KRELL KRS-1

Commentary

Monaural preamplifier developed as a reference standard.

KRS in the model name means Krell Reference Standard.
The KRS-1 is not limited by its marketability as a product or its ease of use in general. It is designed to achieve the full performance of a power amplifier by simply amplifying the input signal.
It is also sold as a stereo pair because it is fully monaural and requires two KRS-1s for stereo playback.

The power supply and body are designed separately to eliminate interference with the power supply.
The power supply section is equipped with two large toroidal transformers per channel. The equalizer stage and flat stage are dedicated power supplies, and the capacity of the entire power supply section is as strong as that of a power amplifier.

The circuit configuration is simple and all complex circuits such as sound field correction circuits are eliminated.
The main circuit consists only of an equalizer amplifier and a flat amplifier.

The CR type is used for the equalizer amplifier section because the capacitor can be eliminated from the NR loop.
In addition, we have solved the SN ratio problem by carefully selecting ultra-first class elements and raising the output level and allowable input of the circuit to a sufficient level, and the RIAA deviation is kept within 0.1 dB.

A rocker switch rocker switch on the board of the equalizer amplifier. The load capacity can be changed from 47 pf to 417 pf in four stages, and the optimum value can be set for the cartridge used.

It has an input terminal for CD only.
The KRS-1 does not treat the CD signal in the same way as the conventional input. The KRS-1 supports the CD input signal by installing a buffer amplifier with a gain of 0 dB and setting the impedance high at 47k Ω.

There was an equalizer board with an MC head amplifier as a separately sold option.
This board has 13-step impedance switching and is compatible with all MC cartridges.

Model Rating

Type	Monaural preamplifier
Input Terminal / Impedance	Phono, CD : 47k Ω Tuner, Aux, Tape1/2 : 10k Ω
Output Terminal / Impedance	Pre out1/2, Tape out1/2 : 10 Ω
Total harmonic distortion factor	Phono : not more than 0.01% Tuner : 0.002% or less
Frequency characteristic	20 Hz to 20 kHz -0.005 dB (Tuner-Pre out)
Signal-to-noise ratio (IHF-A)	Phono:95dB Tuner:100dB
Phono/CD maximum allowable input	Phono:180mV CD:12V
Pwer	100 VAC, 50Hz/60Hz
Power consumption	20W (per unit)
External dimensions	Body / Power Supply : Width 483x Height 68x Depth 373 mm (Includes Connector)
Weight	Body : Approx. 4.4 kg (1 Unit) Power Supply Part : Approx. 6.7 kg (1 unit)
Sold Separately	Equalizer board for KRS-1 (with built-in MC head amplifier) (1 set of 2, ¥ 300,000)