Great article about Class A amp operation

heiney9
heiney9 Posts: 25,165
edited August 2008 in 2 Channel Audio
I alway find these articles from Nelson Pass very informative. Of course I like his design philosophy but he seems to be able to break it down into basic units of information the hobbiest with a little knowledge can understand.

Take some time and read it answers some questions that are asked here a lot regarding Class A operation and Class A/B operation of amplifiers.

http://passlabs.com/pdf/articles/leaving_class_a.pdf

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 Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
Post edited by heiney9 on
· Share on FacebookShare on Twitter

Comments

  • steveinaz
    steveinaz Posts: 19,538
    edited July 2008
    Cool.
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
    · Share on FacebookShare on Twitter
  • engtaz
    engtaz Posts: 7,663
    edited July 2008
    Thanks H9.

    engtaz
    engtaz

    I love how music can brighten up a bad day.
    · Share on FacebookShare on Twitter
  • dmaic
    dmaic Posts: 8
    edited July 2008
    Good info, thanks!
    · Share on FacebookShare on Twitter
  • reeltrouble1
    reeltrouble1 Posts: 9,312
    edited July 2008
    Nelson Pass is my hero because he understood a fully balanced circuit was better before buying balanced connectors became vogue with audiofools.

    RT1
    · Share on FacebookShare on Twitter
  • heiney9
    heiney9 Posts: 25,165
    edited July 2008
    reeltrouble1 wrote: »
    Nelson Pass is my hero because he understood a fully balanced circuit was better before buying balanced connectors became vogue with audiofools.

    RT1

    The utter simplicity of his balanced circuit and his absolute commitment to 3 or less gain stages is what has always impressed me. Plus the fact that he is very involved in the DIY community and always has released his designs after they have run their course, usually within 5 years. I don;t know of any other pioneering audiophile that lets his schematics out and then helps DIYers build his designs.

    I will own a piece of his one day. Right now it seems when I have the cash in hand there are none to be found and when the money's spent there are 2 or 3 available.

    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 Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
    · Share on FacebookShare on Twitter
  • mhardy6647
    mhardy6647 Posts: 33,803
    edited August 2008
    The thing I appreciate most about Nelson Pass is his willingness to share his ideas pretty freely for the DIY community.
    www.passdiy.com
    · Share on FacebookShare on Twitter
  • stuwee
    stuwee Posts: 1,508
    edited August 2008
    Great read! I struggled with all the "new" class A configs, like my goobby-**** Yamaha I settled on, "Hyperbolic Drive" WTF is that?? Yamaha can't even give a straight answer,:confused:, I like the sound :D so, :), alot of the 'old' designs, though straitforward, have some parts in the good luck finding them if they fail catagory. the Pioneer Series M's back in the 80's for instance. Everything is fixable if you know ways around problems or, have Nelson Pass, Bob Carver, or crazy James Bonginorno to help out.

    I guess I miss the good ol' days of KISS, made by characters for characters and sounded sweet, where's my space heater Futterman's :eek:

    Craig
    Thorens TD125MKII, SME3009,Shure V15/ Teac V-8000S, Denon DN-790R cass, Teac 3340 RtR decks, Onix CD2...Sumo Electra Plus pre>SAE A1001 amp>Martin Logan Summit's
    · Share on FacebookShare on Twitter
  • ben62670
    ben62670 Posts: 15,969
    edited August 2008
    mhardy6647 wrote: »
    The thing I appreciate most about Nelson Pass is his willingness to share his ideas pretty freely for the DIY community.
    www.passdiy.com

    He is great. Also Walt Jung, and Peter Daniels(kinda dry though). I know I am leaving out a few, but these guys have helped me quit a bit. Another great one I have meet is Anatech. This guy is stellar. He had an accident a while back, and is suffering pretty bad so those who pray if you could kindly add him to your list that would be great.
    Thanks again H9 for the introduction to Chris.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
    · Share on FacebookShare on Twitter
  • mhardy6647
    mhardy6647 Posts: 33,803
    edited August 2008
    Two other pros who share freely out of proportion to their "obligation" to do so.

    Pete Millett www.pmillett.com
    Erno Borbely http://www.borbelyaudio.com/

    Characters?
    Jim "Great American Sound/Ampzilla" Bongiornio

    http://www.ampzilla2000.com/James_Bongiorno.html

    He pops up on DIY forums, but has a tendency to end up in urinating contests with folks who ultimately drive him away (too bad, IMO, 'cause he's a heck of a resource).

    son-of-ampzilla-amplifier-bongiorno-photo.jpg
    · Share on FacebookShare on Twitter
  • Systems
    Systems Posts: 14,873
    edited August 2008
    mhardy6647 wrote: »
    The thing I appreciate most about Nelson Pass is his willingness to share his ideas pretty freely for the DIY community.
    www.passdiy.com
    Yes he certainly has been generous to DIY'ers.Back in the mid 90's I built one of his ZEN amps that he published in Audio Amateur magazine and since then have built several of his preamps.His articles gave me the know how to build my own components for a fraction of what it would have cost to buy.
    Testing
    Testing
    Testing
    · Share on FacebookShare on Twitter
  • sucks2beme
    sucks2beme Posts: 5,601
    edited August 2008
    I had a chance to meet Pete Millett last year at a Head-fi meet.
    He had several of his new prototype headphone amps out for display.
    Heck of a nice guy!
    "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
    · Share on FacebookShare on Twitter
  • ben62670
    ben62670 Posts: 15,969
    edited August 2008
    This hobby is pretty cool. I have been in touch (internet anyways) with some great guys. MP even sent me some advice on building my custom SDA's. I felt like I had meet... well not Jesus, but it deffinetly was a thrill that him, and a lot of these brillient men are down to earth.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
    · Share on FacebookShare on Twitter
  • heiney9
    heiney9 Posts: 25,165
    edited August 2008
    ben62670 wrote: »
    He is great. Also Walt Jung, and Peter Daniels(kinda dry though). I know I am leaving out a few, but these guys have helped me quit a bit. Another great one I have meet is Anatech. This guy is stellar. He had an accident a while back, and is suffering pretty bad so those who pray if you could kindly add him to your list that would be great.
    Thanks again H9 for the introduction to Chris.
    Ben

    Chris (Anatech) is a straight shooter and knows his sh#t. Certainly as asset to the DIY community. If he wans't in Canada I'd send my gear to him for an overhaul/upgrade.
    "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 Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
    · Share on FacebookShare on Twitter
  • ben62670
    ben62670 Posts: 15,969
    edited August 2008
    heiney9 wrote: »
    Chris (Anatech) is a straight shooter and knows his sh#t. Certainly as asset to the DIY community. If he wans't in Canada I'd send my gear to him for an overhaul/upgrade.

    Have you seen him around? If you bump into him let him know I have been thinking of him. The last year he has come, and gone. I saw a thread pertaining to this very same thing. He has been my mentor when it comes to fixing Adcom's.
    Ben
    Please. Please contact me a ben62670 @ yahoo.com. Make sure to include who you are, and you are from Polk so I don't delete your email. Also I am now physically unable to work on any projects. If you need help let these guys know. There are many people who will help if you let them know where you are.
    Thanks
    Ben
    · Share on FacebookShare on Twitter