CH Precision P1.5 Phono Stage

The P1.5 replaces the P1 as CH Precision's 1-Series phono stage, carrying architecture developed for the P10 reference directly into a more accessible package.

The circuit uses three active gain stages with equalization split between two passive filter sections. Distributing the work this way lets CH optimize noise, overload margin, and linearity at each stage independently, rather than asking one amplification block to handle everything at once.

Two dedicated current-sensing inputs handle low-impedance moving-coil cartridges by presenting a virtual ground. The cartridge drives the stage from its current output directly, without a conventional resistive load in the path. For moving-magnet and voltage-mode moving-coil cartridges, a separate voltage-sensing input offers more than 400 selectable load values between 20 and 70,000 ohms.

Compared to the P1, the P1.5 reduces equivalent input noise by 6 dB on current-sensing inputs and 4 dB on the voltage-sensing input. Available gain headroom increases by 6 dB in current mode and 5 dB in voltage mode. Gain is adjustable in precise 3 dB increments. At phono level, those improvements surface detail that was previously buried.

An optional equalization module expands the P1.5 beyond RIAA with seven additional curves: EMI, Columbia LP, Decca/London, DGG/Teldec, NARTB/NAB, Capitol/AES, and Philips. A Neumann 50 kHz pole and 7 Hz anti-rumble filter provide further control. For serious vintage collections, this is how those records were meant to be played back.

Built-in setup tools remove the guesswork. The Gain Wizard establishes the correct gain for any cartridge and input. The Loading Wizard measures actual frequency response as loading values are changed, so optimization is based on what the cartridge does in the system, not nominal specs or approximation.

The P1.5 also includes dedicated stereo and mono replay modes, with options optimized for two-coil and single-coil mono cartridges. It is compatible with CH Precision's X1 External Power Supply, which moves critical supply circuitry to a separate chassis for a quieter electrical foundation.

Existing P1 owners can upgrade their units to P1.5 specification. Contact us for pricing.