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John Curl's Blowtorch preamplifier part III
John Curl's Blowtorch preamplifier part III
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Old 25th August 2019, 11:08 PM   #28171
RNMarsh is offline RNMarsh  United States
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Quote:
Originally Posted by jneutron View Post
Wasn't it stated that a pre filter was required and that it was an invert of the speaker? That means no speaker swapping, it's no longer a turnkey system.

Dan, you are so incorrect I don't know where to start!!!
Actually, I do. First and third quadrant are resistive. You meant second and fourth.

Jn
No pre-filter required and no inverted signal

??

-RNM

Quote:
Originally Posted by john curl View Post
I suspect Richard is creating a negative damping factor by adding a small amount of positive current feedback along with a lot of voltage negative feedback. The current is picked up by a small resistor in series with speaker ground return, but it has to go to a positive feedback point. Well, Richard, is this what you are proposing?
Like this ---> 1985 TAA: Took an existing circuit and upgraded it and added the 0.15 Ohm --- in art I show the before and after THD reduction from the speaker I have also shown that here in this forum before.

Marsh MFB ckt.pdf

[This is also what Joe is ranting and raving about. BTW ]

So. help Joe; What is the reason THD from speaker was lowered?

THx-RNMarsh
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Old 26th August 2019, 01:07 AM   #28172
Joe Rasmussen is offline Joe Rasmussen  Australia
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Originally Posted by jneutron View Post
The force on the cone is a result of current, but it is easily considered a voltage device. The current drawn is what the device wants in order to try and keep up with the driving voltage.

Class dismissed.
Not yet!

Not so quick, what textbook says the driver is a voltage device? Or do we just have to take your word for it?
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Old 26th August 2019, 01:38 AM   #28173
indra1 is online now indra1  Indonesia
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Originally Posted by jneutron View Post
... Assuming phase response is different V drive vs I drive, does anybody do final mix down with current driven monitors? If so, does anybody know if soundstage imaging differences occur as a result?...
Good question. It may be deduced that the phase of the force is coherent with current but phase of acoustic output is another beast that needs further investigation.
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Old 26th August 2019, 01:39 AM   #28174
jneutron is offline jneutron  United States
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Quote:
Originally Posted by Joe Rasmussen View Post
Not yet!

Not so quick, what textbook says the driver is a voltage device? Or do we just have to take your word for it?
Nobody, at any time, has to take my word on anything. In fact, I prefer that nobody does, but instead either understands and agrees, understands but disagrees, or doesn't understand and tries to learn. Valid, well stated conflicting thinking is always welcomed.. My belief is that most learning comes from disagreement, constructive dialogue, and brainstorming.

I have done that three times in the last 25 years, and the results..what I did 24 years ago is still beyond state of the art..granted, it is a high energy physics thing that no normal person understands or cares about. More recently, we made a three order of magnitude improvement on motion control of magnetic devices used to make x rays in a 3rd generation synchrotron.

I do my best to break down every problem into smaller easier to understand components. Not only is keeping it simpler the best way, it makes it much easier for all to understand. Engineering in fact, is by design, the method of breaking complex problems down into easier to understand components...solving each component, then assembling the components into a well understood whole.

Having worked at the highest level of magnetics for a quarter of a century now (actually, I hated typing that... ), I am rather confident that I have a better understanding of electrodynamics, energy conversion, EM field theory, magnetic flux containment control and modeling, t line understandings, and even simple inductance understandings... than a tech who has tried to self teach concepts either online or by knowing some audio guys. While I have worked with techs who are significantly better than many engineers I know, they are few and far between.

There are quite a few here who can dance circles around those you claim are experts. You really should be trying to learn from those very smart experts rather than aggressively dissing them.

While I feel I know a lot, I am smart enough to know that the posters here have a huge amount of knowledge that I can learn from and draw upon.. The list is huge...and, they are not all phd's and engineers. In fact, I learn the most from the techs that work for me..

So instead of aggressively attacking the smart people here in a feeble attempt to achieve world domination, I recommend you tone it down and act like those here actual know something. You will get a lot farther being nice.
Jn

I am very unhappy that you push me into a position where I feel the need to put you in your place. Please reconsider your stance.
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Last edited by jneutron; 26th August 2019 at 02:01 AM.
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Old 26th August 2019, 02:50 AM   #28175
mountainman bob is offline mountainman bob  United States
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Originally Posted by billshurv View Post
Well enough accepted by who? I generally rate a company by the spec sheet. Janzen get 3 out of 10 in that there are 'some' specifications. But the rest of the product sheet is pure high end marketing BS http://www.jantzen-audio.com/wp-cont...mber-Z-Cap.pdf for example.

But if you are happy with your purchase and not trying to tell us that our systems will never sound good if we don't use these parts (and this does happen) then all is cool.
I never once alluded to that. Why do you fellers get so ruffled about caps and wires?

Things are manufactured, some things are manufactured better than others.

Grizzly,delta,jet,powermatic and several other brands of shop tools are all manufactured at the same plant in Taiwan but vary extensively in quality.

If jantzen products are just glorified crap then they’ve certainly fooled me, but I also like Cornell dubilier, cheap, no frills, no hype......is it ok to use them?
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Old 26th August 2019, 03:01 AM   #28176
indra1 is online now indra1  Indonesia
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Originally Posted by mountainman bob View Post
Why do you fellers get so ruffled about caps and wires?
Not only those Bob, almost everything. So many of us are grumpy about marketing stuff. We have all been bitten on our rear side once too often.
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Old 26th August 2019, 03:01 AM   #28177
syn08 is offline syn08  Canada
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Originally Posted by scott wurcer View Post
Same question not clear the difference is understood.
Does it even matter? The point in this thread is to talk, not to make sense. Those making sense are strangers in a strange land here.

Last edited by syn08; 26th August 2019 at 03:05 AM.
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Old 26th August 2019, 03:05 AM   #28178
indra1 is online now indra1  Indonesia
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Originally Posted by syn08 View Post
Does it even matter? The point in this thread is to talk, not to make sense.
Let's hope you do not decide to follow that.
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Old 26th August 2019, 03:07 AM   #28179
Terry Demol is offline Terry Demol  Australia
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Originally Posted by waltzingbear View Post
Reputedly, the Kii speaker from Bruno uses current drive as part of his solution to the problem (of building a speaker). None of the reviews of the speaker mention any problem with imaging. I seem to recall just the reverse.

Cheers
Alan
I believe Bruno started using some amount of current drive on the Grimmaudio LS1 speakers.
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Old 26th August 2019, 03:17 AM   #28180
RNMarsh is offline RNMarsh  United States
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Quote:
Originally Posted by jneutron View Post
Nobody, at any time, has to take my word on anything. In fact, I prefer that nobody does, but instead either understands and agrees, understands but disagrees, or doesn't understand and tries to learn. Valid, well stated conflicting thinking is always welcomed.. My belief is that most learning comes from disagreement, constructive dialogue, and brainstorming.
hi JN,

no one is even attempting to answere my questiion at #28172.

Would you take a stab at it, pls. You may be able to help designers develop better drivers and/or amp/spkr interfacing .

THx- RNMarsh

Last edited by RNMarsh; 26th August 2019 at 03:29 AM.
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