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John Curl's Blowtorch preamplifier part III
John Curl's Blowtorch preamplifier part III
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Old Today, 11:18 AM   #28021
jneutron is offline jneutron  United States
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Quote:
Originally Posted by DF96 View Post
You don't need to be Einstein to realise that almost all of the voice coil inductively stored energy goes into heating the voice coil, since this is likely to be the highest resistance in that current loop.
There will be a time constant accociated with the loop. If the signal require the system move faster than that time constant, the amp has do work absorbing energy.
Above resonance, the amp will be needed in Q2 and 4 to discharge the energy. Below resonance, the amp is needed to support the energy as the vc is dissipating it, Q1 and 3.

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Old Today, 11:20 AM   #28022
Jakob2 is offline Jakob2  Germany
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As DF96 already mentioned it is a definition of an ohmic resistance, if the relationship holds true then it is an ohmic resistance.
The same material, when used under different conditions, can exhibit a different behavior and isn't an ohmic resistance anymore then.
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Old Today, 12:32 PM   #28023
Bonsai is online now Bonsai  Europe
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Originally Posted by DF96 View Post
You don't need to be Einstein to realise that almost all of the voice coil inductively stored energy goes into heating the voice coil, since this is likely to be the highest resistance in that current loop.


It would be better to say that the 'return current' splits in this way. If the ampifier is a voltage source, or approximately so, then almost none of the energy ends up there or in the damper. Almost all of the energy ends up in the voice coil resistance.


Misleading question, as the same is true for a voltage output amplifier.

There may be some confusion between current and energy? To get energy produced or dissipated you need current and voltage together.

No confusion. The point I was making is that the amplifier in voltage mode must absorb some of the return energy (volts x current x time) even with Joes damper network. And in the big scheme of things any decent solid state amplifier will deal with this quite adequately (feedback - awesome stuff!) so you really don’t need the damper. For example, one of my amps will comfortable handle > 60 amps for short periods what will a damper bring to the party? Not much IMV.

The current drive comment was simply saying if you have an very high output impedance in parallel with the speaker and damping network how does the system deal with the return energy? A prompt to think a bit differently about the damper to Dan et al.

Last edited by Bonsai; Today at 12:34 PM.
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Old Today, 12:38 PM   #28024
Bonsai is online now Bonsai  Europe
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Originally Posted by scott wurcer View Post
Why would you say that? I've watched folks randomly mixing and matching components for years, they sometimes end up with something that makes them happy. I like some and hate others and have yet to have faeries carry each note lovingly to my ears.
You’re not smoking the right stuff!

Watched a video of one of the Stereophile reviewers (a popular one in almost every issue) discuss his (perhaps occasional) weed habit despite his advancing years and I thought to myself ‘hmmm, there’s a music loving hippy . . . ‘
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Old Today, 12:52 PM   #28025
Joe Rasmussen is offline Joe Rasmussen  Australia
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Wow!

This forum is finally talking about speakers.

The comments I see are often a bit off the mark, but that is OK. For example, with current drive (which I am not promoting) there is no reactive current, no matter how reactive you might consider the load. Think about it. What happens to the inductance in the driver? It becomes something measurable with a voltmeter. This is interesting, I would like to know what others might think, but please tone down the aggro. OK?
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Old Today, 01:15 PM   #28026
jneutron is offline jneutron  United States
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Quote:
Originally Posted by Joe Rasmussen View Post
Wow!

This forum is finally talking about speakers.

The comments I see are often a bit off the mark, but that is OK. For example, with current drive (which I am not promoting) there is no reactive current, no matter how reactive you might consider the load. Think about it. What happens to the inductance in the driver? It becomes something measurable with a voltmeter. This is interesting, I would like to know what others might think, but please tone down the aggro. OK?
Do not confuse detailing why your explanations are incorrect.... with aggressiveness.

jn
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Old Today, 01:35 PM   #28027
Bonsai is online now Bonsai  Europe
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Quote:
Originally Posted by Joe Rasmussen View Post
Wow!

This forum is finally talking about speakers.

The comments I see are often a bit off the mark, but that is OK. For example, with current drive (which I am not promoting) there is no reactive current, no matter how reactive you might consider the load. Think about it. What happens to the inductance in the driver? It becomes something measurable with a voltmeter. This is interesting, I would like to know what others might think, but please tone down the aggro. OK?
What happens if the current suddenly goes to zero - say you open a switch between the amp and the speaker?
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