PC as sig gen - max 2V output...best circuit to crank this up?

[HankMcSpank]

Having just bought a h/w sig gen from the far east, I'm finding myself wanting for a sig gen where I can immediately input the required frequency from a keyboard (& to 2 decimal places.....my new h/w sig gen is only good for one decimal place & even then...it's a pain!)

there are plenty of free good sig gens for PCs, but from an output 'level' perspective all are limited to the soundcard's maximum output - 2V peak to peak.

No when I'm testing some circuits, I find myself wanting more (like 10V peak to peak.

Now I know I could just use a simple opamp 'preamp' to boost the line level of the soundcard...but I don't want to introduce any distortions from that, so I was wondering if others had already travelled this path (I can't imagine that 2V peak to peak is going to satisfy many!)


Many thanks,
Hank.

[infinia]

Mostly depends on what you plan on using it for.
Op amps are good as or even better than your sound card, after all they are used in them as well. You can verify the performance of an added opamp circuit by using freeware software in loopback testing and comparing the results. They (opamps) don't like low impedance loads < 600 ohms or so (with a 3dB -6 dB output buffer pad).
For low impedances I usually use an old audio poweramp instead of an opamp. You could also employ a chipamp or some other commercial chip amp kit.

[AndrewT]

2Vac is quite a high line level signal voltage, only pro balanced signals exceed this significantly.

Very few amps/receivers need this high a voltage to exceed maximum output signal.

Or do you want more current to drive lower impedance loads?
If so, then you should be looking at a buffer circuit to "crank up" the power not voltage.

Most PC sound card software limits the maximum output frequencies to ~20kHz.
This allows sinewaves <5kHz and squarewaves/sawtooth <2kHz. But preferably half these limiting frequencies.
This is very limiting for test signals.