Will class t chips change solid-state?

[Colin]

Class T amplifiers offer both the audio fidelity of Class AB (which you'd likely find in your home stereo reciever) and the power efficiency of Class D amplifiers (often used to provide the punch for subwoofer amps). consider low distortion to be both THD+N of less than 0.1% over the full 20Hz to 20kHz audio bandwidth and IHF-IM (high-frequency intermodulation distortion) of less than 0.1% . Tripath Class-T amplifiers have THD+N of significantly less than typically 0.08% over the full audio bandwidth and IHF-IM less than typically 0.04% and therefore deliver whats often defined as audiophile performance.

http://www.tripath.com/downloads/an1.pdf

Tripath TA2022

You may ask why DIY when one can buy the Sonic Impact amp for USD20? Well, the Sonic Impact amp uses a different chip (TA2024) which gives up at ~15W. The Tripath TA2022 chip not only puts out more power (2x100W), it's THD doesn't rise as you increase the power (the smaller chip used in the Sonic Impact amp does). Why heck, just the TA2022 chip alone is more expensive than the Sonic Impact amp! Commercial amps like the Carver ZR1600 and the Bel Canto Design EVo 200.2, which retail in the USD1-2k range, use the larger 2x300W TK2350 which is also available from Jan in his AMP2 kit.

http://www.diyparadise.com/tripath.html

[Nklipsch]

There is never a cure-all. Just another set of advantages and disadvantages. Something would be wrong with the universe if there was a free lunch.

THD measurements by itself is useless for audio, see the cheever_thesis

http://w3.mit.edu/cheever/www/main.htm

Interesting topics such as THD

Weightings applied to THD

Negative feedback and distortion products

Distortion products which are not only 'nice' to the ear,but masked by the ears own natural harmonic generation.

More interesting is the transfer function,look at distortion vs power. Is it amazingly low then shoots up to some huge figure? Does it sound good? Or is it smooth with low order harmonics that dont sound so bad, and/or are masked by the ear/brain so you dont even hear them?

"A Futurewithout feedback?"

By: Martin Colloms (From: Stereophile 1/98)

"Some defectsin amplifier performance not covered by standard specifications"

By: Norman Crowhurst (From: JAES10/57)

"Soundof the machine: The hidden harmonics behind THD"

By: Lynn T. Olson & Matt Kamna(From: Glass Audio, No,4, 97)

Mike.e

[Daddy Dee]

Interesting question. Class T (or D) is certainly impressive for the cost. Makes sense to me that it would sweep the consumer electronics market first.

[Nklipsch]

Exactly,people who havent heard better will simply enjoy the average sound.

The more critical market,music lovers,'audiophiles' etc will speak of the subjective effects under sighted testing while the abxers will assemble some testing...I think it will be a gradual infiltration of a/b but not a complete take over.

The final question is how does it sound?It might not sound warm enough to analog fiends.

[Colin]

excellent articles that help explain why tubes sound better over the long run, great pictures, some plain English, thanks!

[Daddy Dee]

yeh, I have to say that when I first heard the tripath chip, I was knocked out. Perhaps as a disclaimer, I should own that getting giggly over the tripath was partially due to the price, though it does sound good in it's own right. Also, it sounds better than alot of amps out there.

However, after listening for a few weeks and going back to tubes, tubes rule. There is just something more complete about the presentation.

[Colin]

a few weeks? I went right back to tubes for a side by side comparison, tubes are defintely better, but while they once looked like a good value compared to expensive solid state amps, they now seem just as expensive!

[dragonfyr]

Maybe it is because I have been involved with the technology for so long, but I always get a kick out of watching the awe and reverance that the word "digital" seems to inspire in many folks!

And it is almost always disproportionate to its actual advantages!

And the reason that digital has inherent advantages over analog is....?

And in response to an earlier post...Yes, I would expect class T amps to replace every other format any week now. I am holding my breath!

[sunnysal]

Price versus performance the tripath lineup whips all comers, no doubt in my mind.

BUT I too reverted to my tube rig in my main system after a short while, I simply liked the tube sound better (warmer, fuller). however the sound was so good that I would not hesitate to use these tripath amps in other applications; my tripath amps (I have two, the teac and the leok) are currently driving speakers in other applications (patio and daughter´s room) and doing a bang up job at it! I also would use them for tweeter and woofer duty in a triamp setup, leaving the mids to my tube rig.

I think these chips will rule the roost in the mass market and possibly the "one step below ultimate" slot eventually. Perhaps newer iterations of these chip amps in higher-end implementations (like we are seeing from jeff rowland, bel canto, etc.) will get all the way top the high end on the tripath base, we will wait and see (listen).

I see nothing to lament here, these are cheaper, higher performance SS devices, power to the people!

warm regards,

tony

[Tom Adams]

I can see these amps making their way into PC's and HTPC's. And in that type of "non critical listening" application, it could complete a true one box A/V solution for a HT or a kick *** PC audio.

Their size should also allow them to be placed inside of todays' small speakers. That would leave one's system consisting of source components and a preamp. My prediction?? Bose will be the first to offer such a system.

Tom

[Rivendell61]

Just to get up on my soapbox....none of these amps are digital. It is true they are often called 'digital'. In fact they are all analog class D.

They do sound very good--some lots better than others.

There is really no issue with THD. One of the reasons these amps do sound so good is the intelligent application of knowledge about how THD does, or does, not matter.

Mark

edit: Also should add--Class T is just a Tripath term for their class D implementation. There are 10+ companies making class D amps.

[Erukian]

There's two types of digital amps.

Digital Hyrbid amps (ones that take in an analog signal, and digitally add gain. And real digital amps, which take in the signal ususally in 1's and 0's and amplifies it then converts the digital to analog right at the binding posts.

I'm sure Colin or someone here could explain to you better than I can about how these two types work, but dont think that because the amp is labelled "digital" that it sucks. It is just a marketting term put on the amp because it uses transistors and a chip that calculates algorithms to amplify and then clean up the audio and then send it out.

In my opinion, since I first heard the teac that cost me $108 shipped, i was so blown away by the price/quality ratio that I can't see them not overtake all SS amps within the next 5-10 years except the high-high end ones that are for the most part entrenched in their niche.

-Joe

[IndyKlipschFan]

Maybe it is because I have been involved with the technology for so long, but I always get a kick out of watching the awe and reverance that the word "digital" seems to inspire in many folks!

LOL Will Klipsch make "Digital Speakers" too? LOL.........

I remember when this was a gimmik a few years back!

[Spkrdctr]

Is there a technical paper on the class T amps? Something with more detail in it than the links from Tripath? They did not give me any real info to understand what they are doing. Thanks for any additional info.

[Rivendell61]

Spkrdctr,

There used to be a long pdf. 'White Paper' on the Tripath site. But I don't recollect if it was an overview of the pulse width modulation technology in general--or just a Tripath sales pitch for its own stuff. They do have .pdf docs for each 'chip'.

Keep in mind, this is not new. Clive Sinclair was advertising 6"x3", 10 Watt, PWM amps, (SI deja vu!) in UK magazine adverts in 1964.

Now everyone makes them (TI, Phillips, Apogee, etc) and they are used everywhere. So there are lots of implementations. Tripaths is, I believe, a bit behind the cutting edge at this point.

A good place for info is here:

http://www.classd.org/indexold.html

The site is dormant (seems the guy was in a motorcycle wreck last year) but click on the 'Q&A' section for a good overview of the technology, analog vs digital PWM, etc.

If you click on the 'OEM Products' he evaluates each manufactures product (including Tripath). And as an 'audiophile' (he seems to have some nice gear) he rates them sonically, etc.

Another good doc. for a general overview is here:

http://www.spectrum.ieee.org/WEBONLY/publicfeature/mar03/dig.html

Its a couple years old but still worthwhile.

---

Leaving aside the fun, good sounding, and net popular SI and Teac amps--which are fairly compromised due to obvious cost constraints from the final product manufacturer--

The best current D class amps can go head to head with any high end A/AB product.

Re 'N's comments above on THD, a good current D class amp has specs which run sub .03 THD straight line from 20-20k, and is flat at 1 watt or 100 watts.

Etc, etc.....

Most important--they sound good!

Mark

[Spkrdctr]

I can't believe that they are calling class D amps Class T. Once again marketing hype goes to the forefront. Sheesh! I agree that class D is now getting to where it needs to be to offer serious power to the home theater user. I wonder how long it will take to get real power (a real 100 watts per channel all channels driven) in the Sony, Pioneer lines.... it is cheaper to make class D amps than the current AB amps. But, like most markets, audio is very resistant to change. We shall see!

[Rivendell61]

It is creeping in....

For instance this Marantz MM9360, 150 Watt x 6 Channel power amplifier seems to use Tripath--

http://us.marantz.com/shop/_templates/Proddetail.asp?model=41&cat=20

Mark

[Mallette]

Those of you holding your breaths waiting for Class T to take over the world, fear not, you won't even turn blue. Why? Two reasons from many...

1. CHEEP

2. CHEEP

...and that is all the average home consumer is interested in.

Except for those (and, though this ol fahrt whose lived through the tubes-to-SS-and-back-to-tubes thing) who will pine for the wondrous vintage Pioneer SS sound, SS is on life support and won't last long.

Here is another news flash: expect the amp to delivered as a rule as part of the speaker. Take a look at the Yamaha YSP-1. 42 speakers each with its own amp...1500.00 (probably a 200% markup or more).

Laugh...but consider that women all over the planet will rejoice at no wires or speakers in the room, while 99% of the men say "The wife loves it, it was cheap, and I can hear the referee's talk JUST FINE, thank you very much..."

Whilst we while away our time here discussing the shimmer of cymbals and THD, the world is changing so fast that when you let that breath go you'll find yourself on another world where 7.1 surround amps are blister-packed at Safeway and your PC soundcard comes with 100WX8 channel amps.

Keep laughing guys...

Dave

[Marvel]

Who's laughing Dave?

My son and I were talking the othe day about speaker size. When I got my JBL 4311s in the early '70s,they were (still are) called bookshelf speakers. Almost the exact same size as the Heresy. In the mid '70s they weren't considered big, but somewhere along the line, fashion came into play. Hi fidelity doesn't really exist for most people.

ALL of the music department staff at the college where I work have little boom box or all-in-one systems for music playback in their offices. They think this is normal. Well, it IS normal to most. But they aren'thigh quality playback systems at all.

The head of the music department paid me to come hook up her new receiver at her house. A lightning strike had taken out her old one. I don't even remember what she has, but both speakers were stacked on top of each other in the corner. So much for stereo.

And I almost forgot. The Promedia Ultra 2.0 uses Class D. Sounds great too. This is an excellent use for these amps.

Bruce

[Spkrdctr]

Are we going to call Class D by its name "Class D" or by the new name Class T? Gee, such important decisions...... I think marketing people whould be checked for a brain BEFORE they are hired.