Thermionic Cultures Vic Keary (on the left) with John Dent.

Mastering engineer John Dent, has recently installed a custom Thermionic Culture Earlybird 2.2 and a pair of Pullet  for his new LOUD Mastering studios in Taunton England as the centre piece of his studio.  

Vic Keary explains about the units modification and application for LOUD Mastering.  "The reason for the customisation is that John has a seriously high quality mastering facility where apart from working from a digital source he often runs from analogue tape to disc at 33.33 rpm. (real "albums").   To get the "Maximum Sound" on to disc it's important to ensure that D.C. & very  low bass is eliminated without noticeable effect, also that if required low frequencies go to centre of the stereo.  Apart from making it easier to cut a record it actually sounds better, even on CD, to have the bass pumping out from both speakers".
 
"When cutting a record in real time its useful to have an option to change settings between tracks & 2 eqs with different settings can be REALLY useful as you often have less than 2 secs to switch both eqs and level.  As a cutting engineer in a previous life I do understand.  Anyway it's good to compare eq settings even just working from computers".
 
The changes we made to the Earlybird are:
 
Bass cut is a sharp drop at 8, 6, 12, 24 & 36 Hz instead of the standard which starts at 40 HZ.
 
 LINE IN is replaced by PULLET 2 (though the MIC settings are retained).
 
We've added a 3 positon Bass to Centre switch and a pot to control Stereo Width.
 
The unit has an external power supply so that any hum is eliminated.  The system at LOUD is completely unbalanced so has a very very low noise level with exceptional bandwith and miniscule phase shift.  Most outboard units have external PSUs.
 
The Gain switch is reduced in range, only 2dB steps, to make it quicker to change levels.
 
All valves are of exceptional quality and carefully matched so that distortion on both channels, with either Pullet connected, is better than 0.006% at 1 kHz!  
 
THE PULLETS were modified to add 3 extra frequencies to the bottom of the Mid Lift, losing 2 from the top.  Also the high end lift/cuts were modified for subtlety.