|
SET Asylum Single Ended Triodes (SETs), the ultimate tube lovers dream. |
|
|
|
SET Asylum Single Ended Triodes (SETs), the ultimate tube lovers dream. |
|
In Reply to: That's funny... posted by PakProtector on August 13, 2011 at 15:25:58:
But we live in the real world and not in a theoretical one - we might be able to build 1ohm speakers with 100db sensitivity - The real world we get stuck with dumb designs like the Apogee Scintilla which goes down to 1ohm with horrible sensitivity and when you can get an amp to drive it - the sound is phenomenally overrated (read lousy and a good reason they went belly up because most people when hearing them chortled to themselves when dealers told them the price of the things).
A flat impedance of 4 ohms would be better than one that dips and dives but is rated at 8 ohms nominal. Magnepan is fairly stable at 4ohms and so there is no good reason a SET can't run them - indeed, the Audio Note Soro at ~15 watts drove them better than 150Watt plus Bryston - the bass was deeper and weightier on the Soro too so there!
"What Tubes Want
Tubes like a resistive load - it's really that simple. A resistive load translates to a flat impedance, and an inductive rather than a capacitive phase angle. A less technical way of looking at an ideal speaker from a tube's point of view is as follows: tubes like consistency. They prefer a speaker that doesn't swing from 8 ohms to 2 ohms and back again. If the impedance is going to dip it should do so gradually, or in small dips. Tubes like a steady load - capacitance is the opposite. When a speaker behaves in a capacitant manner, it presents an uneven load to the amp, asking for current in sudden spurts. Tubes don't like to pump out current at the drop of a hat. They prefer a consistent and predictable load.
Naturally it is sometimes difficult for speaker manufacturers to keep all the aforementioned variables in their ideal ranges. If phase angles must be capacitive, impedance should be high. The lower the impedance, the flatter it must be, and the less capacitive the phase angles must be. All three variables (slope of impedance, value of impedance, value of phase angle) together determine how good a match a speaker will be for a tube amp.
For this reason, the argument that only speakers with an impedance of 8 ohms or higher will work on tubes is incorrect. There are many tube friendly speakers whose nominal impedance is 4 ohms. If the speaker's impedance is relatively flat and consistently hovers around 4 ohms, and if the phase angles are only slightly capacative, or better yet inductive, there is no reason why a 4 ohm speaker cannot perform well on a tube amplifier. Some of our favorite tube friendly speakers are 4 ohms! It is also important to recognize that one need not use the 4 ohm taps on a tube amp with 4 ohm speakers. Many 4 ohm speakers sound their best when hooked up to 8 ohm, or even 16 ohm taps. If the speaker presents a resistive load (i.e. the impedance is flat - even though it is low) the 8 or 16 ohm taps will work fine, and always sound better than the 4 ohm taps. If the speaker requires more current because the impedance is low and and not terribly flat, the 4 ohm taps will likely offer better bass control at the expense of definition in the highs and mids." http://www.dhtrob.com/overige/tubefriendly_lsp.shtml
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: That's funny... - RGA 20:46:39 08/13/11 (1)
- Efficiency vs. sensitivity and then there's impedance - kurt s 23:13:18 08/13/11 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
