It all started with Bob Katz’s idea of tweaking his own xfilter. So Ruben surely took this pretty serious and spend some time for tweaking components on the circuit board until he and of course Bob were 100% convinced with the overall sound by checking serval recordings in our elysia Class-A Lounge – Studio in Nettetal, Germany.
Now the result: The xfilter Mastering Edition is a very sophisticated, handcrafted analog stereo 4-band equalizer, with both channels linked for stereo operation. All four bands provide a precise control range of +/-5dB.
This fine Stereo Mastering EQ produces the high-end sound of a Class A equalizer at an amazing value for the money. He produces an absolutely precise stereo image based on the use of computer-selected components with extremely low tolerances.
Using an analog EQ on a stereo buss can be quite tricky, as only very few units offer the possibility to link their two mono channels for true stereo processing.
As a result, the user needs to fiddle around with many knobs in order to cope with the tedious task of matching the settings for both channels as good as possible. The problem gets only worse when the controllers do not have any steps for reference.
But while there are so many compressors in the market that can be linked for stereo operation, why are there almost no EQs which can do this, too? One of the main answers is component tolerances. Obviously, you want the two linked channels to behave exactly the same, but the natural tolerances that especially potentiometers and capacitors have counteract this ideal characteristic.
To make a long story short: The xfilter Mastering Edition solves this problem by using computer-selected dual and quad layer pots as well as special low tolerance caps.
In a linked stereo EQ, the potentiometers need a lot of layers. The pots for setting the mixers (gain) have two layers each, while the pots for setting the frequencies even have a total of four layers each!
The problem occurs that every single layer has its own component tolerance, and while layer A could be at the absolute minimum of the allowed tolerance, layer B could be at the absolute maximum. As a result, the filter stages of the left and right channels would not behave the same.
To solve this, every single potentiometer in the xfilter Mastering Edition is measured and selected with an Audio Precision rig and computer routines written exactly for this task. As a result, only 65% of the dual layer pots and only 50% of the quad pots we buy go into production – the rest is put aside.
It’s a true custom shop option we are proud to offer with every xfilter Mastering Edition free of any up-charges.
