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Old 24th May 2012, 08:05 PM   #71
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Default are you more Wittgenstein?

Quote:
Originally Posted by Coris View Post
As a note to my previous post, I wish to precise the follow for those who come in in this thread:
This thread is meant to provide ideas and suggestions as some results and impressions about modifications of this sound card. The rest of the work belong to they who will find those ideas here worth to proceed to it. I do not need and even care about one or another will believe me or not. Read what is here, think self, do it self, and assume your own risks about this work. Find your own way in this work. Do one come here with own informations, and results, this is only positive and they are welcome. In this way the thread will develop it self and will can bring more informations to more interested people.
I have no intention to prove something to one or another one here, and I will not use my time to present here all kind of detailed informations. Find your self what you need!
I think I`ve did enough publishing much enough informations, detailed pictures and I answered to they who asked about.
Letter grade for above: C+
Have trouble trudging thru your 2nd-lang. English. But your English is better than my Norwegian.
The problem with your "picture" approach is that it cannot be Search Engined (or searched via Find util.). You may need to re-read Orwell's 1984 and Bradbury's Fahrenheit 451 ... the picture/comic approach has it's limits. Or are you more Wittgenstein?
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Old 27th May 2012, 06:11 PM   #72
frog993 is offline frog993  Germany
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Hello andreudze

Quote:
Originally Posted by andreudze View Post
frog993, let me explain how power supply is arranged. Strart with molex +12V and + 5V
1.) +12V thru three 3.3 Ohm resistors feeds the 7805, that in his turn supplies analog part of DAC and auxilary consumers (ADC and relays)
2) +5V is converted by the HF invertor into +15V, that feeds the 7812 and into -12V (in fact, it would be better to have -15V and 7912 then, while there is place for 7909 on the PCB). Thus, we have splitted power supply (+/-12V) for I/U and output stage as well as for the headamp.

+3.3V comes directly from the PCI and feeds digital part of PCM as well as DSP.

The picture belows shows the power paths.
Thanks for your picture and explaining the powerpath. This explains why on the 5V line flows so much current.

When cutting the 3.3V powerpath from the PCI bus(see picture) the DAC is the only consumer on the 3.3V line there ?
Have you build seperate supplys for your xonar soundcard ?

Last edited by frog993; 27th May 2012 at 06:40 PM.
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Old 28th May 2012, 06:51 AM   #73
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Quote:
Originally Posted by frog993 View Post
Frog:
About your attached image ... is this a SCANNER photo? (i.e. you put the Xonar on the flatbed of a scanner)
Nice work on labeling and tracing.
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Old 28th May 2012, 07:43 AM   #74
Coris is offline Coris  Norway
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Quote:
Originally Posted by hollowman View Post
Frog:
About your attached image ... is this a SCANNER photo? (i.e. you put the Xonar on the flatbed of a scanner)
Nice work on labeling and tracing.
This is definitively the most important in this case: how the picture were made...

Thanks for your valuable contribution to this thread!
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Old 28th May 2012, 11:50 PM   #75
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Default Scanner photography phil. 101

Quote:
Originally Posted by Coris View Post
This is definitively the most important in this case: how the picture were made...

Thanks for your valuable contribution to this thread!
Actually, yes, but not in the way you may be thinking (= not outside the box).

Many will reach for their DSLR or iPhone or other digital camera to snap a shot when -- if they have a tradit. flatbed scanner on their desk -- right there in front is the easiest, highest-quality solution. And it can produce VERY high-quality results.
scanography- Scanner Art
etc.
Similarly, some will take a linear-topology, or wheel-reinventing approach to a PC sound-card PS -- which involves tons of labor, $$, man-hours, soldering fumes, employing risky (floating ground) topology, etc. -- when an excellent-quality (SQ-wise), much more reliable, comes-with-warranty, little-fuss option is avail. The better-rated (and tested, using objectives science and methodology, publicly disclosed) SMPS I noted earlier.
The PS in your design involves risky design choices, and risky trace-cutting of the orig. SC. Also, you provide little or no objective measurements of your results.
In the end none of my criticisms matter if some of the primary goals of DIY are met: e.g., Pedagogy and Didacticism -- actually learning/acquiring/retaining NEW knowledge skills and science. I don't find much of that that in your project.
I do find some of that at better DIY PC/hardware sites:
Hardware Secrets Power Supply Test Methodology | Hardware Secrets
Seasonic X-Series 650 W Power Supply Review | Hardware Secrets
etc.
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Last edited by hollowman; 29th May 2012 at 12:07 AM.
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Old 29th May 2012, 01:12 PM   #76
dhbiker is offline dhbiker  Slovenia
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hi there

just a quick question... i replace 4 caps on I/V stage (0805 SMD) at first with 10pF ... now i changed to 100pF for test.. problem is one channel is louder than the other + when the relays switch on for output i get a huge spike..

any idea whats wrong ?

thanks for your reply
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Old 29th May 2012, 03:38 PM   #77
Coris is offline Coris  Norway
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Quote:
Originally Posted by dhbiker View Post
hi there

just a quick question... i replace 4 caps on I/V stage (0805 SMD) at first with 10pF ... now i changed to 100pF for test.. problem is one channel is louder than the other + when the relays switch on for output i get a huge spike..

any idea whats wrong ?

thanks for your reply
For one or another reason you have a high DC level on the output of that channel (where you register that spike). If you still have the isolation caps on the output (just before RCA connectors), then it happened something wrong when you changed out that I/V caps. Here we talking about decoupling caps of the involved opamp. Review once again if everything is all right (traces, no soldering drops between components), and if the issue persist, then just resolder the original caps.
One may be very carefully with SMD components. It get destroyed quick if the soldering time is too long (not more than 2 s), or the temperature of the soldering iron is not adequate. Specially, the isolation material used in SMD caps are very sensitive to temperature excess.

You may also measure the power tensions on the respective caps to confirm if OK. Measuring on this board while it is placed in to the motherboard is very difficult. I will recommend to find an (no matter quality, but DC filtered) 12vDC power supply and an 5v one, use an Molex connector to supply the power (simultaneous12v and 5v) to the board outside of the computer (on the bench). Then measure the power rails, the tension on the decoupling caps, and (important) the output levels on RCA connectors. On RCA should not be any DC level (0 or 0,something). If one removed already the isolation caps, then this DC levels on output RCA (offset) are very important to be very near 0 and equal as possible between channels.

If you may take and publish a picture of your board after cap changing, it will be better to understand what about...

Last edited by Coris; 29th May 2012 at 03:47 PM.
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Old 29th May 2012, 05:08 PM   #78
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Default A worthy project?

Quote:
Originally Posted by dhbiker View Post
...just a quick question... i replace 4 caps on I/V stage (0805 SMD) at first with 10pF ... now i changed to 100pF for test.. problem is one channel is louder than the other + when the relays switch on for output i get a huge spike.. any idea whats wrong ?
Coris noted ..."If you may take and publish a picture of your board after cap changing, it will be better to understand what about..."

How much risk/effort makes a PC-based project WORTHY?

Constantly (de)-coupling (de/re-energizing) of the PSU and/or sound boards -- or any other similar components for that matter -- from the chassis or motherboard is not without important risk or effort.* PC DIY -- unless the setup is very strategically located on a workbench -- is too manual and mechanical.

Maybe you have deep pockets, or unlimited time, or REALLY enjoy "DIY" ... so these risks are unimportant.

* Personally ... I don't even like to turn PCs/laptops off as I feel cycling power stresses out PSUs and other PC components; and the often-used daily/nightly shut-downs and re-power-ups are further sources of electrical, mechanical and thermodynamic stress. [Simply go to any PC repair shop and poll the most-repeated time of failure (or research this issue/topic online). Answer: power-up. Indeed my most reliable PC or laptops are "always on", and only cycled if/when absolutely necessary or beyond my control ("Act of God", Rolling blackouts, etc.)

As an alternative to the PS project, why not invest the $$/effort into better (DIY if you like) power/line-conditioning projects?
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Last edited by hollowman; 29th May 2012 at 05:18 PM.
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Old 29th May 2012, 07:26 PM   #79
dhbiker is offline dhbiker  Slovenia
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i do not have that last caps by the RCA outputs

i just measured the voltage on the ouput.. left channel 0.01V right channel 3.22V so i guess something went bad...
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Old 29th May 2012, 07:57 PM   #80
Coris is offline Coris  Norway
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Quote:
Originally Posted by dhbiker View Post
i do not have that last caps by the RCA outputs

i just measured the voltage on the ouput.. left channel 0.01V right channel 3.22V so i guess something went bad...
Yes, something is wrong with those 3,2v... It is possible that one of the caps you changed is conducting, and so is unbalanced the +/- power rails. I do think that is not a catastrophic fault... Just verify again the "operation area", and take a look at the +/- rails on I/V stage. I hope you will find the fault.
Is better to not reuse the SMD components after desoldering...
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