Question: Disclaimer: I'm computer scientist

I have a sinus wave generator (handyscope H3-5) from TiePie but the output power is insufficient for my application. The specification is [here](https://www.tiepie.com/en/usb-oscilloscope/handyscope-hs3). I need at least 60W. I would like to know if it is OK to connect the generator to the input line of an audio amplifier. I need only a signal below 20kHz.

The amplifier is an SMSL SA 98E. I only have a [french data sheet](https://www.audiophonics.fr/fr/amplificateurs-audio/smsl-sa-160-amplificateur-tda7498e-2x-100w-4-ohm-amplificateur-casque-noir-p-9716.html). The data sheet states that the input line is 400mV-2V.

I'm not sure what it means.

Also I know that the generator is 50Ohms. Do I have to care about that ?

I plan to buy an RCA<->BNC cable. These are sold for video connections. I think they are 70Ohms. Would it be OK ?

Answer: 
> 
> The data sheet states that the input line is 400mV-2V.
> 
> 
> 

That is probably OK; I'd assume you can easily set your output to that amplitude range.

> 
> Also I know that the generator is 50Ohms. Do I have to care about that ?
> 
> 
> 

Not in this case: the input impedance of an audio amplifier will be very high, so that the source doesn't have to drive much load (i.e. be able to supply much curent).

And, at 20 kHz you don't have to care about wave impedances etc: your cable is much, much smaller than the wavelength of a 20 kHz electromagnetic wave.

So, this will work.

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Note that your generator is absolutely overkill.

A sound card would do just as well – these are audio frequencies, after all!

Also, everything but the worst sound cards have astonishingly high fidelity, so that's often an attractive choice. You'll want to be a little careful when using a sound card that it has (or you add) good anti-imaging filtering (i.e. to suppress harmonics that arise from the discrete-time sampling).
*OK to connect the generator to the input line of an audio amplifier?*

Yes, this is done all the time.

The cable impedance is not important at audio frequencies.

Set your function generator output level to about 0.5 V p-p.

What are you connecting to the output of the amplifier? Here is where you need to be more concerned. Audio amplifiers are not tolerant to low impedance, 4-8 ohms is usually the minimum, look at the specs.

If you are driving speakers, beware. A speaker may not tolerate a lot of energy at one frequency.