Knif V804 Pre high-end vacuum tube microphone preamplifier
Knif V804 Pre high-end vacuum tube microphone preamplifier logo and slogan

Features

  • Vacuum tube microphone preamplifier available in two and four channel versions

  • Flawless performance with very low noise, high headroom, and high gain

  • Two stage minimalist design with unrivaled sophistication

  • SQ German NOS pentodes

  • Lundahl input and output transformers

  • No electrolytic capacitors in the signal path

  • Optional DI input

Knif V804 Pre high-end vacuum tube microphone preamplifier rear

Overview

Knif V804 Pre is a high-end vacuum tube microphone preamplifier available in two and four channel versions. 

The preamplifier pays homage to West-German engineering from the 1950’s while utilizing modern components and construction techniques. The front end is based around the Telefunken EF804S, a very special and sought-after NOS pentode, combined with a high step-up ratio Lundahl® input transformer. The most distinctive feature in the classic German 1950’s designs was the use of pentodes in the first stage of sensitive electronics. 

Thanks to the special front end, the self noise of V804 Pre is very low, fully comparable to the best solid state rivals and the maximum gain is also very high. The latter of the two tube stages in the amplifier also features a SQ pentode, the E180F. This stage is also coupled to the outside world through a Lundahl® transformer. The core of this transformer is silicon iron which adds a hint of thickness and smoothness to the top register. 

The gain of V804 Pre is adjusted in 4 dB increments via an Elma® rotary switch. The gain adjustment is equipped with an automated -20 dB pad for the lowest gain settings. There are no electrolytic capacitors in the signal path. 

The V804 Pre is also available with optional DI inputs with capacitance of only 15pF. This vanishingly low value is roughly equivalent to one foot of the very best cables available and greatly helps in squeezing out the last bits of treble from Hi-Z sources, such as guitars.

There are no other tube microphone preamplifiers on the market with such degree of sophistication and minimalism. The performance of the V804 Pre is flawless.

Pricing and options

V804 Pre, two channel version

2800 €

DI inputs

+200€

V804 Pre, four channel version

5100 €

DI inputs

+400 €

All prices excluding VAT, duties and shipping costs

Tech specs

MIC / LINE INPUT

Impedance

1 kΩ

Maximum Level

+26 dBu

DI INPUT (OPTIONAL)

Impedance

2 MΩ, 15 pF

Gain

0 … 52 dB

OUTPUT

Maximum Level

into 10 kΩ

into 600 Ω

+32 dBu

+25 dBu

Frequency Response,
gain 20 … 60 dB

±0.5 dB, Ref. 1 kHz, 50 Ω source

±0.5 dB, Ref. 1 kHz, 150 Ω source

10 Hz … 40 kHz

15 Hz … 22 kHz

THD + N,
20 dBu Out

10 kΩ load, 0 … 64 dB gain, 30 Hz … 20 kHz

600 Ω load, any gain, 30 Hz … 20 kHz

0.4%

<0.6%

Crosstalk,
Gain 0 … 60 dB

100 Hz

1 kHz

10 kHz

-90 dB

-95 dB

-68 dB

Crosstalk,
Gain 72 dB

100 Hz

1 kHz

10 kHz

-80 dB

-80 dB

-55 dB

0 … 72 dB

Gain

XLR female, Neutrik, 3‑pin, gold-plated

Connectors

6.35 mm jack, Neutrik, locking

Connectors

Impedance

<200 Ω

XLR male, Neutrik, 3‑pin, gold-plated

Connectors

PERFORMANCE

-1 dB, Ref. 1 kHz

High Frequency Cutoff, max gain

20 kHz

Any gain

Channel Balance

better than 0.1 dB

A-weighting

Noise (EIN) 60 dB gain, 50Ω source

-133 dBu

MAINS

Mains Frequency

50 / 60 Hz

Power Consumption

2 channel version

27 W

Connector

IEC, C13

TUBES

EF804S

2 pcs

E180F

2 pcs

GENERAL

Dimensions (w × l × h)

430 × 352 × 132 mm (3U)

Weight

10.3 kg

CONTENT

V804 Pre

1 pcs

Spare tubes (E180F, 2pcs)

1 set

115 / 230 VAC, selectable

Mains Voltage

WARRANTY

2 years (for terms and conditions, refer to Warranty section)