Class-T Amplifier sound quality?

Re: Class-T Amplifier sound quality?

You're taking a limited sample and stretching your conclusions too far. Class T and Class D amps have come a very long way, but as the power levels increase, so do their inherent shortcomings. It's possible to overcome most all of these shortcomings, but cost-wise, it becomes cheaper to return to Class AB1 or especially Class AB2 amps when the power levels start exceeding 100 watts RMS per channel. Even though the power supply may become (often is) more expensive than the actual amplifier for Class AB2 and more so for Class AB1, the "support circuitry" for high power Class T and D amps can cost more than the savings of Class ABx amps. There's always the exception to the rule, of course, and I don't want to over generalize. For "popularly priced" stereo gear, this is a decent "rule of sore thumb". Just like in gas powered "daily driver" cars you're usually money, maintenance, effort ahead with a larger 4, than with a high-strung half-displacement turboed 4, for now. "No replacement for displacement." We are getting much closer to the "break-even" point on amps and engines, and that's a crude analogy. Several very well respected stereo companies still stake their bread-and-butter on very carefully designed super low distortion Class AB amps, and will for years to come. It's hard to argue with their results.

Re: Class-T Amplifier sound quality?

I have had my Topping TP60 for three months and I'm very pleased with its sound quality. It is a serious amp and yields excellent results for speakers which have moderate sensitivity (mid to upper 80's SPLs). I never turn up the volume knob beyond 2/3ths to 3/4rd position for my 4 ohms MTM speakers. Do not believe the 80/50 watts per channel rating at 4/8 ohms load as that is at 10% distortion. Do believe 48/27 watts at 4/8 ohms at less than 0.1% distortion. After operating for hours the case is cool to the touch! My only caution is to not drop it on your foot as it is seriously heavy for its small size.

Re: Class-T Amplifier sound quality?

Since all my class T amps (DTA-100a) (lepai) were purchased for a fraction of the normal price ($4, $6, $15).... They carry an amazing value :D

That aside, the used market on standard audio gear still dominates in terms of value. You can pick up really good old amps for $20-50

Re: Class-T Amplifier sound quality?

Thanks Whitneyville1 & Jim, Sidi for your opinions.
I have never heard of Class AB1/AB2, is the difference between the two the amount of bias current? (one being closer to Class A). I have seen that most subwoofer plate amps are Class D - is this because the the difference in performance at low frequencies is less audable? Could a Class D amplifier have audiophile quality if it only amplified the 30-300Hz range in a bi-amplified speaker? And use a AB amp for the 300Hz-20kHz range.

Re: Class-T Amplifier sound quality?

I am slightly unsure what you mean by audiophile sound quality. To an engineer an amplifier should have no sound of its own, that is, it should sound neutral. But to many audiophiles valve amplifiers, for example, that are not audibly neutral are often described as having a high sound quality whereas audibly neutral amplifiers (in the sense of blind tests) are not.

Class D amplifiers can cheaply and efficiently supply lots of power at low frequencies which are often needed for bass drivers in small sealed cabinets. One of the downsides of class D is that it is relatively difficult to maintain audibly neutral performance at high audio frequencies. Class AB is less efficient than class D and more expensive to make work at the high powers often required by bass drivers in small sealed cabinets. It has less issues in being audibly neutral at high frequencies for the more modest power requirements of mid and tweeter drivers.

A class D module for bass and class AB module for mid and high frequencies would be a reasonable thing to do.

Re: Class-T Amplifier sound quality?

Class AB1 and Class AB2 mostly differ (in tube amps) by the amount of bias current used. In solid-state amps, it's mostly in the amount of negative feedback applied to prevent self-oscillation and rising THD. Personally, don't really don't like the "sound" of lots of negative feedback in an amp. While it reduces the THD, to my ear, it also "squeezes", or take the fullness from the music. Certain brands of amps are known for their lack of negative feedback (NAD, Harmon-Kardon, Carver, and some more).
A Class AB2 amp is a little more efficient in terms of watts output vs: power in watts input. With computer aided design, and other "smarts" available today, it's VERY hard to hear any difference in AB1 or AB2 in a good solid-state amp. Several people on the forum are using tube pre-amps and Class D power amps with outstanding results. There are reasons this should work well. One of the mid- late 1970's 70 lb. Sansui intergrated amps or receivers (150-175 WPC) are GREAT power amps to this day, and command top dollar on audio sites like Audiogon and other used audio gear sales sites. Most guys change the hot dial lights out to LEDs and replace the old control pots and clean the switches, and they are ready to Rock and Roll for another half-Century.