Hi Dean:
Peter Millett, the designer of the Wheatfield headphone amps, says that the AKG K-1000 headphoes must be driven with a low output impedance amp. So he designed an amp for the K1000s with a 7 Ohm output impedance.
Here is what he says....
"This little guy is a headphone amplifier that I designed mainly to drive the fine AKG K1000 headphones. K1000's are hard to drive, as headphones go. Their impedance is pretty typical of headphones, at 120 ohms... but they require a lot of voltage (power) to get to a good listening level. They're rated at 1 watt maximum, which corresponds to 11V RMS, and at their stated efficiency of 74dB/mW, you need 400mW of drive to get to 100dB, which is a good target for a maximum listening level. This amp will drive 325mW, which gives about 99dB... plenty loud for me."
"My OTL tube amps can get close to this power level, but the problem is that the K1000's don't sound very good unless they're driven with a really low output impedance. They were designed to be driven by a "normal" power amplifier, with a Zo of only a few ohms. When you drive them with an amp that has, say, 30-50 ohms Zo, they sound very thin (especially in the bass)."
That says it all! I took that quote from the following page. This page has photographs and a schematic of the K-1000 amp...
http://www.pmillett.addr.com/ecc99_s...dphone_amp.htm
My questions...
I wonder how your K1000s sounded with your new Canare headphone cable. Did it sound full with plenty of bass? Or did it sound thin due to excessive output impedance?
Tube amps versus solid-state amps...
Usually, solid state amps have a very low output impedance. Meaning? You can get full bass with the K1000s and a solid state amp. I believe Nick Dangerous of Dallas has this combination. However, the K-1000s have a slightly metallic tone to them. That's why the best solotion is to mate a tube amp with the AKG K-1000s! Of course, the tube amp's output impedance should be on the low side (7 Ohms in Millett's K1000 amp).
OK! I hope you make some comments on this post!
I am thinking of trying your cable. However, I am in Puerto Rico, which is 1000 miles east of Miami, FL. I would use USPS Priority Mail to ship the cable. That takes 3 to 5 days. Where are you, Dean? Anyway here's my email:
gariver911@yahoo.com
I have the following combination...
--Audio Valve RKV amp with NOS PCL805 tubes.
--AKG K-1000s with the AKG Extension cord.
BTW, I bought my RKV amp from Meier-Audio.com during the August sale for $750. It is now selling for $850 (my AKG K-1000s are from Jan also). Yes, it is still a bargain!
http://www.audiovalve.de
http://www.meier-audio.com
According to Jan Meier, the RKV's output impedance is under one Ohm (0.06 Ohm)! Amazing! With this ultra low output impedance, the RKV avoids the problems Pete Millett mentions above. Ha! Pete recommends 7 Ohms, and the RKV has O.06 Ohms of output impedance! Overkill!
Results? Full Bass! Yes, this is a marriage made in Heaven! This Germanic couple sure swings with everything you throw at it: Beethoven Sonatas, Mozart Quartets, Tito Puente's Latin Jazz and my former neighbor Ricky Martin singing La Vida Loca! Wunderbar! Muchas Gracias to Audio Valve and AKG Acoustics for allowing me to reach Sonic Nirvana!
Gariver
San Juan, Puerto Rico....The Enchanted Island!