Dramastic is offering this SL version partly due to supply chain shortages on transformers and long backorders. In the future when transformers become available in-stock again, you will have the option to upgrade your unit if desired to a transformer version. For the upgrade process, you can mail the unit back to Dramastic for installation and calibration, or do self installation with supplied instructions. Self installation will require taking off the lid cover, disconnecting ribbon cables, undoing some screws and replacing the old circuit board with replacement transformer circuit board. You'll also need to adjust some internal jumpers and perform calibration to trimmers in conjunction with any DAW that can read to 0.01db. Zero soldering required. Contact us for estimated costs and timeline.
The Obsidian SL version will have a wider frequency response range (extended high frequency response) with no transformer coloration. This may be preferable to some studios, for example for mastering situations requiring cleaner signal path.
This is a fantastic sounding unit, high build quality and superb analog sound. It's our favorite SSL-style bus compressor, incredible for mixing, mastering and even tracking too, especially drums.