John Curl's Blowtorch preamplifier part III

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That's confusing. Joe R's "Elsinore" speaker is described as "current compatible". What does this mean?

Well I hadn’t looked at Joe’s site. I am impressed.
Joe, you have put a lot of work in there. Congratulations!
So, you know very well how to measure impedances and such.
I am sorry that I gave you those suggestions. I just had the wrong impression that you are seeking some answers.
Now all these that you are asking here can be found on your site.
So, my understanding is that you are not asking for to get an answer.
And I see you do have a lot of space in this site for to educate members with the theory and implementation that you think is optimum.
The "Elsinore Project" Thread
Joe Rasmussen Usher S520 "Current Compatible" Crossover
Joe Rasmussen "Trans-Amp" - 40 Watt Transconductance "Current Amplifier"

So back to basics for us the rest.

George
 
Since a horn was used (#3652) for the most important part of music (mid-range), the directivity of it will help a lot.
That is exactly my point of view.
Well, the first benefits I can see of the use of horns and compression drivers are their high efficiency, and the ability they give-us to work in "piston" (Ie not fractionate) in the most sensitive and critical frequency range (around 300Hz, where our ears show a peak of sensitivity, according to the studies of Fletcher and Munson). A 23 driver can run easily from 700 to, let say, 15000.
The second one is their directivity remains (with well designed horns or wave guides)) more or less constant all over this frequency range. Means the acoustic power will remain constant, and less modified by the room's reflections.
The last (but not least) interesting thing is that the diameter of the source (at 700 Hz) can be fixed more or less equal to the one of the bass driver. This means the same kind of directivity curve for the both transducers at the crossover frequency. Everybody can understand the benefit.

What about the upper range (between 15000 and 25000) ? I don't know if it is due to my age, but I did not miss nothing, and each attempt I made in my life to add a "super tweeter" was just like adding distortion and unnatural treeble). Just like this, in my system, everything (mainly drums) sound so near to real.
 
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Ha. This reminds me. In some cases I think the term AI is a little boastful; I prefer AS (Artificial Stupidity).

By current standards automatically opening doors at the grocery store are AI... the term gets thrown around like it's worth gold itself.

Yes, I am under that misconception. Mainly because your sig links to a current-driven speaker you designed. Also, you complain about the variable impedance of drive units "corrupting" the vocie-coil current when voltage driven.

What are you promoting?

I've chatted with Joe before, and when he isn't being as defensive the convo is good. But in this case I'm really not sure, just like you, what exactly Joe has for goals now. That's why I suggested that if we don't want current drive amps, then what else are we going to do besides use big *** series resistors in speakers to get some kind of medium between voltage/current from the amp?

Read my posts!

I have been, and I'm still not sure what you're saying except current is important, but you don't support current drive. And the thing is I know you know a bunch about all of this stuff... I'm probably not the only one wanting to pay enough attention to learn something more than how far you're willing discuss whether or not you support current drive.
 
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This is a solid 1/4 wall of tube gear, mono blocks with each driver has it's own amp, plus each other piece of gear had it's own pre amp too.

The sound was stunning yes.

<snip>
It would be interesting to hear their explanation how the op-amp based (4558/5532 variety) Accuphase F-25 crossover fits their 4 way DHT concept. :devilr:

And that computer without the lid and its PSU a feet or so away from the audio gear surely isn't emitting anything.

[party pooper mode OFF]

😀
 
I have been, and I'm still not sure what you're saying except current is important, but you don't support current drive. And the thing is I know you know a bunch about all of this stuff... I'm probably not the only one wanting to pay enough attention to learn something more than how far you're willing discuss whether or not you support current drive.

The last thread closed quickly after it was clear that the concept of Norton/Thevenin equivalents was not understood (at all).
 
Can you post the article? Sometimes I'm finding things challenged: LINK

My article to lower speaker's THD was in TAA 3, 1985.

The results from a VFA power amp with a moderate amount of NFB was modified as I described and the THD near resonance was much lower from the speaker.
View attachment TAA2.pdf
View attachment TAA 5.pdf

PS.... I did not try to see how low the THD could be made to attain.... and a high NFB amp might be better for this app. It was just to test the concept.

So, is it current or voltage that matters? 🙂

THx-RNMarsh

Limited file size here doesnt allow for the whole article to be shown.
 
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