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).
Yes you will be fine - but beware that very LOW frequencies (less than 20Hz or so) may cause problems. Audio amps (good ones) block DC and frequencies below about 10-20Hz, for good reason : that stuff can kill speakers at high levels.

What are you actually driving? what's the load, and what's the application?