Step up Xformer Question - Amp

Discussion in 'Amateur Radio Amplifiers' started by KK4YDR, Dec 19, 2015.

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  1. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    That amp was reviewed in the latest issue of QST. Pretty good review.
  2. N8MSA

    N8MSA Ham Member QRZ Page

    No scientific evidence to support these tired assertions; tests by accredited organizations as long ago as the 70s found that both SS and tube amps sounded the same until overloaded:

    Early CDs, almost all of which were mastered on Sony equipment that had design issues that were overlooked for years, had a noticeable spectra imbalance relative to LPs. This was largely corrected in the 90s. LPs have a form of mechanical compression (resulting in at least 40 dB less dynamic range) and a non-linear response curve that some people prefer. I have a listening system with, among other things, a premium turntable/tonearm/cartridge and most of the people that have listened to it are hard-pressed to tell the difference. The few that can notice the the LPs sound "louder" because of mechanical compression, with opinion split between "like" and "dislike".
  3. KA9JLM

    KA9JLM Ham Member QRZ Page


    Most of the cars that had 8 track players had a lot of mechanical compression too. :D
  4. KK4YDR

    KK4YDR XML Subscriber QRZ Page

    Regardless of your yelling at me to correct my own rightful opinion, I like the sound of tubes better period. But again I am not opposed to an AL-1300 or 1306 due to the fact it can do 6 meters over a KW out of the box. And there are no tube issues to sort out. But I personally think tubes sound better no matter how much science you want to toss at it. Oh I believe in Christ also no mattet how much science is tossed around. Merry Christmas everyone.
    Last edited: Dec 25, 2015
  5. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    LPs on vinyl are analog and not digital, so there isn't any sampling. They just play what's there.

    CDs have never been quite like that; although personally I can't really tell the difference. However, those with better and younger ears sometimes can, in double-blind tests. I admire their hearing.

    Re tubes vs. transistors, they distort in different ways. Most high-end tube amps are push-pull which greatly reduces even order distortion and it can be easier to transform a high-Z source to a low-Z load than the other way around as is required for SS amps.

    I can't really tell the difference either, but then I don't have teenage ears anymore.

    A lot of the magic in audio amps is in the magnetics.
  6. KM1H

    KM1H Ham Member QRZ Page

    It took me 11 years to find a nice looking factory optional AM/FM 8 track multiplex radio for my 68 Impala SS 396 convertible. Will I use it....Nope just eye candy adding value to the car.
    KJ4NOO likes this.
  7. KM5FL

    KM5FL Ham Member QRZ Page

    You still got that old thang??? :)

    KK4YDR likes this.
  8. KM1H

    KM1H Ham Member QRZ Page

    Yep, Im lucky if it gets 2-3K miles a year on it which as you remember is death on the QJ.
  9. N8MSA

    N8MSA Ham Member QRZ Page

    I'm not "yelling at you"; my point is that you can't just hand-wave the science away, which is why we get into subjective debates in threads such as these when the answers are fairly well understood. Tubes, transistors and antennas weren't found in caves - they were developed and described by physicists, mathematicians, chemists and inventors. Tubes and transistors are both the result of theoretical research and practical engineering, with well-understood characteristics. Human hearing is well-understood as well and there has been considerable research in the topic of incremental differentiation or, in lay terms, the ability of humans to hear small differences in similar sounds.

    I've designed and built audio amps since I was a teenager, I have an MSEE and I've been through every bit of research on this topic that I can find: two amplifiers, with similar transfer functions and operated within their linear ranges, will - irrespective of the devices used to build them - will provide identical performance. You may like a given amp better because it sounds pleasing to you, but that's typically due to a conscious design decision to give it "warmth" and not just because the amp has a tube in it - this can be done with any kind of amp, and often is on low-end consumer gear.
  10. N7ZDR

    N7ZDR Ham Member QRZ Page

    I have used my Acom 1500 for about a year now and love it. It's about as close to a SS amp as you'll ever get without being SS. Can run on 120 volts if needed at reduced power.

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