Is the K1000 safe to use out of a T-amp directly? When the phenomenon started, power resistors were being used in parallel for impedance matching, just want to make sure im not destroying my now-rare K1Ks.
I have tried it both ways, with and without the use of impedance-matching resistors. In all cases, I have found the sound to be better without the resistors. They seemed to act as a high-pass filter and reduced the bass response of my K1Ks slightly. I have tried this with the following Tripath amps that I own or have owned:
Virtue One Classic
Winsome Labs Mouse
Little Dot T_150
In addition to driving my K1K's directly from the speaker terminals, I also do the same with all of my other balanced headphones:
HE-5LE, AKG K340, K501 and Sony SA5000. Smaller balanced phones that also sound great when directly driven from the speaker terminals are my Koss KSC35 and Yuin G1A.
As most amps use a log-taper volume control, the use of the speaker terminals to drive your phones is not likely to cause any more likelihood of damage to your phones than to a speaker of equal sensitivity and impedance. In fact, the higher impedance found in most phones adds a further measure of protection.
I do ensure that the volume control on my amp is at a minimum setting before powering up the amp, but this is only common-sense good operating practice regardless of what you are driving from your amp.
Needless to say, I am not an advocate of using power resistors in parallel with the headphones when using the speaker outputs.
As both positive and negative outputs are actively driven and do not share a common ground, do not, under any circumstances, attempt to drive a SE headphone with a T-amp!!! The use of phones requires separate + and - for each channel, exactly as used by speakers.
From the AKG K1000 manual, it states an impedance of 120 ohms and from the frequency response chart, it shows the phones to be quite flat in response from 50 to 20,000 hz.
Response drops by approx 3 db at 40hz, 9db at 30hz and 20db at 20hz.
Sensitivity is 74db for 1mW freefield output.