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So Monoprice has an actual tube amp now...

Discussion in 'Tube Audio' started by Nixxuz, Apr 28, 2018.

  1. Nixxuz

    Nixxuz AK Subscriber Subscriber

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  2. soundmig

    soundmig AK Subscriber Subscriber

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    Looks interesting. The inclusion of a line in, bluetooth in and phono in - along with pre-outs makes this a very versatile unit - if it is any good. I didn't read very carefully - is the phono stage tube or some sort of chip?
    Oh, I see that the pre-out is fixed level so you can't use it to drive subs - bummer.
     
  3. Mr.Jim

    Mr.Jim President of nothing Subscriber

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    With phono, seems like a good price. EL84's.
     
  4. 39cross

    39cross AK Subscriber Subscriber

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    Specs say: Total Harmonic Distortion = 1%. How is that for a tube amp?
     
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  5. Tubeglowpio

    Tubeglowpio Active Member

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    That is possible, depends on how they measured it, maybe at 1 watt? For example a dynamo st35 is under 1 percent at full volume. Some tube amps may have more than 1 and some have less.
     
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  6. shelly_d

    shelly_d Not An Audiophool

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    Similar to the Dynaco ST-35, also an EL84 amp. The Dynaco is generally thought of as a fine sounding amp.

    Shelly_D
     
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  7. Lavane

    Lavane AK Subscriber Subscriber

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    Huh, try to click on the full specs button. Nothing. I'm guessing from others like it I've seen the phono is chip based. That doesn't have to be a bad thing though.
     
  8. MCdeltaT

    MCdeltaT Active Member

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    Website states there are three 6N3 tubes for the preamplifier stage
     
  9. Lavane

    Lavane AK Subscriber Subscriber

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    So, a 5670 could be used to replace them? I built a preamp awhile back that used 6n1's, 6n3's among others. I kept the 6n3's, they acually sounded good.
     
  10. EJC1

    EJC1 Active Member

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    I was shocked to see 1%THD. That's a deal killer for me, especially since they don't give the test points

    My 50yr old HK 500A is rated at 0.5%THD at full power
     
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  11. Tom Bombadil

    Tom Bombadil AK Member Subscriber

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    1% THD at rated power is a common specification for tube amps. Heck, some of them measure at 3% THD at full rated power.

    For single-ended tube amps, 1% THD is actually a very good measurement.
     
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  12. Tubeglowpio

    Tubeglowpio Active Member

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    I'm pretty sure this one runs in push pull. If it was single ended with 2nd harmonics being most of the distortion it would be pretty good.
     
  13. The Fuxtor

    The Fuxtor AK Subscriber Subscriber

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    How does it get 25 wpc with 4 EL84?
     
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  14. Tim64

    Tim64 Super Member

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    I saw 10 watts per channel further down in the description.
     
  15. Dandy

    Dandy Super Member

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    It would be more interesting to see what OPTs are under that cover. The 1% THD is measured at 1kHz. The equivalent figure for the Dynaco SCA-35 is between 0.3 and 0.4. See the AEA report here: http://aeaaudio.com/wp-content/uploads/2015/07/Dynaco-SCA-35-Performance-Report.pdf

    Note their comment on hum: "Transformer hum: The nature of tubes and transformers can produce a natural hum emanating from the transformer. This hum should not be audible through the speakers, but can be concerning for first time users. As long as moderate listening levels mask the hum, there is nothing wrong with your amplifier."

    TBH, this amp looks nothing special as PP EL84 amps go. But then it is built to a low price.
     
  16. BuzzK

    BuzzK AK Member Subscriber

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    I bought one of their "tube" amplifiers. I don't think the tubes actually did anything. It was deceptive junk. I returned it for a refund.
     
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  17. whoaru99

    whoaru99 Epic Member

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    If one puts any stock on inflation/deflation calculators, bear in mind the ~$100 kit price (from some review referencing 1971) of the SCA-35 makes it roughly twice as expensive in adjusted dollars as the Monoprice unit of topic.

    This just goes to reinforce your comment about the price point.
     
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  18. mmickk

    mmickk AK Subscriber Subscriber

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    So you had the unit in your possession but didn't bother to test to see if the tubes actually were doing something. And yet you can definitively tell us It is a "deceptive" piece of junk. Okay! Nice review!
     
  19. RamblinE

    RamblinE (╯°□°)╯彡┻━┻

    I've known about their hybrid tube amp for a while. But not this one. I spent half the thread wondering if ya'll had lost your minds being so open-minded about this. But no, looks legit. I'm looking forward to some reviews.
     
  20. Dandy

    Dandy Super Member

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    Yes, I think the price issue is relevant. There are price limits on the lowest possible manufacturing cost of a worthwhile tube amp, unlike say the amazingly low cost of making good class D chip amps. This is why we go on about the relative cost advantage of standard but still good vintage gear here on AK.
     

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