I seem to have misread your schematic. 10 watts, not 10 amps! 1 amp is possible with the transistors you have specified and a relatively beefy opamp, but a pair of transistors is still probably better.
actually i'm using recycled in old stock C2238 NPN and A968 PNP power BJT, not exact complement, but well, i'm quite sloppy on this one, please excuse me. important part is they have both better hFE (25-35) @ 1A, the 200mA output opamp still can handle them directly (with heatsink of course!). i have better TIP122 and TIP125 darlingtons, but i will keep that for another day. this APSU one is a bit sloppy, as long as it works, its fine, and i feel more secure in case they blow up, i still have better stock
Essentially you want a power amplifier with good wide bandwidth, such as an RF amplifier. You can then drive the RF amp with the FG to get varying output frequencies, and if the bandwidth can take it, it could output the other waveforms well [ square, triangle etc.,]; any RF amp design can do it, distortion rises with more power output, but a basic design should work for your need then limit output power to get better frequency response.
http://www.nxp.com/acrobat_download/various/SC19_POWER_AMPL_DESIGN_1.pdf
i'm using Texas Instrument's THS3062 for the job (discussed last time in another my opamp thread), its not classified as RF, but this new breed of CFB opamp really rocks (hence the 500ohm in the line of feedback there). NONE opamps in my stock i've tried ever comes close to the performance of this 7V/ns opamp, you name it 324, 741, 4558 they are all far behind. you got to see it to believe it, but one thing is that you seldomly see an opamp will smoke so easily like this 3062, already burnt a pair last time. thanks for the link.
it seems it tends to wander to technical smorgasbord side of the design rather than its "sociology", the thing is the circuit above is "quick tested" and working as i've expected, however under heavy load, the output will distort so badly, but let be realistic with this 10W circuit. i'm yet to make the real testing, driving and analyzing the smps transformer, but i will test the low wattage working condition first, hence the low spec of 1A... soon. picture below is the finished "no so tidy" deadbug to save time. it gets its input signal from Hantek DDS3x25 (with my 10x25 amplification in between).
anyway, Short Circuit indicated it does exist (german site i cant understand) so its good to know, i wonder how they are priced, seems like a serious equipments. however i have to agree on low frequency capability, that there will be less usefulness for high frequency, i cant imagine what, except for simulating mains frequency, can be made as an audio amplifier (if the input port is provided) for testing DIYers winded speakers, smps etc, maybe above 2-5MHz will be pointless, up to tens and hundreds of MHz, i believe it will invite EMI law enforcer to come home, not to mentioned the annoyed hams
(none around here
safer for me)
For your average function generator you can get a power amplifier stage;
http://www.tti-test.com/products-tti/text-pages/gen-wa301.htm
i believe the wa301 is signal or voltage amplifier, not power amplifier since there's no mentioning about the wattage. and ...
"can drive up to 300mA peak into a low impedance or short circuit" is not that tempting for power amplifier (normal FG spec).
for the
http://www.signaltestinc.com/Rigol-PA1011-10W-Power-Amplifier-For-DG3000-p/pa1011.htm, i believe thats what i'm looking for, but working as an addon for DG3000 series (not standalone), 10W at $300+ is quite a fortune IMHO. i just built a 10W 2MHz (5MHz actually, up to 30-50MHz with very bad heat dissipation and signal attenuation due to the opamp heat) out from junkyard for free.