SB Live! input impedance

I would like to record my acoustic piano.
I have a Realistic (Radio Shack) electret condensor PZM (boundary) microphone. It has DC power. It s impedance is 600 Ohms, the sensitivity is -74 dB (0.2 mV/Pa). If I assume that its max SPL is 20 dB, then my microphone max output level is 26 dBu.
I want to use that microphone to record into my Sound Blaster SB Li've! version 2.00.32 sound card. It has a EMU0K audio processor. The sound card is an internal sound card and, by looking at my computer, it looks like the number 8900/0 has been stamped into the metal.
What is the impedance of the sound card input
Should I record using MIC IN or LINE IN
Which pre-amplifier specs should I look for if I intend to purchase a pre-amplifier
Thanks
JJW

Re: SB Li've! input impedance? The model/serial number on your SB Li've would be useful in identifying your particular card. If you have a mic input jack, use that for your microphone. You don't need a preamp for that except for a low impedance "studio mic." Here are the specs for input/output of Creative Soundcards of that vintage:
MIC-IN
Sensitivity : 0mv to 200mv
Impedance 500-600 Ohms
Stereo input jack:
TIP Signal
RING Bias (if available)
SLEEVE Ground
If it's a condenser mic the TIP and RING should be tied together.
Studio mics, like low 25 Ohms, do not work with PC sound cards.
Suggestion: For cleaner recordings use a powered/pre-amped mic
into the line-in.
Line-In:
Line level inputs.
Sensitivity: 0v to 2v Most new PCI cards are RMS, most or all
the old ISA cards are peak to peak.
Impedance 47K-50K Ohms.
Normal input should be about V.
Line-Out:
0 to 2V RMS or peak to peak.
Normal output level about V.
Impedance assumed 0K Ohms, some cards 600 Ohms.
Described as: Gi'ven a full Sine wave at Khz tone
and a 0K Ohm > Load should produce about V RMS
output.

Similar Messages

Incorrectly calculating hfe/input impedance

Hello
Multisim calculates wrongly the input impedance of a common emitter stage - judging from the voltage drop on the base resistor network it appears it assumes a hfe of about 10, when the real value is over 500. I used the 2N2222A as a model, and the error is there on multiple transistors with hfes many multiples of 10.
Could you please let me know what I am witnessing here?
Thanks
Akis

Hi All,
I also ran this test and found that the HFE value was around the 220 mark. I wonder if you are looking at a different flavour of 2n2222A transistor? A quick look on google revealed the following components
Microsemi - HFE between 50 and 100
Philips Semi conductors - HFE 75
SemiLab - HFE between 100 and 300.
I think the thing to note is that these transistors can have a quite varying value for HFE. If you navigate to the component browser, find the 2N2222A component and click on the button marked "Detail report". You can see that the hFE value will vary between 35 and 300.
I hope this helps,
Many thanks,
Andrew McLennan
Applications Engineer
National Instruments

Pxi 4070 input impedance

I am trying to modify the input impedance of the pxi 4070 dmm with the NI DMM property node. When I set the input impedance to greater than 10 giga ohms, I am getting an error outputted after running niDMM Configure Measurements Digits.vi. The signal that I am measuring is 5V, so I should be able to use the 10 giga ohm input impedance. I set the niDMM Configure Measurements Digits to autoscale. Could this be an issue that the pxi-4070 is not allowed to have its input impedance changed when the dmm is set to autoscale?

You are correct. When the range is selected, the API automatically selects the input impedence. If you need to do this programmatically based on the measurement, then you could use a case structure that checks the range being used and then sets the input impedence based on this. Do you know if the value you are trying to read at the time would set the range to a value that is compatible with the input impedence?
Thanks,
Sean Newton
Applications Engineering Specialist - Semiconductor Test
National Instruments

Change Input impedance from 1M to 50ohm of 5133

The input cable and all the other parts are 50ohm. Also I observed a reflection and oscilaition when inject a single pulse wave. If use 50ohm input impedance oscilliscope, it will not appear. I want to change the input impedance to 50ohm. Can I do so. Can I parallel a 50ohm resistor at input, thanks.

The spec points out only a 1M input impedance, so the only option I see is to use a 50Ohm termination ( usually a 50Ohm feedthrough is hard to find in the lab, but a T coupler and a 50Ohm 'terminator' )
And yes, you can use one resistor, however depending on the frequency range it is wise to use 4 200Ohm SMD and solder them in a cross from the shield to inner conductor. (And clean the flux )
(and 200R are better to get than 50R) Don't use standard wired resistors, due to their inductivity. Standard SMD is fine up to 1GHz.
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

LogicPro Multicore handling in "Live input Mode"

Hi,
I'm using LogicPro 9.1.3 to mix a band live. This means that I have 24 tracks with input monitoring enabled assigned to a 7.1 surround output and a latency of 128 samples. Plus a few aux return tracks for effects.
Unfortunately, as explained on this thread : http://support.apple.com/kb/HT3161 Logic Pro does not support multicore when in "live input mode".
Why not ? MainStage supports "live input mode" but can't mix to a surround output.
Any chance for MainStage to support Surround sound output in a near future ?
Any chance for LogicPro to support multicore while in live input mode ?
Thanks for your help

Hi there,
Thank you for participating.
Indeed I'm very happy with Logic Pro, and it works fine with no crashes or latency issues. I use a buffer size of 128 samples to have a bit more CPU power.
The only issue is that even if I can already do plenty of real time sound treatment with all sorts of plug-ins. I am almost overloading one CPU, while the other stands there doing nothing.
If apple could find a way to use both CPUs while in live input mode, it would be great. I could then probably use altiverbs for my reverbs instead of Lexicons. I know that they managed to do it on MainStage. So why not on Logic ????
Please, apple guys, can you do something ???

What is the PCI-1422 external trigger input impedance?

I wish to drive this line and would like to avoid mismatch problems.

The trigger lines on the 1422 go straight into TTL buffers which have very high input impedance (in the megaohm range).

Audigy 2 ZS Notebook Input Impedance and Capacita

Hello, anyone here know the input impedance and capacitance of this card? TIA

OK, thank you for the information. More than likely something has gone wrong with your Windows registry. Rather than delve into that, I would suggest that you go back into Device Manager, and 'Uninstall' you 'On Board' sound card, and reboot your machine. While the notebook is off, remove the PCMCIA card, and this will force the OS to reinstall the on board sound into Device Manager and hopefully the registry as well. Once this is done, you should see a return of your on board sound card's functions and be able to hear you on board speakers.
Please note, that it may take a secondary boot prior to hearing your on board sound card kick in. Simply 'Uninstall' the on board sound (and have the 'Drivers and Applications' CD/DVD from your notebook at hand... and the OS installation disc too), reboot then when the system logs back on it should reinstall the on board sound. It may ask you for the drivers CD/DVD and the OS CD/DVD during this process. That is why I suggested that you have it there when you start. Once this is complete, you should reboot and when your system comes back up you should have sound in your notebook's speakers.
If not, leave a message. There is one instance, I can think of, where you would successfully reinstall the on board sound (and it's system registry entries) and the sound NOT come from your speakers.
Enzo Matrix

NI 9234 input impedance

What is the input impedence for the NI9234 inputs and where do I typically find this in the data sheets?
Solved!
Go to Solution.

If you scroll down about 3/4 of the way through the on-line data sheet you find this:
The differential input impedance is also on the Specifications tab of the NI 9234 product page on NI's web site.
Lynn

Input Impedance in Differential Mode

Hello everyone,
When I bought the USB 6212 card, I was impressed with the high input impedance stated for it - 10 GOhm.
In the specification, this is stated to be for between AI+ and AIGND.
So what is the input impedance under differential connection?
Solved!
Go to Solution.

Hi Navneet,
The question you have posted is actually a Multifunction DAQ question. You should post these questions in Multifunction DAQ Forums. You would get much faster responses to questions that are posted in the correct forums.
The input impedance, in differential mode is a little less then twice the impedance of AI referenced to ground. What this means is that it will be ~20 to 19 GOhms. The actual value is not available because it is such a high input impedance.
Best Regards,
Jignesh

Question about input impedance

Hi everyone,
I was trying to measure a voltage source with 10kohm internal impedance, and I connect the source directly with NI-USB 6009. When the voltage source is 5.043V, the data recorded by labview is around 4.8V. I checked the manual of USB-6009 and found that the input circuit (see the attachment). So I guess when the device was taking data, it was actually taking the data on the crossing node and then converted it back with impedance figures shown in the graph. That's why I got data lower than it should have been.
I was wondering is there any way to deal with it, other than calculating back and converting it with correct impedance?
Regards,
Jude
Solved!
Go to Solution.
Attachments:
屏幕快照 2013-07-18 下午12.19.32.png ‏22 KB

Hi Jude,
you could use an OpAmp to amplify your signal (1:1) an so lower the impedance seen by the USB6009. You could also use some other DAQ hardware with higher input impedance.
In the end the conclusion is: you have to choose your DAQ hardware according to specifications of signal source. You have chosen the wrong hardware...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

NI 5734 Low Input Impedance

I recently got a NI 5734 along with a FlexRIO card and am running into an issue when I connect the ADC up to one of my sources. I noticed on the specifications sheet that the input impedance of the 5734 is 50Ohms. This seems relatively small causing a higher current than one would expect at higher voltage (i.e. 10V input). Knowing that, I couldn't find any current limits on the card. I am guessing it is in the specification sheet, but those sheets have a lot of values with which I don't fully comprehend.
With the above established and knowing that 50Ohms isn't a lot of input impedance. Is there a way that I can increase the input impedance to decrease the current draw from a source? Also, I know that LabVIEW sometimes has functionality selectable (hidden) with Property Nodes. Is there something I can leverage with Property Nodes to aid in my issue?
A preemptive thank you for the assistance.
-You can never have too much power...

Hi MBoyd,
While you don't have to worry about the 5734 being within current limits (we spec it at +/-10V with the 50Ohm impedance), I can understand your concerns about drawing more power from your device. There isn't a way to do this on the card unfortunately; it is set at 50Ohms. I believe this is due to the fact that we typically see this sort of Scope adapter module at higher acquisition rates and smaller voltages, where impedance matching is more of a concern than power draw.
So to decrease current draw from the source, I would look at lowering the voltage of the signal you're acquiring, if possible, and if not then using some additional BNC attenuators in line with the cable from your device to the 5734. There is a wide assortment on sites such as DigiKey here (http://www.digikey.com/product-search/en?FV=fff40036,fffc01f5), so I would explore that route as a workaround for your issue.
Best Regards,
Matt Lee
National Instruments
Applications Engineer

Input impedance of NI 6602 Card

Hi All,
Why is the Input impedance of the PFI's are Finite? In the data sheet it is mentioned that input impedance is 25k-500k ohms. I have measured the impedance of the PFI channel using a Multimeter and it shows that as 9k ohms. In any case (say even if 25k ohms), why is the input impedance finite?
When i connect my PWM signal to a PFI channel it is pulled down and so pulses ar not detected. I have had to use a pull up to count pulses. So, can any one explain why this input impedance is finite.
Thanks in advance

A typical project for one of the 660x RLP examples needs to include the following source code files:
../OSinterface/osiBus.cpp - generic register I/O interface used by the example code
../OSinterface/Linux/osiUserCode.cpp - OS specific adapter used by osiBus to access registers on the hardware in the specific OS
../ChipObjects/tTIO.cpp - abstraction of the chips and registers on the hardware into C++ classes and properties
and one of the examples files, e.g.
../Examples/gpct_ex1.cpp - implementation of a specific operation, including all initialization of the hardware
(The same is true for the examples for other boards although the names of the ChipObject and examples will be different.)
Each of these files needs to be compiled to give y
ou object files, and then all of the object files need to be linked together to build an application (executable binary). The errors you list seem to indicate that you are not using all of these files.
There is more information on the RLP example architecture in the attached PDF document.
Christian Loew, CLA
Principal Systems Engineer, National Instruments
Please tip your answer providers with kudos.
Any attached Code is provided As Is. It has not been tested or validated as a product, for use in a deployed application or system,
or for use in hazardous environments. You assume all risks for use of the Code and use of the Code is subject
to the Sample Code License Terms which can be found at: http://ni.com/samplecodelicense
Attachments:
Register_Level_Programming_Architecture.pdf ‏165 KB

Set high input impedance on Tektroniks DMM4040

I'm using a Tektroniks DMM4040 with SE to log voltage data. When the DMM is used in manual mode, there is an option for high input impedance (>10 GOhm) when measuring potentials.
Can this option be switched on when the DMM is controlled by SE ?
Thanks in advance !
marc
Solved!
Go to Solution.

Hi Marc,
I apologize, that is actually the screen for the "NI-SCOPE Acquire" step. I have checked my resources and I can't seem to find any way to change the input impedance on a DMM/Switch Acquire step.
Since we don't actually support the hardware you are using, I am not able to replicate the issue. I was able to find this image in which someone was using Tektronix hardware with SignalExpress and changing the input impedence. Maybe it will help.
In regards to the measuring rate, I believe this can be changed in the Timing tab. Are you able to see this?
Nick
Applications Engineer
National Instruments
Attachments:
Picture.JPG ‏314 KB

What Is Input Impedance Spec For Old SB

I have an old Soundblaster 6, PCI version. I seem to have misplaced the documentation.
I am working on a project where I would have to know the input impedance of the mic-in and the line-in of that card.
I know the documentation is available at the Creative webstie, but I am stuck with 28.8 dialup and the documentation is 7 MB, which is a long, long time for me to download.
If anyone has the specs handy, could they tell me the input impedance, (not output impedance), of the old SB 6 for the mic-in and the line-in? I think it is 0K ohms, but I am not sure. This is important for my project.
Thank you.

Another brand (two models) is Grass Valley
Old forum message, message now gone, but here's the summary - I have not used, only made note of the product "Matt with Grass
Valley Canopus in their tech support department stated that the 110 will suffice for most hobbyist. If a person has a lot of
tapes that were played often the tape stretches and the magnetic coding diminishes. If your goal is to encode tapes in good
shape buy the 110, if you will be encoding old tapes of poor quality buy the 300"
http://www.grassvalley.com/products/advc110 for good tapes, or
http://www.grassvalley.com/products/advc300 better with OLD tapes

Excessive noise with PCI6143 and hi impedance input

I have a PCI6143 installed in a Windows XP computer for evaluation right now. The test I'm evaluating for is reading up to 5 DC signals from battery cells at up to 1Ks/s. For calibration and verification purposes I need to use a voltage calibrator on the inputs. When I read the cells there is no problems. When I use a calibrator I get a significant noise in the signal. It only affects the channel the calibrator is hooked up to and not the rest and it's only at sample rates of 100s/s or higher. The noise is not AC. The pattern is usually 10 samples at the right voltage and 5 at 0.5V less. It doesn't seem to change this pattern for sample rates up to 100ks/s.
Is there a problem with the input impedance mismatch here? I've used different calibrators and power supplies with the same results. I've checked their outputs on desktop DAQ devices at 100ks/s and there is no appreciable noise.
Any thoughts or possible solutions?
Thanks

Otis,
By 'calibrator' I mean a precision voltage source. Since we can't use the actual battery cells for the test run we normally use a source like this to check the voltage readings each day prior to testing. The output impedance of the calibrator is <10 milliohms, which is pretty close to what the cells are. When I use another power supply to check the voltages with a higher output impedance (1kohms) I still get the problem. The PCI-6143 is used to measure the voltages of the cells during the test. It measures the cells perfectly but we need to verify that once per day with a precision source during a test run (customer requirement).
Yes the cycle is pretty much independent of the sample speed above 100 samples per second. It always seems to be 10 samples correct with 5 samples low. Below 100 S/s it doesn't seem to be there at all.
It happens on any channel the calibrator is attached to. I have tried it alone on each channel and simultaneously with as many as 6 cells each on various channels and it still happens.
Another thing is that if I do the same test using a benchtop DAQ (i.e. Nicolet Vision Xe) it doesn't happen. We are trying to move toward simpler test setups and having a card in the computer is easier than hauling around an external device with its keyboard and mouse and something to set it on along with all the data collection headaches. Plus the internal card is much cheaper and easier to use for most of our testing.
Thanks,
Jack

SB Live! input impedance

Similar Messages

Maybe you are looking for