In the context of blind equalization, a new class of Bussgang techniques called Constant Norm Algorithm (CNA), which contains the well-known CMA, is developed. From this class, two new cost functions designed for QAM modulation are derived. The first, named CQA for Constant sQuare Algorithm, is better adapted for QAM than the CMA. It results in a lower algorithm's noise without an increase of complexity. The second, is a weighting between the CMA and the CQA to get the advantages of both. The weighting coefficient is dynamically driven and justifies the name of Constant Dynamic Norm Algorithm (CDNA), which performs the same convergence speed as the CMA with a lower algorithm's noise.