I use it with tube amp Marshall DSL20HR at home and I am sure, that this attenuator can release all power of your amp with great sound! This device will show you a huge diffrence between using a tube amp on low master volume level with high risk to disturb your neigbours and using it with normal master level and acceptable loud, especially with high gain. I was afraid, that it reduces sound quality, but since I got it, I don't see any alternate to use tube amp at home without attenuator now.
Simple in use and good quality.
For such price there is few features, but I bought it only for good sound quality at low volume and I got the desired.
Also, there is no any active cooler inside, so you will not hear any extraneous noise.