Free Shipping on All Orders 1-866-764-1801

Vist our Online Store
+ Reply to Thread
Page 2 of 6 FirstFirst 1 2 3 4 5 6 LastLast
Results 31 to 60 of 174
  1. #31

    Member Sales Rating: (4)

    Join Date
    Nov 2008
    Posts
    3,326

    Default

    Quote Originally Posted by FTGV View Post
    Brock,he gives his XA.5 series the Pure Class A moniker whilst they utilize a push/pull ouput stage.
    I believe it's where he called "Leaving Class A" and the paper explains the intent clearly.

    I also believe I have read his definition of Pure Class A is when an amplifer has a continuous power draw (even at idle)that is equal to or greater than twice the rated Class A output.
    But to some, Pure Class A is not about power draw, not about output wave, but about Single Ended Output Stage and nothing else matters.
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone.

  2. #32

    Member Sales Rating: (26)

    Join Date
    Oct 2006
    Location
    The tube lair in Charlotte, NC
    Posts
    11,322

    Default

    So, I take it that there is no clear definition as to whether an amplifier is or isn't a Class A amplifier, like the definition of pregnant? You are or you aren't...
    In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence.

    The best way to enjoy digital music reproduction is to never listen to good analogue reproduction.

  3. #33

    Member Sales Rating: (0)

    Join Date
    Dec 2009
    Location
    Canuckistan
    Posts
    3,146

    Default

    Quote Originally Posted by megasat16 View Post
    But to some, Pure Class A is not about power draw, not about output wave, but about Single Ended Output Stage and nothing else matters.
    I seem to recall reading something to that effect,but I'm comfortable with Papa's definition.

  4. #34

    Member Sales Rating: (58)

    Join Date
    Feb 2003
    Location
    6 Underground
    Posts
    25,306

    Default

    Quote Originally Posted by treitz3 View Post
    So, I take it that there is no clear definition as to whether an amplifier is or isn't a Class A amplifier, like the definition of pregnant? You are or you aren't...
    Good lord ....it's not an easy question since even within Class A, topology can vary drastically from one manufacturer to another.

    A Class A amplifier is running high current output at all times, from start to finish of the input signal. They are usually very inefficient because they draw so much power due to running both rails and don't switch like and AB amplifier. The draw more power in order to cover the entire waveform. I'm not sure if that's the scientific answer but its a rough explanation. When I get home, I'll open the book and get something more concrete if it hasn't been hit already.

  5. #35

    Member Sales Rating: (2)

    Join Date
    Jun 2004
    Location
    New England
    Posts
    8,284

    Default

    My brain is exploding. Class A still has nothing to do with topology (SE vs. PP) and everything to do with bias (operating points of the active device(s)).

    http://www.learn-about-electronics.c...fications.html
    http://www.smeter.net/amplifiers/cla...-operation.php
    (that latter reference is very clear - it refers to "RF amplifiers"; but one may just substitute "AF" for "RF" when reading the explanations of the amp classes)

    Jeepers, folks, there is marketing and there is technology. The intersection of those two sets tends to be rather scant in hifi. The trade-offs as one marches from Class A to AB to B to C is from highest linearity to highest efficiency.

    I fall squarely in the camp of "trust" your ears... but I also take a cue from Picasso (who learned the conventions and rules of art before he trampled them all): it's really good to understand the nuts and bolts so as to have context to understand and appreciate the "why" of differences one hears. Besides being more intellectually fulfilling, it can probably reduce investment in things like jars of magic pebbles and Quantum Purifiers for hifi applications.
    Last edited by mhardy6647; 05-02-2011 at 08:30 AM.
    all the best,
    mrh

  6. #36

    Member Sales Rating: (58)

    Join Date
    Feb 2003
    Location
    6 Underground
    Posts
    25,306

    Default

    I mean topology as in the design.....and as far as verbage goes. John Curl's Class A circuit isn't the same as a Nelson Pass circuit....or are we not using the word circuit here? I believe I'm going to Heiney roll and just stick to my own thoughts on audio.
    Last edited by dorokusai; 05-02-2011 at 08:28 AM.

  7. #37

    Member Sales Rating: (4)

    Join Date
    Dec 2004
    Location
    flower mound, tx
    Posts
    4,326

    Default

    Class "a" is the resulting output, NOT how you get there.
    Yes, some class "a" amps may not sound better.
    "The legitimate powers of government extend to such acts only as are injurious to others. But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." --Thomas Jefferson

  8. #38

    Member Sales Rating: (2)

    Join Date
    Jun 2004
    Location
    New England
    Posts
    8,284

    Default

    Quote Originally Posted by dorokusai View Post
    I mean topology as in the design.....and as far as verbage goes. John Curl's Class A circuit isn't the same as a Nelson Pass circuit....or are we not using the word circuit here? I believe I'm going to Heiney roll and just stick to my own thoughts on audio.
    You are a wise man -- wiser than I (which I knew already, but I just wanted to point it out for the masses).

    But (better late than never) - I'll just go back to my decidedly single-ended (and thus class A by definition) amps in the living room when I get home...
    all the best,
    mrh

  9. #39

    Member Sales Rating: (58)

    Join Date
    Feb 2003
    Location
    6 Underground
    Posts
    25,306

    Default

    Quote Originally Posted by mhardy6647 View Post
    You are a wise man -- wiser than I (which I knew already, but I just wanted to point it out for the masses).

    But (better late than never) - I'll just go back to my decidedly single-ended (and thus class A by definition) amps in the living room when I get home...
    I'm not sure about that Mark and I believe we're simply splitting hairs without ever really getting into what we both know. At least it isn't cables and there would be death threats and hate filled PM's

  10. #40

    Member Sales Rating: (2)

    Join Date
    Jun 2004
    Location
    New England
    Posts
    8,284

    Default

    I don't post about cables... anywhere!

    I do like stuff that sounds good - to me. Oh, and I am a cheapskate when it comes to anything that stands between me and early retirement. Pretty much sums it up.
    all the best,
    mrh

  11. #41

    Member Sales Rating: (16)

    Join Date
    Mar 2005
    Location
    In A Van Down By The River
    Posts
    21,236

    Default

    Quote Originally Posted by dorokusai View Post
    I mean topology as in the design.....and as far as verbage goes. John Curl's Class A circuit isn't the same as a Nelson Pass circuit....or are we not using the word circuit here? I believe I'm going to Heiney roll and just stick to my own thoughts on audio.
    That's fine.....Tom started another thread and I linked to the 10+ page thread we all had a discussion on not too long ago about class A. I also linked the same articles I've linked numerous times over the past few years from NP's POV. Because 1) they are my most handy bookmarks 2) he has a way of explaining more complicated ideas in a simple easy to follow way and he gives the "why" behind the idea/circuit. That's not to say his is the only way.

    For me Pure Class A is pretty cut and dried (it's Single Ended), but there are lots of interpretations by other audio designers and people like us that just love the hobby.

    I have yet to hear any other amplifier that "sounds" like a single ended class A amplifier. And, no I haven't listened to every amplifier made. There is something special about a Pure Class A amplifier which I find especially pleasing and intoxicating. The cost, heat and hardware certainly mean they aren't for everyone. And there are numerous rigs they aren't the best choice for such as very, very power hungry speakers or perhaps a huge listening roon or someone who ultimately cares only about reaching ear bleeding spl's. It just works very, very well in my system and the synergy is incredible. I have never needed anything more than the 30wpc it provides and I have yet to really see the limits of the amplifier.........and I've tried.

    I am going to sit this one out as every other time this subject has come up I've made my POV known and I was even sent a PM once and asked to give it a rest not all that long ago. It seems some don't enjoy my passion for this subject.

    H9

    H9
    Last edited by heiney9; 05-02-2011 at 09:51 AM.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30; Eastern Electric Mini Max; Adcom GDA600; MIT S3/Z Pc; SDA 1C; Squeezebox; Tubes add soul!

  12. #42

    Member Sales Rating: (58)

    Join Date
    Feb 2003
    Location
    6 Underground
    Posts
    25,306

    Default

    H9 - I know what you mean and knew that everything existed here already...let alone recently. I wondered why Treitz posted it at all but figured he had a reason and just added a couple comments, of which he probably doesn't care about anyways.

    Do you guys have any other books that you've read concerning amplifier design and the like, that I may want to pick up?
    Last edited by dorokusai; 05-02-2011 at 09:55 AM.

  13. #43

    Member Sales Rating: (16)

    Join Date
    Mar 2005
    Location
    In A Van Down By The River
    Posts
    21,236

    Default

    Quote Originally Posted by treitz3 View Post
    So, I take it that there is no clear definition as to whether an amplifier is or isn't a Class A amplifier, like the definition of pregnant? You are or you aren't...
    For me there is, atleast for the term Pure Class A; it's Single Ended.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30; Eastern Electric Mini Max; Adcom GDA600; MIT S3/Z Pc; SDA 1C; Squeezebox; Tubes add soul!

  14. #44

    Member Sales Rating: (0)

    Join Date
    Dec 2009
    Location
    Canuckistan
    Posts
    3,146

    Default

    Quote Originally Posted by mhardy6647 View Post
    My brain is exploding. Class A still has nothing to do with topology (SE vs. PP) and everything to do with bias (operating points of the active device(s)).
    Game, set, match.

  15. #45

    Member Sales Rating: (0)

    Join Date
    Dec 2009
    Location
    Canuckistan
    Posts
    3,146

    Default

    Quote Originally Posted by dorokusai View Post

    Do you guys have any other books that you've read concerning amplifier design and the like, that I may want to pick up?
    Bob Cordell and Doug Self both have excellent books regarding amplifier design.

  16. #46

    Member Sales Rating: (16)

    Join Date
    Mar 2005
    Location
    In A Van Down By The River
    Posts
    21,236

    Default

    Quote Originally Posted by mhardy6647 View Post
    My brain is exploding. Class A still has nothing to do with topology (SE vs. PP) and everything to do with bias (operating points of the active device(s)

    .
    But it's still A/B unless the power devices never turn off. Splitting hairs I known, but it's mostly because the claim and phrase Class A has been so abused by marketing departments that the term is watered down and used for everything under the sun.

    Pure Class A is singled ended, end of story in my eyes. Everything else is A/B.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30; Eastern Electric Mini Max; Adcom GDA600; MIT S3/Z Pc; SDA 1C; Squeezebox; Tubes add soul!

  17. #47

    Member Sales Rating: (2)

    Join Date
    Jun 2004
    Location
    New England
    Posts
    8,284

    Default

    Quote Originally Posted by heiney9 View Post
    But it's still A/B unless the power devices never turn off. Splitting hairs I known, but it's mostly because the claim and phrase Class A has been so abused by marketing departments that the term is watered down and used for everything under the sun.

    Pure Class A is singled ended, end of story in my eyes. Everything else is A/B.

    H9
    We're in total agreement about the marketing part, my friend.
    (as well as about the devices never turning off in true class A)
    all the best,
    mrh

  18. #48

    Member Sales Rating: (6)

    Join Date
    Feb 2002
    Location
    Rockledge, Florida
    Posts
    11,600

    Default

    I feel by design PP are AB class, and can't be A class.

    Speakers
    Carver Amazing Fronts
    CS400i Center
    RT800i's Rears
    Sub Paradigm Servo 15

    Electronics
    Conrad Johnson PV-5 pre-amp
    Parasound Halo A23
    Pioneer 84TXSi AVR
    Pioneer 79Avi DVD
    Sony CX400 CD changer
    Panasonic 42-PX60U Plasma
    WMC Win7 32bit HD DVR



  19. #49

    Member Sales Rating: (0)

    Join Date
    Dec 2009
    Location
    Canuckistan
    Posts
    3,146

    Default

    Quote Originally Posted by disneyjoe7 View Post
    I feel by design PP are AB class, and can't be A class.
    I disagree, the amount of bias is what differentiates between A or A/B in a PP design.

  20. #50

    Member Sales Rating: (16)

    Join Date
    Mar 2005
    Location
    In A Van Down By The River
    Posts
    21,236

    Default

    And to add another twist, single ended class A sounds quite a bit different than high bias class A or push/pull class A as some would call it. Notice I carefully said different and not better or worse. That's for the listener to decide.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30; Eastern Electric Mini Max; Adcom GDA600; MIT S3/Z Pc; SDA 1C; Squeezebox; Tubes add soul!

  21. #51

    Member Sales Rating: (4)

    Join Date
    Nov 2008
    Posts
    3,326

    Default

    Quote Originally Posted by mhardy6647 View Post
    We're in total agreement about the marketing part, my friend.
    (as well as about the devices never turning off in true class A)
    hehe...

    Brock, I know you are not wrong but your view of Class A is incomplete. It's missing a hole in the middle.

    May be...just may be, your Papa Pass can fill you in about PP Class A
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone.

  22. #52

    Member Sales Rating: (16)

    Join Date
    Mar 2005
    Location
    In A Van Down By The River
    Posts
    21,236

    Default

    Quote Originally Posted by megasat16 View Post
    hehe...

    May be...just may be, your Papa Pass can fill you in about PP Class A
    James, I'm fully aware of the X and XA series and in the words of "papa" the hybrid topology of marrying the original Aleph (single ended Class A) topology w/ the super symmetry (push/pull) of the X series.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30; Eastern Electric Mini Max; Adcom GDA600; MIT S3/Z Pc; SDA 1C; Squeezebox; Tubes add soul!

  23. #53

    Member Sales Rating: (4)

    Join Date
    Nov 2008
    Posts
    3,326

    Default

    Quote Originally Posted by heiney9 View Post
    And to add another twist, single ended class A sounds quite a bit different than high bias class A or push/pull class A as some would call it. Notice I carefully said different and not better or worse. That's for the listener to decide.

    H9
    Frankly, High Biased Class AB is a later development. There is something called Push Pull Class A using output transformer in the earlier design that doesn't involve with the high biasing Class AB design. It's already biased for SE design and use the output transformer to sums the output. It increase efficiency of SE design.

    It's very much the same to PP Tube Ultralinear amplifiers. In the case of transistors amplifiers, the output devices conducts all 360 degrees of the waveform and there is no crossover distortion to occur.

    And the sound of SE vs. PP Class A amplifiers, you got to be kidding me. The sound of an amp is not based on what class or topology it uses, it's based on how well it's made.
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone.

  24. #54

    Member Sales Rating: (0)

    Join Date
    Dec 2009
    Location
    Canuckistan
    Posts
    3,146

    Default

    Quote Originally Posted by heiney9 View Post
    And to add another twist, single ended class A sounds quite a bit different than high bias class A or push/pull class A as some would call it.

    H9
    Potentially,but it could also be said not all SE designs will sound a like.Lots of variables .

  25. #55

    Member Sales Rating: (16)

    Join Date
    Mar 2005
    Location
    In A Van Down By The River
    Posts
    21,236

    Default

    Quote Originally Posted by megasat16 View Post

    And the sound of SE vs. PP Class A amplifiers, you got to be kidding me. The sound of an amp is not based on what class or topology it uses, it's based on how well it's made.
    Wow!!! I completely disagree!! Each topology sounds completely different.

    I agree with starting with how well it's made. I guess my reference point is from a single designer (NP) and how he has all types of different topologies using a few different types gain devices and they all have their own distinct sound signature.

    Current source, voltage source, Jfets, MosFets, transformer coupled, single ended, super symmetry, Stasis and they all sound the same????? What did he waste his time making so many different types of amps available if all he had to do was make sure they were all well made?

    So in your eyes the X series amp will sound exactly the same as the XA series amp and First Watt amps even though the topologies are different enough?

    H9
    Last edited by heiney9; 05-02-2011 at 01:18 PM.
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30; Eastern Electric Mini Max; Adcom GDA600; MIT S3/Z Pc; SDA 1C; Squeezebox; Tubes add soul!

  26. #56

    Member Sales Rating: (4)

    Join Date
    Nov 2008
    Posts
    3,326

    Default

    Quote Originally Posted by heiney9 View Post
    Wow!!! I completely disagree!! Each topology sounds completely different.

    I agree with starting with how well it's made. I guess my reference point is from a single designer (NP) and how he has all types of different topologies using a few different types gain devices and they all have their own distinct sound signature.

    Current source, voltage source, Jfets, Mosfest, output transformers, single ended, super symmetry and they all sound the same. What did he waste his time making so many different types of amps available if all he had to do was make sure they were all well made?

    So in your eyes the X series amp will sound exactly the same as the XA series amp even though the topologies are different?
    Coz Mr. Pass is not the only one who made amps. There are lots of competitors out there using Class AB topology that sounds as good as any Class A topology. Mr. Pass Love KISS and lots of his design are based on the good solid Engineering. But the Engineering doesn't stop there.

    As for the sound comparison between X and XA, I don't know about the later X.5 series sound. But as I stated in CP long ago, a friend of mine sold XA30.5 and bought X600.5 or something. He said he is very happy with the bigger power. I haven't been to his place since he bought the X.5 amps since he lived about 400 miles near from me.

    Brock, I have amps I can put up against any NP SE Class A amps at my disposal. If we live closer, we can make a shootout sometimes.

    P.S. One other reason it came to my thought is that very fundamental again. Not everyone likes the same taste in sound. What is special to you with Class A amp may be nothing special at all to another person.
    Last edited by megasat16; 05-02-2011 at 01:20 PM.
    Trying out Different Audio Cables is a Religious Affair. You don't discuss it with anyone.

  27. #57

    Member Sales Rating: (16)

    Join Date
    Mar 2005
    Location
    In A Van Down By The River
    Posts
    21,236

    Default

    Quote Originally Posted by megasat16 View Post
    Coz Mr. Pass is not the only one who made amps. There are lots of competitors out there using Class AB topology that sounds as good as any Class A topology. Mr. Pass Love KISS and lots of his design are based on the good solid Engineering. But the Engineering doesn't stop there.

    As for the sound comparison between X and XA, I don't know about the later X.5 series sound. But as I stated in CP long ago, a friend of mine sold XA30.5 and bought X600.5 or something. He said he is very happy with the bigger power. I haven't been to his place since he bought the X.5 amps since he lived about 400 miles near from me.

    Brock, I have amps I can put up against any NP SE Class A amps at my disposal. If we live closer, we can make a shootout sometimes.

    P.S. One other reason it came to my thought is that very fundamental again. Not everyone likes the same taste in sound. What is special to you with Class A amp may be nothing special at all to another person.

    It's not about shootouts or what I think is better. I cannot believe as much as you and Fred have been around this stuff that you can make a blanket statement that topologies don;t matter only how well it's built. That's ridiculous.

    Written words in a few paragraphs never can take the place of a good face to face discussion over a few ice cold beers so as I stated before I am sitting this one out. Way to many assumptions are added by the readers in threads like these (myself included).

    I would appreciate an answer as to why all of NP's designs using various topologies sound different if topology has nothing to do with the way something sounds. I guess he just wasted the 30 years of his life when all he had to do was make sure things were well built then all his amps would sound the same. :tongue:

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30; Eastern Electric Mini Max; Adcom GDA600; MIT S3/Z Pc; SDA 1C; Squeezebox; Tubes add soul!

  28. #58

    Member Sales Rating: (0)

    Join Date
    Dec 2009
    Location
    Canuckistan
    Posts
    3,146

    Default

    Quote Originally Posted by heiney9 View Post
    So in your eyes the X series amp will sound exactly the same as the XA series amp and First Watt amps even though the topologies are different enough?

    H9
    The X and XA share the same basic super sym. circuit topology but I would expect some SQ differences because of the way in which they are biased.

  29. #59

    Member Sales Rating: (16)

    Join Date
    Mar 2005
    Location
    In A Van Down By The River
    Posts
    21,236

    Default

    Quote Originally Posted by megasat16 View Post

    P.S. One other reason it came to my thought is that very fundamental again. Not everyone likes the same taste in sound. What is special to you with Class A amp may be nothing special at all to another person.
    Never said we all had to have the same taste, I said there are difference's in sound and they can be based on topology chosen. I didn;t mean to imply that was the SINGULAR thing.

    You guys read way too much into posts sometimes.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30; Eastern Electric Mini Max; Adcom GDA600; MIT S3/Z Pc; SDA 1C; Squeezebox; Tubes add soul!

  30. #60

    Member Sales Rating: (0)

    Join Date
    Dec 2009
    Location
    Canuckistan
    Posts
    3,146

    Default

    Quote Originally Posted by heiney9 View Post
    It's not about shootouts or what I think is better. I cannot believe as much as you and Fred have been around this stuff that you can make a blanket statement that topologies don;t matter only how well it's built.
    Whoa chief where did I say that?As for blanket statements I believe I have pointed out your doing such on a few occasions.
    Last edited by FTGV; 05-02-2011 at 01:43 PM.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

     

Similar Threads

  1. sound of class d amps vs class ab
    By killerb in forum Car Audio & Electronics
    Replies: 26
    Last Post: 01-05-2012, 11:58 PM
  2. Replies: 34
    Last Post: 02-08-2010, 11:15 PM
  3. Class A, Class B amps, etc.?
    By Norm Apter in forum Electronics
    Replies: 10
    Last Post: 05-26-2008, 09:34 AM
  4. amp shootout
    By mule in forum Electronics
    Replies: 3
    Last Post: 05-20-2008, 06:47 PM
  5. PDX4.150 Class D Midbass against Soundstream Class A/B Midbass
    By Polkemon in forum Car Audio & Electronics
    Replies: 35
    Last Post: 04-10-2008, 08:36 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts