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Post by Deleted on Aug 24, 2011 21:05:00 GMT
Looks good, Will! I added a couple of boards to your spreadsheet, if I'm not too late? I need to brush up on the SMD soldering... Hey Shaun - you can solder that chip using the splurge/solderwick method, but do check the joints with the continuity tester afterwards!! Hi Jon thanks for the tip but that sounds quite like the method that i usually employ as you may have noticed panic has set in again. but as they say no pain no gain and for me learning the ropes is going to be useful. green with envy take care
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jonclancy
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Post by jonclancy on Aug 26, 2011 14:48:15 GMT
I'm short of some power!!
Got a super-reg at 10V, a couple of 3V3 Fleas. My hex inverter will use a full 50mA Flea-full. I only need 17mA for the WM8804. Will, what sort of current does the Sabre require, pse?
Cheers
Jon
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Will
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Post by Will on Aug 26, 2011 18:40:28 GMT
Hi Jon,
The only info I have is that is uses 23mA quiescent, with nothing on the outputs. I don't have the dac to hand to measure current under 'working' conditions, but I originally used a LE33C regulator for it's supply, which was 100mA max.
Perhaps one of the guys who have one could measure the current draw, and post it here?
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leo
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Post by leo on Aug 26, 2011 19:06:17 GMT
Think I measured around 27mA for the 9022, I tried Wills other dac board run from a couple of 3v3 A123 batteries , they lasted quite some time. Just be careful with AD797 used in the flea though, it can be detroyed quite easy. Flea can be modded page 2 of the Flea article www.acoustica.org.uk/ should be ok for the ES9022, not tried it myself though so can't be sure of any start up issues etc for the chip BTW, nice work on the newer layout guys
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Post by Deleted on Aug 26, 2011 19:13:20 GMT
Do you know what are the differences, if any, between the 9022 and the 9023?
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leo
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Post by leo on Aug 26, 2011 19:18:44 GMT
ESS are very secretive about the internals of their dacs, I have the datasheet for the ES9022 and can't see anything very helpful. Not seen the 2023 datasheet yet I'd love to compare the two sonically
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Post by Deleted on Aug 26, 2011 22:28:29 GMT
Hi Will I've read that the 22/3 are pretty much the same chip with a few small revisions. ::)i may have that wrong though (not for the first time) ESS seem to closely guard their data sheets with a sign on the line secrecy clause. I'd love to get a look see at one but i just know that's going to be nearly impossible by the way whats the story with the O/P filter. some seem to use it and others not. I've heard it talked about on a few other threads (DIYAUDIO) but opinion seems to be divided on it's usefulness. I'm assuming that it's in the data sheet. take care
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Post by Deleted on Aug 26, 2011 22:35:00 GMT
Thx Leo. Searched for an answer everywhere but nothing. As they have exactly the same specs it is probably down to newer fabrication process or something similar.
Btw, can you explain what is the purpose of C12 C13 R15 & R16? Will's board doesnt' have them but yours does.
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Post by leo on Aug 26, 2011 22:38:37 GMT
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Post by leo on Aug 26, 2011 22:57:14 GMT
Thx Leo. Searched for an answer everywhere but nothing. As they have exactly the same specs it is probably down to newer fabrication process or something similar. Btw, can you explain what is the purpose of C12 C13 R15 & R16? Will's board doesnt' have them but yours does. Output resistors/filter caps , I just used 22R (you can use wire links) and the sockets for the caps to allow quick swapping. Any caps used here really affected the sound so its worth experimenting.
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Post by PinkFloyd on Aug 26, 2011 23:04:15 GMT
Thx Leo. Searched for an answer everywhere but nothing. As they have exactly the same specs it is probably down to newer fabrication process or something similar. Btw, can you explain what is the purpose of C12 C13 R15 & R16? Will's board doesnt' have them but yours does. Output resistors/filter caps , I just used 22R (you can use wire links) and the sockets for the caps to allow quick swapping. Any caps used here really affected the sound so its worth experimenting. Leo, I have a truckload of Russian/ UK vintage parts.... anything you need?
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leo
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Post by leo on Aug 26, 2011 23:39:56 GMT
The standard output filter is 4700pf , I tried a few values going down to 1000pf and prefered the lower values, tbh I liked it best without the caps. The caps I tried may not have been that great, they was those FKP Wima's. Don't suppose you have any Russian Teflons around 1000pf to 2200pf? Mind you I bet their bigger than the pcb
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Post by Deleted on Aug 27, 2011 1:08:29 GMT
Hi Leo that's handy Just as an aside I'm wondering how much the quality of the PSU's used effect the need for the OP filter. take care
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Post by Deleted on Aug 27, 2011 1:21:11 GMT
Hi Leo that's handy Just as an aside I'm wondering how much the quality of the PSU's used effect the need for the OP filter. take care Shaun Without a suitable output filter, some amplifiers may not like the ultrasonic artifacts. Also, without an output filter of some kind, the DAC is likely to be VERY sensitive to the type of, and length of the interconnects used. Alex
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Post by Deleted on Aug 27, 2011 6:33:58 GMT
In the pics (and with my very limited knowledge) it looks like only the resistors (0 Ohm in the pic? ) are really in the path while the caps are for decoupling or am I wrong?
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Will
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Post by Will on Aug 27, 2011 6:45:38 GMT
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leo
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Post by leo on Aug 27, 2011 8:09:48 GMT
I'm wondering how much the quality of the PSU's used effect the need for the OP filter. take care
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Post by leo on Aug 27, 2011 8:15:55 GMT
Using 22R on the output with no filter caps I've had no problems at all so far , certainly worth experimenting in this area and see what works best in your own setup
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Post by Deleted on Aug 27, 2011 10:00:59 GMT
Hi Leo that's handy Just as an aside I'm wondering how much the quality of the PSU's used effect the need for the OP filter. take care Shaun Without a suitable output filter, some amplifiers may not like the ultrasonic artifacts. Also, without an output filter of some kind, the DAC is likely to be VERY sensitive to the type of, and length of the interconnects used. Alex Hi Alex yes very good point and i have read that the 9022 is pretty sensitive in terms of performance to the I/P impedance of the following device. I'm sure you wont like my slow thinking but maybe a buffer would keep the 9022 in it's sweet spot. (I'll duck now) i think that this could be a good way to get around cable sensitivity and give the DAC something constant to drive rather than going straight to volume control (which will vary IP impedance a little). it's just pure speculation as I've not tried the above but am interested in a conversation on the idea. i was thinking that given the 9022 intended use (mostly in relatively inexpensive stuff) that the OP HF filter could just be a little ESS insurance against the not so good PSU (switch mode)likely to be used by some manufacturers. still a ramble befitting the time of day. but a good point from you. take care
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Post by Deleted on Aug 28, 2011 1:21:39 GMT
Looking very nice Jon, good stuff. Here's the pcb layout for the Pocket Knife Dac, for those interested. Hi Will, I am watching with interest. Your DAC is the next one I am building, but I am still gathering parts which is not always easy from Australia unless you pay through the nose for postage. regards
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Will
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Post by Will on Aug 28, 2011 8:09:56 GMT
Hi Greg,
I'll shoot you an email later that might be of interest, parts wise.
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Post by Deleted on Aug 28, 2011 8:53:35 GMT
Hi Greg, I'll shoot you an email later that might be of interest, parts wise. Thanks matey.
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jonclancy
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Post by jonclancy on Aug 28, 2011 10:07:29 GMT
Think I measured around 27mA for the 9022, I tried Wills other dac board run from a couple of 3v3 A123 batteries , they lasted quite some time. Just be careful with AD797 used in the flea though, it can be detroyed quite easy. Flea can be modded page 2 of the Flea article www.acoustica.org.uk/ should be ok for the ES9022, not tried it myself though so can't be sure of any start up issues etc for the chip BTW, nice work on the newer layout guys Thanks Leo! I was about to post last night and saw this. I revisited Martin's page and realised that my 50mA Flea output assumption was a bit over-optimistic!!! I've got my two 3v3 Fleas up and running, got the 50MHz XO installed, and all wiring done. I connected everything, powered up and ... nothing! Whaaaat??!! Then I realised I hadn't actually connect the powr rails for my Hex Inverters!! Genius like this can't be naturally occuring!! Anyway, I then saw your post and I'm glad I did! AD797 are pricey!! So, I will implement the current dumping mod, but remove C8 and use it as shown by the cut track in the diagram here. Thanks for the pointer! Cheer Jon
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Post by Deleted on Aug 28, 2011 15:51:30 GMT
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Post by Deleted on Aug 29, 2011 15:47:20 GMT
Hi Alan interesting stuff I've had a look through the first thread that you posted and it looks pretty interesting. the Czech stuff I'll translate and have a read of when time allows. thanks for the info Alan take care
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