• 01-30-2007, 05:41 PM
    VE4CAN
    Is This Statement Correct?????
    I copied and pasted this from another site and I'm no expert..

    QUOTE:
    All cheap amplifiers use feedback, and there are no amplifiers above 30 -40 Watts without feedback. This is a very important point. There is no solid state amplifier that can be designed totally without feedback.

    Are they correct??????????
  • 01-30-2007, 09:45 PM
    Dusty Chalk
    No, I'm pretty sure the Pass Labs amplifiers have no feedback.

    The 30-40 watts part may be correct. When one doesn't use feedback, one has to run basically a lot of modules in parallel to get more power and lower output impedance.
  • 01-31-2007, 05:52 AM
    Feanor
    Different ways of implementing feedback
    Quote:

    Originally Posted by VE4CAN
    I copied and pasted this from another site and I'm no expert..

    QUOTE:
    All cheap amplifiers use feedback, and there are no amplifiers above 30 -40 Watts without feedback. This is a very important point. There is no solid state amplifier that can be designed totally without feedback.

    Are they correct??????????

    I'm no expert either, and if anyone wants to correct me, I wish they would.

    Feedback can be implemented in different ways, some supposedly worse than others. For example there are many S/S amplifiers with "zero global feedback", for example, my current Monarchy amps or my previous Bel Canto amp. As you may know, most amps, (including power amps), are implemented with 2, 3, or sometimes more stages of amplification; as I understand it, early stages supply mostly voltage gain while latter stages supply the current. "Global" feedback spans multiple stages of gain and is considered the kind most to be avoided. "Local" feedback is considered more inoccuous; it affects only a single stage. Then too there can be more or less feedback applied, whether to a single stage of multiple stages.

    I don't know if there a any S/S amps with no feedback at all, but if so they are very rare. On the other hand there are quite a few that use only small amounts of local feedback. To my knowledge feedback can and often is used in tube designs.
  • 01-31-2007, 07:36 AM
    JoeE SP9
    According to the web site Pass X series amps have no feedback. The X1000.5 is rated to produce 1000Watts into 8 Ohms. That's a lot more than 40Watts!
    That quote should have said "most amplifiers use feedback".
    Are they correct? NO!:ihih:
  • 01-31-2007, 10:14 AM
    VE4CAN
    Quote:

    Originally Posted by JoeE SP9
    According to the web site Pass X series amps have no feedback. The X1000.5 is rated to produce 1000Watts into 8 Ohms. That's a lot more than 40Watts!
    That quote should have said "most amplifiers use feedback".
    Are they correct? NO!:ihih:


    Joe where can I find that on on the Passlabs site???????????
    I did a QUICK read on the X1000.5 and couldn't find the [no feedback]
    article...
    Is it in their white papers???????????
  • 01-31-2007, 10:53 AM
    Resident Loser
    Let me take...
    Quote:

    Originally Posted by VE4CAN
    I copied and pasted this from another site and I'm no expert..

    QUOTE:
    All cheap amplifiers use feedback, and there are no amplifiers above 30 -40 Watts without feedback. This is a very important point. There is no solid state amplifier that can be designed totally without feedback.

    Are they correct??????????

    ...a guess here...The above quote is from a site that has a vested interest in tubed (valved) electronics...or some other bit of pseudo-esoteric tom-foolery

    If so, this is a textbook case of caveat emptor...

    Honestly, I don't know, nor do I really care...I've never lost sleep as to what type or the amount of negative feedback my gear might have...

    Did they say anything about feed-forward?

    jimHJJ(...just my 2 cents...)
  • 01-31-2007, 11:04 AM
    GMichael
    Quote:

    Originally Posted by Resident Loser
    ...
    Did they say anything about feed-forward?

    jimHJJ(...just my 2 cents...)

    Snicker snicker.... Bwahahahahahaha....
  • 01-31-2007, 11:06 AM
    bobsticks
    Divorce yourself from the idea that all feedback is inherently bad.
  • 01-31-2007, 01:07 PM
    Resident Loser
    Of course...
    Quote:

    Originally Posted by bobsticks
    Divorce yourself from the idea that all feedback is inherently bad.

    ...too much of the wrong type of feedback can be inherently bad and might likely result in divorce...

    jimHJJ(...like the wrong answer to: "do these pants make me look fat?"...)
  • 01-31-2007, 01:25 PM
    bobsticks
    Amen to that RL. That's why I prefer being single, every few months you get all the fun of divorce without the financial outlays. BTW, I prefer the phrase "Certainly not, the pants have nothing to do with it.".

    I love being the set-up guy...
  • 01-31-2007, 01:41 PM
    JohnMichael
    Quote:

    Originally Posted by bobsticks
    Amen to that RL. That's why I prefer being single, every few months you get all the fun of divorce without the financial outlays. BTW, I prefer the phrase "Certainly not, the pants have nothing to do with it.".

    I love being the set-up guy...



    Yes divorce when there is no legally binding contract is so much easier. Get your sh!t, get out and I am changing the locks.:ihih:
  • 01-31-2007, 02:13 PM
    Dusty Chalk
    Well, I looked around on the Pass Labs website, and didn't find any proof that they don't use feedback, but all the same, they seem to know what they're talking about -- they seem to know the difference between feedback used well and feedback used ...erm... "less wisely".

    So it's not really an answer to your question -- I.E. the statement may in fact be correct -- but if you want to "drill down" deeper, I recommend you look around their site.
  • 01-31-2007, 02:21 PM
    icarus
    Quote:

    Originally Posted by JohnMichael
    Yes divorce when there is no legally binding contract is so much easier. Get your sh!t, get out and I am changing the locks.:ihih:

    its even easier than using a prenup.. the problem is when you become common-law thats when it starts to get interesting. I think after a year she is entitled to 50%.... stupid laws...

    so the kick out date is at 363 days into the relationship... still easy... and you get to keep all your stuff....

    i like more the 12 hour relationships.... nice and simple names come and go, just as fast as they do.
  • 02-01-2007, 05:38 AM
    Resident Loser
    Never could...
    Quote:

    Originally Posted by bobsticks
    ...I love being the set-up guy...

    ...resist a good straight line...but, be of good cheer. What would Costello have been without Abbot, Hardy without Laurel, or Lewis without Martin?

    jimHJJ(...or Lewis without the French?...)
  • 02-15-2007, 12:27 PM
    hydroman
    This was the hallmark phrase Harmon Kardon used to describe their high currrent amplifiers.

    I also agree that it isn't inherently a 'bad' thing - listen to the equipment. If you don't hear a diference - then don't pay the difference'.
  • 02-25-2007, 10:23 PM
    poweredamp
    I don't think that thing is true. There must be just some fool out there wanting to create an impression.

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