OTL Asylum OTL, Output Transformerless Amplifier User Group.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ OTL Asylum ]

---

[ Alert Moderator ]

---

RE: Modern OTL definition?

Posted by Ralph (M) on June 6, 2008 at 12:56:44

In Reply to: Someone Please Explain. posted by Larry I on June 5, 2008 at 15:23:29:

Years ago the acronym was created for a tube amp that had no output transformer. In the late 1960s/early 1970s, Allied Radio Shack and possibly a few others did use the acronym to describe a fairly (by today's standards) generic transistor amp. They used 'ITL' to say Input TransformerLess as well. At that time there were transistor amplifiers that had input transformers to the final stage, AR, Eico, Pioneer (and therefore Alled Radio Shack) were all guilty of this. Some, like the MacIntosh, had output transformers as well. as transistor designs gained sophistication and diverged from tube-style topologies, the acronym lost its value, which had been used strictly for marketing reasons to being with.

Obviously for any amplifier that employs transistors in the output, the acronym has little real meaning today. So the term 'OTL' comes with the assumption that the amplifier is all-tube (the same thing that it did in the 1950s): a tube amplifier that operates without an output transformer of any sort to drive its load. Clearly the Tenor does not meet this definition, nor did the NYAL Moscode.

If what you say is true, the moderator of the Tone Audio forum was operating out of ignorance as the facts above *are* generally known.

This post is made possible by the generous support of people like you and our sponsors:

Schiit Audio

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---