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11 

 

GETTING STARTED 

  
  
1.  Having powered up the Ebony A1 and ensured all the gain controls are at minimum 
connect  its  line  output  to  the  desired  line  input  on  your  console,  recorder  or  sound 
card. Avoid connecting the line output of the Ebony A1 to the microphone input of a 
console or soundcard - this could well result in level and impedance mismatches, with 
a resultant loss of quality (but is easy to do in error since both normally use the same 
type of 3 pin XLR connector!) Aim for a balanced XLR to jack cable to connect into 
your console or soundcards line input. 
  
2.  Ensure that the console, recorder or sound card has its input gain set to a sensible 
level (0dB is a good starting point).  
   
3.   Then connect the desired mic or instrument source to the relevant Ebony A1 input 
(microphones  will  use  the  rear  panel  XLR  and  instruments  will  use  the  front  panel 
0.25” jack).  
  
4.   If a condenser microphone is the sound source, then depress the +48V phantom 
power switch. You may see a transient thump register on the Ebony A1 meters as you 
do this (which is why it is important to have the gains at minimum). Then gradually 
bring  up  the  Ebony  A1  input  gain  level  until  the  signal  starts  to  register  a  healthy 
reading  on  the  VU  meter.    When  the  tube  stage  is  ‘IN’  and  you  also  turn  up  the 
‘warmth’ control, the Drive LED starts to glow as the mic or instrument are used.  
  
5.    Now bring up the Ebony A1 output level control - you should now start to hear 
some sound, and as the output is increased the red signal LEDs will start to illuminate. 
Set the output level to a comfortable level so that you are getting a good metered level 
on the piece of equipment the Ebony A1 is driving into. Remember that some digital 
recorders  and  sound  cards  require  a  large  amount  of  level  to  fully  modulate  their 
meters,  so  you  may  need  to  apply  a  significant  amount  of  output  gain  to  do  this 
successfully.  By  contrast  a  standard  analogue  console  will  require  much  less  level. 
Please  beware  not  to  let  the  signal  ever  clip  (go  into  the  red)  on  your  DAW  input 
(Logic, Pro Tools, Cubase etc).  Clipping will cause digital distortion which a square 
wave and signal degradation. 
  
6.  Experiment with the 90Hz filter - you should notice how it removes extreme LF 
content  (particularly  noticeable  on  close-miked  male  voices)  and  the  30dB  pad  will 
reduce the signal level quite markedly. The pad is only normally used on very loud 
sources  where  even  minimum  gain  settings  will  drive  the  Ebony  A1  preamp  into 
distortion. The phase reverse switch should have no real effect unless you are using 
multiple mics through the Ebony A1 and some phase cancellation is occurring.  
  
7. Experiment with the tube warmth rotary knob.   Turn the rotary knob level up so 
that  the  Drive  LED  glows  brighter  -  you  should  notice  an  audible  change  in  sound 
character as the tube stage is driven harder. This variation in tone is one of the great 
strengths of the Ebony A1 - you have the option of running it very clean, or nice and 
warm as you increase the valve drive via the ‘Tube Warmth’ control.

Содержание Ebony A1

Страница 1: ...T L Audio User Manual Ebony Series A1 Dual Pre Amp TL Audio Limited Letchworth England Tel 01462 492090 Fax 01462 492097 www tlaudio co uk email info tlaudio co uk...

Страница 2: ...7 Audio Inputs 7 Instrument Inputs 8 Outputs 8 Ventilation 8 OPERATION 9 Microphone Input 9 Instrument Input 9 Input Gain 9 30dB Pad Switch 9 Phantom Power 9 Tube Stage Drive and Peak LEDs 10 Output...

Страница 3: ...fers superior analogue processing to accompany a digital world Why Class A Class A circuits are designed with a constant current flowing through all of the transistors which is sufficient to drive the...

Страница 4: ...phase connections which form a differential pair independent of the ground or earth connection Noise particularly mains hum and high frequency interference can often be present in unbalanced systems d...

Страница 5: ...d a dedicated valve input stage Phase reverse and high pass filter switches are provided affecting both mic and instrument inputs The tube stage has a variable drive control with the signal level indi...

Страница 6: ...rved All mains wiring should be installed and checked by a qualified electrician Ensure the mains operating voltage stated on the rear panel is correct before connecting to the mains supply Never oper...

Страница 7: ...6 BLOCK DIAGRAM...

Страница 8: ...taken to an approved service centre Alternate supply voltages may also require a different power cable or mains plug If in doubt consult local electrical regulations Warning attempted operation on the...

Страница 9: ...as follows Pin 1 Ground screen Pin 2 Signal Phase or hot Pin 3 Signal Non Phase or cold If an unbalanced output is required pins 1 and 3 should both be connected to ground Ventilation The unit generat...

Страница 10: ...normal to have to apply larger amounts of gain for less sensitive microphones such as dynamic types and similarly apply much less input gain for high output condenser mics some of which may even need...

Страница 11: ...nic distortion The distortion is predominately second harmonic unless very high drive levels are used in which case the tube is eventually pushed into harsher saturation indicated by the tube Peak LED...

Страница 12: ...hould now start to hear some sound and as the output is increased the red signal LEDs will start to illuminate Set the output level to a comfortable level so that you are getting a good metered level...

Страница 13: ...Distortion THD Noise 0 025 20Hz to 20KHz 40dB gain Noise EIN 127dBu unweighted 22Hz to 22KHz 150 ohm source termination Instrument Input Tube input stage plus discrete Class A circuitry to output Gain...

Страница 14: ...Bu on output VU Meter Switchable to Channel 1 or 2 and Input or Ouput Nominal calibration 0VU 4dBu 10dB switch calibration 0VU 14dBu Power Requirements Internally set to 230V 50Hz or 115V 60Hz operati...

Страница 15: ...hip will be repaired free of charge The warranty excludes damage caused by deliberate or accidental misuse tampering operation on the incorrect mains voltage or without the correct type and value of f...

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