# guides
here is a small collection of useful tricks and techniques to really make Furnace sing.
- [using samples with limited playback rates](limited-samples.md)
- [choosing emulation cores](emulation-cores.md)
- [using OPLL patch macro](opllswitching.md)
- [using AY/SAA hardware envelope](envelope.md)
# links
- [FM Synthesis of Real Instruments](http://www.javelinart.com/FM_Synthesis_of_Real_Instruments.pdf): an in-depth tutorial on creating FM patches from scratch.