Linear User Manual - Henley Designs Ltd.
Contents
1. EN Lehmannaudio Linear Headphone amplifier Single Source Preamp User manual Lehmannaudio Manual Linear page2 Dear customer congratulations for buying the Lehmannaudio Linear You will be rewarded with the best possible sound from your headphones You can use practically all dynamic headphones on the market Carefully selected components and a highly sophisticated circuit design guarantee a very high level of audio reproduction Please read this manual carefully and keep it nearby the unit for future reference even if you have experiences with other headphone amplifiers Precautions Please read the following before operating your Linear While installing the Linear Be careful to use an appropriate cable for the connection between your power outlet and the Linear Make sure that you have the appropriate version for your mains voltage Be careful to prevent Linear from getting wet do not allow water to enter the unit especially when raining or snowing or near a body of water Otherwise fire or electrical shock may result Do not place heavy objects on the power cord If the cord is damaged fire or electrical shock may result In particular it is possible that one might accidentally place a heavy object on a carpet that covers the cord definitely avoid these situations Do not install the Linear in a place where it might be exposed to oil smoke or steam for example near a cooking table or humidifier Othe2. a matching combination or go for a headphone amplifier with switchable gain that can be used with a wide variety of headphones Purchasing the Linear was a perfect step in the right direction gt All figures were taken from freely available data sheets of different manufacturers and have been partly recalculated from other dimensions Voltage and power are referring to effective values and not to peak values All figures are given without any guarantee Lehmannaudio Manual Linear page 8 Elements at the front section Lehmannaudio 1 Power LED When this LED lights the Linear is connected to mains voltage switched on and ready for being used 2 Headphone output 1 6 3mm headphone jack for common headphones When a headphone is connected to this headphone output the line output at the rear side of the unit will be muted Warning when you are also using the line output please make sure that the volume knob is turned to minimum position counter clockwise to avoid sudden signal peaks Please have in mind that the same signal amplitudes can result in very different volume levels connected to power amps or to headphones 3 Headphone output 2 6 3mm headphone jack for common headphones When a headphone is connected to this headphone output the line output will not be muted This enables you to listen to headphones and your loudspeakers at the same time You can connect to headphones of the same type at the same time to the Line
3. al to noise ratio THD Channel separation Interchannel mismatch Output power Output impedance Connectors audio Mains connector Fuse Power consumption Dimensions Wh eigh t Lehmannaudio Manual Linear page 11 47kOhm odB 10dB 18dB 20dB switchable underneath the unit 10Hz 0 3dB 35kHz dB gt 95dB Gain odB lt 0 001 6mW 300 Ohm gt 70dB 10kHz lt 0 3dB with volume to maximum 300 Ohm 200mW 60 Ohm 400mW Line Out 50 Ohms Phones Out 5 Ohms Neutrik headphone jacks 6 35mm with gold plated contacts 1x muting line out 1x parallel RCA connectors with gold plated contacts and Teflon isolation IEC receptable 100 120V AC 500mA slow or T 200 240V AC 250mA slow or T lt 10W with internal regulated low noise power supply 280x110x 44mm case only app 1 5kg Lehmannaudio Manual Linear page 12 Notes Manufacturer s address Lehmannaudio Vertriebs GmbH Richard Zanders Str 54 51469 Bergisch Gladbach Tel 49 2202 280 62 40 Fax 49 2202 280 62 39 email info lehmannaudio de Web www lehmannaudio com www headphone amplifier com
4. ar Please avoid using two different headphones This may result in very different levels 4 Volume knob Here you can adjust the desired output level Turn clockwise to get a higher volume and counter clockwise to lower the volume WARNING While using headphones you can easily reach volume levels that can seriously damage your hearing Every time before you put on a pair of headphones you must make sure that the volume is set to an appropriate level Lehmannaudio Manual Linear pageg Elements at the rear side 1 Line input Stereo RCA connectors for the source you want to hear with the Linear 2 Line output Stereo RCA connectors for the connection of your power amplifier or active loudspeakers Depending on which headphone output you are using on the front side of the unit the signal is either fed through the Linear to the line output or muted The RCA jacks are connected in parallel to the Linear s output stage and not just passively connected to the input connectors so that you benefit greatly when you use the unit as single source preamp 3 Power switch This switch separates the primary coil of the power supply transformer from the mains voltage There is no stand by mode 4 Fuse holder Fuse holder for the primary fuse In case of replacement you must use the same type 100V 120V AC soomA slow or T 200V 240V AC 250mA slow or T If there is a mechanical noise rattle when you move the unit the Linear i
5. egions Taking a look at laws in the US and in Europe reveals tremendous differences in what is thought to be suitable for the listener Permissible noise exposures in Germany dBA hours per day per da ee D ON ER a Ce DEN Ta EEE EN BE SED Permissible noise exposures in the USA dBA hours per day per da PT A EN NE eZ Roughly harmonized throughout Europe Figures taken from US department of labour noise regulations Lehmannaudio Manual Linear page6 Overview of power consumption of different headphones at different signal levels level Headphone impedances Vere Voltage needed for 1mW power Headphone impedances same som moms mom tee mw Lee foo la fie odB 775mV odB 1V Lehmannaudio Manual Linear page7 Table of effectivity of common headphones Type Impedance Efficiency Voltage for Power for 100dB Ohms dB imW 100dB SPL SPL un __ K24ODF me A en w Koo 6 P93 P 40oomW DT660 Fo wmm w k DT880 25 ee u 2 mn mo 2 98 z pm u CS BEE HE EEE Potpro rene a bs o o o o MT ise o zer HD80o HFI Hse HFI HFl 550 a 100 HFI 700 BE EEE 75 548mV m It can easily be seen that even among the products of one manufacturer there can be huge differences as far as impedance and or efficiency are concerned This makes it very important that you either choose headphone and headphone amplifier as
6. is given as dB mW which means the resulting sound pressure level at mW not perimW Lehmannaudio Manual Linear pages If the power is doubled then the resulting sound pressure level is 3dB higher If this is calculated the other way round it means that only half of the power is needed when using a headphone with 3dB more efficiency to reach the same sound pressure level The 3dB formula is valid for headphones and for loudspeakers From the given efficiency the power needed for a certain sound pressure level can be derived The power for the same sound pressure level can differ up to a factor of 500 for the different headphones on the market In the end what counts when selecting a headphone or a headphone amplifier is if the desired volume can be reached without distortion At least equally important is to avoid damage for the headphone and most important to avoid damage for your hearing The maximum power rating is a figure that can be found in the data sheet of the headphone From this power rating the maximum voltage can be derived If the voltage will be higher then the voice coils of the headphones will be destroyed Today most headphones allow hearing levels well above a secure level for the listener This means that a standard pair of cans might survive extremely high levels without any degradation of long term performance but the hearing of the listener might be seriously damaged Especially interesting are the standards of different r
7. n modified devices If you think the Linear needs to be checked for maintenance or repair consult your dealer Do not place a container of water or any small metal object on top of the Linear If water is spilled or if the metal object gets inside fire or electricalshock may result This applies to vases potted plants glasses cosmetic bottles medicine etc Do not damage process bend twist stretch or heat the power cord If the cord is damaged fire or electrical shock may result When you are connecting other audio devices to the Linear make sure that you first turn off the power to all devices to be connected Refer to the user s guide for each device and use the specific cable for connection Set the volume levels of all devices including that of the Linear to minimum before connecting the Linear to your actual setup and to the AC outlet Otherwise an extremely loud noise could damage your loudspeakers or even your hearing If you plan not to use the Linear for a long period of time such as when you are on vacation remove the power plug from the AC outlet Otherwise a fire could possibly result If any abnormality occurs while using the Linear remove the plug from the AC outlet In this case first shut off the power amplifiers or turn down the volume controls and so on to avoid possibly damaging transients If you notice any abnormality such as smoke smell noise etc remove the plug from the AC outlet Co
8. nfirm that the abnormality is no longer present then consult your dealer for repair If you continue using the Linear under abnormal conditions fire or electrical shock may result If a foreign object or water enters inside the equipment remove the Plug from the AC outlet and consult your dealer for repair If you continue using the Linear under this condition fire or electrical shock may result If the power cord is damaged for example if it is cut or if the core wire is exposed ask your dealer for a replacement If you continue using the Linear under this conditions fire or electrical shock may result If the Linear is dropped or if the case is damaged remove the plug from the AC outlet and consult your dealer If you continue using the Black Cube under abnormal conditions fire or electrical shock may result Maintenance Before cleaning the Linear remove the power plug from the AC outlet for safety Otherwise an electrical shock may result Do not open the Linear There are hazardous voltages inside that might result in an injury or an electrical shock Lehmannaudio Manual Linear page 4 Why headphones When you use headphones you can reach a very high level of sound reproduction at a fraction of the price you would have to spend for a regular hifi setup with high quality loudspeakers Detail resolution and dynamics of even the best loudspeakers can easily be reached with the best headphones In most cases head
9. phones will be used to enjoy music either to acoustically disclose a noisy environment to just to be able to listen to louder levels without disturbing other people What makes headphones different There is a number of parallels between dynamic headphones and loudspeakers Technically they are complex loads for the amplifiers driving them and should therefore be used with stable outputs There are headphones with higher impedance that need a higher signal voltage and low impedance types which need more current for optimal sonic results Just connecting a headphone to any given headphone output without considering the headphone s electrical characteristics will most likely yield dissatisfactory results Impedances of dynamic headphones can vary from 30 Ohms to 600 Ohms Transferred to loudspeakers this would result in impedances from 4 Ohms to 80 Ohms The same signal amplitude results in a power consumption difference of factor 20 Loudspeakers and headphones are manufactured in a dazzling variety Irrespective of their impedance headphones and loudspeakers can have very different efficiencies which means that the electrical signal is converted more or less effective to acoustic energy When comparing loudspeakers the dimension used is the sound pressure level SPL reached at a given power of 1W at 1m distance There is a similar parameter for the efficiency of headphones except for the fact that the standard power is mw 1 1000W The figure
10. rwise fire or electrical shock may result Do not place the Linear on an unstable surface such as an unstable bench or slanted surface Otherwise the device may fall or drop resulting in an injury Do not place the power cord near a heating device Otherwise the cord sheath may melt resulting in fire or electrical shock Do not locate the Linear in a place subject to excessive heat such as inside a car with all the windows closed or in direct sunlight Otherwise fire may result Do not handle the power plug with wet hands Otherwise you may receive an electrical shock When you remove the power plug be sure to hold the plug Never pull on the cord Otherwise the power cord may become damaged resulting in fire or electrical shock The Linear offers superb sonic quality To ensure best possible results you should use the best quality connecting cables that you can afford Regular maintenance involves keeping all connections clean using a quality contact cleaner Lehmannaudio Manual Linear page3 Using the Linear Do not touch the Linear under the following circumstances If you hear thunder remove the power plug from the AC outlet as soon as possible If you fear a lightning hit and the Linear has been connected to an AC outlet do not touch the power plug Otherwise you may receive an electrical shock Do not attempt to modify this equipment Otherwise fire or electrical shock may result Warranty is void o
11. s equipped with a spare fuse which is also placed in the fuse holder 5 Mains connector IEC receptable for the connection to mains voltage Please connect the power cord here You must make sure that you connect the Linear to the appropriate mains voltage The mains voltage and fuse type needed are both printed on a sticker underneath the unit Lehmannaudio Manual Linear page o Adjustment of maximum gain You can easily adjust the maximum gain of the Linear to use any available headphone with best results independent from efficiency or impedance The gain setting has direct effect on the active gain of the input stage which is placed after the volume potentiometer It is recommended that you choose a setting which at the maximum potentiometer position turned clockwise results in a volume level that is slightly higher than your normal listening habit so that you have a bit of reserve with lower level signals You also make sure that extraordinary high levels can be avoided much easier Gain with volume turned to Switch 1 Switch 2 maximum The gain setting is done for each channel separately Please make sure that both channels show the same setting Otherwise you will hear an abnormally twisted stereo panorama Warning Do not change the gain setting while listening to avoid sudden peaks that might damage your loudspeakers or even your hearing Technical Data Input impedance Maximum gain Frequency response Sign
Download Pdf Manuals
Related Search