Class-T digital amps?

[Marcos]

Someone told me these are brilliant and can run full speakers at great quality on little power, whats the story? If this is true, why arent they the norm now?

[dablk]

I wouldnt stretch that far . One of my mates got one to run some small missions..

It works, it does not sound too bad considering. However with around 11w when running off the mains(i think its less when running off battery), it certainly cant drive the bass like he was used too from the speakers.

Infact their very very bright now with nearly all treble. It also produces are reasonable amount of hum when turned to its maximum.

The unit is tiny though..about the size of your hand.

My verdict would be what it can do is suprising but nothing to get any other manufacturer sweating.

[Mark.Yudkin]

"Class T amplifier" is a registered trademark name for a type of class D amp, held by Tripath. Tripath have filed for bankruptcy. A trademark is used to protect use of a term by other companies.

Perhaps you are asking about class D amplifiers in general? Class D amplifiers use switching power supplies to reduce power requirements. Ths disavantage is significant harmonic distortion and artefacts, which must be cleaned up afterwards. Doing so reduces the power requirement advantage.

As a result, class D amplification is almost ubiquitous within an active subwoofer, where relatively high levels of distortion are irrelevant. They are also common in Pubic Address systems, as these have similar performance requirements.

[Phlog]

" ... Class D amplifiers use switching power supplies to reduce power requirements... "

Mark, some actually use linear power supplies; they still claim the benefits you mention.

[Mark.Yudkin]

Your are of course correct. A class D amplifier use pulse width / density modulation (or sigma delta modulation, etc.). It is the switching of the output device rather than the switching of the power supply that is relevant.

It is however simpler to think of pulse width modulation as being like a switched power supply, although it is technically incorrect when looking at the internal construction.

[Marcos]

ahhh....interesting, so i'll scrap that thought and go for a regular amplfier, thanks!

[Mark.Yudkin]

There's no need to scrap the idea of a digital amp - I was only answering the question as to why they aren't the norm, and what class T was. There are some very nice class D amps on the market, and the lower power requirements will benefit your electricity bill.

[Marcos]

But it sounds like i'll lose sound quality, bass, and volume. Which are pretty important to me

And if i can get a decent regular amp for ~£100, Class T would have to have be pretty cheap to offset the bad points

[Mark.Yudkin]

Let's forget class T can we, since it's a trademark for a specific manufacturer's type of class D amplfier, and he has anyway filed for bankruptcy?

Class D amplification does not suffer in general from bad sound quality, bass and volume After all, they're almost ubiquitous in subwoofers, where power, bass and volume are paramount.

However, it also doesn't have any great advantages (except reduced power consumption), so buy what sounds best for your budget instead of concentrating on the underlying internal technology.

[CJROSS]

Originally Posted by Marcos

And if i can get a decent regular amp for ~£100, Class T would have to have be pretty cheap to offset the bad points

Marcos there are so many amps on Ebay for £100 that would toast the little Tripath Amps in both facilities (input & output connections – remote control) and performance. Look for classic amplifiers from Harman Kardon (HK6500/HK6150/HK6350/HK6550/HK680/HK690) also keep an eye open for any Sony ES amps from yesteryear, these can easily be had around the £100 mark.

(I have heard the Sonic T amp. Nice little thing for a low level listening but these amps suggested above to me are much better VFM)

[Mr_Sukebe]

Some additional thoughts from a class T owner.

As already stated, class T is a variant of class D digital amplication using Tripath chips. Excluding the obvious sonic T amps, there's not a massive amount of groups using it, though I believe that Nuforce aswell as Bel Canto have class T solutions.
The most common replacement for Tripath has been the B&O produced "Icepower" chips.

Like most hi-fi kit, the core technology is seemingly less important that how well it's implemented. I've played with a couple of Sonic Ts, and didn't really rate them, though at their price, they're an interesting option. The Bel Canto I presently use however usurped £4.5k worth of Naim pre-power combination, and I've still yet to come across any sanely priced amp that I'd prefer, and I've heard quite a few, including direct comparisons with 300B valve amps.
I've also compared to the newer Icepower versions, which did the "hi-fi" bits very well, but really didn't involve me aswell as the older Tripath BC.

As for the OP, the first thing you really need to consider is what speakers you will use your amp with. One of the key things I've learned is that synergy between a speaker and amp combo, is often more important than outright performance of a single component. Mix a bright sounding amp with bright speakers, and you're in for a world of uncomfortable recordings ripping your ears off. So considering what you'll use the amps with will be the first point of call.
Digital amps tend to do detail, air, space and bass control well, but can sound sterile and if over-driven, will sound simply nasty as their distortion is far less pleasant than from say a class B amp.

At the end of all of that, your budget is really the restricting factor. Yes you could get some of the cheaper sonic-T style solution, but as already mentioned, you're probably better off getting a good s/h stereo amp.