From: utzoo!decvax!harpo!eagle!mhuxt!mhuxj!mhuxi!cbosgd!npois!houxm!houxa!houxi!houxz!ihnp4!ixn5c!inuxc!pur-ee!uiucdcs!emrath Newsgroups: net.audio Title: Re: connecting cables and damping - (nf) Article-I.D.: uiucdcs.1749 Posted: Wed Mar 23 22:25:38 1983 Received: Fri Mar 25 20:05:07 1983 #R:dvamc:-104300:uiucdcs:22700010:000:1989 uiucdcs!emrath Mar 23 18:27:00 1983 I tried very carefully to compare the sound from my speakers with a damping factor of 100 (or whatever my amps are capable of-I haven't bothered to measure them) versus a damping factor of 2. I convinced myself that even if somebody could hear the difference in an A/B compare, this difference is of NO significance to ME, and it will be forgotten within 10 seconds of switching. This is all strictly my opinion, and I fully agree that some people will find special speaker cables to be worth their price. Notes: 1) I always assume that a stated damping factor is a minimum over the audio frequency range (20-20KHz), unless otherwise specified. 2) As for losses, using a .639 ohm wire (100 feet of 18 Ga. copper @ 68 deg. F) with 8 ohm speakers causes less than a 10% drop in current, which is a loss of less than 1dB (i.e. inaudible), and a damping factor slightly greater than 10 (assuming output impedance of amp is much lower than that of wire-it generally would be). By the way, I am currently using a homemade amplifier (not the amps mentioned above) which is 1 Watt per channel. The amps clip at 4.9 volts into 8 ohms at 50 Hz, both channels driven (same phase). I built my own LED peak indicators. Yellow triggers at +/-1.33V, red at +/-4.0 Volts. (a 4 Volt 0-peak sine wave is 1W rms into 8 ohms). Attack time is less than 50 microsecs. An overvoltage of this duration guarantees that the LED comes full on for at least 25 millisec (which is quite visible). I sometimes turn the volume up to where the yellows are flashing, but I seldom turn it up to where the reds are activated. In testing, I found that I could raise the volume 12dB above that level which never triggers the reds before I could perceive the distortion, even though I knew damn well the thing was clipping! I originally built this thing as a headphone amp, but it worked so well with my speakers (Pioneer CS-63s kind of old, but rather efficient) that I have been living with it for almost a year.