HEED AUDIO QUESTAR. Phono MM and MC preamplifier (external source)

MM OR MC PHONO PREAMPLIFIER (WITH EXTERNAL SUPPLY)

The QUESTARs are destined to be the best entry-level options of the Heed modular line for vinyl reply that money can buy. Under the hood of their hefty, shielded steel chassis beats the heart of our reference Quasar MM/MC phonostage, conveniently divided into neatly-specialized a' la carte portions.

The QUESTAR MM largely incorporates the Quasar's unsurpassed MM circuitry, while its sibling, the QUESTAR MC deploys a streamlined version of the Quasar's MC stage, eliminating the need for jumper switches by optimizing the amplifier to suit the 300-600 µV/100 Ohm output range characterizing the vast majority of today's moving coils. Considering its generous 18 dB headroom, ideal cartridge matching is virtually assured.

The internal construction of the QUESTARs meets the most critical high-end standards in every respect. The amplifier employs an entirely dual-mono configuration and uses a two-stage – passive/active – RIAA equalisation. Gain adjustment has been optimized for maximum headroom and highest signal-to-noise ratio. Component parts are selected to exacting tolerances matching those of our flagship Quasar.

The QUESTARs are suitable for any line-level amplifier input, and can easily drive virtually any length of interconnect. There is no internal wiring or binding, and all high-current parts of the circuit are shielded. Both models feature gold-plated RCA terminals soldered directly onto the PCB, limiting all signal paths to a bare minimum.

The QUESTARs utilize an external “wall-wart” power supply to avoid undesirable electro-magnetic interference within the chassis. Sonic performance can be even further enhanced by upgrading to the Quasar’s substantial separate box Q-PSU, constructed around a massive 60 VA toroidal transformer with low-density magnetic field and minimal dispersion. With substantial 40,000 µF capacitor filtering, the Q-PSU can feed the QUESTAR’S circuitry with the kind of super-clean current usually delivered only by battery-based supplies, even with extreme dynamic swings.

Technical characteristics:

Input sensitivity:

2.5 mV (MM), 220 μV (MC)

Input impedance:

47 kΩ (MM), 470 Ω (MC)

Output level / impedance:

500 mV / 100 Ω

Frequency response (+0, -1 dB):

10 Hz – 100 kHz

RIAA accuracy:

0.3 dB in whole range

Signal to noise ratio (A-weighted):

82 dB (MM), 74 dB (MC)

Channel separation:

> 55 dB

Headroom:

20 dB (MM), 18 dB (MC)

Dimensions (WxHxD):

9.5×7.2x25cm