An almost free, and appreciable, upgrade in sound for your EMU 0404
codifus
supply. It converts AC to 5 Volts of fluctuating DC. I found an old
power supply from a zip drive I had that puts out 5 V of real DC, or
linear DC. After converting the Zip drives power supply to work with
my EMU, I hooked it up and gave it a listen to my music in my library
again. This is what I found;
Sound was much smoother, especially in the high frequencies.
The EMU seemed to be able to resolve more as well.
Also, the quiet passages were, um, quieter:)
This was an easy upgrade that improved the sound of my 0404
significantly!
For all you budget audiophiles out there who can't quite justify a
DAC1 or a DA10, you should really give this 0404 with minor upgrade a
try.
A minor note on power supplies: it would be very easy to replace the
non linear power supply with another non-linear one. I have found that
some zip drives came with linear PSes and some didn't. Make sure to
get a Linear one. They're the bigger, classic wal warts and get warm.
The non linear ones are smaller.
Here is a typical linear PS;
http://www.alibaba.com/product-gs/211126448/Linear_Power_Adapter_5V_28V_AC/showimage.html
Switching, non linear ones are smaller, like this;
http://www.alibaba.com/product-gs/51343917/Switching_Mode_Power_Adapter_5V_DC/showimage.html
Make sure to get a linear PS, and enjoy the music!
CD
Arny Krueger
news:gfd4b...@news1.newsguy.com
> I recently learned that the 0404 USB comes with a "dirty"
> power supply. It converts AC to 5 Volts of fluctuating
> DC. I found an old power supply from a zip drive I had
> that puts out 5 V of real DC, or linear DC. After
> converting the Zip drives power supply to work with my
> EMU, I hooked it up and gave it a listen to my music in
> my library again. This is what I found;
> Sound was much smoother, especially in the high
> frequencies.
> The EMU seemed to be able to resolve more as well.
> Also, the quiet passages were, um, quieter:)
The proof of the pudding would be to run an Audio Rightmark, with each power
supply:
The software is free.
Rob Tweed
have to say that the sound seems much improved. Certainly worth the
20 minutes it took to make the change, and the old power supply was
just sitting gathering dust so it didn't cost me anything.
Turns out there are some people who make even more radical mods to the
EMU 0404
(http://www.head-fi.org/forums/f6/emu-0404-usb-modding-finished-297141/).
Not sure I'd be brave enough myself!.
It would be interesting to get some measurement data to prove whether
or not Codifus and I are simply imagining the differences we're both
sure we've heard! Anyway I'm pleased with the results which is the
important thing :-)
---
Rob Tweed
Company: M/Gateway Developments Ltd
Registered in England: No 3220901
Registered Office: 58 Francis Road,Ashford, Kent TN23 7UR
Web-site: http://www.mgateway.com
codifus
> "codifus" <codi...@optonline.net> wrote in message
I suppose I could do that, but I do not need to. I know there was a
difference and I'm not about to clarify my results by posting the
technical papers in some science journal. Rather, I'll take the 5
minutes to try the experiment and be done with it.
This is not to say that the technical explanation for the change would
not be interesting to see. I would be very interested. I just don't
have that kind of time. I'd much rather spend it enjoying the music.
Besides, I completely destroyed the original power supply:)
CD
Arny Krueger
news:gfeok...@news3.newsguy.com
> I tried this out myself - also converting an old Zip
> drive supply. I have to say that the sound seems much
> improved. Certainly worth the 20 minutes it took to make
> the change, and the old power supply was just sitting
> gathering dust so it didn't cost me anything.
>
> Turns out there are some people who make even more
> radical mods to the EMU 0404
> (http://www.head-fi.org/forums/f6/emu-0404-usb-modding-finished-297141/).
> Not sure I'd be brave enough myself!.
>
> It would be interesting to get some measurement data to
> prove whether or not Codifus and I are simply imagining
> the differences we're both sure we've heard! Anyway I'm
> pleased with the results which is the important thing :-)
The proof of the pudding would be to run an Audio Rightmark, before and
after the mods.
The software is free.
http://audio.rightmark.org/downloads/rmaa6.exe
Runs in about 5 minutes.
Arny Krueger
> On Nov 11, 7:03 pm, "Arny Krueger" <ar...@hotpop.com>
> wrote:
>> "codifus" <codi...@optonline.net> wrote in message
>>
>> news:gfd4b...@news1.newsguy.com
>>
>>> I recently learned that the 0404 USB comes with a
>>> "dirty" power supply. It converts AC to 5 Volts of
>>> fluctuating DC. I found an old power supply from a zip
>>> drive I had that puts out 5 V of real DC, or linear DC.
>>> After converting the Zip drives power supply to work
>>> with my EMU, I hooked it up and gave it a listen to my
>>> music in my library again. This is what I found;
>>> Sound was much smoother, especially in the high
>>> frequencies.
>>> The EMU seemed to be able to resolve more as well.
>>> Also, the quiet passages were, um, quieter:)
>>
>> The proof of the pudding would be to run an Audio
>> Rightmark, with each power supply:
>>
>> The software is free.
>>
>> http://audio.rightmark.org/downloads/rmaa6.exe
>
> I suppose I could do that, but I do not need to.
Right, you know that you are right, and no tecnical confirmation is
required.
> I know
> there was a difference and I'm not about to clarify my
> results by posting the technical papers in some science
> journal. Rather, I'll take the 5 minutes to try the
> experiment and be done with it.
Which experiment?
> This is not to say that the technical explanation for the
> change would not be interesting to see. I would be very
> interested. I just don't have that kind of time. I'd much
> rather spend it enjoying the music.
Yes, spending 5 or 10 minutes to do the Rightmark test would separate you
from the music you love, for far to long of a duration.
> Besides, I completely destroyed the original power
> supply:)
However, we have another test of a typical unmodified unit.
codifus
Apparently, someone has already done the test . The results from the
link below compare the 0404 using host power against battery power.
The DC voltage generated from batteries, as I'm sure you know, is
regarded as one of the best sources of smooth DC power;
http://magsy.net/headfi/Comparison2.htm
As you can see, the performance of the 0404 improved, somewhat
dramatically even, when its power source was upgraded. >10 db
improvement in noise and dynamic range right off the bat. >15 db
improvement in stereo crosstalk. THD also improved with one anomoly.
Oddly enough, intermodulation distortion became 2 times worse. Given
that I use the 0404 as a music server, this may not apply to me as
intermodulation distortion is defined as the distortion generated when
multiple signals are input into the device. The only signal that is
input into my 0404 is from my airport express. Or, is this
intermodulation distortion a result of the 2 signals that are the
stereo left and right channels, I wonder?
So, would you like some more pudding:)
CD
Bill Noble
> not be interesting to see. I would be very interested. I just don't
> have that kind of time. I'd much rather spend it enjoying the music.
>
>
if you could describe the circuitry of the "bad" power supply, I would be
most intrested - your description of the power output is provacative, but
not definitive - sometimes someting as simple as adding another filter
capacitor will do the trick - remember to parallel a high value electrolytic
with a 1 uf or lower mylar, and then ideally a 1000pf ceramic or mica - the
impedance of the caps can in some circuits affect sound
Arny Krueger
> Apparently, someone has already done the test . The
> results from the link below compare the 0404 using host
> power against battery power. The DC voltage generated
> from batteries, as I'm sure you know, is regarded as one
> of the best sources of smooth DC power;
> http://magsy.net/headfi/Comparison2.htm
All of those results seem to be atypically poor. The are not the same as
using a switchmode external power supply.
Test
24/44- USB Pwr 24/44 24/48-USB Pwr 24/48
Frequency response (from 40 Hz to 15 kHz), dB:+0.09,-0.04 +0.09 0.04
+ 0.10, -0.03 +0.10, -0.03
Noise level, dB
-83.8 -94.7 -85.4 -94.2
Dynamic range, dB (A):
84.3 94.7 85.5 94.4
THD, %:
0.0040 0.0020 0.0042 0.014
IMD, %:
0.016 0.030 0.020 0.050
Stereo crosstalk,
-77.8 -96.4- 79.6 -95.5
> As you can see, the performance of the 0404 improved,
> somewhat dramatically even, when its power source was
> upgraded.
Contrast those results with these:
http://magsy.net/headfi/laptoppowered.htm
Testing chain: Toshiba Tablet PC to Emu 0404, Sampling mode: 24-bit, 44 kHz
Test
Laptop on AC - USB Powered - Laptop on battery 5.25v Nimh
Frequency response (from 40 Hz to 15 kHz), dB: +0.09, -0.04
+0.09, -0.04 +0.09, -0.04
Noise level, dB
-96.5 -96.5
-96.5
Dynamic range, dB (A): 96.4
96.3 96.4
THD, %:
0.0017 0.0017
0.0017
IMD, %:
0.0095 0.0096
0.0099
Stereo crosstalk,
-97.0 -96.1
-96.6
As you can see, the performance of the 0404 was generally better to far
better, but remained unchanged
even when its power source was upgraded. There are a number of other 0404
USB tests on the web, and they are generally consistent with the results for
the 3 tests, above.
> >10 db improvement in noise and dynamic range
> right off the bat. >15 db improvement in stereo
> crosstalk. THD also improved with one anomoly.
I think anomaly would be a good term to use.
codifus
I agree with you in that adding a capactor in the right place may make
all the difference. The problem is that the power supply in this case
is so small that the effort in modifying the circuit would be
significant. It is much much easier to substitute a better power
supply.
CD
codifus
> "codifus" <codi...@optonline.net> wrote in message
I think I see what you are getting at. The test is a bit misleading
because it mentions USB powered. The EMU 0404 USB does not work on USB
power. It needs an external power supply. So when it says USB power
its really with the standard power supply. The test result you quoted
pretty much echos what I saw earlier, and it still shows that the
0404s performance improved with the upgrade in the power supply to a
linear DC one.
The 2nd test you quoted shows how the performance changes, if at all,
when the laptop driving the 0404 switches the laptop's power supply
from AC to battery. The EMU 0404 USB remains unchanged in terms of the
power supply it uses. I don't think that test is relevant to this
thread.
Also, how are these results bad, or atypically poor, as you say? These
tests are at 24/44.1 and 24/48, and the dynamic range and noise
results are pretty much at the limits of what you could achieve with a
sampling rate of 44.1 or 48 Khz.
CD
Rob Tweed
>The proof of the pudding would be to run an Audio Rightmark, before and
>after the mods.
>
>The software is free.
>
>http://audio.rightmark.org/downloads/rmaa6.exe
>
>Runs in about 5 minutes.
>
Some advice on how to hook it all up to run the tests please. I don't
have another particularly high quality sound card to use as the
reference. Here's what I have at my disposal:
- Dell laptop with its own standard soundcard on which I can load up
RMAA6
- Edirol UA-1EX USB audio interface (which may or may not be better
than the Dell's own sound card so may act as a better reference card).
and of course the EMU 0404 USB which is what we want to measure with
the original and modified PSUs
So what would you recommend I connect to what, and which RMAA6 test(s)
should I run?
Many thanks
Rob Tweed
>"codifus" <cod...@optonline.net> wrote in message
>news:gfg34...@news5.newsguy.com
>
>> Besides, I completely destroyed the original power
>> supply:)
>
>However, we have another test of a typical unmodified unit.
>
If I get some time in the next week or so I'll try to run a test and
report back. Due to the way I did the PSU adaptation, I can re-attach
my original power supply to its plug and therefore get a before and
after comparison.
The differences I've heard seem significant so I really would expect
to see some genuinely different measurements.
bob
>
> Also, how are these results bad, or atypically poor, as you say? These
> tests are at 24/44.1 and 24/48, and the dynamic range and noise
> results are pretty much at the limits of what you could achieve with a
> sampling rate of 44.1 or 48 Khz.
What does sampling rate have to do with dynamic range? This is being
done at 24 bits, which should give you dynamic range well over 100 dB.
And does, as this review demonstrates:
http://www.digit-life.com/articles2/proaudio/emu-0404-usb.html
Those results are with the stock power supply, needless to say.
The results you quoted suggest one of two things. Either the person
doing the measurements was measuring a defective unit, or he screwed
up the measurements.
As for your personal experience, I'd lean toward an explanation in the
psychoacoustic realm.
bob
codifus
My bad. You are correct. I confused the sampling rate with bit depth.
Bit depth determines dynamic range and at 24 bits, the theoretical
limit is around 144 db. So Arny was correct as well, in that the
quoted results should be much better. I keep thinking 16/44.1 even
though the test was run at 24/44.1.
As for your personal opinion, thank you for pointing me towards which
realm to look into. I am quite familiar with the acoustic realm.
Perhaps I could get some advice from you on the psycho realm?
CD
jwvm
<snip>
> Some advice on how to hook it all up to run the tests please. I don't
> have another particularly high quality sound card to use as the
> reference. Here's what I have at my disposal:
>
> - Dell laptop with its own standard soundcard on which I can load up
> RMAA6
>
> - Edirol UA-1EX USB audio interface (which may or may not be better
> than the Dell's own sound card so may act as a better reference card).
>
> and of course the EMU 0404 USB which is what we want to measure with
> the original and modified PSUs
>
The Rightmark software is actually intended to evaluate sound cards
and not other equipment but that is possible also. Given that your
Edirol UA-1EX is essentiall a sound card, you only need to plug its
output into its input and run the software selecting the Eridol
hardware. The trickiest part (but really not hard) is to select the
correct input port (typically line) and set the input gain and output
signal level to reasonable values so that a proper input signal level
is obtained. Then you can just run the test.
It is possible to test other other equipment by inserting it in the
signal path from the sound card output to its input but that can be
misleading and even dangerous to the sound card if the input signal
level is too high. The assumption here is that the sound card has
greater fidelity than the equipment being tested which may not be true
but is not a relevant concern for testing your Edirol.
Rob Tweed
You misunderstand - it's the EMU I want to measure so we can compare
its performance with the old and new PSU. However from what you say
I'd simply plug the EMU into my Dell, connect its outputs to its
inputs, set its input and output gains appropriately and run the test.
OK I'll give it a shot.
Rob Tweed
and the Zip drive PSU. Interestingly there was almost no difference
between the measurements. See what you think. I ran 4 consecutive
tests with each power supply. Everything else was kept identical,
even the power socket that I plugged the supply into.
Original power supply:
http://gradvs1.mgateway.com/misc/emu_original_PSU.jpg
Using Zip drive power supply:
http://gradvs1.mgateway.com/misc/emu_zip_PSU.jpg
And by comparison, here's the results for the cheapo Edirol USB UA-1EX
http://gradvs1.mgateway.com/misc/edirol.jpg
My conclusion is on these measurements alone, I must be imagining the
differences I thought I heard between power supplies, but it at least
vindicates my view that the EMU sounds a lot better than the Edirol!
Bear in mind that the test I ran was the one where the outputs were
connected to the inputs so I was running through both the ADC and DAC
stages of the EMU. However, since every other parameter was constant,
I was looking for differences in measurements, and not particularly
concerned about the absolute values. You'll notice that what
differences there were between the tests with the two different power
supplies are barely different from the differences between each test
run for each PSU. The measurements I suppose are consistently
fractionally better with the Zip drive PSU, but it's marginal!
Rob
---
codifus
Rob,
thanks for doing the tests. The improvement I observed was subtle, and
I gather that the tests may bear this out. A subtle difference
shouldn't cause a huge change in tests results, should it? Fact is,
the Zip power supply on average was providing better total harmonic
and intermodulation distortion figures. Not much, but it was there,
and it was there consistently. Given that when we listen to music via
the EMU we are only using the digital to analog pathway as opposed to
the round trip that this test was performed on, I wish there was a way
to test the D to A part only.
Also, to add to my initial observations, the change of power supply
was most noticeable in high frequencies. Splashes of treble were much
smoother. Cymbals in the music fizzled more pleasantly.
So while i think that this test shows a little bit of how the improved
PSU bettered the EMU 0404, a better test would be to test the D to A
only, and perhaps do separate tests on different groups of
frequencies; 8000 to 16000 Hz for one test, 20 Hz to 500 Hz, for
another etc. All D to A only.
CD