Pls. explain 'single ended'

Discussion in 'Amps and Cabs' started by AaeCee, Mar 15, 2006.

  1. AaeCee

    AaeCee Member

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    Could you explain this phrase in the simplist terms? I understand some tube amp basics, but declaring myself anything but a novice in the area of electronics is a stretch. Thanks, AC
     
  2. johnny5

    johnny5 Supporting Member

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    single ended amps discibe a type of amp topology. normally in guitar amps their is at least one gain stage, a phase splitter, and a power section of at least two tubes. each one or pair of these power tubes amplifies only one-half of the signal (top or bottom half of a sine wave).

    in a single ended amp, there is no phase splitter and usually there is only one power tube which takes and amplifies the enitire signal. they are different sounding and way less efficient which makes them great for lower volume amps.
     
  3. Jon Silberman

    Jon Silberman 10Q Jerry & Dickey Gold Supporting Member

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    The simplest terms? I'll give it a try:

    The whole tube is on all the time.
     
  4. gregc

    gregc Member

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    Sometimes you'll see the 'single ended' phrase used to describe a method of eliminating noise and grounding loop/hums by only connecting one end of a cable shield to 'ground'. Simply called, 'single ended'. It works!

    gregc
     
  5. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    I give it up to Randall Aiken for the most in depth description for both Class A, and single ended and push/pull type amps. Read about it here:
    http://www.aikenamps.com/ClassA.htm
     
  6. AaeCee

    AaeCee Member

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    Great stuff all. Thank you. So can you have a 'single ended' amp with 2 output tubes? Something tells me the answer may be yes, but in the strictest definition, it would seem to be no. Thanks again...as I said, I'm kinda thick when it comes to issues dealing with current. AC
     
  7. reaiken

    reaiken Member

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    Yes, you can have a single-ended amp with two (or more) tubes. It is called "parallel single-ended" or PSE. The "single" part refers to the fact that the tubes are connected to a single side of the output transformer instead of both sides, as in push-pull (double-ended). The other side of the output transformer is connected to the supply voltage.

    Randall Aiken
     
  8. Scumback Speakers

    Scumback Speakers Gold Supporting Member

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    Hey, no worries! Yes, you can have one, two or four power output tubes in single ended designs. I hear there's an amp called the "So Flo Smart Aleck" that's got three 6V6 tubes in single ended Class A, too.

    They run in parallel, and while not watts efficient, they put out a very full sound with both even and odd harmonics, resulting in a rich tone.
     
  9. AaeCee

    AaeCee Member

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    Thanks, Randall. And BTW, LOVE my (now sadly discontinued) #8 Intruder...with the real plexi panel!
    And Southbay, I'll be calling you in the next few days. Need one of your legendary speakers for a new cab (not the Aiken). :AOK AC
     
  10. riffmeister

    riffmeister Gold Supporting Member

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    THD Univalve is an example of a single-ended amp with one power tube.

    THD BiValve is an example of a parallel single-ended amp with two power tubes.
     
  11. AaeCee

    AaeCee Member

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    OK. One more question, guys. Promise. Is there a characteristic 'sound' to single ended vs. double ended (push-pull...see, at least I get one part)? And are there any major advantages, other than tonal, to one vs. the other? I know this can get deep and complex, so just a few central points. Many thanks, AC
     
  12. riffmeister

    riffmeister Gold Supporting Member

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    push-pull is more efficient, I believe.
     
  13. AaeCee

    AaeCee Member

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    'Efficient', meaning more decible per watt?
     
  14. riffmeister

    riffmeister Gold Supporting Member

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    meaning more decibels out per volt going in

    also, I can't remember which way it goes, but one arrangement has a greater amount of even order harmonics, the other arrangement has a greatrer amount of odd order harmonics.
     
  15. JJman

    JJman Member

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    I find the lumberjack analogy works best when describing both SE vs PP and Class:


    SE:
    One (or more) lumberjacks all on the same side of the saw (all need to push then pull at all times to avoid stopping the saw's movement, so also Class A.)

    PP:
    One (or more) lumberjacks on each end of the saw

    Class A:

    All lumberjacks are pushing or pulling at all times

    ClassAB:

    All lumberjacks are pushing 50% of the time and pulling less than 50% of the time

    Class B:

    All lumberjacks push 50% of the time and never pull.
     
  16. Serious Poo

    Serious Poo Armchair Rocket Scientist Graffiti Existentialist Gold Supporting Member

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    FWIW, another great resource is Randy Smith's writeup at the Mesa Boogie site. I found it very helpful in learning about this stuff.
     

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