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LACHAPELL AUDIO MODEL 983M

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SAFETY PRECAUTIONS

•  Always provide adequate ventilation. Due to the vacuum tube and high voltage internal power 

supply, the 983M will get warm. Blocking or defeating any existing vent(s) is not recommended.

•  Never position the 983M directly above other heat generating sources such as a power amplifier.
•  Do not place the 983M in an area where there is a potential for fluids to fall, spill onto or come in 

contact with the 983M. If you notice fluids or moisture present inside the unit DO NOT turn power on! 
Contact Digital Audio Labs for direction.

Summary of Contents for 983M

Page 1: ...Chanhassen MN 55317 952 401 7700 support digitalaudio com www digitalaudio com LACHAPELL AUDIO 983M USER GUIDE Single Channel Half Rack Vacuum Tube Preamplifier for Microphones and Instruments Version 1 February 2019 ...

Page 2: ... direct sun light or heating units as the internal components temperature may rise and shorten the life of the components 7 Do not defeat the safety purpose of the polarized or grounding type plug A polarized plug has two blades with one wider than the other A grounding type plug has two blades and a third grounding prong 8 Protect the power cord from being walked on or pinched particularly at plu...

Page 3: ... place of purchase Please write the RMA number on the outside of the shipping carton Any product sent to us without a valid RMA number will be refused Include the following with the product a brief description of the problem your name return shipping address phone number and the RMA number Do not include any accessories DAL is not responsible for any damage to or loss of the product during transit...

Page 4: ... LIMITED WARRANTY 1 REPAIR POLICY 1 WARRANTY SERVICE 1 NON WARRANTY SERVICE 1 INTRODUCTION 3 BEFORE YOU GET STARTED 3 SAFETY PRECAUTIONS 4 CONTROLS 5 CONTROL DETAILS 5 GETTING STARTED 6 983 FREQUENCY RESPONSE 7 HPF 50HZ 7 HPF 150HZ 7 LPF 5KHZ 7 LPF 10KHZ 7 LACHAPELL AUDIO 983M SPECIFICATIONS 8 LACHAPELL AUDIO SUPPORT 8 ...

Page 5: ...ry by technically competent individuals Tube replacement Turn power supply off and remove 983M from the chassis wait five minutes to allow the vacuum tube to cool before attempting to remove it Using your fingers apply a slight circular rotating motion as you pull it away from the socket It is important to replace the tube with the same type When a replacement tube is installed ensure that the cor...

Page 6: ...efeating any existing vent s is not recommended Never position the 983M directly above other heat generating sources such as a power amplifier Do not place the 983M in an area where there is a potential for fluids to fall spill onto or come in contact with the 983M If you notice fluids or moisture present inside the unit DO NOT turn power on Contact Digital Audio Labs for direction ...

Page 7: ...es the polarity of the output signal MUTE Output level mute The MUTE LED will illuminate red when the channel is muted VU METER This detects the microphone input signal not output level The LED is calibrated to detect input signals as low as 50dBu When 4 is illuminated it indicates that line level has been achieved The Clip LED is intended to be a warning that clipping may occur if output signal s...

Page 8: ...ack RACK KIT CONTENTS 2x L Shaped Rack Brackets 1x U Shaped Center Bracket 1x Hex Tool 12x Mounting Screws MOUNTING A SINGLE 983M UNIT To mount a single 983M unit in a 19 rack with the Rack Mount Kit position the L Brackets as shown in the image above The brackets will attach to the 983M with 2 mounting screws per side Using the Hex Tool screw two Mounting Screws into the provided holes on either ...

Page 9: ...he microphone type TUBE HARMONICS AND COMPRESSION With the TUBE DRIVE set at around 75 LEVEL around 25 and the PAD off you will get incredible tube harmonics and natural tube compression This would be a great starting position for those wanting to hear what the 983M s harmonics are all about It s also a great place to start when using ribbon or dynamic mics HEADROOM AND WARMTH The 983M provides gr...

Page 10: ...LACHAPELL AUDIO MODEL 983M 8 983M FREQUENCY RESPONSE HPF 150HZ LPF 10KHZ HPF 50HZ LPF 5KHZ ...

Page 11: ...27 8dBu 1 THD N 22Hz 20kHz Frequency Response 9Hz 40kHz THD N Variable 0 01 18 per tube drive input gain control with 40dBu input at 1Khz Noise EIN 124dB S N Ratio 92dB 30dB of gain 22Hz 20kHz Input Impedance microphone 1 5 KOhm Input Impedance Hi Z 100K Ohm Output Impedance 8 Ohm Tube Complement Type 1 x 12AX7 ECC83 one per channel NOTE Stated specifications are typical measurements but subject t...

Page 12: ... 2014 2015 Digital Audio Labs 2017 2018 Digital Audio Labs Patents pending ...

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