The use of multiple isolation transformers and filter accomplishes the Isolation I said was needed. However, you should not be ganging equipment together on a common outlet/strip - even after line isolation.
Also, I didnt say how much was common-mode and how much is differentail mode in the noise -- you need to learn about that in order to make effective filters. Thx-RNM
Also, I didnt say how much was common-mode and how much is differentail mode in the noise -- you need to learn about that in order to make effective filters. Thx-RNM
Yes, if you don't want crazy damping factor. They have quite high resistance.
That i was looking for, as i 'tend to prefer cables witch conduct electricity". But they have a W22 gauge for the best of them: need a lot of cables in //. Occasion to ask to Jneutron how to build a cable with 6 ohms impedance from several 100 Ohms ones ?
And not to veer too much here, but generalizations of nonlinear system behavior that look at all systems, with feedback local and global, feedforward, and feedback-free, will demonstrate many features in common, particularly the origin and growth (including the special cases of cancellations) of harmonic and intermodulation distortions. And when one tosses in nonsmooth or nonmonotonic behavior, like certain types of crossover distortion, it really gets messy.
It was half a joke, i will not add a 6 ohm resistance at the output of my amps and i can live with ns of echo. -)
mikelm, the 'resonances' you describe are simply wonky stability. Many (all?) Golden Pinnae power amps suffer from this.
If you test them with real speakers, you often see bursts of oscillation on part of the waveform. This will be dependent on the level and thermal & signal history of the amp. Easily visible on a scope and audible too. No ABX bla bla needed.
If you measure distortion under those conditions, you'll see distortion MUCH greater than on the usual 8R loads.
No wonder Golden Pinnae amps sound different but in my book, these are NOT good amps.
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An important take on this for preamps is that decoupling & stability are VITAL for good sound.
The physical PCB layouts are an important part of this and few people understand what is needed.
Many people substituting HP OPAs for cheapo in circuits are simply hearing really bad oscillation & distortion cos these high strung racehorses dun like the mundane environments they are suddenly shoved into.
Frank, Microwave Office might sim. what such PCB layouts do but IMHO, the design of PCB layouts for good sound is, if not an Art, still a Craft, requiring both experience & good insight.
_______________
But to get back to Blowtorch ...
JC, what results did you get with the Hirata tests you conducted on Fri?
Quan's patent is US20110002472A1.
If someone can build a Quan box and bring it to JC, we'll see how a first class preamp performs on this really important test.
If you test them with real speakers, you often see bursts of oscillation on part of the waveform. This will be dependent on the level and thermal & signal history of the amp. Easily visible on a scope and audible too. No ABX bla bla needed.
If you measure distortion under those conditions, you'll see distortion MUCH greater than on the usual 8R loads.
No wonder Golden Pinnae amps sound different but in my book, these are NOT good amps.
_______________
An important take on this for preamps is that decoupling & stability are VITAL for good sound.
The physical PCB layouts are an important part of this and few people understand what is needed.
Many people substituting HP OPAs for cheapo in circuits are simply hearing really bad oscillation & distortion cos these high strung racehorses dun like the mundane environments they are suddenly shoved into.
Frank, Microwave Office might sim. what such PCB layouts do but IMHO, the design of PCB layouts for good sound is, if not an Art, still a Craft, requiring both experience & good insight.
_______________
But to get back to Blowtorch ...
JC, what results did you get with the Hirata tests you conducted on Fri?
Quan's patent is US20110002472A1.
If someone can build a Quan box and bring it to JC, we'll see how a first class preamp performs on this really important test.
Just take the feedback point in a poweramp from elsewhere than the exact output point (with symmetrical path to each side of the power devices outputs) , and you have all the chances to see distortion increased by a factor of 10.
Experienced in 1970.
Never be known
LOL
There are some things that will never be known...[why are we here? What is beyond the end of the universe?] This, I believe is one of them.
LOL
There are some things that will never be known...[why are we here? What is beyond the end of the universe?] This, I believe is one of them.
LOL
Yes, and how blind tests can help to solve such problems?
Yes indeed! A few years back Gary Pimm and I were testing some AC line filters. One in particular seemed better at keeping noise in than keeping it out.
I.E., the AC line at the plug was dirtier with, than without, the filter because it prevented noise from draining out down the AC line. You certainty would not want to gang together a noisy and a sensitive device on that same line.
Mike, this should not happen. Even if a refrigerator or any contactor starts, there should be nothing at the speaker's terminals. And it is achievable.
LOL
Latest thinking I heard was that there is no end to the universe - it is infinite & expanding
Latest thinking I heard was that there is no end to the universe - it is infinite & expanding
Can you confirm that by measurements?
Hitting the sound board is a mechanical impulse it excites all resonances. If you take a 1 MHz parallel resonant circuit and put a 1kHz oscillator across it you will not get any 1 MHz unless there is some rectification or non-linearity that makes a 1 MHz excitation.
John, do you have the title of this paper and the name of the journal where it appeared ?
One trafo feeds the power amp, one feeds the pre-amp/phono stage combo, one feeds the CDP and the fourth feeds gear with switching PSUs, namely universal player, music/home theater PC and home theater receiver. When listening to stereo music, most of the times those 3 with switching PSUs are switched off. The PC may be turned on at times, in the future. The turntable motor is fed from a different power line.
Also, to the TV goes screened power cord, connected to AC mains filter/splitter, which also feeds the satellite TV receiver/converter.
Both common-mode and differential-mode RFI are filtered. I didn't measure it, however, practically, I got very good results, judging by the improvement in sound quality.
Would anyone suggest better filtering, I'll try it.
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