I've enjoyed Yamaha separates like their C-2 pre-amp and B-2 power amp for decades. Never owned any of their receivers or integrateds but used to sell them. Yamaha components were conservatively rated and fairly warm sounding. Seem quite accurate to my ears, of course they do build some fine musical instruments as well which has to have some influence on their audio products. Never did care for their speakers though.
for 70s stuff i'm partial to pioneer (sa9100, sa9800) and kenwood (krxx00, kaxx00). if you dip into the early 80s, i think tandberg (2055, 2075) and luxman (rx series) were more refined and sounded a little better, with particulaqrly good tuners and phono stages. the mid-80s kyocera are also great a real bargain now.
Ive got about 50-60 of these and have tried lots of others. Brands I would avoid are: Sony, Yamaha (Natural sound), Tandberg, Realistic...to my ears they are sub-par.
Many Kenwoods are also pretty lame....If you want one stick to the 9600 or the later "50" Series (7050/8050). Dont bother with the "Nines" or "Elevens". They look stunning...I have several...but are Mediocre performance wise
Top 3 Marantz's are the 2330, 2285 (Not B) and 2325 although you wont find any in your price range. The 2270/2275 are OK but nothing to brag about at all. Avoid the lower end models.
Pioneer 9100 Integrated is very nice. Im sure the 9800 is at least as good BUT will run you more than 600 most likely.
Sansui in your price range I would strongly suggest the EIGHT DELUXE (Not the Eight). Other ones to consider are the 881, 5000x. Many other great ones but not in your price range.
Pioneer receivers: 1010, 939, SX-950, SX-1050 should fit the bill.
Technics - SA-700 or SA-800
Sherwood - 9910A
Luxman R1070 or R1120. These are great for detail/clarity...you will hear stuff with these that are missing on almost all of the above receivers BUT they are geared more to acoustic or softer music. If you play "congested" Hard Rock you will lose all the detail that separates them from the rest of the pack.
Hope you find this helpful
$500-$600 for high end vintage is going to be rough. I had a Pioneer SA9900 for 30 years. Best integrated they ever made. When I went to find another they were all $1000 +. You'll need to find someone anxious to sell who needs money. It took me a while(6 months) to find a Marantz 2252B. But I got it for $98.
Still using my Kenwood KA-7100 that I bought new for $200. back in 1978 when I was in college. One channel finally let go, so I’m looking to upgrade to separates. It was trouble free for 40 years, mostly driving Energy 22 Reference Connoissuers.
Budget is a bit bigger now thankfully. I’m thinking Don Sachs and maybe Odyssey Stratos, But, I’m having lots of fun looking. Plan on keeping the Energys.
Good luck with your search and have fun!
I love the retro styling of such units, but it pays to remain realistic. An excellent new 2x100 watt amplifier with integrated DAC like the Yamaha AS701 will only cost you $800. The similar 2x85 watt Yamaha AS 501 will even cost you only $550. Both measure and sound exceptionally well, and you make a fresh start, without any need to recap etc. And these modern Yamaha amps even have a somewhat retro look.
See here for tests of the earlier units without digital inputs:
If you are into a receiver, the 2x100 watt Yamaha RN803 with all kinds of modern facilties is only $750.
These Yamaha integrateds are very good indeed, as those in depth reviews show, with for example a load independent frequency response that beats just about any amp on the market. Harbeth used an AS701 at the Bristol hifi show to demo their P3ESR, if only to make their point that you do not need an expensive amplifier for their speakers to sound their best.
I like those old Kenwood receivers. I have a KR3600 that I bought for very little years ago. It looks stunning, but there are the occasional noises from the volume control etc, but that may be because I no longer use it. Power output of that KR3600 is only 22 watt per channel, which is audibly anaemic.
The tuner part was always a big asset of these Kenwood receivers, but for me that no longer matters. I have come to the conclusion that on balance the higher bitrate internet radio stations sound at least as good as FM, even if the respective weaknesses of lossy internet radio and FM are not directly comparable. Internet radio will only get better, and you already have this enormous range of stations from all over the world.
A properly restored Pioneer SX-1250 is very hard to beat with the right speakers (can sound a little bright otherwise). I have one that I rebuilt myself and it produces some of the cleanest most detailed sound I have heard (gives up nothing to my old Proceed Amp 3). Have heard many Marantz but they are too woolly sounding for my taste. Many feel the 1250 is the best of the vintage Pioneer receivers. Will never part with mine.