Does anyone know of a small in line volume boost plug or cable? I am looking for something very small and portable. Here is what I have. I bought a jamstack portable amp that mounts to my guitar. It purports to make an electric guitar nearly as portable as an acoustic, for things like campfires and beach use or playing around the house. It does work as designed and works well with one caveat. It is not very loud. I am in search of a small lightweight solution that I could use, onboard (no pedals). I had envisioned a small plug that simply plugged into the guitar side or the Jamstack side that would give me some gain but so far I cannot see that exists. I found a cable called a powerwire which purports to be a volume booster (uses batteries) and found one on Reverb from CME for a very affordable price ($20) but it arrived DOA. CME was really great about it and instantly refunded my $$, but now I am back to zero. Jamstack has announced a new version that fixes the volume issue but I am several hundred dollars into it now (I bought 2) and am searching for an after market solution to increase volume without adding a lot of weight bulk to this rig. Anyone? Please advise.