100W amp

[Mihkel]

Would this do?
I'm concerned about this:

If you try to increase output power even more by increasing the input signal it will lead to serious distortion due to saturation.

Does this mean I can't use the preamp?

[spongebob]

http://www-s.ti.com/sc/psheets/sloa105/sloa105.pdf

Calculating Correct Gain Settings for Audio Power Amplifiers

This application report explains the different types of audio power amplifier configurations, such as the single-ended (SE), the bridge-tied load (BTL), and the fully differential audio amplifier. Each configuration is illustrated with a block diagram, gain equations, and an example using realistic scenarios to illustrate to engineers how to calculate the gain of their audio amplifier.

This is one of the many helpful PDFs you can find on the TI homepage, a very good read if you want to design your own power (op-)amp.

[Nasse]

I would invest for most efficient speaker set that you can get, too. There is huge difference what is the end result if you use speakers that have near 100 dB at 1 m at 1 watt. 50 watts RMS is quite nice amount of power, but as they say with solid state amps you need some extra for headroom. Maybe for heavy metal or very loud rock act outdoors or for very big audience lots of power is needed. But quess Fender Twin and Vox AC-30 are known to be loud animals, and big part of that is two very efficient 12 inch speakers... Some local heros told a Twin is just much too loud for small places, after touring with Link Wray in the old days (maybe he had two knobs at 11)

EDITED LM4780 looks like a nice chip for 100 watter, dunno the cost and availability

[Mihkel]

I think I'm going to use the preamp with the LM3886 68W amp from GGG.