LCSeminole
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Res firma mitescere nescit.
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Post by LCSeminole on Aug 2, 2017 18:13:26 GMT -5
That is correct..... neither the XPA Gen3 nor the BasX amps use a classic Darlington topology. I think Keith is playing with words... since an image is worth a thousand words, the only thing I really would like to know is this: do the BasX amps use IN ANY WAY the non-classical Darlington (aka "Triple Darlington") configuration for the output stage, as pictured below? This is a very simple question, with a very simple answer: yes or no! Keith, can you please give me a straight answer? PS: The last transistor in the picture can also represent several paralleled transistors. So take this into account when answering. Also, please ignore any resistor between any of the transistor's emitter and the base of the next transistor if that is the case. It looks like KeithL answered your question two posts back.
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Post by garbulky on Aug 2, 2017 18:16:43 GMT -5
That is correct..... neither the XPA Gen3 nor the BasX amps use a classic Darlington topology. I think Keith is playing with words... since an image is worth a thousand words, the only thing I really would like to know is this: do the BasX amps use IN ANY WAY the non-classical Darlington (aka "Triple Darlington") configuration for the output stage, as pictured below? This is a very simple question, with a very simple answer: yes or no! Keith, can you please give me a straight answer? PS: The last transistor in the picture can also represent several paralleled transistors. So take this into account when answering. Also, please ignore any resistor between any of the transistor's emitter and the base of the next transistor if that is the case. He said no.
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klinemj
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Post by klinemj on Aug 2, 2017 18:27:03 GMT -5
"No means no..."
And again...how about asking folks who have listened to each provide input on the sound. That is what matters...
To borrow Keith's car analogy, I have driven GREAT V8's, and bad V8's. Likewise, GREAT 4 cylinders and BAD 4 cylinders.
Mark
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Post by Jim on Aug 2, 2017 19:52:14 GMT -5
I think that using the label "classic" makes the answer more ambiguous.
Classic topology... classic car?
(See, I made a car reference too!)
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hemster
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...still listening... still watching
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Post by hemster on Aug 2, 2017 19:57:27 GMT -5
I do believe Keith answered the question. His response was pretty clear and refuted my understanding. So I stand corrected (actually sit... sipping a lovely glass of Shiraz (my 3rd!)". Perhaps the OP was disappointed with Keith's response? And may need to change his username to "Emo-NON-Classic-Darlington"!
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Post by emodarlington on Aug 2, 2017 21:30:24 GMT -5
It looks like KeithL answered your question two posts back. No he didn't... he said "neither [amps] use a classic Darlington topology". This is a classic Darlington configuration: Does it have three transistors (triple)? No! So, no classic Darlington pair... but what about the triple Darlington configuration?
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Post by audiosyndrome on Aug 2, 2017 21:41:33 GMT -5
Emod- are you buying an amplifier or an output stage? Lots of ingredients in an amplifier not "just" an output stage.
Russ
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Post by garbulky on Aug 2, 2017 23:35:05 GMT -5
It looks like KeithL answered your question two posts back. No he didn't... he said "neither [amps] use a classic Darlington topology". This is a classic Darlington configuration: Does it have three transistors (triple)? No! So, no classic Darlington pair... but what about the triple Darlington configuration? So out of curiosity, what's your intention with the interest in darlington? Are you looking for an amp that has it?
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Post by leonski on Aug 3, 2017 1:56:27 GMT -5
I'm just curious? Does the handwringing over topology mean anything or are the questions driven by curiosity?
I remember the endless debates over class 'A' power which IMO are just so much smoke.
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Post by emodarlington on Aug 3, 2017 7:28:37 GMT -5
So out of curiosity, what's your intention with the interest in darlington? Are you looking for an amp that has it? Among others, I'm looking for a new condition, affordable Emotiva stereo amplifier with a triple Darlington output stage.That's it! Therefore, I just want to know if the Emo BasX series amps have a triple Darlington output stage. It's a very simple and legit question. I really don't know what's the fuss is all about?! Moreover, I only came across the Emotiva brand precisely because I read "Output design: Triple Darlington with On output stages" or "Output topology: discrete triple Darlington with On Semi output devices". And now these are absent from the technical description of their amps and it was replaced for a much more generic "short signal path class A/B output section", which doesn't mean that the triple Darlington isn't, in fact, implemented! Why?! I can only guess... I just need a confirmation! But there are some clues: "The circuitry [of the XPA Gen3] in each output module is based on Emotiva's exceptional-sounding short signal path Class A/B output circuits that were designed for their XPA Gen1 and Gen2 amplifiers."
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Post by pedrocols on Aug 3, 2017 7:59:16 GMT -5
This is creepy! Are you going to change your username after you get a straight answer Mr. Darlington?
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KeithL
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Post by KeithL on Aug 3, 2017 8:39:18 GMT -5
I made the distinction of "classic" because lately some folks have taken to calling other similar topologies things like "pseudo Darlington". (Note that a triple Darlington is a classic Darlington with an extra transistor - so you can't have a triple Darlington unless you have a classic Darlington as part of it. ) No, none of our current amps use a triple Darlington output stage. [EDIT: Correction: I misspoke..... the XPA-1 Gen2 does still use a triple-Darlington, although comprised of separate transistors, and it is still current - at least for now. ] I'm also not sure which of our previous models used it; I'd have to look it up. While some design engineers have obsessions with using (or not using) specific topologies, and there are sort of fads in the audiophile world with some of them, this really isn't something that most of us would consider to be terribly important. It is a relatively high gain topology, as are most of the ones we use, but I am NOT aware of any specific sound quality associated with Darlingtons. (It kind of falls under "tech trivia that's cool to know and sounds good in the marketing brochure" - but that's about as far as it goes.) So out of curiosity, what's your intention with the interest in darlington? Are you looking for an amp that has it? Among others, I'm looking for a new condition, affordable Emotiva stereo amplifier with a triple Darlington output stage.That's it! Therefore, I just want to know if the Emo BasX series amps have a triple Darlington output stage. It's a very simple and legit question. I really don't know what's the fuss is all about?! Moreover, I only came across the Emotiva brand precisely because I read "Output design: Triple Darlington with On output stages" or "Output topology: discrete triple Darlington with On Semi output devices". And now these are absent from the technical description of their amps and it was replaced for a much more generic "short signal path class A/B output section", which doesn't mean that the triple Darlington isn't, in fact, implemented! Why?! I can only guess... I just need a confirmation! But there are some clues: "The circuitry [of the XPA Gen3] in each output module is based on Emotiva's exceptional-sounding short signal path Class A/B output circuits that were designed for their XPA Gen1 and Gen2 amplifiers."
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Post by emodarlington on Aug 3, 2017 9:38:23 GMT -5
I made the distinction of "classic" because lately some folks have taken to calling other similar topologies things like "pseudo Darlington". (Note that a triple Darlington is a classic Darlington with an extra transistor - so you can't have a triple Darlington unless you have a classic Darlington as part of it. ) No, none of our current amps use a triple Darlington output stage.
[EDIT: Correction: I misspoke..... the XPA-1 Gen2 does still use a triple-Darlington, although comprised of separate transistors, and it is still current - at least for now. ] Thank you very much Mr. Keith! It wasn't that hard, was it?!
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Post by leonski on Aug 3, 2017 13:13:46 GMT -5
I'm just curious as to how and perhaps why emodarlington latched onto that as somehow important? Does he own stock in On Semiconductor? Is emo a fan of NASCAR and has an early childhood experience at Darlington Speedway?
Keith makes additional points about the 'fad' nature of some circuittry. It comes and goes as other circuits continue. Also? You could build a darlington topology device out of Discrete (single) transistors or buy an off-the-shelf solution in a single package. And while 'stacking' transistors in the Darlington fashion was done in the past, I think these days a SINGLE device could easily take its place Electrically.
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Post by garbulky on Aug 3, 2017 13:15:51 GMT -5
Though I thought Keith's initial response was pretty clear, I'm glad you got your more definite answer! Now you can get an XPA-1 gen 2! Best amp I've heard!
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Post by emodarlington on Aug 3, 2017 16:23:48 GMT -5
Though I thought Keith's initial response was pretty clear, I'm glad you got your more definite answer! Now you can get an XPA-1 gen 2! Best amp I've heard! At those power ratings there's also the Rotel RB-1090 (2000), discontinued for some years now, and its late replacement the Rotel RB-1590 (2015)... both announced as Class AB amps, BUT both having 1)Dual Differential input stage with cross linked current sources; 2)Triple Darlington output stages. Does it ring a bell? Try to find if there is a similar "sonic signature" between the Rotel's and the Emo XPA-1 Gen2.
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Post by garbulky on Aug 3, 2017 16:40:03 GMT -5
Though I thought Keith's initial response was pretty clear, I'm glad you got your more definite answer! Now you can get an XPA-1 gen 2! Best amp I've heard! At those power ratings there's also the Rotel RB-1090 (2000), discontinued for some years now, and its late replacement the Rotel RB-1590 (2015)... both announced as Class AB amps, BUT both having 1)Dual Differential input stage with cross linked current sources; 2)Triple Darlington output stages. Does it ring a bell? Try to find if there is a similar "sonic signature" between the Rotel's and the Emo XPA-1 Gen2. Well neither of those do the same thing as an XPA-1 gen 2. However those amps are impressive. Nice finds. The xpa-1 gen 2 is a fully balanced high bias class A (class A/B) amp.
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klinemj
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Post by klinemj on Aug 3, 2017 21:07:44 GMT -5
I was using a Rotel RB980bx before I bought my XPA2 Gen 1, and i noticed a huge step change. From what I recall, the Rotel had Triple Darlington output stage. I know the RB-960bx did and I am 99.44% sure the 980 also did.
Frankly, I can't say what part(s) of the XPA-2 made me like it better...lots of variables involved. But, the Emotiva had more punch/attack, more total power, more neutral sound overall, and just sounded better.
I still have the Rotel and use it for other needs. But, I preferred the XPA-2 and prefer my newer amps over that.
And, at risk of sounding like a broken record...don't sweat 1 part of a design over a totality. Just go listen...
Mark
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Post by leonski on Aug 4, 2017 0:55:54 GMT -5
I don't get the infatuation with circuit topology. Class 'A'? High Bias A-A/B? 'D'? Some things which do seem to make a difference are being skipped over. YOU decide. And yes, by any and all means, GO LISTEN. General wisdom is that for a moderate load speaker, amps not driven to clipping sound very similar. Amps differ substantially in the ability to drive various odd-loads and highly reactive speakers, none of which it is likely you own. Except perhaps, for those pesky ElectroStats. I owned a Rotel RB-1070 for about 5 or 6 months. Awful, incapable of properly driving my 4 ohm panels. I don't care if the outputs were Chipmunks in a Wheel. It was not really capable of what I asked. And I'm not a headbanger. www.rotel.com/sites/default/files/RB-991%20Stereophile.pdfSome data on the RB991
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Post by petew on Aug 4, 2017 14:35:11 GMT -5
I don't get the infatuation with circuit topology. Class 'A'? High Bias A-A/B? 'D'? Some things which do seem to make a difference are being skipped over. YOU decide. And yes, by any and all means, GO LISTEN. General wisdom is that for a moderate load speaker, amps not driven to clipping sound very similar. Amps differ substantially in the ability to drive various odd-loads and highly reactive speakers, none of which it is likely you own. Except perhaps, for those pesky ElectroStats. I owned a Rotel RB-1070 for about 5 or 6 months. Awful, incapable of properly driving my 4 ohm panels. I don't care if the outputs were Chipmunks in a Wheel. It was not really capable of what I asked. And I'm not a headbanger. www.rotel.com/sites/default/files/RB-991%20Stereophile.pdfSome data on the RB991 I've got two RB991's and a RB993 (three channel version). They are great sounding amps and have been very reliable. The only gripe is the crummy toggle switch to select between XLR and RCA inputs. Sometimes I have to jiggle it. They run hot too - I have active cooling for them My current configuration is one 991 running left main and surround, one 991 for the right main and surround, and the 993 running the center and two back surrounds. If I ever get around to finishing my DIY speakers I'm going to reconfigure and push the left and right corner horns with the Emotiva XPA-2 I picked up recently, the 991's running surround duty, and the 993 powering the center channel (three way, active XO) It's all good stuff!
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