1970's receivers and integrated amps...

The better ones (like Tandberg, Sansui, Nikko, Sony, Marantz, Yamaha, Onkyo, Kenwood and Pioneer) can sound very good if in good working order, in a well set up system, and used with the right speaker setup.

Their weak point in general will be current delivery in that power supplies in most receivers and integrated amps do not match up to those in separates. This can be a handicap when used with many modern speaker designs that are harder to drive optimally.

The deficiencies will often be noticed in the bass. Use of a good powered sub to offload the bass can be an effective solution to help deliver top notch performance.

It can be hit or miss about the absolute sound quality of some of these products. And as others have said you have to make sure they are in proper working order. Craigslist is an excellent source of these products. You can find them for under $100, throw another $100 in for cleaning and repairs and you'll end up with a very workable second or third system amp.

That said, at best the amps sound okay to good. One thing that is indisputable is that the tuner sections are excellent and easily keep up with best of modern tuners.

tandberg, mac,revox, kyrocera, marantz, hk, nad, and others made some sweet stuff. condition is everything today.

But God are they BEAUTIFUL!!!

i just love my Yamaha A-1 integrated amp from the very late 70s. while Yamaha's circuits are never "simple" in and of themselves, this was one of their simplest TOTL efforts. the design and execution is quite modern and elegant, somewhat ahead of its time. with new electrolytic capacitors throughout the power supply, the sound quality is top-notch vintage. i use mine in a pseudo-nearfield TV room setup with some old-school Infinity WTLCs. while i don't feel the need to look for anything better, it would still be very interesting to compare it to some modern integrateds at some point.