Not forgetting the classic "I'm sorry, I don't understand the question, can you phrase it differently please?"
If you meant the original post by JC, then it is still there:
John Curl's Blowtorch preamplifier part III
Isn't this signal classification from Randall (Brüel & Kjaer Book) ?
Still a useful one (and indeed a DC would qualify for "static") but usage of terms might nevertheless sometimes different by different people.
From the context I'd assume that John Curl was referring to "steady-state measurement" for "steady-state measurement", but you might have noticed that even this quite common descriptor wasn't appreciated by all parties..... 🙂
Which seems to imply that the question is not placed "for real".
If it is meant that way, I do wonder why you could not accept that I ask for rephrasing because I really think/feel that I don't understand the question!?
Still don't understand complex algebra?
The inductance of a speaker called "back-emf" impedance labeled as a voltage source? Is that really what you are showing? You are also demonstration voltage vs current drive I though that was ruled out. Could you repeat this for the low frequency half of your speaker with a voltage source with and without the shunt networks. Also "real" as opposed to "imaginary" has a specific meaning in an engineering context.
So in the end you have a speaker that behaves the same for all your friends with high output resistance tube amps, there is nothing wrong with that.
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It depends, sometimes the question/comment can be rephrased/explained numerous times and still dismissed/ignored, no problem. I have learned that when someone does ask for it to be rephrased etc, the chances are that it's one long waste of time. A classic example would be the Joe saga
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Its interesting how people yada yada on about how very low distortion amplifiers don't sound especially good. Or that amplifier with feedback sound like crud (The late Charles Hansen - RIP - favourite subject).
And then when they hear a really low distortion amp (which of course would have had to be engineered well to achieve that kind of performance) they go 'wow - that's amazing'.
Benchmark is a case in point.
On Halcro, I understand the parent company made much more money doing professional electronics (which I believe is still going) and that's why they abandoned the Halcro Audio project . Besides, not many people have 20 or 30 grand to throw at a power amp. I also think as soon as certain reviewers heard that it had feedback, it was going to be labelled as 'not sounding good' - whatever that means - anyway.
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I think this is the guy who actually said it
Quote by Robert McCloskey: “I know that you believe you understand what you...”
😉
Yes, I first did it in the early eighties, I do not understand that there should be so much objection to this simple electrical engineering concept. Evidently nobody else except for you, me, Joe and Tournesol have dared to venture from the same old path and perform this experiment. IME in the case of mid-fi amps and receivers loudspeaker impedance eq is essentially mandatory for acceptable subjective performance and no amount of 'tweaks' like cable rolling etc will correct this elementary error. The likes of MIT cables and others incorporate RC networks which can be diy'ed for a few dollars and turn a system from mediocre/irritating to enjoyably musical and intelligible, win/win for less than the price of a coffee and cake.
Dan.
I have had a couple of old blokes tell me that putting a piece of gold on the search coil improves detection.
This could be an old prospectors tale, then again maybe not !.
Eclipse mono power amplifier $135,000/pair of monoblocks 😱.
Dan.
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All amplifiers show ringing into complex LC loads with fast rise times. I suspect that terminating the loudspeaker end of a cable with a Zobel network - assuming it is not already done inside the speaker box - might have some benefits arising out of the damping action at HF. Keep in mind that there is little any amplifier can do between its output terminals and the load - once the signal is launched its 'on its own' so to speak.
Some practitioners eschew output L's because they say it 'sounds better'. If your amplifier is ZGFB, then you can get away with it but you will still have ringing - it just happens at higher frequency.
Some practitioners eschew output L's because they say it 'sounds better'. If your amplifier is ZGFB, then you can get away with it but you will still have ringing - it just happens at higher frequency.
Depends where measured, right? (amplifier output terminals or end of the speaker cable). Yes terminating speaker cable with R or R-C value close to cable wave impedance helps to make nicer step response at the cable end and also reduces captured HF EMI. I was doing some experiments with this, with a measurable, however inaudible effect. I of course assume that the amp discussed must be stable under such conditions.
Depends, but chances are much lower for a ZGFB amplifier... Ringing is in general due to the inherent inductive output impedance of most audio power amplifier with feedback, resonating with a capacitive load. I cringe when I see such amplifiers "ringing tests" with 1uF in series with a few ohms, since usually the worst case is a low ESR/ESL cap of 10-100nF directly to the output terminals (which may create a massive oscillator, not unusually self destructing).
I'm following the Scott saga, maybe later I'll ask him to rephrase some thoughts....
Agreed, 10 - 100 nF capacitive load is the value where the amp might be most probably oscillating. 1 uF usually only slows the rise, however current might be enormous when step driven.
Both Scott's
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Sorry to disappoint, now that mid-fi and/or poorly designed amplifiers as well as SET amps, etc. are included there is no point in a discussion.
Yes, IME with 'mid-fi' amplifiers it is very necessary to damp this ringing and except for some expensive speaker designs RC Zobel is never incorporated inside the loudspeaker, no doubt due to assumptions and/or economics reasons.
Perhaps 'happens at higher frequency' reduces the audibility of secondary effects. Another reason could be implementation/location....series output coil is a transmitter antenna and as discussed previously this can magnetically couple into upstream stages causing modulations/intermodulations/looping distortions. Another factor could be the actual components used in the Thiel output network causing 'signature' despite low drive impedances. I have 75R resistors across each end of my all copper RG59 coax speaker cables and the type/chemistry of these shunt resistors is audible.....CF sounds warm/fat but definitely 'coloured', MF sounds clean and flat in comparison.
Dan.
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