The Phasemation CM-1500 is a high-end hybrid passive preamplifier developed from the technology and design philosophy of the reference CM-2200.
Rather than using a conventional active gain stage, the CM-1500 employs Phasemation’s patented Hybrid Passive Attenuator, combining the advantages of resistive and transformer-based volume control.
This architecture is designed to achieve the ideal combination of high input impedance and low output impedance while preserving an exceptionally direct signal path.
The result is a highly transparent preamplifier designed to deliver precise image localization, natural tonal expression and excellent compatibility with a wide variety of power amplifiers.
Control Meister Philosophy
Phasemation has long pursued its unique Control Meister concept, a passive preamplifier architecture developed to avoid the sonic influence of conventional active amplification circuitry.
The reference CM-2200 demonstrated how transformer-based attenuation could provide both purity and practical system compatibility, including selectable gain.
Introduced as its more accessible sibling, the CM-1500 brings the same fundamental technology into a simplified chassis structure while retaining the essential qualities of Phasemation’s hybrid passive approach.
Patented Hybrid Passive Attenuator
At the heart of the Phasemation CM-1500 is the company’s patented Hybrid Passive Attenuator.
The system combines selected advantages of resistive attenuation and transformer-based volume control to achieve high input impedance together with low output impedance.
By avoiding a conventional active amplification stage in the signal path, the CM-1500 is designed to preserve subtle musical information, transient speed and natural tonal expression.
The result is an exceptionally direct presentation with strong transparency, fine detail and precise spatial definition.
Newly Developed Balanced Attenuator Transformer
The CM-1500 uses a specially developed balanced attenuator transformer with separate windings for the HOT and COLD sides of the balanced signal.
Both attenuator windings are wound onto a single transformer core, allowing balanced volume control to be performed directly within the transformer structure.
Even when an unbalanced RCA source is connected, the transformer generates the corresponding COLD-side signal internally, allowing the CM-1500 to provide a fully balanced output.
This architecture is designed to achieve excellent frequency and phase characteristics across a wide bandwidth while reducing phase distortion within the audible range.
The result is improved sound-image localization, greater spatial precision and a particularly clear presentation.
Super Malloy Core and PC-TripleC Windings
The attenuator transformer uses the same advanced core technology developed for the reference CM-2200.
An ultra-thin 0.1mm Super Malloy core is used to achieve excellent magnetic characteristics and strong low-frequency linearity.
The transformer windings use PC-TripleC polyurethane wire, selected specifically for high-quality audio signal transmission.
Combined with the large transformer core, these materials are designed to provide powerful and realistic low-frequency reproduction together with smooth, delicate and relaxed high-frequency performance.
Three Selectable Gain Settings
The CM-1500 provides three selectable gain settings: -10dB, 0dB and +6dB.
The +6dB transformer gain technology is derived from the CM-2200 and gives the CM-1500 considerably more system flexibility than a conventional passive preamplifier.
The attenuator provides 23 contact positions, allowing precise level control across a broad attenuation range.
The transformer winding structure has been optimized to maintain wide frequency response and stable impedance characteristics regardless of the selected gain setting.
This makes the CM-1500 suitable for systems using low-sensitivity loudspeakers, lower-gain power amplifiers or sources requiring more precise volume adjustment.
Balanced and Unbalanced Connectivity
The Phasemation CM-1500 provides extensive connectivity for both balanced and unbalanced systems.
Three RCA inputs and two balanced XLR inputs are provided.
The output section includes two RCA outputs and two balanced XLR outputs.
Balanced and unbalanced outputs can be used simultaneously, providing greater flexibility when integrating power amplifiers, subwoofers or other system components.
Fully Balanced Signal Conversion
One of the distinctive features of the CM-1500 is its ability to generate a complete balanced output even from an unbalanced input signal.
Because the HOT and COLD transformer windings are integrated within the same attenuator transformer, the COLD signal can be generated internally when an RCA source is connected.
This allows users to connect an unbalanced source while still taking advantage of the balanced XLR outputs.
Rigid Copper-Plated Chassis and Magnetic Shielding
The CM-1500 incorporates extensive mechanical and magnetic shielding measures to protect its transformer-based signal path.
A 10mm-thick slanted aluminium front panel follows the elegant design language of the reference CM-2200.
The chassis and top cover are constructed from rigid 1.6mm copper-plated steel, helping reduce the influence of external electromagnetic interference.
The top cover also uses a low-dielectric coating, while double magnetic shielding is installed beneath the attenuator transformer.
Heavy metal insulators constructed from different materials help isolate the chassis from external vibration.
Together, these measures are designed to produce a cleaner and more focused sound with reduced blur and unwanted coloration.
Premium Signal Components
Phasemation uses high-quality signal components throughout the CM-1500.
All rotary switches use gold-plated contacts to maintain reliable low-resistance connections.
The RCA terminals are manufactured from machined brass and finished with gold plating, while the balanced XLR terminals are premium Neutrik gold-plated connectors.
These component choices reflect Phasemation’s focus on maintaining signal integrity throughout the entire preamplifier.
When the SA-1500 is used in DIRECT mode, its internal volume control is bypassed and the amplifier can operate as a dedicated 300B stereo power amplifier.
In this configuration, the CM-1500 handles source selection and volume control through its transformer-based Hybrid Passive Attenuator, while the SA-1500 provides the pure Class A 300B power stage.
Together, the CM-1500 and SA-1500 form a highly purist Phasemation amplification system designed around transformer technology, passive signal control and non-feedback tube amplification.
Reviews
There are no reviews yet.