idea to allow for different kind of ASR's, as I think besides SPDIF or I2S, an USB type of input would be nice. |
If done without the reclocker it would be done that way to be able to accept one. So, of course, can be used for I2S directly, but I did not think about the USB compatibility. With flip-flops included on the board one can experiment with different can oscillators. I yet have to decide about this.
| quote: | Originally posted by Calimero
PS: your web-site is well documented and it is hard to imagine you do this for hobby. It has a very professional look. |
Thanks. I did not do it professionally until now but this may change soon. As about the look of the site, it takes some time to design it, but once the layout is made, it can be easily filled with the content (as it arrives).
Pedja |
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| Pedja |
| quote: | Originally posted by jean-paul
Please do consider the use of an input transformer with CS8412, my guess is that you'll like it as much as I do. |
I must say I did not try the input transformer previously. Since at this moment it would take some time to do that, it would make all the process certainly slower.
| quote: | | A second suggestion is to integrate the power supplies ( except transformers ) on the pcb avoiding wiring. Inexperienced participants sometimes have hum after putting a DAC together and integrating power supplies would be a solution for that. It's just an idea ;) ( using RCA connectors directly on the pcb for input and outputs could be a suggestion too with the same objective ). |
Else than the reclocker for which I am still not sure what to do (if I read correctly the previous posts, the “modular concept” could be preferable but from the experience I know that the much of possibilities rarely lead to the much of the executions), the board will accept all the parts except the mains transformer(s). The output connectors will be at the upper right corner of the board (where they conventionally belong) but the situation with the S/PDIF input is not that simple. While I was designing the first board I have spent some time rotating and moving the chips trying to finish with S/PDIF input at the same side of the board, but the result always was worse for many other things. Finished with what you could see. The input could be still routed anywhere using the board, but in the previous case, considering the distance, I have decided to use the coax.
| quote: | | If you need help I would be delighted to help you out with the layout as long as you do the TDA part :D |
Thanks for the offer. Actually there are not a lot of things that still have to be decided and then all should go relatively fast. I think I tried hundred options for routing around 1541 – none is perfect. The way Peter did it is probably the best I saw but it needs skills/nerves/time...
Pedja |
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| Pedja |
| quote: | Originally posted by Nuuk
Hello uncle Pedja ;)
I have been looking at the Scott Nixon 1543 kit. Is your 1541A a better sounding DAC and if so how much more complicated would it be to put together for a complete DAC novice? |
Hello uncle Nick, :cool:
You could make both for the price of one conventional CD player and be the first who will report about that. :idea:
Seriously, this is the interesting question, you in fact left me without some resolved answer. So, it seems I could not offer you more than this few facts/thoughts.
Firstly, I have never heard Scott’s DAC but I do have something like that made with slightly different parts. Scott’s layout (done with a help of the others on the Chip Amp Forum some time ago but it is finally his own design) is excellent and I must say here he was the one who helped me when I was designing my own board for TDA1543. I firstly wanted to buy his one but he had the problem with the e-mail account at that time; when he answered after some time I have did a lot of work already and he offered me the help to finish it, yes, for free, and he was a great help for me then.
TDA1543 DAC is the gainclone among the DACs, it makes you not to forget the line between the engineering and the designing with the goal of the good sound. At one side it is as simple as the DAC can be and at the other not a lot of that will sound better. I know many that simply can not think seriously about the TDA1543 and they are very wrong.
I still certainly prefer my TDA1541A with reclocker and I/V I am using now to the TDA1543 with passive I/V, but I have also put much more effort into it.
This project will not require any special skills to build but the things might be clearer if you wait a bit to see the way it will look definitely. Anyway, feel free to ask further if the answer was not acceptable... ;)
Pedja |
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| Whit |
| I'd like two or three boards. :) |
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| tg3 |
| I'm in for at least two boards. Would like an option for I2S input. |
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| Borc |
| I'm interested for one too. |
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| SPWONG |
Hi, I want one please or may be two if it is in good price.
Thanks. |
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| Pedja |
Well, my decisions:
No reclocker on the board. The I2S lines will be cut and I will put probably 2 row 10- or 8-pin header footprint there..." but none is supposed to use them actually, everything can still be made with solder (which is normally better as a final solution). I will probably make the additional mounting holes in the board to make easier mounting of the reclocker and the holes will match to those on Elso’s reclocker board. I will also make soon one daughter board with reclocker driven by the can oscillator.
So, CS and TDA will be positioned a bit closer but generally similar as in the previous board and I/V stage will, most generally speaking, take the physical position of the reclocker. This means that the final dimensions of the board will be similar. The previous one was 12.5x12.5cm; if this is important for anyone, its green color is in the reality fresher but my scanner can not capture it.
For the board of such dimensions at this level of interest the price will be about 25EUR, assuming I will not have much troubles and reasons to go again and again with the prototypes.
I have yet to see what will be the analog stage (it won’t change the price anyway).
Pedja |
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| infield |
| I'll take one or two. |
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| seppstefano |
Ciao,
I beg your pardon for my fat ignorance but, would you point me to your site, so that I can get convinced in ordering one PCB of yours :D
Thanks a lot,
Stefano |
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| Andypairo |
Just press the "www" button that appears under Pedja's posts! ;)
BTW I'm still collecting parts to populate the two boards you sent me (I had to order a bunch of transformers!) - one is still untouched - I have to read the whole thread to see if the newer version will be that better to feel the need of an upgrade :D
BTW the onboard I/V will be discrete or based on AD844?
Cheers
Andrea
PS I only could find OPA660 (actually 3 of them) so I'll try Thorsten's I/V (and even his tube output stage) to see which sound best. |
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| seppstefano |
Ahemm... err..., many thanks for help!
Really a wonderful source of info, thanks Pedja (and Andrea).
Ciao,
Stefano |
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| jsuen |
| I will probably get one too. |
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| Pedja |
| quote: | Originally posted by Andypairo
(...) I'm still collecting parts to populate the two boards you sent me (I had to order a bunch of transformers!) (...) |
This is interesting, I was not aware of that the transformer could be a problem.
I can order locally the transformers with any windings I want for quite modest price and I found lately one manufacturer where the additional windings do not raise the price significantly. I have used previously one transformer for the digital part and another one for the analog stage but I believe also that the analog stage can be fed from the same transformer (but from the independent windings) without much of compromise.
However, as I do not have an intention to sell the kits or any part for this project, I recommend checking the solution for the transformer(s). Ideally, the digital part, excluding a reclocker which might be additionally hooked to the line which feeds, say, the digital part of the CS8412, needs 4 secondary windings of 7VAC and one of 22VAC. I/V in the case of AD844 needs something like 2x15V or 2x18V, probably a bit higher voltage if it will be discrete.
| quote: | | BTW the onboard I/V will be discrete or based on AD844? |
Still don't know. Will have some info about this in a few days.
Pedja |
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| bzo |
Pedja, what is the VA rating on the transformers you're currently using? In North America, it shouldn't be too hard to obtain these custom transformers from a vendor such as Victoria Magnetics.
Anyone know of any vendors for the TDA1541A? I have one that I've been saving for such a project, but wouldn't mind building two. |
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| machinow |
Interested! Obviously we are close....
Can I help you with anything?? |
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| Kari |
I would be interested in two boards.
/Kari |
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| cjunk |
I am interested in a couple of boards...
Carlo |
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| Rotellian |
| I would be very interested in a 1 or 2 boards at 25 eur, unless postage to UK is ridiculous. Will have provision for I2S? What will I/V be - or is that undecided? |
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| Pedja |
| quote: | Originally posted by bzo
Pedja, what is the VA rating on the transformers you're currently using? In North America, it shouldn't be too hard to obtain these custom transformers from a vendor such as Victoria Magnetics. |
The bigger one, used for the digital part, is 100VA rated. Five secondary windings are (actually) 8V and two of 1A are feeding CS, two of 1.5A are feeding TDA’s digital part and one of 2A is feeding the reclocker. Secondary winding that feeds the analog part of the TDA is 22V, 2A.
The smaller one is 50VA, 2x18V and feeds the AD844 analog stage.
| quote: | | Anyone know of any vendors for the TDA1541A? I have one that I've been saving for such a project, but wouldn't mind building two. |
I do not know if this info is any helpful for you but my source (via local distributor) was Reichelt, Germany.
| quote: | Originally posted by Rotellian
I would be very interested in a 1 or 2 boards at 25 eur, unless postage to UK is ridiculous. Will have provision for I2S? What will I/V be - or is that undecided? |
Now the price of 25EUR is not in question. The price for shipping by the registered mail for the European countries is about 8EUR and it is probably the same whether the one or two boards are sent. It should not be much higher for the rest of the world.
| quote: | | Will have provision for I2S? |
Yes, I2S protocol will be used and lines will be cut and will have the pads.
| quote: | | What will I/V be - or is that undecided? |
Stay tuned for a few days.
| quote: | Originally posted by machinow
Interested! Obviously we are close....
Can I help you with anything?? |
As I dealt with some issues the previous time I will now just move the solutions. It should not take much time to do the rest. Will see...
Pedja |
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| Pedja |
Jean-Paul, I saw you have mentioned in the other thread latch-up problem if separate supplies are used for the analog and digital side of CS8412. I always used separate supplies and never had a problem with it. Did you, or anyone else, have? I could put in two just_in_case diodes relatively easily considering the space but I am simply not convinced this can really be the issue and I just do not like to put anything not really needed (problems are almost always around the corner).
Pedja |
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| Peter Daniel |
| I always used separate supplies and never had problem either. |
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| hifi |
I think the CS8412/14 dies if the voltage between VD+ and VA+ is more than a diode drop or so, this might cause a problem if the regulators for the different lines takes different time to settle.
/ micke |
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| Pedja |
To be clear from the start, I like what AD844 used as a common base stage delivers soundwise and I like the simplicity of its implementation. What bugged me was the AD844’s harmonic distortion figure. Its internal circuit is just fine but for such an application somewhat higher bias would result in the lower distortion. So I tried similar discrete circuit, i.e. symmetrical diamond transistor with its “emitter” running at some 3.5mA. This circuit’s measured harmonic distortion at 1kHz/0dBFs is 0.012% and it is almost entirely the 2nd harmonic (about -79db below the signal); else than barely visible 4th harmonic the rest was below the noise floor of the measurement setup at about -110dBFs. With the -6dBFs (50%) signal the distortion drops to 0.006%. I will post the circuit and graphs to my site soon. Btw, this stage surely might be made for somewhat better specs.
<review> Sonically, I would rather talk about the different results than about one being preferred to the other. This lower distortion seems to really sound cleaner and one could find better resolution as well, but I doubt that anyone would say that the AD844 per se is not clean. Because of the less grain, the discrete stage was better for female voices (Diana Krall, Laura Fygi), though I doubt that anyone would find the AD844 per se being grainy. At the other hand I would certainly rather listen to Robbie Robertson (Contact From The Underworld Of Red Boy ) using AD844. The AD844 was generally more dynamic and fuller to me. </review> There could be more reasons for this, for instance the presence of the output buffer or slightly different supply, but I can not (once again) escape the feeling that there is the truth in the claims the monolithic is generally preferable “layout” to the discrete one. I could now proceed building/tweaking this discrete stage but I am afraid it might finish with the project which will be indigestible for some. If anyone can urge to guys in Analog to make the same or similar chip running at bit higher current, the result might be all we ever needed about the I/V… (I had a post to National asking them if they have a plan to make one chip with externally available transconductance node using the circuit of or like the LM6181 and with somewhat higher current but, despite of the fact I am registered at their site for a few years, I got the reply with the questions about my company, expected production volume etc. :xeye: – if I’ll have one day enough nerves I will proceed with this correspondence.)
Finally, I should mention that the distortion of the AD844 could be better realized if it is considered as a form of clipping and it decreases as the signal level decreases; the graph you can see in my site is done using 0dBFs signal. With -6dBFs (50%) the harmonic distortion is 0.09% and with -12dBFs (0.25%) it is below 0.04% comprising mainly 2nd and 3rd harmonic.
So, this is the situation:
Contra AD844:
- Measured distortion is higher than it is usual for the solid state circuits.
Pro AD844:
- Regardless of the measured distortion it sounds excellent as it is.
- Easy to put together.
- The layout of this I/V will be compatible with classic I/V stage based on any applicable single opamps, so anyone who considers the specs more important than I do, can achieve them quite easily.
- Can drive almost any load. You can use it without its internal buffer as well. Though I liked it better with it.
Contra discrete:
- Adds to complexity.
- Additional buffer adds to complexity even more.
Pro discrete:
- Measures well still being common base based I/V.
Hence I am planning to go with AD844 for this board. Once I might make and offer another board with a discrete I/V but that will not happen in the next half year and probably not this year at all and this only might happen, no promise of it.
____________________________________
As about the protection diodes for CS8412, I’ll put the pads so anyone who considers them necessary can use them. The active divider’s decoupling caps of TDA will be as in the previous board, WIMA MKP10 0.1u/250V, and the same can be used in CS’s filter (there will be enough space here for 0.22u/250V if one wants to go with wildmonkeysects solution). MSB decoupling caps footprints are somewhat fatter and are intended for WIMA MKS4 2.2u/63V. Output caps will be Black Gate.
So, that is the conception. I am starting with drawing and hopefully will finish it till the end of the week or so. Then it will take about 10 days till I receive the prototype boards. Volunteer or two ready to test the prototype can contact me on react_71@yahoo.com and have it for somewhat smaller price, but the offer is valid only for those able to accomplish it for a reasonably short time.
Pedja |
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| dhaen |
| Assuming the cost is reasonable, I would buy at least 2 boards as long as it would be possible to connect an off-board I/V transformer and valve stage. I expect this will be feasible. |
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| Pedja |
| There will be the pads at the TDA’s output so you can tap the signal from here but be warned that the making of better than on-board I/V won’t be the trivial task. ;) |
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| dhaen |
| quote: | Originally posted by Pedja
....be warned that the making of better than on-board I/V won’t be the trivial task. ;) |
I'm sure you're right, but I'd like to try both ways ;) |
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| bzo |
| Pedja, would it be possible to also put in SOIC pads in addition to the DIP pads for the CS8412? That would allow easy use of the CS8414. It seems like the availability of the CS8412 is starting to get a little low. |
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| Pedja |
Hi Bzo,
Interesting idea but I have neglected it because I am trying to ignore SO packages as long as I can come across the DIP units.
There is that problem some lines are currently using top layer beneath the receiver so I should firstly reroute them. Let me think about this.
Pedja |
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| Luke |
Hi Pedja,
Im interested too:) |
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| George Kubitsch |
I am interested too, for one PCB.
Thanks
George |
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| gchrist |
Count me in also for a board.
George |
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| Coulomb |
I would like a few also, How long until a Wikki is up?
Regards
Anthony |
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| finneybear |
Hi Pedja,
I'd like to have two.
Thanks. |
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| Cobra2 |
Count me in for one...
Arne K |
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| Tensop |
i'm interested in a board, but a few newbie questions first, as i dont know much about these.
Can it take a signal directly from a PC soundcard, for example an creativelabs audigy 2? which has a digital output..
are these boards 2 channel, or single?
is it possible to put a TOSLINK input, instead of the wired method
what is the cost of the board going to be, are the components required easy to come by, possibly by sample order?
what about other parts that are needed, such as traffos, filter caps and regulator boards.. will these be expensive also? |
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| Pedja |
| quote: | Originally posted by bzo
Pedja, would it be possible to also put in SOIC pads in addition to the DIP pads for the CS8412? That would allow easy use of the CS8414. It seems like the availability of the CS8412 is starting to get a little low. |
Bzo, I tried some options and there seems to be the way to go, however the DATA line must be longer in that case. This might not be ultimately critical but makes me feel a bit frustrated. It is probably even more pity to use SO part such way.
So, I am leaning to give up of this. Reichelt (again) still sells CS8412 and, I do not know if it is still valid offer, but forum member Elib has been selling it even for somewhat lower price.
| quote: | Originally posted by Tensop
Can it take a signal directly from a PC soundcard, for example an creativelabs audigy 2? which has a digital output. |
I do not know what the Audigy puts out, the CS8412 should be able to decode the data up to 55kHz.
| quote: | | are these boards 2 channel, or single? |
This is the stereo DAC. ;)
| quote: | | is it possible to put a TOSLINK input, instead of the wired method |
I guess no problem to put it but there will be no optical receiver on board.
| quote: | | what is the cost of the board going to be, are the components required easy to come by, possibly by sample order? |
No new info about the price, until I possibly notify about the change, consider it is 25EUR, shipping not included. The CS8412 and TDA1541A are discontinued parts and I do not believe anyone sends the samples of such parts. Last time I was checking, the AD844 was not on the Analog’s list of the available samples.
| quote: | | what about other parts that are needed, such as traffos, filter caps and regulator boards.. will these be expensive also? |
As soon as I finish the designing of the board I will upload most relevant info about the project on my own site. There will be online parts list and schematic of the final project.
I will try to make the fuss free project as much as I can and I will try to be helpful but do not expect the official support for building from me. It will not require any special skills but it is not recommended as a beginner project.
Pedja |
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| Coulomb |
| quote: | | The CS8412 and TDA1541A are discontinued parts and I do not believe anyone sends the samples of such parts |
Global Electronics has them.
Type TDA1541 in the search bar |
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| Andypairo |
$16.59... a real deal!
Reichelt has doubled the price but is still at about 6.5€!
Cheers
Andrea |
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| bzo |
| quote: | Originally posted by Pedja
Bzo, I tried some options and there seems to be the way to go, however the DATA line must be longer in that case. This might not be ultimately critical but makes me feel a bit frustrated. It is probably even more pity to use SO part such way.
So, I am leaning to give up of this. Reichelt (again) still sells CS8412 and, I do not know if it is still valid offer, but forum member Elib has been selling it even for somewhat lower price.
|
Pedja, thanks for trying. One can always use a SOIC->DIP converter if necessary. It looks like there are still a few sources to get the CS8412, thanks to all who mentioned them. |
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| mozfet |
Just added my name to the WIKI but I've no idea how to get it into a table format.
Mozfet:bawling: |
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| Pedja |
Solved. :cool:
You were closest the first time:
||#||username|||# of boards|
Should be:
||#||username||# of boards|| |
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| gchrist |
Pedja,
How are the orders going? Will we see any pcb's soon?
George
Athens-Greece |
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| slawney |
| One pcb for me, as well. |
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| Pedja |
Work on the layout has been longer than I expected but I have finished it (if anything here can be finished) four days ago. I expect to have the prototype board around Wednesday.
Here is the components arrangement.
Pedja |
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| bzo |
| looks good. Do you have a parts list available yet? |
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| Pedja |
| Just working on this. I will upload the schematic, parts list and components outlines (as above but like 1:1 scaled pdf) to my site in a few days (will post here info when I upload it). This will keep preview status but I believe it will be practically the final version. |
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| jean-paul |
I want one ! Excellent job, Pedja. Thanks for the time and effort you put in this. When and where can we order ?
BTW do some of the regulators need coolers ? Not enough time to look into it now but IC 6 is close to C17, that's why I ask. |
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| Pedja |
| quote: | Originally posted by jean-paul
I want one ! Excellent job, Pedja. Thanks for the time and effort you put in this. When and where can we order ? |
Thanks Jean-Paul,
Just a bit of patience, I would like to make at least one board working to be sure everything is right. This will save both me and others of potential problems. The first board will be finished tomorrow and I hope I will populate it in a few days.
| quote: | | BTW do some of the regulators need coolers ? Not enough time to look into it now but IC 6 is close to C17, that's why I ask. |
Well noticed, I must say! I simply could not resist to put that regulator in row with IC4 and IC5. [joke… ok, partially it is not]
This is the situation. With R12=220R the current through IC6 is about 40mA which will lead to, if we are inside the suggested secondary voltage for this rail, 200-250mW dissipated power on the regulator (that is why the range of the suggested voltages for this secondary is tighter than for the others). For TO-220 package this is quite acceptable and the heat goes up and a majority of the caps of this capacitance (somewhat smaller capacitance might be used as well) are shorter than the regulator. The regulator can always be sloped ahead and if someone insists there is a place for TO-220 heatsink (U shaped, but I really think this will not be necessary). I have in the previous board similar situation with 24V regulator (pic below), it is a bit warm there but everything works fine. I even firstly used 180R (as shown in the schematic of the first project’s supply), and later I did put 220R here but this was rather because of TL431 (though it still could work and IME TL431 likes the current).
Pedja |
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| mikelm |
this looks interesting
two boards for me please
mike |
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| dhaen |
Hi Pedja, excellent work :).
I particularly like the method of tying Va+ to Vd+ with diodes, as I've had latch-up with Crystal devices in the past.
Something I forgot to ask about was whether the SPDIF gnd connection can be broken. I use balanced interconnects. If it's too late, don't worry, I'll find a way ;) |
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| sugano |
Hi Pedja,
I want one of them too so how do I prceed?
Thanks,
Peter |
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| rwagter |
Very nice indeed, also interested.....
Ralph |
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| Pedja |
| quote: | Originally posted by dhaen
I particularly like the method of tying Va+ to Vd+ with diodes, as I've had latch-up with Crystal devices in the past. |
Hi John,
I personally did not have this problem but these diodes are something like my insurance.
| quote: | | Something I forgot to ask about was whether the SPDIF gnd connection can be broken. I use balanced interconnects. If it's too late, don't worry, I'll find a way ;) |
I hope this pic answers your question.
Pedja |
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| dhaen |
| quote: | | I hope this pic answers your question. |
I can cope with that :)
Thanks Pedja |
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| Pedja |
I did not plan anything special about this, you can place the order using a simple e-mail. But again, it is still early for this. The Wiki page looks better than I have expected and there are also some AFAICS seriously interested for board in this thread who are not signed in Wiki. I also have some interest received by mails and all this will push me to deal more seriously with the ordering/shipping issues and I will dedicate some time to this after the designing work is finished.
And thanks to all for believing in me and for the kind words I received in this thread, I am not sure I can always recognize myself in these.
Pedja |
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| Peter Daniel |
Why no option for smaller bypass caps? Those are pretty big.
Otherwise really nice looking board;) |
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| Pedja |
| Those two bypasses that should go beneath the TDA? |
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| Peter Daniel |
| C105 - C 118 |
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| Andypairo |
Pedja, excellent work!
My compliments!
Cheers
Andrea |
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| Pedja |
Thanks. And thanks.
| quote: | Originally posted by Peter Daniel
C105 - C 118 |
Else than those for MSB, the footprints are for WIMA 0.1u/250V MKP10. It is true MKP4 for example are smaller but MKP10 are (supposedly, at least WIMA claims so) better for pulse applications. But the fact is I could put additional set of pads.
Any other smaller MKP?
Btw, it is not a problem to make the board that could accept parts of different size. But it is a problem to make it to get the best layout in all the cases. Actually you finish with the solution that is the compromise with something that will not be actually used. So if I would decide to use MKP4, I would in fact be sorry not to make layout tighter (they are not only shorter but also thinner).
Pedja |
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| Peter Daniel |
So the current spacing on those is 0.60"?
It is fine, but some people just might have some other caps at home and will not proceed with buying those Wimas. Like for instance, I have substantial quantity or ROE MKT caps and those would be OK here, but the spacing on them is 0.30". There is also an alternative for those in US, who want to buy Panasonic caps from DK (as they might be also good in that application) and I guess spacing on those would also be less, as they are not rated 250V.
Of course this is not a big issue, and any way will work, but it would be just more convenient to provide more options for people. |
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| Pedja |
Yes, 0.60” (15mm).
I somehow discarded all the MKSs (MKTs) for usage here and have looked on the possible MKPs. But I will think about this again.
Take note that, though probably not available everywhere, these WIMAs are quite cheap, Buerklin (part # 43 D 642) sells them for 0.3EUR/piece, 0.24EUR for 10 or more, which means 12 needed 0.1u caps cost 3EUR.
It would be useful if anyone can post info about the American suppliers of these.
I will change a bit my plan considering the passive parts, at least for this unit I am soldering, since I stayed without some caps I have ordered. Newark does not sell OS-CON SG anymore, so I will use BG’s NX I have at hand instead (for the receiver and TDA’s digital supplies) which will be, according to Peter’s latest findings good thing. The bad thing is that I will be shortened for more objective insight about the differences produced by the layout only.
Pedja |
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| Pedja |
| quote: | Originally posted by Pedja
Newark does not sell OS-CON SG anymore (...) |
I meant Farnell (part 664455). |
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| bzo |
Did a quick check, and the only large vendor I could find for those WIMA caps in the USA was Mouser. Unfortunately, they don't carry the 250V .1uf MKP10.
By the way, is the value for these decoupling caps critical? I seem to recall seeing some people using larger values for a few of the LSBs. |
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| Peter Daniel |
| I don't think it's that critical. I was using 0.68 and it worked;) |
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| siu sin man tho |
hi,
I know that the de couple cap of the tda1541a large will use 1uf.
due to many diyer had different taste, so I design my TDA1541a PCB was fit for different size cap. The large was wima.
pls see the lay-out of my PCB. the 4 pin holes beside the TDA1541a was fit for different size & different value of the de-couple caps.
otherwise, more grounding area will better.
thanks
thomas |
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| jean-paul |
Mmm, now that I read the latest posts I understand some of the wishes. Normally I would use Wima MKP10 0.1 uF 160V so I won't be able to use them. But in case of a nice layout that will be worse when edited I would advise you to make this PCB an as-is offer. The caps are not that expensive and/or hard to get. BTW the best caps are big, aren't they ? ;)
Do not edit the board in this stage to cater for anyones wishes. It will slow down things and chances are that it will be an neverending story leaving Pedja with a bad feeling. Everybody has different wishes and if you want to incorporate all those wishes the board will never be finished. It is impossible to keep everybody satisfied and you need the time for testing/measuring/debugging the DAC which seems more important. It is a bad experience to ship something and later discover it has flaws.
If people want a board they should accept what you offer at the moment or design a PCB themselves ( or hardwire ). Maybe next time it is wise to show the design in an earlier stage leaving room for suggestions.
edit: I just checked and 0.1 uF 160V MKP10 fits on the PCB, just as 0.1 uF 250V MKT and even 0.1 uF 630V MKT provided that 15 mm is the correct format. It seems bigger at the picture. 15 mm spacing is pretty standard in MKP, in many cases it'll be only MKT that is smaller ( till 5 mm spacing ). |
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| siu sin man tho |
hi paul,
| quote: | | If people want a board they should accept what you offer at the moment or design a PCB themselves ( or hardwire ). |
I did not know this message U was talking to me or not.
But really, I design this PCB only like to design a good PCB to diyer.
the photos show was the back screen. U can see the de-couple cap was also shield by the grounding to lower the noise.
thisPCB is test print I added more functions which compare with the standard specification that at first posted on this forum.
1. include I2S input which was very close the CS8414 to prevent the data error during passing the message.
SYN-SCK-SDATA.
Reclocking input also reserve for my coming reclocking parts.
I was waiting for my japan friend posting lower than 30PPM crystal to me to build the reclocking parts.
Diyer can make choice use or not.
for more information, pls visit.
http://www.sakurasystems.com/
2. added one dip.switch.
for setting for different mode.
syn mode or aysyn mode.
3. I tested that the input pulse transformer is much better than use a 75ohm resister. The T1 space on the PCB at first I deside come with the RS Pulse (H.F.) 75ohm input transformer. Ratio is 1:1.
But recently I received some news & due to I had links with japan many brand audio transformers.
I received that Tamura had one new developed Pulse transformers which design for the digital interface for professional audio equipment as prescribed in EIAJ standards.
the band width is more width than RS.
Tamura from 100Khz~6MHz. Its made by Amorphopus core.
I was waiting for the sample.
If the price that japan offer to me is good. I will use into the kits.
thanks
thomas
www.diyaudioicraft.com |
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| jean-paul |
Hi Thomas, I was adressing to Pedja of course as this is "his" thread discussing his design. Please discuss your board in your thread as crossing the subjects will work confusing.
I don't know Tamura digital pulse transformers but I think 6 MHZ is poor compared to the established brands. The ones I use have 340 MHz bandwidth. Audiobrands like Tamura and Audio Note produce very fine transformers but I think the field of pulse transformers is better left to specialists in that area. Of course this is just my opinion which might be totally wrong. |
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| JonPike |
| quote: | Originally posted by jean-paul
edit: I just checked and 0.1 uF 160V MKP10 fits on the PCB, just as 0.1 uF 250V MKT and even 0.1 uF 630V MKT provided that 15 mm is the correct format. It seems bigger at the picture. 15 mm spacing is pretty standard in MKP, in many cases it'll be only MKT that is smaller ( till 5 mm spacing ). |
OK, you guys have already found the .1uF 160V caps.. I was going to mention here in the US, Mouser stocks them at something like $0.53 each.
We have some of these at my work.. and a high end LCR meter.. the MKP10 caps are about 1/10th the ESR of good ceramics and even polyester film caps. Polyproplyene and good design.. makes for a great cap..
So, when is this board going to be available?
Jon |
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| siu sin man tho |
hi paul,
can U tel me which transformers had 340Mhz band-width.
I had audio-consulting digital transfortmer. Still cannot run in 340mhz.
which one U are using.
thanks
thomas |
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| siu sin man tho |
hi banana,
thanks for your information.
But looks the price of all this transformer is quite expensive.
I choose the small 75ohm input transformer was setting use in the standard.kit to relief the 75 ohm resister.
If diyer like to upgrade, i think must upgrade by themself.
Because I considerate DIY kits cannot two expensive.
if DIY kit in high price, I was afraided that users will buy second hand products because they had resell value. Diy kits looks cannot had resell value. So I think the selling price of the kits looks USD 150~200 with EMS postage to overseas & cheaper to hong kong people was best I can was do this.
Include two 1541a, cs8414 all OS-con, dale resisters, Elna gold &
diode use MBR 160 or Schottky.
all this parts I cannot maintain too low price. I only like to produce a good produce to all diyers.
hope diyers will agree.
peter.
I saw some messages was talking about using different size de-couple cap of 1541a. So I post my design that will multiple for different caps. This will easy to all diyers. I only like to share experience to others.
thanks
thomas
www.diyaudiocraft.com |
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| Pedja |
The part with decoup caps was practically left as it was in the previous board. As far as I remember, when I was thinking about the caps for this place, I was looking for as thin as possible piece (I guess it is not hard to understand why) and these 0.1uF/250V appeared as best (I did not use them because I had them at hand…- I have ordered them! ;)).
For C105-C110 and C113-C118 lead spacing is 15mm, available width is 5mm, available length is 18mm (in fact there is some more mm of length, C119 could be mounted beneath the board to make a space for C113/C114). The dimensions are the same for C111/C112 (MSB) with that exception the available width is 6mm thus they fit for WIMA MKS4 2.2u/63V (MKP would be really big in this case).
At one point it was easy to put the additional pads here, ground is just beneath and it could be done literally in one minute, but once you fill top layer with ground plane the things become a bit (b)locked. Now the adding of these pads will turn me back to the point from which is not bad to think about making another prototype (and I am not a factory). I will probably do what Jan-Paul has said and take this into account in the possible next rev.
| quote: | Originally posted by jean-paul
I just checked and 0.1 uF 160V MKP10 fits on the PCB, just as 0.1 uF 250V MKT and even 0.1 uF 630V MKT provided that 15 mm is the correct format. It seems bigger at the picture. 15 mm spacing is pretty standard in MKP, in many cases it'll be only MKT that is smaller ( till 5 mm spacing ). |
What is interesting about MKP10 0.1u/160V is the fact Buerklin gives the same dimension for these like for 0.1u/250V while WIMA datasheet claims something else.
http://www.buerklin.com/gruppene/KapD/D103240.asp?l=e
http://www.wima.com/wimaforhcr.pdf
Mouser confirms WIMA’s data:
http://www.mouser.com/catalog/617/451.pdf
What are the real dimensions? Or are there two same capacitance/voltage pieces of the different dimension? It is specified sometimes in WIMA’s datasheets, not in this case though.
| quote: | Originally posted by bzo
By the way, is the value for these decoupling caps critical? |
I guess it is not a problem to use values somewhat higher than 0.1u at all the pins but I do not know if thus something will be gained or not.
| quote: | Originally posted by JonPike
So, when is this board going to be available? |
Do not expect the board to be available before the end of April.
Pedja |
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| Peter Daniel |
| quote: | Originally posted by Pedja
Now the adding of these pads will turn me back to the point from which is not bad to think about making another prototype (and I am not a factory). I will probably do what Jan-Paul has said and take this into account in the possible next rev.
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Leave it as it is then. If one is desparate to use different caps, they can always drill additional holes and scrape the paint to make new pads.;) |
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| bzo |
| quote: | Originally posted by JonPike
OK, you guys have already found the .1uF 160V caps.. I was going to mention here in the US, Mouser stocks them at something like $0.53 each.
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The mouser catalog lists these as 10mm leads, which if correct, won't fit on the current board. |
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| mdlover |
hi pedja,
nice board! :cool:
i'm now doing a new 1541 board design and facing the same problem that whether i should cater different lead pitch for those decoupling caps. :confused:
cheers |
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| Peter Daniel |
| quote: | Originally posted by bzo
The mouser catalog lists these as 10mm leads, which if correct, won't fit on the current board. |
It is quite possible as the 160V caps will have less spacing than ones rated at 250V.
One solution would be to include the 0.1/250 Wimas with the board.;) |
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| Pedja |
| quote: | Originally posted by Peter Daniel
Leave it as it is then. If one is desparate to use different caps, they can always drill additional holes and scrape the paint to make new pads.;) |
DIY the hole you need!? Don't forget to remove there the ground plane from the top layer too. ;)
May this link be of help?
http://www.wima.com/navig/rep.htm
Taw Electronics seems to have 0.1u/250V (type MKP10 0.1uF). But I know nothing about them and/or their conditions. |
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| bzo |
It doesn't look like the right WIMAs will be easy to acquire in the US. What are some good alternatives? How about the BC Components MMKP 383 Series, AC and Pulse Double Metallized Polypropylene Film Capacitors?
http://dkc3.digikey.com/pdf/T041/0794-0798.pdf
Peter, were the Panasonics you mentioned, the ECQP also found in the above URL? |
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