They all say that. My rule of thumb is take the total
wattage rating (both channels) and multiply it by 2.5.
This would be the likely draw of a pure Class A amplifier.
Example: 2 channels at 200 watts each gives 1000 watts.
Then take the ratio of the actual idle draw of the amp
in watts, divide it by the 1000 watts and square that
number.
As an example, a 200 watt idle is a pretty toasty value.
Example for an stereo amplifier rated at 200 watts/ch
with a 200 watt idle: (200/1000)^2 = .04
Multiply that number by the rated wattage of a channel:
.04 * 200 = 8 watts - this is the probable Class A figure
for the amplifier. The peak value will be twice that figure,
so for audio I would say that such an amplifier will leave
Class A at 16 watts peak.
I leave it to you to decide if your amplifier is operating
Class A in your listening situation.
Cheers, I'll bear that in mind and might actually do that sometime.
The designers are someone called Ian McCarthy (the one I spoke to, from what I gather he used to work with someone called de Paravicini at E.A.R.) and Terry Clarke, founder of Klark Teknik. May be you know them?
isochronous mode doesnt use the complete bandwidth, and it still carries crc information that error corrects problems with the transmission assuming not entire block gets corrupted. with spec cabling i fimd it hard to believebthat there ia enough errors to cause audible differences forbthe average listener. while not completely out of the realm of impossible it is unlikely.
in particular the reviewers of these cables tend to talk about thensiund becoming "warmer, more siundstage, richer etc etc" which i claim is an examole of psychological bias rather than any real transmission improvememt of the bit stream.
i personally know one of owners of a billion dollar audio cable manufacturer ad in private he wiol fess up to that its just marketing and packaging that sells. he is selling an experience and excusivity, audiable benefit is implied and if you dont hear it then you must not be sophisticated enough.
my personal favorite are the guys who buy the $500 power outlets with pure silver/good/whatever to get the special sonic benefit.... what a waste...
I'm not sure where you got this Pano but it doesn't need for jitter to be this bad (if there ever is such a level of jitter)for it to be heard in the sound. Bit perfect is just the baseline performance needed for digital - there is a lot more beside.
Are you sure about this? What about the influence of the power that's carried in the wire alongside the signal wires. Yes they are supposed to be differential but is the wiring configuration done correctly? Is the impedance spec of the data pair correct? Are they terminated correctly? Is it fully differential at the receiver end?Urgon said:
well of course they are. otherwise the cable wouldnt be compliant with the spec. if you run a windows style pc you would have messages such as usb speed reduced due to errors or if you have a linux box you can see this in the syslog messages. what in the world makes you think that a computer wouldnt report if the interface would have to operate in degraded mode. the physical, electrical and signalling standard of the various usb specs 1, 2, 3 etc all defne behavior and fall back modes when performance can not be guaranteed.
but audio isochronous mode is so simple to implement and signal due to its relative low bandwidth that i just dont see how this would be such a hard task to operate in. the standard was designed with the environment you describe in mind so its not like its an extreme case for usb to cope with.
ow if you run it inside a 10kwatt transformer in a power station with floating earth and the lots of interference then i can buy into it, but not in the use cnases described here which is what the standard was designed for"
AVE...
2. Differential signaling and twisted pair wiring are made to reduce the crosstalk and interferences. It works great. Basic explanation is below:
3. There are physical standards for USB cables. And most companies obey them because it's more cost effective to make good cable for extra two cents, than make crappy cable and loose clients. Almost all cables are bought by computer equipment manufacturers - we are talking about thousands of cables per month per company...
1. If you believe that fluctuations of 5V DC will distort the differential signal enough to make it unusable, then you should take basic physics course at nearest high-school. Take your oscilloscope and measure voltage fluctuations across +5V and GND lines in your USB cable...
2. Differential signaling and twisted pair wiring are made to reduce the crosstalk and interferences. It works great. Basic explanation is below:
3. There are physical standards for USB cables. And most companies obey them because it's more cost effective to make good cable for extra two cents, than make crappy cable and loose clients. Almost all cables are bought by computer equipment manufacturers - we are talking about thousands of cables per month per company...
Where did i say unusable? You said that it wouldn't have any unwanted noises & distortions - are you sure?
I know how differential signalling works, thanks.My question to you is - what is the twist ratio in USB cables. Is the cable + USB receiver effective at noise/distortion removal? Do you have some references or have you measured this yourself?Take your oscilloscope and measure voltage fluctuations across +5V and GND lines in your USB cable...
2. Differential signaling and twisted pair wiring are made to reduce the crosstalk and interferences. It works great. Basic explanation is below:
OK then it should be easy to find these test results everywhere?
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First, let me say this: I love music and I listen to music quite a bit. I have a system that many would like to own, and I built this system to listen to music. I certainly didn't build it to listen to amps or cables.
It's like work - leave it behind when you go home. I leave all of the BS nonsense of amp differences behind when I listen to music.
If YOU (or others) want to waste your time straining to hear which cap sounds more transparent, 'evaluate' away.
As for you not being sure of my expertise, I'm not offended. After all, I didn't claim any and I wasn't offering any.
Here's a no charge nugget though: free you mind of all of this 'evaluation' garbage and you may enjoy listening to music again.
AVE...
Even if there are any distortions and noises, they will be too small to matter. Bigger noises can be generated by tracks between the connector and DAC chip...
All common cables are made according to specs. You can search for physical layer of USB protocol somewhere in the Google. But this information is unimportant since you are just looking for complications in something that's simple and well-tested by everyone, who uses USB...
You're really bored, ain't you?
Go on then give me a link - be kind to an old man!
As I said above, if datasheets are not produced then it leaves the door open for charlatans who can make any claims they want & equally not produce datasheets. I'm surprised the objectivists haven't realised this?
If you think bit perfect is it, then enjoy your perfect sound forever!
As long as it is bit perfect it is still digital and thus not yet audible but as long as my computer delivers a bit perfect version of the file to my convertor nothing else matters up to that point.
However I like to leave usb to deal with the stuff it was designed to deal with: Keyboards, mice etc. I use firewire for streaming.
However I like to leave usb to deal with the stuff it was designed to deal with: Keyboards, mice etc. I use firewire for streaming.
AVE...
You are not only bored, but also lazy...
Yes, they publish the specs (http://www.usb.org/developers/docs/usb_20_081810.zip) and they also provide the technical manuals for performing various electrical tests on USB 2.0 devices (USB.org - Documents)...
You are not only bored, but also lazy...
Read more carefully before abusing someone - do the USB cable manufacturers publish the spec of their cables is the question I asked
AVE...
The manufacturers are signing the agreement that makes them follow the official USB specs. If they don't follow, they will be sued...
Thread closed for now. Backroom discussion is in order.
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