synthiaks

Signal generator Impedance Question
« on: May 19, 2020, 04:27:15 PM »
This is probably a stupid question but I'm asking it anyway.

I have a BFE Kompressor that say in the calibration notes that output Impedance of the signal generator used should be 10ohms or less.  Most of the generators i have come across have 50 or 600Ohm s output Impedance. Is this because i only have and have seen the cheap ones or How does this 10Ohm come about?

S
« Last Edit: May 19, 2020, 04:31:40 PM by synthiaks »
"ex observer in silence"


JohnRoberts

Re: Signal generator Impedance Question
« Reply #1 on: May 19, 2020, 04:38:31 PM »
10 ohms  is not typical for professional signal generators. Good ones are switchable between 50 ohm or 600 ohm.

Use 50 ohms

Maybe get a different compressor. ::)

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

synthiaks

Re: Signal generator Impedance Question
« Reply #2 on: May 19, 2020, 04:54:50 PM »
Thank's John!

Ok, I will use the 50ohm on My generator.

Do you have any idea where the 10ohm comes from? The BFE/Filtek company did a lot of German Broadcast equipment and their Specifications are quite detailed. No low quality equipment.

S
"ex observer in silence"

Re: Signal generator Impedance Question
« Reply #3 on: May 24, 2020, 08:05:16 PM »
You can add a buffer to your signal generator with a good opamp like the LM4562 and a 10 ohm resistor output, the distortion and noise should be negligible

gyraf

Re: Signal generator Impedance Question
« Reply #4 on: May 25, 2020, 05:06:55 AM »
If really needed, and if you have plenty signal level in your generator, you can always lower signal source impedance by passively attenuating - e.g. 40 Ohms in series, then 10 Ohms to ground - will give you a ca. 10 Ohms source at 1/5 the original level.

But as mentioned above, you may not need it..

/Jakob E.
..note to self: don't let Harman run your company..

JohnRoberts

Re: Signal generator Impedance Question
« Reply #5 on: May 25, 2020, 10:16:27 AM »
Any decent quality audio amplifier that can drive loudspeakers will have an output impedance in the mOhm range.

As Gyraf suggested a simple resistive pad can also drop the source impedance to 10 ohms.

It might be interesting to see of you measure any difference between 10 ohm and 50 ohm.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

synthiaks

Re: Signal generator Impedance Question
« Reply #6 on: June 01, 2020, 07:39:23 AM »
Thank's for all the help!

I tested it roughly with the 50ohm generator. When i have time i might get back and do a test with the resistors

S
"ex observer in silence"


 

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