Amplifiers
|
DESIGN PHILOSOPHY
Conventional amplifiers have serious problems when forced to drive electrostatic loudspeakers. Roger Sanders has developed the first amplifier specifically designed to drive these unusual speakers.
• .
Conventional amplifiers have serious problems when forced to drive electrostatic loudspeakers. Roger Sanders has developed the first amplifier specifically designed to drive these unusual speakers.
Electrostatic loudspeakers (ESLs) are very different from conventional magnetic speakers and place unusual and difficult demands on the way amplifiers deliver power to them.
A magnetic speaker presents a resistive/inductive load to an amplifier, while an ESL appears mostly as a capacitor.
|
|
WHAT IS THE DIFFERENCE BETWEEN THE ESL AMPLIFIER AND THE MAGTECH AMPLIFIER?
Both the ESL and Magtech amps use the same special amplifier modules that Roger designed to drive electrostatic speakers. The difference between the two is that ESL amps use a conventional, free-floating, unregulated power supply while Magtech amps use Roger's unique, 100% efficient, linear, regulated power supply.
Magnetic speakers draw tremendous current from an amplifier and that causes the internal power supply voltages to fluctuate dramatically in response to the music (typically by about 30%). This reduces the power from the amp and causes the distortion and bias to be modulated by the music.
A regulated power supply maintains stable internal voltages at all times. This is a tremendous improvement over a free-floating power supply. All amplifiers should use regulators, but virtually none do because their designers have not figured out how to make a powerful regulator that doesn't waste vast amounts of heat. Our regulator is unique in that it runs cold and wastes no heat. So we offer virtually the only regulated power supply amplifier on today's market.
Electrostatic speakers operate on voltage, not current. So they don't cause major fluctuations in the internal voltages like magnetic speakers do. But they will still cause some voltage modulation and mains voltage is not stable either. So even electrostatic speakers will benefit from an amplifier with a regulated power supply.
A regulated power supply will provide the best performance, so most of our customers (even our electrostatic speaker customers) opt for the Magtech. We keep the ESL amp in our line-up because it costs less than a Magtech and so represents a tremendous value. So those customers for whom money is a major concern, use the ESL amp instead of the Magtech.
In summary, the Magtech amp is the best for all speakers because it not only has the electrostatic amplifier modules, but it also includes a regulated power supply. So unless money is a major concern where the value of the ESL amp is essential, Roger recommends the Magtech.
What is the Difference between the old Innersound ESL amp and the new Sanders ESL amp?
- The chassis is now aluminum.
- All chassis parts are thicker to eliminate resonances.
- XLR connectors are genuine Neutrik. They use professional metal sockets with locking devices.
- RCA connectors are Cardas with Rhodium plating.
- The power transformer is larger and more powerful. This has increased the amplifier's power from 300 watts to 360 watts/channel.
- The power transformer is now fully shielded in an aluminum cylinder and potted in epoxy.
- A new power supply circuit board is more compact and all wire has been eliminated (except for a 2" piece connecting the circuit board to the speaker binding post).
- The amplifier is now completely modular in construction.
- The face plate is "cleaner" and less cluttered.
- The low-level, input amplifier circuitry has been redesigned to use the latest and best transistors.
- The bias circuitry has been upgraded to provide more stable operation.
- More powerful and linear output transistors are used to handle even more power and reduce distortion.
- The new circuitry and transistors allow the use of less bias so that the amplifier runs even cooler than the original amp.
- The speaker binding posts are placed at 45 degrees for ease of routing stiff speaker cables.
ESL MK II Monoblock Amplifier
Price: $12,000 pair
The Sanders Sound Systems ESL amp is now available as a Monoblock power amplifier. Performance is similar to the ESL amplifier with the exception of dramatically increased power output capability! As with the Sanders Sound Systems ESL amplifier, the ESL Monobloc offers superb build quality, superlative sonics with extremely high output capability.
FEATURES
-
The quality of construction is typical of the finest components made today
-
All exterior and interior aluminum parts are anodized. Steel parts are powder-coated
-
Resistors are high reliability, precision metal film, 1% tolerance.
-
Capacitors are of the highest quality, and none are used in the signal path.
-
Connectors are gold plated. Both balanced and unbalanced connectors are standard.
-
Wire has been eliminated wherever possible. Where wire is necessary, it is silver-plated copper, 141 strand, 18 gauge, with silicone insulation.
SPECIFICATIONS OF ESL MONOBLOCK AMPLIFIER
Electrical Specifications
|
Power 1200 watts RMS into an 8 ohm load |
Bandwidth DC through 100kHz |
|
Class of Operation Class AB |
Slew Rate 500 Volts/microsecond |
|
Input voltage required for full output 2.2 Vrms |
Input Impedance 100 K unbalanced 1 K balanced |
|
Gain 26dB |
Noise More than 120dB below rated output |
|
Damping Factor Greater than 600 into an 8 ohm load |
THD Less than 0.005%, 20 Hz - 20 KHz. |
|
Voltage Voltage is user selectable for use world-wide. |
IMD Less than 0.004%, 20 Hz - 20 KHz |
Weight and Dimensions
|
Weight 55 pounds (25 Kgs) |
Dimensions 17" wide x 6" (including feet tall) x 15" deep (including binding binding posts) 43cm x 15.2cm x 40.6cm 17" wide x 5.5" (NOT including feet) tall x 14" deep (NOT including binding binding posts) 43cm x 14cm x 35.5cm |
Speakers and Electronics are manufactured in Conifer, Colorado.
Magtech Amplifier
Price: $7,000
with a linear, voltage regulator
The popularity and success of the Electrostatic Amplifier (the "ESL Amp") for driving electrostatic speakers led to many requests for a companion amplifier that was specifically designed for driving conventional magnetic speakers. Two years in development, the Magtech amplifier is that amplifier.
The Magtech Regulated Power Supply White Paper
DESIGN PHILOSOPHY
Magnetic speakers differ from electrostatic speakers in one fundamental way -- they require massive amounts of current and power. This causes the power supply voltages in an amplifier to change dramatically (typically by 30%) between idle and full power.
Electronics have their lowest distortion and optimum performance at a specific design voltage. If the voltage varies, the amplifier's performance will suffer.
An additional problem in amplifiers is that they require bias to eliminate crossover notch distortion and determine their class of operation. The bias will vary as the voltage does, which will further reduce performance.
An amplifier's voltage will fluctuate wildly as dynamic music is played. This causes the amplifier's distortion and bias to vary constantly and fail to meet its full performance potential.
As if all these problems are not enough, as an amplifier's voltage sags under load, the power it can deliver is greatly reduced. If the voltage would remain stable, the amplifier could produce much more power. Since most audiophile speaker systems require several hundred watts of power to avoid clipping and compression of the dynamic range, power is extremely important.
THE SOLUTION
All quality, line-level electronics use voltage regulation in their power supplies to produce a stable voltage, regardless of load or the mains voltage. Audiophiles would not consider using a source component that did not have regulated power supplies. So why use amplifiers with unregulated supplies?
The main problem is heat. Amplifiers operate at much higher voltages and currents than line level source components. These higher voltages and currents forces conventional regulator designs to waste large amounts of energy, which wastes expensive electricity and causes the amplifier to get very hot.
Also, many regulator designs radiate RF (Radio Frequency) energy when switching high currents and voltages. This RF gets into the amplifier's electronics and can cause instability, oscillation, and noise. As a result of these problems, modern power amplifiers do not use regulated power supplies and fail to take advantage of the benefits available from doing so.
Sanders has solved these problems by developing a voltage regulator that is essentially 100% efficient. There is no heat dissipated by the regulator system. There is no high-power/high-voltage switching that causes heat generation or RF problems.
The regulator in the Magtech amplifier maintains a stable voltage regardless of load or reasonable changes in the line voltage feeding the amplifier. It runs stone cold, produces zero RF energy, and is simple and reliable.
Unlike other amplifiers, the distortion in the Magtech amplifier is virtually unchanged regardless of power level. The bias is stable regardless of load.
RECIPIENT OF THE ABSOLUTE SOUND'S GOLDEN EAR AWARD
The regulator makes it possible to obtain a 50% increase in power over the same amplifier operated unregulated. In its stereo form, the Magtech will deliver 500 watts/channel into an 8 ohm load and 900 watts/channel into a 4 ohm load.
The Magtech is built into the same chassis as the ESL Amp, so it is compact enough (17" wide, 5-1/2" tall, 15" deep) to place on a shelf or into a cabinet. It is also light enough (54 pounds) to be picked up. Like the ESL amp, it runs very cool and may be left on continually without concern for power usage.
The Magtech amplifier also uses the same advanced technology that makes the ESL amp able to drive the most difficult loads without performance-degrading, protective circuitry. The Magtech amplifier features a linear voltage regulator. The result is a compact, yet extremely powerful amplifier that is ideally suited to driving the most difficult magnetic speakers.
SPECIFICATIONS OF MAGTECH AMPLIFIER
Electrical Specifications
|
Power (Stereo Version) 500 watts continuous per channel into an 8 ohm load |
Bandwidth DC through 100kHz |
|
Class of Operation Class AB |
Input Impedance 100K unbalanced, 1K balanced
|
|
Input voltage required for full output 2.2 Volts |
Noise More than 110dB below rated output |
|
Gain 26dB |
THD Less than 0.01% |
|
Damping Factor Greater than 600 into an 8 ohm load |
Voltage Voltage is user selectable for use world-wide.
|
Weight and Dimensions
|
Weight 55 pounds (25 Kgs) |
Dimensions 17" wide x 6" (including feet tall) x 15" deep (including binding binding posts) 43cm x 15.2cm x 40.6cm 17" wide x 5.5" (NOT including feet) tall x 14" deep (NOT including binding binding posts) 43cm x 14cm x 35.5cm |
Speakers and Electronics are manufactured in Conifer, Colorado.
Magtech Monoblock Amplifier
Price: $14,000 Pair
with a linear, voltage regulator
DESIGN PHILOSOPHY
Magnetic speakers differ from electrostatic speakers in one fundamental way -- they require massive amounts of current and power. This causes the power supply voltages in an amplifier to change dramatically (typically by 30%) between idle and full power.
Electronics have their lowest distortion and optimum performance at a specific design voltage. If the voltage varies, the amplifier's performance will suffer.
An additional problem in amplifiers is that they require bias to eliminate crossover notch distortion and determine their class of operation. The bias will vary as the voltage does, which will further reduce performance.
An amplifier's voltage will fluctuate wildly as dynamic music is played. This causes the amplifier's distortion and bias to vary constantly and fail to meet its full performance potential.
As if all these problems are not enough, as an amplifier's voltage sags under load, the power it can deliver is greatly reduced. If the voltage would remain stable, the amplifier could produce much more power. Since most audiophile speaker systems require several hundred watts of power to avoid clipping and compression of the dynamic range, power is extremely important.
THE SOLUTION
The main problem is heat. Amplifiers operate at much higher voltages and currents than line level source components. These higher voltages and currents forces conventional regulator designs to waste large amounts of energy, which wastes expensive electricity and causes the amplifier to get very hot.
Also, many regulator designs radiate RF (Radio Frequency) energy when switching high currents and voltages. This RF gets into the amplifier's electronics and can cause instability, oscillation, and noise. As a result of these problems, modern power amplifiers do not use regulated power supplies and fail to take advantage of the benefits available from doing so.
Sanders has solved these problems by developing a voltage regulator that is essentially 100% efficient. There is no heat dissipated by the regulator system. There is no high-power/high-voltage switching that causes heat generation or RF problems.
Unlike other amplifiers, the distortion in the Magtech amplifier is virtually unchanged regardless of power level. The bias is stable regardless of load.
The regulator makes it possible to obtain a 50% increase in power over the same amplifier operated unregulated. In its stereo form, the Magtech will deliver 1600 watts/channel into an 8 ohm load and 2000 watts/channel into a 4 ohm load.
The Magtech is built into the same chassis as the ESL Amp, so it is compact enough (17" wide, 5-1/2" tall, 15" deep) to place on a shelf or into a cabinet. It is also light enough (54 pounds) to be picked up. Like the ESL amp, it runs very cool and may be left on continually without concern for power usage.
SPECIFICATIONS OF MAGTECH MONOBLOCK AMPLIFIER
Power (Monoblock Version) 1600 watts RMS into an 8 ohm load Bandwidth DC through 100kHz Class of Operation Class AB Input Impedance 100K unbalanced, 1K balanced Input voltage required for full output 2.2 Volts Noise Nore than 110dB below rated output Gain 32 dB THD Less than 0.01% Damping Factor Greater than 300 into an 8 ohm load Voltage Voltage is user selectable for use world-wide. Weight 55 pounds (25 Kgs) Dimensions 17" wide x 6" (including feet tall) x 15" deep (including binding binding posts) 43cm x 15.2cm x 40.6cm 17" wide x 5.5" (NOT including feet) tall x 14" deep (NOT including binding binding posts) 43cm x 14cm x 35.5cmElectrical Specifications
2000 watts RMS into a 4 ohm load
Weight and Dimensions
Speakers and Electronics are manufactured in Conifer, Colorado.
