background image

 

12 

 

‘compressor on’ switch is engaged. Once the Gain Make Up has been adjusted, use the 
Output Level control to set the overall output level of the Ebony A2.    
  

Compressor On.  

  
This  switch  enables  or  disables  the  compressor  stage,  thus  allowing  an  A/B 
comparison  to  be  made  between  the  original  untreated  signal  and  the  compressed 
signal.  Any  gain  make  up  applied  to  the  signal  only  becomes  active  when  the 
“Compressor  On”  is  enabled.  An  associated  status  LED  indicates  when  the 
compressor is active. The Gain Reduction on the VU meter will monitor the level of 
compression regardless of the compressor stage being active or non active.  
  

Equalisation.  

  
The Ebony A2 equalizer section has three bands, each with a continuously variable cut 
and boost control up to plus/minus 15dB. The mid band has a rotary knob to select the 
centre frequency and is variable between 150Hz and 7KHz. Remember that there is a 
good  deal  of  gain  available  from  the  EQ  section,  and  greatly  boosting  one  or  more 
bands can cause the red Peak LED to illuminate as the Ebony A2 is driven towards 
clipping. In this case you need to compensate by bringing down the Ebony A2 output 
gain control until the Peak LED is extinguished.  
  
  

LF Band.  

  
The LF (Low Frequency) band of the equalizer  has a  shelving characteristic - i.e. it 
extends  from  the  selected  frequency  to  the  extreme  low  frequency  limit  of  the 
equaliser’s response.  
  
The cut or boost is controlled by a continuously variable, centre-dented, rotary knob - 
up to 15dB of cut and boost is available. The slope of the shelf is 12dB/octave. 
  

Mid Band.  

 
The Mid Frequency band has a peaking characteristic - i.e. it boosts or cuts a section 
of the audio spectrum around its selected centre frequency only. The centre frequency 
of  the  Mid  band is  selected  by  a  rotary  switch  from  150Hz  to  7kHz.  The  mid  band 
possesses a fairly low Q value of approximately 0.5, for a response which results in 
effective equalisation without harshness.  
 

HF Band.  

  
The HF (High Frequency) band has a shelving characteristic, complimenting the LF 

Summary of Contents for Ebony A2

Page 1: ...T L Audio User Manual Ebony Series A2 Stereo Processor TL Audio Limited Letchworth England Tel 01462 492090 Fax 01462 492097 www tlaudio co uk email info tlaudio co uk...

Page 2: ...Overview of Compressor Operation 10 Threshold 10 Attack and Release 11 Gain Make Up 11 Compressor On 12 Equalisation 12 LF Band 12 Mid Band 12 HF Band 12 EQ On 13 EQ Pre 13 EQ Side Chain 13 Sidechain...

Page 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...

Page 4: ...an audio system A balanced signal consists of signal phase and non phase connections which form a differential pair independent of the ground or earth connection Noise particularly mains hum and high...

Page 5: ...A and B channels are compressed identically in order to preserve the stereo image The Equaliser has 3 bands The HF and LF controls are shelving whilst the mid control is a swept peaking filter The equ...

Page 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...

Page 7: ...6 BLOCK DIAGRAM...

Page 8: ...e 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 t...

Page 9: ...If an unbalanced output is required pins 1 and 3 should both be connected to ground Ventilation The unit generates a moderate amount of heat internally which should be allowed to dissipate by convect...

Page 10: ...loading distortion problems as well as raising the level of the quieter parts of the audio signal Before the introduction of compressors the only way this could be achieved was by gain riding whereby...

Page 11: ...se position Any signal below the Threshold passes through the unit unaffected while signals above the Threshold are reduced in gain and are thus compressed This does depend on the Soft or Hard knee to...

Page 12: ...eavy signals the compressor is forced in and out of compression during one cycle of the waveform and distortion results The Ebony A2 has a built in Hold facility which delays the onset of release for...

Page 13: ...gain available from the EQ section and greatly boosting one or more bands can cause the red Peak LED to illuminate as the Ebony A2 is driven towards clipping In this case you need to compensate by bri...

Page 14: ...Hz The EQ section is used to exaggerate the offending frequencies so that when they occur the compression is triggered It s also useful for cutting frequencies that you don t want to compress Output G...

Page 15: ...eful for slaving the Ebony A2 A D card to an existing digital setup without the Ebony A2 needing to be the digital master in the system Output Peak LED Each channel has an output Peak LED adjacent to...

Page 16: ...s to the channel tape return inputs of your console then connecting one channel of the A2 into the relevant console channel insert point The off tape signal will then be fed into the A2 s line input v...

Page 17: ...to set up the gains of the A2 With the compressor and EQ stages switched out start with the A2 input gain at minimum and output gains at 0dB 2 Gradually bring up the A2 input gain until the chosen sou...

Page 18: ...doubt aim to use compression gently as it can be difficult to compensate for over compression if you later decide that too much effect was used On the other hand there are no rules so if extreme sett...

Page 19: ...025 10Hz to 40KHz Noise 94dBu 22Hz to 22KHz 0dB gain at input and output Outputs Gain Range 20dB Maximum Level 22dBu 2Kohm load 26dBu 10Kohm load Tube Stage Typical Distortion 1 to 10 depending on Dri...

Page 20: ...ut VU Meter Switchable to Channel A or B Input or Ouput and Gain Reduction Nominal calibration 0VU 4dBu 10dB switch calibration 0VU 14dBu Power Requirements Internally set to 230V 50Hz or 115V 60Hz op...

Page 21: ...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...

Reviews: