Why does this circa '75 receiver sound so good?

I was a salesman in the audio business in 1975 and understand what you are talking about. The Yamaha and Kenwood electronics of that era were particularly great for the buck . I remember one Yahama receiver, about 20 watts per channel and sold for less than $200.00. It was a terrific sounding unit with a variable loudness control, a good tuner and a five year warranty.

If you are getting good sound, why not enjoy it until you can afford something that is much better?

I have an old Pioneer SX 650. I think it's 35 watts. I use it for breaking in speakers, and it sounds very good compared to some S. State stuff of today in the same price that the Pioneer sold for in it's day.

Albert, you likely also sold the Yamaha CR-620 (35 w/ch). I bought one new in 1978, for somehere around $325. It was, and still is, a workhorse. Used it in a two-channel system for some time, then used it in a modest HT system for five years. Now, my son has taken it to college to use in his dorm room. Driving a pair of PSB Image2's and a lower-rung Klipsch sub, it sounds pretty dang nice. Good tuner, too.

My favorite receiver (and B.T.W., that of many British audio reviewers) from the mid '70's was the Sony STR-6800 SD. It was built like a brick s**t-house, used a quality attenuator, not just a cheapo volume pot. Had an interesting Dolby FM de-emphasis switch (Broadcast Dolby FM was never implemented), and all control switches were of very high quality. It was conservatively rated at 80 wpc, and NEVER failed to deliver less than 105 wpc at the yearly McIntosh clinics. It totally destroyed a Marantz that I was previously using. The dealer did a blind A/B test (receivers hidden) between the Sony and a Pioneer (I forget the model #) rated at 160 wpc (twice that of the Sony's power). All the "victims" picked the Sony. I say victims, because those invited to the A/B test were all owners of the Pioneer! This Sony sold for about $500-, and flew off dealers shelves as soon as new inventories were received. I also liked the fact that it was very stable when driving 4 ohm loads (most home speakers in the '70's were rated at 8 ohms). You could toast marshmellows over most receivers when driving 4 ohm loads, and the bass damping and control went out the window with many other amps, including the Marantz.

Fatparrot - I recall that receiver, too. There is one of these on E-Bay right now for a current bid of 20 clams!