Solid State Logic XR626 Stereo Bus Compressor Module for X-Rack by Glenn Bucci
The Solid State Logic stereo bus compressor has been used on thousands of records over many years. It’s known to add that snap and attack that makes it so unique compared to many other compressors out. The 1U G Series compressor has been around since 2005, and before that model there was the G384 compressor in 1991. The main difference with the older units’ is the VCA started to roll off around 40kHz while the newer ones start to roll off higher.
Compared to the 1UG Series compressor, the compressor on the XL Desk, AWS, Duality, X Rack, and 500 versions have additional ratio (1.5:1, 2:1, 3:1, 4:1, 5:1, 10:1) and release settings (0.1, 0.3, 0.4, 0.8, 1.6 and auto release) compared to the 1U G Series compressor (ratio of 2:1, 4:1, & 10:1) and release settings (0.1, 0.3, 0.6, or 1.2s, or an automatic release) making it more flexible. The 500 series even added a hp filter for added flexibility. However the X Rack unit has a Key in aka side chain, you split the input out into a filter/eq and then back into the key in. Plus many times you will use the compressor with a slow attack and a faster release, so I don't find I miss this feature.
I personally found the auto release to work very well on many situations. A common setting for a 2 bus is the attack on 10, release on 2, ratio on 2:1, and the threshold adjusted to about -2db with the making up gain up.
What makes the X Rack version very attractive is the ability to save your settings. You simply save your setting on the X rack with the record buttonand to recall, you just dial the number you saved and push in the knob. The lights around the knob will either be green or red. Turn them to the left if its green and turn to the right if its red. When the light disappears the setting is back to what you saved it at.
The UAD SSL Bus Compressor plug in (ver 2) is the closest to the hardware that i have experienced. The UAD version sounds great and anyone with a home or project studio, you will do just fine without the hardware version and you will save a lot of money. The plug in will help add that forward sound to your mix quite well. The difference is not that big and on standard car speakers, the general public would not notice the difference.
Is the hardware different enough to justify paying additional thousands of dollars for the serious engineers and artist who take their music further than making music for yourself and friends? For about a 10 percent difference, I would say yes. I found that software company's can model EQ's closer than they model compressors due to the complexity of compressors.
The hardware brings forward the vocals and instruments in a mix that adds this energy and excitement that the plug in lacks. I heard the delay of a guitar more clearly in one example I tried it on. The reason is, it brought it a little more forward than the plug ins out there. There is also the fun factor when using hardware over using a mouse and software. But sometimes (like any piece of gear) it's not the best choice for a song based on its style or perhaps the way it was recorded. I found with some music, I preferred my Rupert Neve Portico 5043 compressor when I needed more weight, and or color added it a mix.
This compressor is a classic, and you can hear why once you use it.