Dec 17, 2017 · The difference between a 12ax7 and a 12ax7a has to do with the way the heaters are wired. The 12ax7 can only be used in circuits where the heater circuit is wired in parallel, …

Feb 16, 2024 · Having owned MC30's, MC75's, single and dual MC275's and the mighty MC2301's along with a half dozen McIntosh vintage & modern preamps you can chase NOS …

May 31, 2018 · 12AX7A is an "updated" lower noise version of 12AX7, and as Mr. Hoffman said it has to do with the way the heater is designed. Another 12AX7 "update" are 7025 tubes which …

Jun 5, 2021 · The 12AX7 is used in most tube amplifiers. I think I heard about every 12AX7 tube ever made including rare European tubes as I owned 1000s of NOS...

Mar 3, 2005 · Okay, while we're at it, anyone have a preference on the best sound in 12AX7A/ECC83 pre-amplifier & 12AT7/ECC81 power driver tubes? Daddy Tonmeister? …

Nov 30, 2007 · Ruby 12AX7A (comes with Bellari, made in China) Sovtek 12AX7LPS; JJ/Tesla ECC83; Tung-Sol New Production 12AX7; Ei 12AX7EG; Mullard New Production 12AX7 …

Jan 22, 2018 · I have three pairs of 12AX7A tubes two pairs of 12AX7A Hit Ray, a Japanese joint venture in the 60's between Hitachi and Raytheon (these are damn cheap and beautifully …

Mar 3, 2005 · Someone on SH sent me these , Baldwin 12AX7A, I believe he told me their pretty similar to the, 12AX7 (2) Mullard NOS Late 1960s, “B” Factory, EICC I have in my Manley …

Mar 3, 2005 · After using an Amplitrex to match up the telefunken 12AX7s in my IO (6 pairs in the main unit plus another sextet in the power supply) I am convinced that to get any idea of what …

Mar 3, 2005 · I've tried, and had good success with the new Gold Lion 12AX7's & 12AU7's. I had one of the Gold Lion 12AX7's go south earlier than I would like.