P1.5 Phono Preamplifier

Resolution. Refinement. Revelation.

The P1.5 Phono Preamplifier advances one of CH Precision’s most celebrated 1-Series components with expanded cartridge compatibility, lower noise, finer gain increments and an expanded gain range, enhanced equalization accuracy, and new tools for replaying mono and historically equalized records. Informed by the architecture of the flagship P10, the P1.5 introduces a more sophisticated gain structure and a substantially improved voltage-sensing input, bringing higher-level CH Precision phono technology deeper into the 1-Series.

Designed for the most demanding vinyl systems, the P1.5 combines current-sensing and voltage-sensing inputs, ultra-precise passive equalization, fully discrete Class-A amplification stages, and software-assisted setup. The result is a phono stage of exceptional flexibility and resolution—able to optimize the interface between cartridge, tonearm, record, and system with the precision expected of CH Precision.

“With the P1.5, we brought key P10 technologies into the 1.5-Series platform, creating a more advanced phono stage in every critical domain: gain architecture, noise performance, headroom, cartridge optimization, mono replay, and historical EQ accuracy. It is a major technical evolution of the P1, and one of the most capable phono stages we have ever built.”

—Florian Cossy, CEO

Built Around the Cartridge

The relationship between cartridge and phono stage is one of the most critical interfaces in analog replay. The P1.5 treats that interface as a precisely configurable environment, supported by a gain architecture informed by the flagship P10 and adapted for the 1.5-Series platform.

Two current-sensing inputs are provided for low-impedance moving-coil cartridges. Operating at virtual ground, these inputs remove the need for conventional resistive loading and allow suitable MC cartridges to operate with exceptional quietness, speed, and stability.

A third voltage-sensing input accommodates moving-magnet cartridges, high-output moving-coil cartridges, and moving-coil cartridges used with step-up transformers. Greatly improved from the original P1, this input benefits from the P1.5’s revised gain structure and offers selectable resistive loading across more than 400 values, from 20 ohms to 70 kilohms. This allows the electrical behavior of the cartridge and tonearm combination to be matched with unusual precision.

Greater Gain Precision

The P1.5 adds 6 dB of gain headroom to its MC current inputs and 5 dB to its MM/MC voltage input, extending cartridge and system compatibility. Gain is adjustable in precise 3 dB steps, while the Gain Wizard recommends the optimal setting for each cartridge and input to preserve dynamic range, minimize noise, and prevent overload.

A new topology uses three active gain stages with passive equalization between each, improving EQ accuracy and lowering noise while revealing more low-level information with greater stability, resolution, and tonal consistency.

Intelligent Cartridge Loading

The P1.5 is designed to make deep optimization accessible without reducing precision. Its gain wizard recommends the optimal gain setting for each input and cartridge combination, helping establish proper level structure quickly and consistently.

For the voltage-sensing input, the Loading Wizard displays the measured frequency response of the cartridge and tonearm combination at several user-selected loading values. Instead of relying on generic cartridge specifications or trial-and-error adjustment, the user can evaluate real-world electrical behavior and select the loading value best suited to the system.

Precision Equalization for Every Era of Vinyl

The P1.5 supports standard RIAA equalization, with an optional EQ curve module pair adding EMI, Columbia LP, Decca/London, DGG/Teldec, NARTB/NAB, Capitol/AES, and Philips curves.

Many recordings—especially European pressings—continued to use proprietary or label-specific correction curves well into the stereo era. For historic pressings, mono LPs, and early stereo recordings, the correct curve is a condition of faithful playback.

Implemented with the precision of the P1.5, the proper curve restores more than tonal balance. It clarifies drive, timing, scale, and musical intent, allowing older records to open up with the energy of the original mastering.

A 50 kHz Neumann pole and second-order 7 Hz anti-rumble filter can be engaged independently with any EQ curve, adding flexibility without sacrificing precision.

The Correct Path for Mono

The P1.5 provides dedicated mono settings for stereo cartridges, two-coil mono cartridges, and single-coil mono cartridges.

With a stereo cartridge, mono can be engaged temporarily, as with other CH Precision components. For dedicated mono cartridges, each input can be assigned the correct mono configuration. Two-coil mono mode sums the left and right input signals and sends identical mono output to both channels.

For single-coil mono cartridges, the P1.5 reads and amplifies the signal from one channel, then buffers and routes it to both outputs. This allows proper mono replay while preserving the standard left/right connection from P1.5 to line preamplifier.

The result is correct mono playback for virtually any cartridge type, without changing system cabling.

Silence, Stability, and the X1 Upgrade Path

Like other CH Precision 1-Series components, the P1.5 can be partnered with the X1 External Power Supply. By moving critical power-supply functions into a dedicated chassis, the X1 further isolates the sensitive phono circuitry from electrical noise, magnetic interference, and mains-related artifacts.

This is especially important in a phono preamplifier. Cartridge signals are extremely small, gain is necessarily high, and the RIAA playback curve itself increases sensitivity to low-frequency noise by boosting bass while attenuating high frequencies. As a result, mains components and their harmonics—whether based on 50 Hz or 60 Hz supply frequencies—can more easily degrade signal-to-noise performance.

By lowering the noise floor and improving power-supply isolation, the X1 allows the P1.5 to preserve more low-level musical information: greater spatial clarity, finer textural resolution, more stable images, and more natural decay.

Document and Firmware Downloads

Built with the same precision and care that define our instruments, the CH Precision Downloads area provides access to the latest manuals, firmware updates, spike installation guides, and product brochures. Each document reflects our engineering culture, meticulous in detail, exact in purpose, and structured to ensure that every component performs precisely as intended.

These materials are intended to support owners and partners in configuring, maintaining, and optimizing their CH systems. Should you have any questions or require further assistance, we encourage you to contact your authorized CH Precision dealer or reach out directly through our Technical Support form. Our teams are committed to providing the same standard of excellence in service that we apply to our engineering, so that every listening experience remains true to the performance we envisioned.

Universal Compliance:

CB Certification represents Universal Compliance: rigorous testing by an independent laboratory and confirmation that the product meets internationally recognized electrical-safety standards. For users, it provides added assurance of the product’s safety, reliability, and quality in everyday use. The Universal Compliance certificate is available for review below.

The CH Control APP

Available for Apple iOS and Android, the CH Controller provides complete app-based control of CH Precision systems, including input selection, volume, mute, configuration settings, and playback functions. It also allows users to access UPnP devices on the network and browse the music stored there, bringing system control and local music access into a single interface.

Its structure follows the same operational logic as the components

themselves, preserving a direct relationship between front-panel control and the mobile experience. True to CH Precision’s engineering culture, the control platform is designed as an extension of the component architecture rather than a separate control layer. It adds convenience and flexibility while preserving the integrity, precision, and musical priorities that define every CH Precision system.

International Press Honors

Gain, Loading, Equalization, Control

The P1.5 recognizes that vinyl playback is shaped before the first note is amplified: by the cartridge, its loading, its gain structure, the record’s equalization curve, and the way mono information is retrieved from the groove. Every cartridge, pressing, equalization standard, and mono configuration presents a different electrical and historical problem. The P1.5 gives the listener the tools to solve it precisely.

With expanded gain range, finer adjustment, current- and voltage-sensing inputs, intelligent setup wizards, selectable EQ curves, dedicated mono modes, and a quieter three-stage gain architecture, the P1.5 brings uncommon control to the most delicate signal in audio. The result is not simply greater accuracy, but greater access: to the cartridge’s full capability, to the record’s original tonal balance, and to the musical information preserved at the very edge of the groove.

Specifications

General

Type: Phono preamplifier
Options: EQ curves module pair to play EMI, Columbia (LP), Decca (London), DGG (Teldec), NARTB (NAB), Capitol/AES and Philips records
Upgrade path: X1 external power supply
Color: Silver (standard), Anthracite or Champagne (option)
Dimensions: 440 x 440 x 133 mm (W x D x H)
Weight: 20kg
Operating conditions: 5°C<T<35°C, 5%<humidity<85% no condensation
Power supply: Selectable 100V, 115V or 230V AC, 47Hz to 63Hz
Power consumption:<0.5W standby, 50W nominal

User interface

Display: 800 x 480 pixels, 24 bit RGB AMOLED
Control: 5-button interface, Infrared remote control, Android and iOS apps
Firmware update: via USB flash drive or the Internet

Analog inputs

Type (each available on both XLR and RCA connectors):
- 2x MC current-sensing inputs (for low internal impedance – almost only MC - cartridges)
- 1x MM/MC voltage-sensing inputs (for MM, step-up transformer couple MC or high internal impedance high level MC cartridges)
Impedance:
- MC: < 100mΩ, virtual ground
- MM/MC: User selectable, 20Ω to 70kΩ
Gain (at 1kHz, on single-ended output – balanced output is 6dB more):
- MC: +56 dB to +77 dB in 3 dB steps (10Ω internal impedance cartridge)
- MM/MC: +42 dB to +75 dB in 3 dB steps
Equivalent input noise (20Hz-20kHz, unweighted):
- MC: < -143 dBu (< -144 dBu with X1) / 1Ω termination
- MM/MC: < -138 dBu (< -139 dBu with X1, < -142 dBu if G>+53dB with X1) / 1Ω termination
Playback EQ curve accuracy: +/- 0.1dB

Analog outputs

Type: 1x balanced XLR, 1x single-ended RCA, per channel
Level: 8VRMS maximum (balanced), 4VRMS maximum (single-ended)
Total Harmonic Distortion + Noise:
- < 0.002%, MM/MC voltage input, gain < 55dB
- unmeasurable (below noise floor) for MM/MC voltage input, gain > 55dB
- unmeasurable (below noise floor) for MC current input, any gain