Lehmannaudio Decade - User Manual

Questions and Answers

D
davidhodgesAug 12, 2025
What to do if there is no signal from my Lehmannaudio Amplifier?
- J
  Jennifer JacksonAug 13, 2025
  If you're not getting any signal, make sure the power supply is properly connected to the device and that the mains cable is plugged into the power outlet. For the Decade model, verify that the cables from the turntable are correctly connected to the input and the cables to the amplifier are connected to the output. Also, ensure that the correct input channel is selected on your amplifier.
D
Daniel KiddAug 16, 2025
Why does my Lehmannaudio Amplifier signal sound hollow, without proper bass and localisation?
- J
  jennifer21Aug 16, 2025
  A hollow sound without proper bass and localization can occur if the pickup system is connected phase-reversed. Ensure that the system cable is connected in-phase. Also, make sure the tonearm ground is connected on the Decade. Furthermore, ground loops caused by connected devices or interference from other power consumers can cause this issue. Try making a correct grounding connection or disconnecting other devices connected to the same electrical circuit to identify any interference.
E
Emily SmithAug 20, 2025
Why does my Lehmannaudio Amplifier signal sound distorted?
- R
  Rachel ObrienAug 20, 2025
  If the signal sounds distorted, the gain on the Decade might be set too high. Lower the gain factor using the switches on the front panel of the Decade, following the instructions in the user manual.
K
kaylajohnsonAug 25, 2025
What to do if the signal level is too low on my Lehmannaudio Decade?
- A
  Angel JohnsonAug 25, 2025
  A low signal level can be due to a non-optimal match between the pickup cartridge and Decade, or the selected input impedance on the Decade being too low. Increase the gain factor using the switches on the front panel of the Decade, following the instructions in the user manual. Also, select a resistance value for the input impedance that is at least 10 times greater than the pickup’s system impedance.
E
Eric CraneAug 27, 2025
How to fix uneven signal on one channel only in my Lehmannaudio Amplifier?
- E
  Emily RichardsAug 27, 2025
  If the signal sounds unevenly on one channel, check the positions of the DIP switches. Make sure that the settings are equal on both channels.
A
Andrea SimmonsAug 31, 2025
How to stop radio interference audible in the background of my Lehmannaudio Amplifier?
- J
  James PaulAug 31, 2025
  If you're hearing radio interference in the background, the tonearm ground might not be connected on the Decade. Connect the tonearm ground on the Decade.
G
goldenadamSep 4, 2025
What to do if left and right channels are reversed on my Lehmannaudio Amplifier?
- L
  Lisa OrtegaSep 4, 2025
  If the left and right channels are reversed, check the connection leads and swap the channels if necessary.
R
Rachel CurtisSep 8, 2025
Why is the LED indicator not lit on my Lehmannaudio Decade?
- K
  Kathleen JohnsonSep 8, 2025
  If the LED indicator is not lit, ensure that the mains cable is properly plugged into the power outlet and that the power supply is connected to the device.

Summary

Important Safety Precautions

Storage and Environment

Warning and Operation Notes

Ventilation Requirements

Power and Electrical Safety

Power Cable and Mains Connection

Use only approved power cables with protective conductor connection and correct polarity.

Protection Against Electrical Hazards

Disconnect during thunderstorms, avoid electric overload, and keep away from fire sources.

Installation and Setup Guide

Functional Description of the Decade

Front Panel Controls

Rear Panel Connections

Input and Output Jacks

Power Supply Unit (PWX II)

Putting the Decade into Operation

System Configuration

Gather information on MM/MC system and required connection resistance for proper setup.

Connection and Adjustment Steps

Sequence for setting volume, connecting power, adjusting gain, resistance, and connecting player/amplifier.

Common Settings and Impedance Matching

Resistance Settings

Input Capacitance Settings

Technical Specifications and Troubleshooting

Detailed Technical Data

Troubleshooting Common Issues

Solutions for faults like no LED indicator, no signal, distorted sound, and audible hum.

Signal Issues and Solutions

Single Channel or Reversed Signals

Diagnosing and resolving issues with signal on one channel only or reversed left/right channels.

Low Signal Level and Muffled Sound

Addressing low signal levels due to impedance mismatch or incorrect gain settings.

Radio Interference and Grounding

Solutions for radio interference and ensuring proper tonearm ground connection.

Lehmannaudio Decade Specifications

General

Type	Phono Preamplifier
Total Harmonic Distortion (THD)	< 0.01%
Output Impedance	100 Ω
Signal to Noise Ratio	> 90 dB
Power Consumption	5 W
Frequency Response	20 Hz - 20 kHz
Input Impedance	47 kΩ
Inputs	RCA
Outputs	RCA
Gain (MC)	66 dB
Power supply	External power supply