Little Dot Tube Amps: Vacuum Tube Rolling Guide A quick introduction: Who is this guide for? (plus some background) When I purchased my first Little Dot amplifier in 2005 I was in a position many of you are in now. I was new to high end headphones, and curious about the ‘tube’ sound. Being a student at the time I wasn’t in the financial league to afford a high end tube amp, and I began to look for the best “bang for the buck” I could find in an intro level amp. It was in that context that I purchased my first Little Dot amp and began my very satisfying journey through the world of tube rolling. Setting aside a little time each week, the following guide and tube ratings are compiled from notes I made during listening sessions with a Little Dot MkIII fed by a HeadRoom Max DAC (lossless files from MacBook Pro via USB). My reference headphone is the Sennheiser HD650 and all of the tubes I listened to are matched pairs unless otherwise noted. The tube descriptions and ratings in this guide are observations from my own subjective experience and as we often say on this forum - your mileage may vary. I hope you will find this guide a useful reference and have as much fun reading as I did while writing it. Please share your own tube rolling impressions in this thread. Happy listening! Which Little Dot amp is this guide for? The tubes reviewed in this guide can be used in all current production (2011) LD tube amps. If you are not sure which tube family works with your amp (including out of production LD amps), please refer to this list for more information or ask us in this thread. - DoA -= Contents =- [click on chapter titles to go there directly] [sections marked in red are incomplete] 1. EF91 FAMILY 1.1 Overview 1.2 Brimar EF91 1.3 Mullard EF91/6AM6 1.4 Mullard M8083/CV4014 1.5 Telefunken 6AM6 2. EF92 Family 2.1 Overview 2.2 Ediswan EF92 2.3 Mullard CV131/6CQ6 2.4 Mullard M8161/CV4015 2.5 MWT W77 2.6 United Electron EF92 3. EF95 Family 3.1 Overview 3.2 Amperex 5654 3.3 Chinese 6J1 3.4 Collins 6AK5 3.5 GE 5654 3.6 GE 5Star 5654 (Gray plate) 3.7 GE JAN5654W 3.8 Mullard M8100 / CV4010 3.9 RCA 5654 3.10 Voshkod 6ZH1P-EV 3.11 Sylvania 5654 3.12 Sylvania Gold Brand 5654 3.13 Tung-Sol 6AK5 3.14 Western Electric 403B 3.15 Westinghouse 5654 4. Power Tubes 4.1 Overview 4.2 Chinese 6N6 4.3 Russian 6H6P 4.4 Russian 6H6P-I 4.5 Sovtek 6H30EB 4.6 Electro-Harmonix 6H30Pi Gold 4.7 6H30P-DR 5. Conclusion 5.1 Can’t Decide Which Tube to Try? 5.2 Online Tube Sellers 5.3 Useful Links .