The SC1999 from Altronics is a DIY compressor for low-level signals such as a microphone or instrument output. It could be great for compressing a mic signal before hitting the preamp to achieve more uniform saturation.

Notable Features:

• Accepts low-level inputs
• Ratio, limiter, input, and output gain controls

Price: $31.95 for complete kit

Order at Altronics.com.au.