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dtel

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DrWho,

I wonder if the Power/THD plots for the Tripath amps in Dean's link are the sort distortion you were talking about.....?

I'll post a Class D plot here for you. It compares favorably with most linear SS amps--and note the actual THD values at sub-watt power. If you are unconvinced re some 'inherant' Class D problem I can post one with even better numbers later.....

Mark

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There's a big article in this month's The Absolute Sound about Class D amps, comparing around 9 or 10 of them. The "D" is a class designation. One of the writers in the magazine mentions that they are not digital amps and are actually analog in nature. The switching type operation doesn't make them digital.

Pat on the Island

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I wonder if the Power/THD plots for the Tripath amps in Dean's link are the sort distortion you were talking about.....?

It turns out the plots I saw were printed out and I'm working on obtaining them or finding them online. It was a good year ago and things are always changing on the websites [6] Dean's links looked close, but not as dramatic as I remember. Everything I've seen so far is similar, but I remember the distortion minimums being closer to the max output. I have no doubt my written description was lacking - maybe I should just draw a picture of what I remember if I can't find them.

I've been doing some poking around looking at graphs, trying to find the dozen or so I remember, but like you said most everything is behaving fairly typical of pretty much any linear amplifier. Either the two guys were feeding us lines and I'm being a bit over zealous, or simply better amps are being built? There is certainly much more involved with the amp as a whole than just the distortion behaviors of the chips being used (so maybe they were talking about the chips?)


For what it's worth, I have nothing against the "digital" amp toplogies - in fact, I hope they continue to improve as their efficiency is such a huge benefit in so many ways. But at the same time I can't ignore my ears. I would certainly love to hear some of the nicer more expensive units out there though. Ultimately, I think you're getting what you pay for with the inexpensive options. Bang for the Buck only works when the Bang is good enough.

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I've been doing some poking around looking at graphs, trying to find the dozen or so I remember, but like you said most everything is behaving fairly typical of pretty much any linear amplifier. Either the two guys were feeding us lines and I'm being a bit over zealous, or simply better amps are being built? There is certainly much more involved with the amp as a whole than just the distortion behaviors of the chips being used (so maybe they were talking about the chips?)

For what it's worth, I have nothing against the "digital" amp toplogies - in fact, I hope they continue to improve as their efficiency is such a huge benefit in so many ways. But at the same time I can't ignore my ears. I would certainly love to hear some of the nicer more expensive units out there though. Ultimately, I think you're getting what you pay for with the inexpensive options. Bang for the Buck only works when the Bang is good enough.

Pat--Yes they are analogue. Some are pseudo-digital ("power DACs") but most of the better ones are not.

DrWho--I hope you get to hear one you like. Class D is actually really difficult to design so right now there are very few good amps out there--and lots of middling dreck. But the good ones really don't have any worry re matching specs or sonics with linear SS. The plot you indicate looks like a TA2024....?

FYI: The amp I posted the THD/Power plot of is not a chip but 3"x3" discrete (see below):

post-12810-13819317384386_thumb.jpg

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The 930 is boxed and shipped.

Big brown truck headed towards Mississippi.

She came from Florida and is headed back home to play the southern rock she plays so well.

arf,

Thank you so much. Dtel is so overwhelmed by the generosity of the people on this forum, as am I. Meeting a lot of the members of this forum in Hope and the Klipsch employees showed me something that I had not seen in a long time. Genuine friendship and compassion. You guys, all of you are the best of the best...

Dtel loves the "big brown truck". When he and the neighbor see "the big brown truck" they always say, "Someone is getting a new toy". This will be one of the times the "toy" is for dtel.[:D]

As for Dr. Who and Rivendell...are you guys trying to hijack dtel's thread?[;)]

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FYI: The amp I posted the THD/Power plot of is not a chip but 3"x3" discrete (see below)

How much does it cost? and which model is it? All of the digital amps I've heard so far have been low powered and I don't think it can handle my listening tastes (I like my transients). 200W from such a small unit is quite impressive. You could mate that sucker with a nice torrodial power supply and fit it all in one of the Hammond Aluminum enclosures no problem.

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Dean got that pretty near. It is a Hypex UcD 400.

He linked to a US dealer--or they can be bought direct from hypex for about 100 Euros (or 130 for the version with the Analog Devices 8620). By the time you get two, power supply, tranformer, etc.....it does get a bit steep just to be curious.

Here is the link to the Hypex website: http://hypex.nl/

And here is the link to the module data sheet: http://hypex.nl/docs/UcD400_datasheet.pdf

Mark

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LOL, I thought about that as I was typing out the post. I could have just said 'amps', which is true. However, it's a contingent of the SET camp that's been the most vocal about the attributes of the better chip amps. I used to own a pair of SET monoblocks that put out a sound a person could have lived with forever. I later tried some different SET amps that only lasted in my system a few hours. I don't doubt that the top shelf brands sound great, and it's the owners of those type amps that are giving them up for this new breed. These people have a zero tolerance for grain and hash in their sound, and I think to a large degree this is what they appreciate about them. The best push-pull can do it too, but those amps typically cost more than most good SET. The point is that these amps are being compared to the best amps out there, solid state and tube alike -- the stuff that runs from three to eight thousand dollars. This won't bring an end to tube gear -- but I think solid state as we have known it is finished.

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People are dumping their SET amps left and right for these things.

rofl - is that supposed to be a big deal? [;)]

Yeah--I wasn't sure if he was praising or damning. There are over-the-top subjective reviews of UcD module based amps like the Kharma Matrix: http://www.positive-feedback.com/Issue25/kharma_mp150.htm

The specs do clearly indicate some of that--like the flat THD/frequency, and the load independant frequency response. Not 'chip' amps....

Mark

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People are dumping their SET amps left and right for these things.

rofl - is that supposed to be a big deal? [;)]

Yeah--I wasn't sure if he was praising or damning. There are over-the-top subjective reviews of UcD module based amps like the Kharma Matrix: http://www.positive-feedback.com/Issue25/kharma_mp150.htm

The specs do clearly indicate some of that--like the flat THD/frequency, and the load independant frequency response. Not 'chip' amps....

Mark

lol...people with big fancy cables (especially power cords) scare me. I shouldn't make fun, but I loved this comment:

I can tell it's a trio

'cause I recognize a guitar, drums, and sax

If that's a big deal, then maybe that explains why all the SET users listen to the music they do...[:o]

I am soooo kidding, but I couldn't resist [:#]

Man, talk about going off topic! I'm looking forward to the dtel review on the old HK's - they really are quite the treat.

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