Preamp Three Phono Mk7

completely balanced tube preamp

Design * Construction

. full tube technique in signal path
· MC- and MM-operation
· low noise phono input signal
· passive phono pre-emphasis
· RIAA-phono de-emphasis stepwise switchable for different cut off frequencies
· switchable input impedances for MC- and MM-operation
· 3-steps MC-adjustment by switchable transmission ratio
· balancing of unbalanced input signals
· completely balanced signal processing in all modes and connection configurations
· pure class A-operation
· equal balanced-unbalanced in-/outputs by transformer technique
· galvanic isolation by input and output transformer coupling
· MC-/MM-transformer and output transformer made by own manufactury
· cartridge modul technique
· all switching processes relay-controlled
· flexible switching functions by processor control
· internal switch mode power supply for all supply voltages
· on / off muting

Front panel rotary switches

· Phono:	phono 1 = MM, MC 1 - 3
	phono 2 = MM, MC 1 - 3
· mode	for choosing the RIAA-phono-cut off frequency
· impedance	for phono 1
· impedance	for phono 2
· on	for on / off

LED-displays

· front right

· front left

red/green
red center
red left

red left
red center
red right
red all

operation display
phono 2
phono 1

transformation ration MC 1:5
transformation ration MC 1:10
transformation ration MC 1:20
MM

Features

· 2 x ECC 808-tubes
· 6 x ECC 81-tubes
· 4 x ECC 88-tubes
· 2 x MC-transformer with MU-metal-shielding
· 2 x MM-transformer with MU-metal-shielding
· 2 x output transformer with MU-metal-shielding
· 7 x circuitry cartridte module
· switch mode power supply 150 VA
· power cable (2 m)

Connectors

· gold plated cinch sockets
· gold plated XLR-sockets
· gold plated 2 mm-sockets (ground)
· AC power socket

Rear panel switches

· toggle switch for balanced or unbalanced phono 1-input
· toggle switch for balanced or unbalanced phono 2-input
· toggle switch for balanced or unbalanced phono output

Specificatons

· balanced input
· unbalanced input
· input impedance MC
· input impedance MM
· input sensivity MC
· input sensivity MM
· phono de-emphasis
· balanced output
· unbalanced output
· output impedance
.·output voltage
· total harmonic distortion (THD)
· frequency response
· signal-to-noise ratio MC
· signal-to-noise ratio MM
· power supply
· power consumption
· Standby

Phono 1 + 2
Phono 1 + 2
100 - 800 Ohm
10 - 100 kOhm
0,1 - 0,2 - 0,4 mV
1 mV
22 µs - 83 µs
Preamp Out
Preamp Out
< 100 Ohm
2 V (RMS)
< 0,1 %
10 - 60.000 Hz
> 70 dB (A)
> 80 dB (A)
90 - 250 VAC, 50 - 60 Hz
80 Watt
0,3 Watt

Option

· front plate / chassis natural anodized

Housing

· 15 mm aluminum front plate brushed and black or natural anodized
· massive aluminum chassis brushed and black or natural anodized
· brass rotary knobs and brass product badge high-glass polished and chromed

· dimensions:
· weight:

483 mm (W) x 315 mm (D) x 100 mm (H)
12 Kg