What is a T-Amp?

http://en.wikipedia.org/wiki/Class_T_amplifier

I just googled "t amp," this was on the first page of results :P 

theyre useful as nicely priced, super efficient, impressively high-powered (for headphone use, at least) amplifiers.  you must recable your headphones to some kind of 4-wire + 4-termination connector, since T-Amps die when the two channels' grounds are shorted together

In car audio, they were hybrid class A/B and class D amps - especially for subs, they'd go into the more efficient but higher THD class D mode for high power transients, and go into class A/B when the power requirement was lower.  An old Tsunami amp, which was a rebadged Avionixx, which was a rebadged elemental Designs, that I had was a class T, and designed specifically for subwoofers.

How much of that applies to headphone amps, I'm not sure, but it's a bit of cross-audio trivia.

Fantastic sound quality potential, second to none at their pricepoint (imho, of course)

also, EXTREME efficiency - they dont need heatsinks, and still barely warm up

Class D amps in general are shunned for some reason in the audiophile world - probably because those with established systems cannot stomach the fact that something costing $100 or less can outperform any number of far higher-tier pieces. 

The exceptions to this are the ICE amplifiers, and other random samples such as the Red Wine Audio amplifiers.  The former are simply fantastic for audiophile and especially home theater subwoofer amplification.  The latter are accepted only because the companies priced their gear over $2000. 

edit:  Don't get me wrong, T-amps are not the be-all end-all, and there are any number of amps that are better - however, none that I have heard can do so at the price of a T-amp.  The best solid state amps (in my experience) are Class A, fully discrete, fully complementary, fully differential, and fully symmetric.  This is exceptionally rare in headphone amps, mostly due to cost (and the fact that the designer has to do some thinking).  Dynalo and B22 come to mind

Quote:

Originally Posted by sridhar3 

Thanks for the info.  Didn't think to dump the hyphen when I was doing my search, hence the confusion.

 

Do they confer any benefits, aside from Moar Power?  Better SQ or anything along those lines?

Don't let the price fool you. If you have a decent set of speakers, it is a must try.

I bought one for a small desk top system and it sounded great. When I hook it up to my main system, my jaw just drop to the floor. In stereo, it mop the floor with my flag-ship Yamaha amp/surround sound processor 50 times the price. In many cases, it sound so good that I prefer the stereo version with the T-amp over the SACD surround version with the Yamaha.

Don't take my word for it, just search for reviews of T-amps. These T-amps totally obliterate the price to performance ratio. It is ultra hi-fi for peanuts.

Quote:

Originally Posted by sridhar3 

I'm intrigued.  Once I get some orthos, maybe LCD-2, I could look into something like this.  Know a good place to start for somebody who doesn't have any DIY skills?  Also, would any of the usual people who do headphone recables also be able to do a recable specific to a T-amp?  Or can it be done with an adapter?

If you follow the HiFiMan HE-6 thread, many of the guys use speaker amps to drive them. The way the HE-6 is cabled, terminated with a 4 pin XLR male, make it very flexible to amp using the various adapters with 4 pin XLR female.

http://www.head-fi.org/forum/thread/493214/hifiman-he-6-planar-headphone/360

This would be ideal for the T-amp. Inside the box, I would hook up an 8 ohm, 10 watt load resistor in parallel of each channel.

T-amp works best with the proper loading. For a flat frequency response from a T-amp, 6 ohm loading is ideal.

With this connector, just add an 8 ohm, 10 watt load resistor to each channel of the speak connection on the T-amp itself.

With this you can still use the standard HP amps.

I think these low power T-amp is a match made in heaven with these hard to drive orthodynamic headphones.

Someone should make a T-amp with a 4 pin XLR build-in, pre-loaded, lower gain and low noise optimized to work with these headphones.

Quote:

Originally Posted by sridhar3 

Quote:

Wow, thanks ETAHL, I couldn't have asked for a better answer.  I heard the HE-6 are difficult to drive, so it makes sense these would be the ideal candidate for a T-amp.  Where do you get a box like that?  I have no DIY skills or tools, and even if I were to pick some up, I wouldn't start with a project this complicated, especially considering if everything isn't connected properly the headphones will go up in smoke.

 

Any thoughts on something like this?: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=300-958

There's also a Virtue Audio ONE and a Muse M20 EX2 TA2020 Tripath on the Amplification FS section.  Any thoughts on those?

 

Thanks again for all the help.

The wiring is pretty basic, it is not to difficult to attempt; or any of the re-cable guys can do it easily.

It is not likely that these headphones will go up in smoke. The T-amps only put out about 5 to 6 watts at the most. With the 50 ohm impedance of the LCD-2, it not likely to even get 3 watts. The LCD-2 is able to take up to 15 watts.

I would go for the more compact and less expensive T-amps like the Muse sold on eBay. Tons to choose from. Here is one very similar to the one I have and very inexpensive.

http://cgi.ebay.ca/New-TA2020-Class-T-Amp-Amplifier-Tripath-Chip-SA-36A-S-/170606603437?pt=Car_Amplifiers&hash=item27b8f22cad

Quote:

Originally Posted by sridhar3 

 

I'll see if I can ask around with some of the recable guys about the box with the aforementioned specifications.  Hopefully I can get some kind of idea on how much something along these lines would cost.  If you have anybody you'd specifically recommend, I'm all ears (although you seem to know a lot about this, so I'm guessing you do your own work).

Very cool T-amp at the Fleabay link, and cheap to boot.  I was looking through the Virtue Audio website, and they made mention of using different caps in their different models.  Any comments/opinions on SQ differences with different caps (i.e. Sonicaps vs. Virtucaps), or with a power supply upgrade?  I was thinking about the TWO.2: http://store.virtueaudio.com/product-p/vrtu-ia-vatwo.2-pbf-1.htm, maybe with the upgraded high-current linear power supply.  It seems like a good mid-range option with a warranty if anything happens to go wrong.

 

Thanks again for all your input.  You and El_Doug have been extremely helpful thus far.  I appreciate you guys helping a noob learn something new.

I am a DIY guy, so I have no clue who to recommend. Maybe someone might chime in with a good recommendation. If you are not using anything exotic, I can't see it costing too much. As a DIY project, it is about $30 to $50 worth of wires and connectors.

The Virtue Audio amps are way over kill for headphone use. Far more power than needed, unless you are using it for speakers.

As for caps, I am don't see much benefit of boutique caps. As long as they are good quality film caps, they sound very similar. The input caps used in the Muse M20 and the S.M.S.L SA36 are good enough quality that they won't be a weak link in the audio system.

What I'd like to see are portable headphone amps using Full-range Class D chips. If the T-Amps for speakers can be powered by a handful of AA batteries, why not a 9v Alkaline/NiMH or a 12v Li-Ion? It could potentially have a longer battery lfe without sacrificing current response on Class A/B opamp designs.

In any case, anyone tried a T-Amp with an HD600?