Many modern solid-state preamplifiers have eliminated the traditional input-coupling transformer altogether, and in many cases the output coupling transformer as well. This not only saves space, weight and money, but also offers a more direct route for the signal to travel as it makes its way through the signal path.
So, do transformerless designs sound better? Not necessarily! Transformers add their own special alchemy to the mix. Call it coloration, but transformer coupled designs tend to sound punchy and full-bodied. Transformers also offer the benefit of true electronic isolation. This greatly enhances a preamp’s ability to interface with other equipment with minimal noise, RF, hum or induced interference. Once again, it’s a matter of taste and, in some cases, budget. Transformer coupled amplifiers usually cost more than their ironless cousins.