I think this is unlikely, because the AA-2120 of the US Proton I was in service at the time was also 120W (8 ohms).
Said here, some people will say that I am dreaming of idiots, really become a Dreamcatcher!
A month later, Simaudio P3+W3 arrived, the same 120W rear class W3 (21kg), moved to the fourth floor, I took a break twice. Three times and five divided by two, connected with the gentleman and JBL, put the second track of "Teegac" of "Teacam" of Telarc, and realized what is the damping number of 800. Although it's just two channels, I really doubt the effect coming out of the 5 JBL and a Yamaha subwoofer.
It turns out that for speakers, they should have their best specific resistance requirements. In general, a power amplifier with a high number of damping can avoid the turbidity of sound caused by more power due to poor control power. On the contrary, the low-amplitude power amplifier makes the counter-electromotive force of the horn weaker. When the amplifier has no signal output, the horn is still in the working state. One is not good, it is not burning the horn, or burning the amp. Even if the equipment is not burned, the low frequency characteristics, output characteristics, high harmonic characteristics, etc. of the horn will be deteriorated.
The number of damping is generally between tens and thousands. For example, the damping level of the Simaudio W5 is 1000, which is equivalent to a professional crown. The following is the calculation formula for damping:
Damping coefficient = acoustic impedance / (power amplifier internal resistance + line resistance)
It turns out that the number of damping in the rear stage of the Proton AA-2120 is only 400. With such a low value, it is no wonder that the sound quality of the original 4410A is very turbid.
Therefore, the damping number represents the ability of the power amplifier to control the unit. The higher the damping number, the stronger the control force. The larger the damping number, the stronger the back electromotive force of the horn. In other words, the more easily the speaker is stopped after there is no electrical signal! For example, Crown's MA series, with a damping coefficient of up to 1000, can deliver pure, powerful low frequencies.
However, it should be noted that the choice of power amplifier is not the higher the damping number, the better, if the low frequency is tight, it is like some small box small speaker box, such as the Rogers 50th Anniversary version of the C620 speaker I am using, The low-frequency sense is thin, and then the high-damping amplifier is used to push, so that the sound will have a very dry feeling.
At the same time, when a large damping coefficient is required, the horn must have a good woofer. If the quality of the woofer is not good, the amp with a large damping coefficient will tear the woofer.
Once, my friend brought a pair of Victor's old 3-channel monitor box, and used my W3 to push the 8-inch white pottery bass, the same track "Star Wars", even let the 8-inch white pottery woofer , pop up, it is not to play back, if not immediately off the amplifier on the spot, I think, that day, the Victor will burn.
Therefore, different speakers will have different matching methods. You can't just ask about the output power, the correct matching, and you can get high-quality sound. If you don't match, the high power will also make your voice.
Q: I don't know if there is a problem. How is the line resistance calculated? Damping coefficient = acoustic impedance / (amplifier internal resistance + line resistance), is the internal resistance of the amplifier not the amplifier input impedance? Does the impedance of the sound refer to the impedance of the speaker?
Here is a clerical error, it should be:
Damping number = speaker impedance / (amplifier internal resistance + line resistance), the internal resistance of the amplifier is the output impedance of the amplifier.
According to the factory data of Simaudio W-3 (http://), the output impedance of W-3 is 0.01 ohm, and the impedance of external JBL 4410A is 8 ohm. Therefore,
Damaudio W-3 damping number (KD) = 8 / 0.01 = 800
Damten number (KD) of Proton AA-2120=8/0.02=400
Here, one problem that can be noticed is that we do not calculate the line resistance when calculating the damping number.
The reason is that wires (such as signal lines, speaker lines, power lines, etc.) are part of the system. It is best to use high-purity copper or silver wires to make the equivalent mechanical quality factor (Qm) and amplifier of the speaker. The damping number (KD) should be matched to a certain extent to make the equivalent resistance of the speaker's feeder small enough, so small that it is negligible compared with the rated impedance of the speaker, that is, the power loss of the speaker line should be less than 0.5dB (about This fit can be achieved with 12%).
Another aspect that can be seen from here is the extent to which good wires affect the entire system. Therefore, the pursuit of wire is not a blind blow. In addition, the good wire referred to here is not the price as far as the track is better. In the words of Dr. Fan Denghao, the (his) wire is faithfully restoring the sound of the system itself.
Q: I don't understand, the output impedance of the power amplifier is 4 ohms and 8 ohms. Is the damping coefficient only 2 and 1?
The impedance of the load circuit of the amplifier you are talking about is only related to the power, not the output impedance. In the general amplifier data, the load impedance is marked, and for the input impedance and output impedance, not every amplifier's data is marked.
The output impedance of a typical power amplifier is small, but some domestic or foreign manufacturers do not indicate the output impedance. Ask the manufacturer or agent if necessary. At the same time, there are also many better quality amplifiers, which will be marked.
In addition, through the connection with some speakers, you can also judge the size of the damping from the sound, such as dynamic, layering, low-frequency solidity and purity. However, this is much more difficult to listen to.
Q: Can the amplifier's internal resistance meter be measured?
1. The internal resistance of the general power amplifier output is very small, very small! If you want to measure it, you should also disassemble the amplifier and test it on the circuit board inside.
But there is another problem, that is, the multimeter itself has impedance, and sometimes the impedance of the multimeter may be higher than the output internal resistance. These factors will affect the accuracy of the measurement.
2. The low impedance can be measured by inputting a sine wave and connecting two different purely resistive loads to measure the two sets of output voltages. The multimeter's resistance is very inaccurate. Generally, the resistance bridge can be used for the calibration.
Yulihua: The only way to increase the damping coefficient is negative feedback. The depth negative feedback has higher requirements on the frequency characteristics of the device, the design and debugging of the compensation circuit, and the cost will increase slightly.
The national standard stipulates that the damping coefficient is above 10, at which time 90% of the maximum damping force is reached, 100 is 99%, and 1000 is 99.9%. It can be seen that the huge damping coefficient has no practical significance, but the transient intermodulation is caused by the deep negative feedback. Problems such as distortion.
Many HI-END amplifiers emphasize the use of triode amps, no negative feedback, and a damping coefficient of only about 1, which does not prevent it from having high quality sound quality.
There are often blown words of current injection type power amplifiers on the Internet. If they are true, their damping coefficient is 0!
There are three factions on this issue:
Large damping coefficient pie, play super stone machine.
The amps are not pursued for the damping coefficient.
Current pie, 0 damping coefficient.
Everyone can see clearly and be self-sufficient.
In engineering, any technical parameters are not absolutely good or bad. A good parameter often means that other aspects are poor.
The responsibility of the engineer is to make a compromise, to achieve a balance of indicators, and to stop, do not deify certain indicators.
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