I have a Boss Pocket GT headphone amp that I use as a pre amp also. It has 99 different pedal settings you can use or set. The first 60 are guitar type settings, the next 20 are bass settings and the last 10 are custom settings. You can pare the unit with a phone or tablet and it opens up all types of customization. There are various Youtube videos on the box. I like the box because I can use it on a guitar one minute then switch it over to the bass the next. I only had the unit for a month and I like it a lot. It follows their Katana series amps that allow you to custom the amp to simulate other amps or pedals.