Helix Models Definitive Cheat Sheet - All model names with descriptions in Helix Posted December 17, 2019 On 2/5/2018 at 8:02 PM, hefonthefjords said: Is there any way to make another copy without all the colors? Just plain text would be far more usable for me. Just plain old plain old text. Or text and columns, but black text on dark color backgrounds in small fonts is not very helpful for older people like myself. Thanks. On 2/5/2018 at 8:02 PM, hefonthefjords said: OK, so after some digging what I've found out is that in the HD500 the Studio Tube Pre model was a model of the "Requisite Audio Y7" tube preamp; a hand built tube preamp that is no longer made as Requisite Audio replaced it in their lineup with a preamp called the "PAL - Preamplifier and Limiter". I can't find any direct mention of the model in Helix's manual or anywhere else credible but I would guess that it may well be the same Y7 preamp. The Y7 is considered the holy grail of studio mic preamps so it has that going for it. If any of the actual Line 6 guys care to comment I'd certainly be interested to know what preamp it actually is modelled from. :) I've added it to the PDF in a separate section of it's own since it technically isn't a guitar amp and updated the file in the original post. Made this in Illustrator so no excel file to post I'm afraid. Sorry.