Should I buy a new amplifier; and if so, what?

The problem is..older amps use large single caps for plus and minus rail voltages. They take up a lot of space as well. Newer amps use many small caps in parallel to make up the large capacitance. The advantage besides size requirements is, small caps have less ESR (equivalent series resistance). This allows the smaller caps to rapidly deliver their current under transient conditions and recover quicker, which in turn makes the amp sound 'fast'. This is especially true in the bottom end i.e. slam.

Hifigeek1

With all due respect, I find your assessment surprising. Cornell dubilier 51000uF/160V replacemet cap for 336 ESR 6.9 mOhms. Using a 10000uf cap ESR 31 mOhms you need 5 caps. It will not fit in Levinson. ESR is lot lower on big caps also ripple current is three times higher. There is a reason Levinson used these Super caps it will give better bass also. Philips caps is the culprit. Replace the caps on Levinson 336 with Cornell dubilier caps or Tech cap 62000uF/125V. The Cornell Dubilier is the worlds best capacitor reason they uses a three stage process to create worlds lowest leakage current, longest shelf life. Also they are made in USA. They have no factory in CHINA. You can watch the youtube on google and see how caps are made. Also Nichicon capacitors are very good for power supply.

The Newer amps uses many small caps to reach large capacitance because it is lot less expensive than big caps. That is the reason.

Bel Canto recently replaced a bad input board on a $3000 amp for well under $200. I would recommend them based good service alone but the product sounds top notch as well.

You sound like an ad for CDE. Your assumption is that I was referring to a high quality capacitor. I wasn't referring to a super cap. Frankly the reason those caps are the price they are is because of the quality of the cap. Point is, many manufacturers are not going to be using caps like that much longer. They are too expensive and take up too much real estate and dictate the height of the product. Generally speaking, newer designs also use power supply caps at the output circuit board so they don't have to distribute voltage from the main filter caps through wires to the output transistors. This somewhat defeats the purpose of using a low ESR part especially if you're using 16-18 gauge wire in long runs, which I have seen. I'm not familiar with Levinson's circuit topology so I don't know what they are doing. Putting additional low ESR caps at the output circuit board is the best place to put them since you now have current delivery right at the point where it's needed the most, the high voltage plus and minus rails. These caps are also used as a 'by-pass' improving the characteristics of the main filter caps. I guess what I should have said was newer, less expensive, high quality, small value radial type caps can be just as good as expensive computer grade electrolytic's. When they are also located at the output transistor circuit board they enhance fast current delivery and improve bottom end performance. I stand corrected.

I have heard both Mac and Ayre amps with good results