John Curl's Blowtorch preamplifier part III

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With reeds and other relays, it is not only a contact issue but the field from the coil.

Yes, that magnetic field is clearly audible. Barkhausen noise modulation creates intermodulation distortion through non harmonic spectral components. Interesting enough, it happens only for the reed relay magnetic fields. Other relays don't have the same type of field from the coil.
 
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The M2 is a package which includes "digital" power amps with DSP crosover. So no. As soon as I get them to Bangkok and have the analog amps then definitely that is a YES. I have already measured the cross-over characteristics i need when I replace the digital amps. Why do you ask?

THx-RNMarsh

BTW --- I did the current feedback -- the data I published was of a 3-way JBL system, How Nazi propaganda encouraged the masses to co-produce a false reality.

THx-RNMarsh
 

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...we've somehow managed to avoid Godwin's Law on this thread, but it seems that it's inevitable.

It naturally would seem to follow the mean-spirited dirty politics debating methodology of some. Obviously, the conduct does not rise the level of you know who, but its still playing dirty politics under the guise of audio. Maybe that's what makes forums successful, I don't know.
 
Because as I said, lip service doesn't count. Show the results, and hopefully they are credible and reproductible. Scott just mentioned his results, and I have no reason to doubt them, since they match my own practical experience (mind you, I have myself a considerable experience in the same semi industry, different branch).

I already have. In this thread. Resistors, capacitors and relays have all been shown. FYI some non reed relays also place a steel signal conductor in the magnetic field and have similar issues.

Barkhausen effect occurs in a changing magnetic field, not really an issue with a stable DC supply to the relay coil. It was used as proof of the existence of discrete magnetic domains. You really do seem to like discussing things with little knowledge of the subject.
 
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There is a guy here who has designed and built it. With in-wall speakers. Unfortunately, I have not heard it, yet.

I did a number of experiments with a setup where the output impedance can be dialed in from lowish to highish. Not all drivers work better with current drive, and some drivers work better with voltage drive for high and current drive for low frequencies, or the other way around. It is very component specific.

Bruno uses a split current/voltage drive for the Kii woofers. Really not that hard to do. Point is: it depends on the driver what kind of drive delivers the lowest distortion, and it is frequency dependant as well.
 
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Devialet is another one. Not sure what they do - or if they are any good!
It'll be interesting to see Purifi's "new" drivers when they appear.

Simple and gets the job done well enough, I tend to trust Murphy. Better for you may not be the same for me. :)

DSP is simpler, really, and much more flexible and accurate. And far easier if you want to try several variations!
 
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