really basic question

[cuallito]

What does OTL stand for and what makes an OTL different from a normal amp? And I did do a search here and on google.

 

[Steve Eddy]

What does OTL stand for and what makes an OTL different from a normal amp? And I did do a search here and on google.

(O)utput (T)ransformer(L)ess. They're different from normal TUBE amps (and some McIntosh solid state amps) in that they don't use an output transformer.

se

 

[SY]

OTL = "Output transformerless" and means just what it says; the output stage is either direct coupled to the load or coupled through a capacitor. In either case, it's done without the benefit (and detriment) of an output transformer acting like a transmission in a car.

The virtues and drawbacks of the approach are many, but in general, they're most suitable for high impedance loads.

 

[ray_moth]

It stands for "Output-Transformer-Less". OTL is different from a normal tube amplifier in that it drives the speaker directly, without an intermediate output transformer, like a transistor amplifier.

Rgds, Ray

 

[cuallito]

thanks, that's kind of what I gathered. What's considered a "high impedance" load anyway?

 

[ErikdeBest]

High impedance

The input of an amplifier (tube or SS) is high impedance. That´s why most pre-amp´s are OTL. Some headphones are also high impedance (300 ohms), allowing the use of an OTL hedphone amp. (Look at www.headwize.com, almost al headphone amps are OTL)

Low impedance are nowadays speakers.

 

[planet10]

thanks, that's kind of what I gathered. What's considered a "high impedance" load anyway?

In today's world 16 ohms or higher ... Philips for awhile built 800 ohm speakers and mated them with OTLs.

dave