I think you meant wall-warts. They are switch mode psu’s (SMPS) that can add noise to the component and can bleed noise back into the AC source.
If this is what you mean, then it is best to replace them with a linear power supply containing a toroidal or R-core transformer. This would provide cleaner power and lower the noise floor. There are also now some good quality SMPS with transformers that can be substituted for a stock wall-wart.
If this is what you mean, then it is best to replace them with a linear power supply containing a toroidal or R-core transformer. This would provide cleaner power and lower the noise floor. There are also now some good quality SMPS with transformers that can be substituted for a stock wall-wart.