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post #11 of 24 Old 04-01-09, 01:45 PM
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Just wanted to share what I have learned about Class D amps. Most Class D amps are at least 80% efficient and upwards of 90% efficient. Translating that means less heat dissipation and less power requirements to reach the rated wattage specified. For example, if a typical Class A amp is rated for 250wpc and generally is only about 40% efficient that means it has to draw 625watts from the wall in order to output at a full 250watts; times that by 7 channels for home theater applications and you've got 1750watts, but in actuality you require a good clean 4375 watts in order to reach that maximum.

Now for class D amplifiers, with its lowest of 80% efficiency that means 250 watts means it will require 450 watts from the wall. Multiply that by 7 again and only 3150 is required to reach its maximum of 250wpc.

As far as Class D amplifiers sound quality lots have changed recently. Originally, what was said was true that the higher frequencies didn't sound all that great, which is why they were used only as subwoofer amplifiers. Fast foward to today, there's a reason why a lot of companies are now starting to use them. The high frequencies have improved greatly. It has the dynamics of a typical solid state, but the highs are smoother like a tube amp. Not exactly like a tube sound, but it's noticeably smoother.

And since we are on the TCA Forum we should remember that the Gizmo is a Class D amp - at least I believe it is.

Rod
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post #12 of 24 Old 04-01-09, 03:32 PM
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Aren't the highly touted ICE amps considered D class switching amplifier?
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post #13 of 24 Old 04-01-09, 03:54 PM Thread Starter
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those dodds sure look interesting !!!!!!!!
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post #14 of 24 Old 04-01-09, 04:15 PM
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Yes, ICE amps are class D.
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post #15 of 24 Old 04-06-09, 05:38 PM
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Jon Liu wrote: View Post
Just wanted to share what I have learned about Class D amps. Most Class D amps are at least 80% efficient and upwards of 90% efficient. Translating that means less heat dissipation and less power requirements to reach the rated wattage specified. For example, if a typical Class A amp is rated for 250wpc and generally is only about 40% efficient that means it has to draw 625watts from the wall in order to output at a full 250watts; times that by 7 channels for home theater applications and you've got 1750watts, but in actuality you require a good clean 4375 watts in order to reach that maximum.

Now for class D amplifiers, with its lowest of 80% efficiency that means 250 watts means it will require 450 watts from the wall. Multiply that by 7 again and only 3150 is required to reach its maximum of 250wpc.

As far as Class D amplifiers sound quality lots have changed recently. Originally, what was said was true that the higher frequencies didn't sound all that great, which is why they were used only as subwoofer amplifiers. Fast foward to today, there's a reason why a lot of companies are now starting to use them. The high frequencies have improved greatly. It has the dynamics of a typical solid state, but the highs are smoother like a tube amp. Not exactly like a tube sound, but it's noticeably smoother.
Kept meaning to post to this thread, but kept forgetting....

Just wanted to add that efficiency of class D amps doesn't mean that you'll use that much less power. Most of the time we're working in single-digit watts of power - we get no where near the max power capability of the amp.

Besides, the amount of current draw by the power supply at idle is also a factor. And if it doesn't have a trigger (or a readily accessable switch), then that current is being drawn all the time. I have to admit that I thought there would be much more savings out of a digital amp than there is, and I was shocked by the amount of current draw at idle for each of the x-amps.

I do think I should have realized it ahead of time, but I also think that in general (not just the x-amps!) the amp efficiency is discussed in such a way as to let you draw the wrong conclusion.

Oh, and putting a power switch on the back to me means it's intended to be left on... Or triggered on and off... :fryingpan:

take care,

P.S. Now Class A: thems some nice room heaters.
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post #16 of 24 Old 04-07-09, 04:03 PM Thread Starter
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thanks for all the info.........not sure if it has been already answered in some other threads regarding best match for the ls series.......i just want to get the best possible sound out of them........and if that is tooooo expensive then whats the next best choice ??
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post #17 of 24 Old 04-07-09, 04:18 PM
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thanks for all the info.........not sure if it has been already answered in some other threads regarding best match for the ls series.......i just want to get the best possible sound out of them........and if that is tooooo expensive then whats the next best choice ??
I'm far from an expert on this, but conventional wisdom says that a pure class A with little or no negative feedback is going to be the best sound. Unfortunately, most of these types of amps have 5 figure price tags.

This will be my next amp upgrade.....but it's a loooooong way down the road. At least this time next year....
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post #18 of 24 Old 04-07-09, 05:25 PM
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This will be my next amp upgrade.....but it's a loooooong way down the road. At least this time next year....
200lbs ... That sucker is a beast.
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post #19 of 24 Old 04-07-09, 06:18 PM Thread Starter
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that thing is huge.......almost scary looking..........i am sure the 9s will love them.......
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post #20 of 24 Old 04-07-09, 06:51 PM
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that thing is huge.......almost scary looking..........i am sure the 9s will love them.......
Hope you're not talking about me....no 9's for me


Here's what I run:


I've been a fan of Rogue's stuff since I first heard them. Solid 100% made in USA. Just got one of their pre's a couple months ago. Everything they do is toobs:smoke1:
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