I Just recently got into the audio world, since purchasing my DD-1, like 3 months ago, have used it to set my gains on two HU, three amps (my equipment), cousins HU two amps, co-workers HU, Crossover, three amps. Trust me having this tool is not a one time use deal. It has paid for itself and more in the short time I've had it. Absolutely don't regret buying it.