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tube fanatic

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  1. What is also nice about these kits is that the manuals explain electronic theory as the amps are being assembled, and his blog has lots of short lessons explaining tube amp theory.  I’m not easily impressed, but this guy seems to be on target.

     

    Maynard

  2. 5 hours ago, boom3 said:

     Always liked their ads, although I never heard the legendary and well-reviewed Model III, designed by James Bongiorno, also famed for GAS and Sumo designs (I use his Electra II preamp). He was generous with his time  and while alive, would answer questions on the Yahoo Sumo/GAS forum.

     

    I don't recall his opinions on Klipsch products. The little alien in the center of the ad is my fave. Recognizable in this mage are the Ohm Model A, the Great Heil and the original Quad ESL.

    Rectilinear ad 1973.pdf 117.57 kB · 18 downloads


    The Rectilinear III in both the high and low versions was my most popular speaker.  I can’t count how many I sold back in that time period.  The plant manager lived in my neighborhood and gave me really good pricing.  That aside, they were truly wonderful sounding speakers (although a very different sonic presentation from horn types).  I sold mine about 30 years ago and have regretted doing so ever since.  

     

    Maynard

  3. A way to protect ourselves from the virus was developed by Hugo Gernsback almost a hundred years ago!  I’m going to build one and take a stroll through my local Walmart with it on.   This seems far more effective than any face mask!


    https://worldradiohistory.com/Archive-Electrical-Experimenter/SI-1925-07.pdf

     

    Maynard

    (apologies Travis, but I believe levity boosts the immune system!  Delete the post if you disagree).

    • Like 1
  4. Spoiler

     

    Although tubes and some transistors share similar characteristics, there are sufficient differences to justify why this discussion should stay in the realm of tubes.  The SS stuff should be in the section of those “other guys.” 😀😀

     

    Maynard

  5. You need to attach the load to the motor shaft, power it with the voltage you want to use, and measure the current draw with your multimeter.  That will allow you to determine the mAh rating the batteries will need for the length of time the motor needs to run continuously.  More details about what you are doing would be helpful.

     

    Maynard

    • Like 3
  6. I think a better question would be if there is tube equipment which approaches SS reliability.  The answer is a definite “yes.”  It is possible for output tubes to last 15k or more hours, and small signal tubes well beyond that.  Even Carver guaranteed the tubes in some of his amps for 5 years.

     

     

    Maynard

  7. 11 hours ago, JMCMAN said:

    I have a Marantz 7C preamp that recently made a sound like a car engine revving up. Quickly shut it down. After looking inside the preamp I noticed some stray voltage when using the high line input selected. When I switch to low line level it zero's out. Not sure where to look for bad resistors or capacitors or switch in that high line input circuit. Any help would be greatly appreciated.

    thank you


    I am not sure what you mean by stray voltages.  Has it been professionally restored?

     

    The first thing I would do is remove the tubes, treat the pins with Deoxit, and re-insert.  The sound you heard is oscillation.

     

    Maynard

  8. 1 hour ago, Bosco-d-gama said:

    Paraphrasing from the blog post: As yet there’s no definitive proof that antibody dependent enhancement ADE is occurring with covid19. And similarly there’s no demonstration of ADE being part of any vaccine pathways (again per the author). 
     

    So while his concerns are actual they are not factual. What is clear from this post is just how complex virology is and why people need to listen to the advice from the medical community. As far as ADE goes it is among many pathways that make microorganisms pathological or more pathological, if you will. Looking for the ADE pathway in covid19 is being done and as the author noted it has not been found. If he chooses to fret himself into an ulcer over its prospect he may as well take anxiolytics for earthquakes, tsunamis and asteroids. For now he is merely borrowing trouble when the world has plenty of real covid19 troubles in play.

    Yes, but did you review the links to the FDA, et al, presented by some commenters?  As reported in this article, there is concern in Japan (and other countries) about this phenomenon:

     

    As reported in Japan Times:  


    https://www.japantimes.co.jp/news/2020/11/25/national/science-health/japan-experts-coronavirus-vaccines-safety/

     

    ‘Dr. Tetsuo Nakayama, a project professor at Kitasato Institute for Life Sciences and director of the Japanese Society of Clinical Virology, says although the vaccines under development by Pfizer and Moderna successfully created antibodies in trials, there are still doubts about whether those antibodies remain a year or two after vaccination.

    There are also underlying concerns about the vaccines’ safety over the long term. Judging from past precedents, their safety and effectiveness are not something that can be determined until at least a year after a massive number of vaccinations have been administered, experts say.

    In a worst-case scenario, antibodies could worsen the disease by essentially helping the infection of cells — a phenomenon called antibody dependent enhancement (ADE) — rather than fighting the virus pathogens.

    For example, a dengue fever vaccine made by Sanofi, based on a yellow fever vaccine embedded with a part of the dengue virus genome, at first appeared to be effective. But it caused the deaths of children who had been given the vaccination due to the ADE phenomenon.

    “Concerns over ADE still remain. I am an elderly person myself, but if I were asked, I would say I don’t want to get a shot,” Nakayama said. “Not all of the 120 million people (in Japan) should get the vaccinations. Children, for example, would not need it because there’s scarcely any risk of severe cases.” ‘

     

    I guess where we differ is that I consider information from FDA and CDC as being the least truthful in comparison with what is disclosed by similar agencies in the rest of the world.  It seems that the domestic point of view is different more often than in agreement.  To each his own.....
     

    Maynard

     

  9. 1 hour ago, Cathedral Guitar said:

    Here is a related question: a lot of simpler designs for tube integrated amps have just 1x volume pot, and 3-way selector switch. These generally have 2 input tubes, a rectifier tube, and the output tubes. On the other hand, many tube monoblocks also have the 2 input tubes, rectifier tube + output tubes -- but without a volume pot, and w/o the selector switch. So disregarding the multiple chassis / PSU of monoblocks, but is the only difference between an 'Integrated Amp' and 'Power Amp' the addition of a volume pot and a selector switch? 


    In some cases only.  Integrated amps are designed for fairly low level sources while some power amps require much higher drive voltages.  The answer has to be considered for a particular unit in question.

     

    Maynard

  10. If the input sensitivity of the amps allows the source to drive them to the needed output power all is well.  An ideal system has as little electronics in the signal path as possible.  Of course you would need to control the output voltage of the source for volume control.
     

    Maynard

    • Like 2
  11. A bill is in the works in NY State which, if passed, will allow the authorities to remove anyone they consider a case, contact, or carrier of a communicable disease which is potentially dangerous to public health.  To my non-legal mind the implications of this are frightening.  It would seemingly allow them to remove from society anyone who tests positive for coronavirus.  Is this happening in other states or countries?

     

    https://www.nysenate.gov/legislation/bills/2021/a416

     

     

    Maynard

  12. 31 minutes ago, dwilawyer said:

    It's a strict requirement in most states.

     

    Vaccines required and no exemptions to get into Nursing, Dental or Medical school. 

     

    Texas is that way  


    I understand.  However, why should faculty and hospital staff be exempt?  Isn’t that a form of discrimination against the students?

     

    Maynard

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