| Menno Van Der Veen/OPT's and sound quality [message #8527] |
Thu, 07 October 2004 14:15  |
Manualblock
Messages: 4973
Registered: May 2009
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Illuminati (13th Degree) |
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Menno wrote an article on testing OPT's in the Issue 5 1997 Glass Audio. In the article he goes over some methodologies for determining the specs of OPT's and how they affect sound. Some interesting conclusions are demonstrated at the end of the article. One of the points he makes is this:
Through extensive testing three postulates are promoted:
Human hearing reacts to pleasureable sounds by producing alpha brain wave activity measured at the 8hz level determined by EEG measurements. Testing has shown an increase in these EEG readings in subjects exposed to Tube amps with damping factors around 4, no negative feedback and rolled off high end starting at 16k.
In amplifiers that measured significant response energy at the 22k level, the positive alpha waves decreased significantly and the sound registered as unpleasant.
Using recordingds made with a double sampling speed DAT.recorded at 48k on speakers with tweeters able to reproduce frequencies in excess of 28k the pleasurable alpha waves and positive response returned to previously high levels.
It is a long article but very interesting. J.R.
In that same issue our own Metasonix has a nice article on modifying an 811 amp to make it sound better.
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| Re: Menno Van Der Veen/OPT's and sound quality [message #8531 is a reply to message #8527] |
Sat, 09 October 2004 19:54  |
Thermionic
Messages: 208
Registered: May 2009
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Master |
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WOW! I don't know what the damping factor and frequency response of my 2A3 amp with Plitron OPTs is, I just know it surely must "increase my positive alpha waves" just fine. Menno van der Veen definitely knows how to design an output transformer, to say the least! They were the first set of Plitrons I bought (PAT-3025), and since then I also got a pair for a PP EL34 amp, which are not yet installed. But, if they're ANYTHING like the SE OPTs.........my positive alpha wave production will go off the scale. Thermionic :)
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| Re: Menno Van Der Veen/OPT's and sound quality [message #8534 is a reply to message #8533] |
Sun, 10 October 2004 08:42 |
Manualblock
Messages: 4973
Registered: May 2009
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Illuminati (13th Degree) |
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Well; there you go. The man may be onto something afterall. I mean a transformer is an electromagnet. I would like to observe something. Once you take a proven and good functioning circuit add reasonable quality passive components, adjust the circuit's parameters through close attention to scope measurements, the only thing controlling the quality of sound is the transformer. In the dozens of amps I have heard through the years of all types of circuitry, the only significant factor that has seperated them from each other has been the quality of the transformers. In the EAR SE 859, he uses very pricey heavy well regulated trans, Yoshino's hand picked. That is one of the better sounding amps built. So how do we determine which circuit to use since so much is riding on the quality of the iron, the circuit seems almost superfluous. J.R.
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