Hi, new to the amp world and I want to know how the damping factor relates to the quality of sound produced by the amp please. thanks

http://www.google.com/search?hl=en&q=damping+factor

Nutshell: lower amplifier output impedance means less effect on speakers' frequency repsonse.  Higher output impedance means more effect on the frequency response.

Generally the higher the damping factor the better in terms of "specs"

Thanks for all the replys guys

Back to hibernation.

A huge amount of bilge has been written about amplifier DF. 

Amplifier DF is pretty much meaningless until it is below about 20. At that point the frequency response can change if your speakers have an impedance that looks like a roller-coaster, and reflex boxes may have to be re-sized.

The Klipsch Cornwall is a reflex box with an impedance that varies about 10:1, yet SET owners love the results they get with Cornwalls and their tubes (SET amps usually have the worst DF of all designs).

The single biggest problem with the spurious DF arguments is that they totally ignore the fact that the DC resistance of the speaker voice-coil is in series with the back EMF generated by the speaker, and that it matters little at that point if the amplifier output impedance is 0.001, 0.01, 0.1, or 1 ohm.

djk: Can you point us in the direction of something to read that discusses the DF but would not be "bilge water"? That would be quite interesting and of assistance to many; thanks//GLA

Q: What is damping factor?

A: A nearly meaningless specification which can be used by amplifier makers to create some sort of meaningless "spec war" to hook neophites who don't understand electronics. Low output impedance is essentially just a "byproduct" of high powered SS amp design. Use lots of transistors, apply a boatload of negative feedback and voila! you have "high damping factor!" This is essentially turning lemons into lemonaide by marketing people. The reason for high damping factor is HIGH NEGATIVE FEEDBACK - a kind of mini-disaster all on its own. 

Secondly, as DJK pointed out, "real" damping factor is rarely over 50 regardless of the amp being rated at 500 or 1000 or anything else, because the speaker wire AND voice coil must be inserted to make an actual real-world measure and this reduces the DF to number like 30 or 50 for nearly all amps!

Thirdly, the assumption that "maximum damping" is best for all speakers, is simply that - an assumption used by those promoting high DF. Many speakers seem to benefit sonically from LESS DAMPING.

Fourthly, many amp famous designers in the past have actually intentionally LOWERED the DF of their amps, so that they would sound more optimum with a wider array of loudspeakers. Early amplifiers included a knob for adjusting DF for the speaker you were using.

Discussion of this subject from back in the old days (2004).

http://forums.klipsch.com/forums/p/42712/398628.aspx#398628 

mdeneen:

Fourthly, many amp famous designers in the past have actually intentionally LOWERED the DF of their amps, so that they would sound more optimum with a wider array of loudspeakers. Early amplifiers included a knob for adjusting DF for the speaker you were using.

Tests were run in the 70s by (I think) High Fidelity Magazine where a 1 or 2 ohm resistor was inserted in series with the speaker line. This reduced damping factor and caused the solid state amp they used to sound more like a tube amp.

So we shouldn't factor damping. :)

Don Richard:

mdeneen:

Fourthly, many amp famous designers in the past have actually intentionally LOWERED the DF of their amps, so that they would sound more optimum with a wider array of loudspeakers. Early amplifiers included a knob for adjusting DF for the speaker you were using.

Tests were run in the 70s by (I think) High Fidelity Magazine where a 1 or 2 ohm resistor was inserted in series with the speaker line. This reduced damping factor and caused the solid state amp they used to sound more like a tube amp.

 

Only in the slimest respect. Yes, it would lower the DF, but adding a resistor to an SS amp hardly makes it sound like a tube amp in any significant way. For those who are sold on DF, great - your shopping is easy, buy your amp with the highest DF. For anyone who is buying amps based on actual sound quality with their speakers, you'd be well advised to do some critical listening before being sold on high DF. 

As always, whatever the heck you think is good, IS not only GOOD, it is "the best! Enjoy!

P.S.

A discussion like this sounds like it was pulled directly from 1975. This is really ancient, ancient territory, but comes up whenever people want to buy amps based on spec sheets. How about the tallest amp? Isn't that worthy too? Maybe the heaviest? Howzabout lowest THD? Lowest noise? Ok, how about the one with the highest current into .1 ohms? How about the one with the biggest, baddest looking meters on the front?  Most watts?

Meters.... Always been like a light for a moth for me.... Can't resist pretty meters, big ones!!!

Meters are neat but create unnecessary paranoia when you watch them bounce high. 

Meters, analog meters, rule.  No paranoia.  I love the meters on my old nakamichi 480 cassette deck.  Also note the meters on old italian cars, guages should be meters.  Oil temp, water temp, gas level,  voltage level, fuel pressure, oh yeah.  I agree with groomy.