Thanks for the tip. I'll try to check out the Vienna Acoustics.
I'm getting the Concerto integrated for $3200. On Audiogon, there's a pair of 201 mono's that just went for $2795. There's a Capri pre-amp up for $2200. $3200 << $4995
Could have gotten a Capri with two 102's for $3300 - but I wanted the 250 watts/channel.
I would have prefered separates I think for flexibility (e.g. perhaps might want to upgrade pre-amp at some point) and the Capri is their latest pre-amp. I've heard the Concerto Integrated is discontinued right now and a new Capri integrated is coming out in April. I've actually talked to Jeff Rowland about whether the integrated would have any different performance than the separates and his answer was more or less - not really.
Capri vs Concerto pre-amp - I'm not sure. There's always the next thing coming out so if your buying used, you're not going to always end up with the latest thing if your hunting for a bargin (whatever that means in this hobby). I'll probably never get a chance to compare them, but I'm really excited to see what this amp does.
BTW - I'm amazed that the owner of the company takes the time to talk on the phone to some no one (me) who sent an email with some questions. I felt almost guilty taking his time.
Relative to power factor - What a watt meter (like the one on your house) will determine your power usage to be is the sum over time of Volts X Amps X cosine(Phase difference between Voltage and Current); were cos(Phase Difference) is the 'power factor'. A load who's voltage and current are in phase has a power factor of 1.0. If your load causes voltage and current to be 90 degrees out of phase, the power factor is 0, a watt meter detects 0 watts, and you get your power for free. A resistive load has a power factor of 1.0. For inductive loads, the current lags the voltage (+phase) and for capacitive loads, the current leads the voltage (-phase).
The power company generally charges customers with bad power factors a premium for their power because the meter reading is not going to reflect the power they are actually using. You can correct the power factor on an inductive load by adding capacitance or on a capacitive load by adding inductance.
None of this really makes much of a difference relative to the device that Rowland is making since an amplifier is not going to have enough of a capacitive load to affect the power factor of your house's power draw - which is mostly resistive (light bulbs, toasters, and heaters are resistors).
The device you describe that converts AC power to DC power will convert the amplifier's load into a resistive load and as such it does correct any power factor that the amplifier may have been presenting to the power company - which maybe why Roland calls it a PFC. However, I think you are also correct that the benefit here is that the amplifier is getting DC power input such that the power supply does not have to filter a half-wave rectified sinusoid to feed its capacitors and has voltage/current to charge the capacitors all the time (rather than only about 1/2 the AC cycle). I would think this should improve 60 Hz ripple noise within the power system and consequently, perhaps reduce the noise floor in the pre-amp and power amp sections. My guess is that it their PFC should work on any of their equipment, but that remains for them to indicate.
The real questions here are - what does it cost and how much better does it make things sound. I don't have any information.
I'm getting the Concerto integrated for $3200. On Audiogon, there's a pair of 201 mono's that just went for $2795. There's a Capri pre-amp up for $2200. $3200 << $4995
Could have gotten a Capri with two 102's for $3300 - but I wanted the 250 watts/channel.
I would have prefered separates I think for flexibility (e.g. perhaps might want to upgrade pre-amp at some point) and the Capri is their latest pre-amp. I've heard the Concerto Integrated is discontinued right now and a new Capri integrated is coming out in April. I've actually talked to Jeff Rowland about whether the integrated would have any different performance than the separates and his answer was more or less - not really.
Capri vs Concerto pre-amp - I'm not sure. There's always the next thing coming out so if your buying used, you're not going to always end up with the latest thing if your hunting for a bargin (whatever that means in this hobby). I'll probably never get a chance to compare them, but I'm really excited to see what this amp does.
BTW - I'm amazed that the owner of the company takes the time to talk on the phone to some no one (me) who sent an email with some questions. I felt almost guilty taking his time.
Relative to power factor - What a watt meter (like the one on your house) will determine your power usage to be is the sum over time of Volts X Amps X cosine(Phase difference between Voltage and Current); were cos(Phase Difference) is the 'power factor'. A load who's voltage and current are in phase has a power factor of 1.0. If your load causes voltage and current to be 90 degrees out of phase, the power factor is 0, a watt meter detects 0 watts, and you get your power for free. A resistive load has a power factor of 1.0. For inductive loads, the current lags the voltage (+phase) and for capacitive loads, the current leads the voltage (-phase).
The power company generally charges customers with bad power factors a premium for their power because the meter reading is not going to reflect the power they are actually using. You can correct the power factor on an inductive load by adding capacitance or on a capacitive load by adding inductance.
None of this really makes much of a difference relative to the device that Rowland is making since an amplifier is not going to have enough of a capacitive load to affect the power factor of your house's power draw - which is mostly resistive (light bulbs, toasters, and heaters are resistors).
The device you describe that converts AC power to DC power will convert the amplifier's load into a resistive load and as such it does correct any power factor that the amplifier may have been presenting to the power company - which maybe why Roland calls it a PFC. However, I think you are also correct that the benefit here is that the amplifier is getting DC power input such that the power supply does not have to filter a half-wave rectified sinusoid to feed its capacitors and has voltage/current to charge the capacitors all the time (rather than only about 1/2 the AC cycle). I would think this should improve 60 Hz ripple noise within the power system and consequently, perhaps reduce the noise floor in the pre-amp and power amp sections. My guess is that it their PFC should work on any of their equipment, but that remains for them to indicate.
The real questions here are - what does it cost and how much better does it make things sound. I don't have any information.