That is $115 in today's dollars but very much very expensive in 1978 terms.
By means you can't possibly understand. That's the difference between real gurus like Jack Bybee (who was Richard Feynman's consultant on superconductivity, but that's a deep secret) and the piddling little minds of conventional scientists.
No SY,
You set out to prove a negative and to your satisfaction did so. For some reason you want to jump on everyone who in any way disagrees with you.
There really are more things out there than resistance, inductance and capacitance.
I will eventually get back to power supplies once I have a bit of time.
Next post will start that.
ES
Intriguing notion but apt to be unpopular. I was reminded of a subwoofer I did for Epson (of all companies), an add-on for one of their tabletop LCD projectors with built-in speakers, where they wanted the gain to be adequate with the volume control barely cracked---I think it corresponded to less than 50mV in for full output power even below maximum gain. It was difficult to do with adequate S/N and frankly not that well-informed, but apparently somewhat traditional. That was when I discovered how truly awful the excess noise is in thick-film resistors!
That OL margin is good, made easier by the somewhat-lower gain of 35.5dB compared to the almost-canonical 40dB.
I am always happy to see actual data. I am less happy with trolling. You have offered exactly zero of the former with regard to John's business partner's scam.
I own a DCX2496: it is my active filter. I replaced the analog ICs for my favorite one (OP260), shorted the symetrical stage, Changed the supplies for two separate for analog and digital. Still have some work to do on it: better clocks, low noise reference voltage.
What secondary (or primary) effects with solid state devices, if no bad welding ? (Specially with SMDs). I recorded hits with an hammer on a preamp, in 24/96, and was not able to ear or see the impacts.
Since this day, I always smile when some is talking about cones under solid state equipment.
Now on to power supplies.
The first issue is the AC power mains. In theory the AC current is produced by many synchronized generators. (An alternator is a specific kind of generator producing AC so I use the general case.) Now one would expect that this would be a clean sine wave from a piece of rotating equipment. It actually is not. In order to build the coils around the magnetic structure gaps have to be left in the structure to get the wire in to make the windings. This results in a small amount of harmonic distortion. Of course the magnetic material is not perfectly linear so some more harmonic distortion creeps in.
Now the voltage from the generator is stepped up for distribution. The power distribution transformers are not just rated for voltage ratio and current capacity, they are also rated for temperature rise. In typical transformer design half of the loss comes from the windings and the other half the magnetic structure (Leakage and magnetization core losses.)
So the higher the rated operating temperature the more the magnetic aberrations and higher harmonic distortion. You might want to look at a power transformer distribution bank and see what they use for cooling. Better transformers have lower temperature rises and are intended to last longer.
Now there is one other issue in transformers and that is leakage through the insulation. This will eventually lead to transformer failure, but until it does there will be some arc induced energy often at high frequencies and although modulated by the line frequency it is not a true harmonic.
Now to provide lots of power the generators are interconnected. They will lock into synchronization. Except there always is some "slippage" this will show up as minor long term variations in the RMS value of the AC Mains.
In a similar manner AC motors are rated for their RPM a perfect motor on a 60 hertz AC line should run at 1800 RPM. A look at a motor catalog will show that 1720 to 1780 is more typical. That "slippage" will also modulate the mains at frequencies as low as .33 hertz.
All this noise before we even get out of the power plant!
ES
The first issue is the AC power mains. In theory the AC current is produced by many synchronized generators. (An alternator is a specific kind of generator producing AC so I use the general case.) Now one would expect that this would be a clean sine wave from a piece of rotating equipment. It actually is not. In order to build the coils around the magnetic structure gaps have to be left in the structure to get the wire in to make the windings. This results in a small amount of harmonic distortion. Of course the magnetic material is not perfectly linear so some more harmonic distortion creeps in.
Now the voltage from the generator is stepped up for distribution. The power distribution transformers are not just rated for voltage ratio and current capacity, they are also rated for temperature rise. In typical transformer design half of the loss comes from the windings and the other half the magnetic structure (Leakage and magnetization core losses.)
So the higher the rated operating temperature the more the magnetic aberrations and higher harmonic distortion. You might want to look at a power transformer distribution bank and see what they use for cooling. Better transformers have lower temperature rises and are intended to last longer.
Now there is one other issue in transformers and that is leakage through the insulation. This will eventually lead to transformer failure, but until it does there will be some arc induced energy often at high frequencies and although modulated by the line frequency it is not a true harmonic.
Now to provide lots of power the generators are interconnected. They will lock into synchronization. Except there always is some "slippage" this will show up as minor long term variations in the RMS value of the AC Mains.
In a similar manner AC motors are rated for their RPM a perfect motor on a 60 hertz AC line should run at 1800 RPM. A look at a motor catalog will show that 1720 to 1780 is more typical. That "slippage" will also modulate the mains at frequencies as low as .33 hertz.
All this noise before we even get out of the power plant!
ES
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Actually I did you and others screamed so much it just wasn't worth pursuing. I have had the discussion with folks who are an order of magnitude smarter than I am and they don't seem to have the qualms folks here do.
You did your experiments and concluded it was no different than a resistor. can you say any more than that?
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I turn red when I see such a case (1. setting-up the first impression. 2. it’s the definition of wrong gain structure. 3. What will happen when the volume is turned up?)
No comment.
Who cares? Is it proper technically?
That’s another big plus of a circuit with low gain. Higher OL margin for the same power rails (or the same OL margin for lower power rails)
Yes Sir
George
Well, it doesnt seem to do enough of anything to be of personal interest. I would be more interested in the 'active' one to measure. But only if I got to test it without paying for it. I have been quite effective in removing noise with more conventional methods.
THx-RNMarsh
Yes, I can say that you still haven't presented a scintilla of contradictory data.
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