SGA1566 emulates a vintage single-channel tube preamplifier. It features two 12AX7 tube amplification stages and a two-band Baxandall equalizer, placed either at the input or the output stage.See also: Free Saturation VST Plugins
The plugin also offers two different CPU performance modes, offering improved stability and compatibility with older and less powerful machines. The low CPU mode is less demanding, at the cost of slightly lower tube circuit emulation accuracy.
SGA1566 sounds especially well on drum loops and synthesized bass sequences. It colors the sound very pleasantly, adding the right amount of tube-style saturation on top. The built-in EQ does its job well in combination with the tube circuit.
The plugin is definitely worth a try if you need a device for coloring your audio tracks and adding a bit of depth and sparkle to digital sounds.
Performance-wise, things could be better. The default performance mode uses around 25% CPU on my Intel Core i3 processor (tested in a 64-bit DAW). The low CPU mode drops this value by around 10%, and turning off stereo mode can reduce the CPU hit a bit more.
On the other hand, increasing oversampling from 1X to 4X on the default setting increases the CPU hit to over 90%. Either way, the plugin definitely sounds good enough to see myself using it for offline editing and sound design in the future. However, I doubt that I’ll be using it as an insert in music projects too often.
But that’s a fair trade-off.
I’ll always take a great sounding effect that puts a bit more strain on the CPU over a low-quality plugin that just doesn’t sound that good. I actually found that using high-CPU plugins can help speed up the music production workflow.
Try bouncing the audio track that uses CPU-intensive plugins and then simply removing those plugins from the project. It eliminates the temptation of re-tweaking various plugin parameters later on in the mixing stage.
Shattered Glass Audio has recently released another interesting freeware plugin called Ace. It is a rather spot-on emulation of the old Fender Champ guitar amplifier, perfect for getting that creamy vintage guitar tone in the box.
Download: SGA1566 (1.12 MB download size, EXE installer, 32-bit & 64-bit VST/AU plugin format for Windows & macOS)