Because what you ask is purely subjective, here’s been my experiences for several of the sets I own and have rebuilt.
All of the receivers in my collection are extensively rebuilt; Elna Silmic’s in the signal path and Panasonic FC’s elsewhere. I typically will leave capacitance the same, but in certain areas increase the rated voltage. 1uf Tanalums replaced with film parts. So, that said, my methods of rebuilding are carried throughout all of my receivers in a similar fashioned.
Remember, everybody has a different listening environment, different electronics, and certainly different ears! My test system consists of a said receiver with an older Teac CD player, Dual 1219 with an Audio Technica Shibata tip cartridge. Speakers are a set of lower end Definitive Technology Bi-Polar floor speakers. All this in a bedroom sized living space. None of it good, none of it bad…
Pioneer SX-1250; LOUD. It certainly has the most punch of all my 70’s receivers. The tuner is pretty good for sensitivity/selectivity. Sound, aside from getting loud, is more machine like to me. Decent bass, perhaps a bit shy on the low end, and shrill on the high end. I love this receiver, but it’s never in the rotation very long as it seems to fatigue my ears faster than others.
Tandberg 2080; love it! FM performance is the best of all I own. It has the lowest bass extension of all I own. Seems to run out of steam quickly, but it also has a power supply without the capacity of others. All around, a very nice sounding set, good lows, smooth and inviting sound to my ears.
Marantz 2270; inviting sound! I like this receiver, and Marantz sold tons of these things in the 70’s. I think I read it was one of the most successful receivers of the day. I like the sound, tight bass, smooth mids, and just right highs. This receiver has a warm and soothing sound about it, I hate to use the phrase “tube-like”, but it is. FM sensitivity is so-so, but if you’re in a major city, shouldn’t be a big deal, but you’re not going to DX with it! Not easy to rebuild, but a great performing set many people love.
Sansui 9090DB; one of my favorites. Sexy looking and good sound. I won’t use bigger words to describe the 9090DB, it’s certainly not great, but there are a lot that are worse in my opinion. I save this for last, because it always seems to end up back in my system as the most run receiver. It doesn’t have the best low bass extension as the Tandberg does, but it’s controlled and tight. Its mids are sweet to listen too, and it provides nice highs, not mechanical like the Pioneer, nor will it scare the dogs away in your neighborhood. The 9090 is loved by many, performs well in all areas, and it’s never disappointing to listen too! Another set that is plentiful!
To conclude, I like all of my receivers, but for different reasons. Each has its own personality and character. Some things each do well and some not so well… I have several different models of Marantz, Tandbergs, Piioneers, and Sansui’s. All rebuilt, and I keep coming back to the Sansui as one of my favorites. For me it’s hard to pinpoint any one model that does everything well, or is a favorite… My suggestion is to build an opinion based on what your ears say to you, what visually appeals to you, and where your budget allows you. There are a lot of Marantz fans, as there are Pioneer, Tandberg, Kenwood, etc… It wouldn’t be fair to say one is better than the other, period. But it is fair to say that some have parts that you cannot get, making it a little more challenging to fix. All of the 70’s sets are old, and will need a rebuild. I would not put much time on any set without some service work first – they are time bombs waiting to fry potentially un-obtainable parts. Plus, rebuilding with today’s parts puts these sets back to better than new. Parts today, even the cheap ones are likely better than what was available in 1975!
It’s a fun, and addictive hobby, start small, and grow from there!
Happy listening!!