Old SS amps

I bought my Quad 303 new in 1978. It was still sounding great when I had it serviced by Quad in 2021. My Sumo Polaris II was untouched and working beautifully when I sold it in 2023, at 28 years old. I bought a recapped Mark Levinson 331 in 2020 - zero problems, and sold it for a profit last year. My star SS amps are my Michell Alecto II monoblocs, serviced by their designer in 2019 and still sounding fantastic at 30.

So I’ve had precisely zero problems with old SS amps over many years. As base class A/AB technology is pretty mature, they’re a good buy, and are a good way to experience different design philosophies and circuit topologies.

@bdp24 Thank You for the reply.

I asked about the IV Bass Panel as their are reports to be found of it used as a Bass Extension.

My 57's are Stacked, and I will one day produce a Ripole Bass to be coupled to them. This design has a Figure if Eight Radiation that has similarities to the 57 Radiation.

To date, but not with 57's all ESL Speakers heard with a Bass augmentation from a Typical Driver has been noticeable for the add on. This is not saying not liked, but noticeable is a distraction. The Ripole description commonly suggest the Bass Source is lost in the space and not detectable. That is the same description I can add for the 57's, hence the attraction to the design.

Many many years past I was demo'd at a Commercial Audio Event a Gradient Dipole with ESL 63's, I don't remember being that impressed, maybe the price at the time to feel the need to pursue the set up.

The most impressive / indelible demonstration and my Benchmark is the Tim De Paravicini 57''s directly coupled to Valve Power Amp's, his demo' room was non emptying, the experience changed my interest in End Sound for life. I have a close mimic version of this End Sound able to be produced today in my own system.   

Usually when I want substantially noticeable bass presence, I bring in the Cabinet Speakers to be hooked up and give them a run for a period of time.

I am not monogamous about End Sound or Orientated to one formed sound only. , This does not cause any concerns, being able to have variances in the flavour of the Sound acle to be produced, there are other Upstream devices at hand to do similar for the Speakers Types when in use.  

People often have their amps recapped unnecessarily. Many amps can go 40+ years before a capacitor goes bad. 

More often, in class A and A/B amps, the bias drifts. 

Outside of Class D and THX AAA designs, amp technology really hasn’t improved much in the last 35 years. Buying a flagship amp that is 20 years old but in great condition is a good way to get top-shelf performance for reasonable money, even if you do have to spend $1K to have it refurbished. 

I don't have the high end stuff that's dominating this discussion, but I recently got my Denon PMA 547 up and running. I bought the amp new in 1987 and shelved it in the early 2000s for an Adcom set up since sold. Took the Denon in and basically just cleaned things up and  it works perfectly. Bench fee was $89.  And it sounds surprisingly clean and really rips. Also have a Yamaha CR 450 bought new in 1976 cleaned up, replaced a couple bulbs, and it also works nicely, though the right channel has just started cutting out. 

I have quite a few vintage or old amps that I use every day. In my living room system I have a Thredhold S200 class A amp running through an Audio Resesrch SP1 preamp into Wilson Watt/ Puppies.

    The Threshold I got was a one owner who had it serviced before I bought it, new caps,etc.. It works and sound very nice. I also have a Krell KSA 150 which I bought after it was serviced by the previous owner. It’s my main amp in my dedicated system and I will never part with it. 
  Some older gear is just as nice sounding as newer stuff, maybe not as low a noise floor and the cosmetics might not be up to snuff for the wife but I wholeheartedly believe you can get some excellent equipment at good prices that will last another 20 years.

   Then at that age they probably would be collector items and fetch a good price on the market. Don’t be afraid to take the plunge and buy vintage gear if it’s been properly maintained. I haven’t regretted one purchase yet and I have a ton of vintage gear.