Unsound,
If the output impedance of the amplifier is a good match for the particular speaker, the output of the amplifier WILL adapt appropriately.
Think of the amplifier as an amplifier having zero output impedance in series with a resistor whose value corresponds to the actual output impedance. If the impedance of the speaker varies significantly as a function of frequency, and if the amplifier's output impedance is significantly greater than zero (e.g., 1 or 2 or 3 ohms or so, as in the case of most tube amps), the voltage divider effect resulting from the interaction of that output impedance (corresponding to Z1 in the first figure of the reference) and the impedance of the speaker (corresponding to Z2 in the first figure of the reference) will result in the voltage at the amplifier output/speaker input varying as a function of frequency. If the amplifier's output impedance is a good match for the design of the particular speaker, that variation in amplifier output will result in minimal variation of the output of the speaker, as a function of frequency.
Audiolabyrinth,
I didn't say that amps operate in a current mode and a voltage mode. Actually, I don't know what that would mean, if anything. What I said is that amplifiers amplify both current and voltage. In other words, the voltage at their output is greater than the voltage at their input, and the current supplied by their output is greater than the current going into their input.
You are probably referring to Krell's CAST concept, as described here. Note the statement in the first paragraph that "A Krell system connected in CAST transfers the signal in the current domain, throughout the signal path to the amplifier output stage where only one current to voltage conversion (I-to-V) takes place."
Following that current to voltage conversion, at the output of the amplifier, both voltage and current would certainly be greater than at the input of the amplifier, or it wouldn't be able to drive the speakers to anything approaching reasonable volume.
I see in the manual for the 700CX that its gain is spec'd at 26.4 db. That corresponds to an increase in voltage of about 20 times. And its 700 watt capability into 8 ohms certainly represents vastly more output current (actually, about 9.4 amperes, when the full 700 watts is being delivered into 8 ohms) than any preamp could ever supply to the amplifier's input.
Best regards,
-- Al
If the output impedance of the amplifier is a good match for the particular speaker, the output of the amplifier WILL adapt appropriately.
Think of the amplifier as an amplifier having zero output impedance in series with a resistor whose value corresponds to the actual output impedance. If the impedance of the speaker varies significantly as a function of frequency, and if the amplifier's output impedance is significantly greater than zero (e.g., 1 or 2 or 3 ohms or so, as in the case of most tube amps), the voltage divider effect resulting from the interaction of that output impedance (corresponding to Z1 in the first figure of the reference) and the impedance of the speaker (corresponding to Z2 in the first figure of the reference) will result in the voltage at the amplifier output/speaker input varying as a function of frequency. If the amplifier's output impedance is a good match for the design of the particular speaker, that variation in amplifier output will result in minimal variation of the output of the speaker, as a function of frequency.
Audiolabyrinth,
I didn't say that amps operate in a current mode and a voltage mode. Actually, I don't know what that would mean, if anything. What I said is that amplifiers amplify both current and voltage. In other words, the voltage at their output is greater than the voltage at their input, and the current supplied by their output is greater than the current going into their input.
You are probably referring to Krell's CAST concept, as described here. Note the statement in the first paragraph that "A Krell system connected in CAST transfers the signal in the current domain, throughout the signal path to the amplifier output stage where only one current to voltage conversion (I-to-V) takes place."
Following that current to voltage conversion, at the output of the amplifier, both voltage and current would certainly be greater than at the input of the amplifier, or it wouldn't be able to drive the speakers to anything approaching reasonable volume.
I see in the manual for the 700CX that its gain is spec'd at 26.4 db. That corresponds to an increase in voltage of about 20 times. And its 700 watt capability into 8 ohms certainly represents vastly more output current (actually, about 9.4 amperes, when the full 700 watts is being delivered into 8 ohms) than any preamp could ever supply to the amplifier's input.
Best regards,
-- Al