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Blackbird

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Posts posted by Blackbird

  1. 1 hour ago, erik2A3 said:

    Yes, you are correct.  I often include extra bits of information in my posts for those who may not be familiar with them.  And your question:  A brand new pair could definitely be made, and all parts are readily available.  I'm of course referring to the Moondog as circuit, not the packaging.  As for improving the circuitry, that is a much more complicated issue.  What aspect of the circuitry?  I think I do understand what you're asking me though - what can be done to make it a better Moondog, correct?  We can use my makeover as an extreme example, and what's left, while quite good sounding to my ears, is most definitely NOT a Moondog.  That's why I'm glad I have another pair that will be left 100% Moondog, even with the bunches of modifications that I know can be done in the name of improvement (which, at the end of the day, might not be as good as the original version).

     

    Ron Welborne designed all of these kits so they could be more straightforward to build for those who may not be familiar with schematics, etc, and it's already a very, very good design.  Lead lengths could be shortened, and more direct connections to grids, plates, and cathodes could be made, etc. but the circuit would remain the same.

     

    But sure.  You could use the same chassis you have, which is THE Moondog, and, if you were so inclined, completely redo the wiring.  This is essentially what I did with the Laurel IIs in this thread.  There are a couple of things I decided would be best left alone since they were doing their jobs well and the associated craftsmanship was good.  But the rest was re-done, while still maintaining the essential Laurel II design.  In other words, I absolutely did not redesign it.   One of the main things I addressed was the proximity of certain parts of the circuit.  I relocated a number of large components, as well as solder terminal strips, in order to 'open things up a bit' for better cooling as well as noise reduction.  Those same sorts of things could be done with the stock Moondog.

     

    I would prefer to keep my Moondogs.

     

    I am not an Electrical Engineer and not even a technician.  I don't know how do handle a solder.  But I know good tube sound when I hear one.  Now what if I can find the Moondog cabinets and have you build me a pair with what highlighted (in bold) in your quote plus MagneQuest OPTs?  The completed Moondogs will be paid for however long it take and no question asked.  I would rather have you build them for me or no one else.  In my opinion, I don't think anyone can build them like you can!

     

  2. On 8/18/2019 at 8:54 AM, erik2A3 said:

    I thank the owner for his exceptional patience -- especially with my possibly a bit overly-meticulous approach.  I just have a high standard for BOTH safety and performance, and want to make sure what I do is the very best I can do.

     

    I can’t even begin to describe the level of dedication that erik2A3 had.  Such a remarkable feat!

  3. 5 hours ago, Jeffrey D. Medwin said:

    I am afraid many / most in audio, don't use good electronics, and its usually the amplifiers that are in dire need of improvement.  Banana plugs fit part-and-parcel with mediocre hi fi implementations, mediocre amplifiers, in all of my experience and, in my own opinion.  Its really simple - to me banana plugs are mid-fi.  Audio quality spade lugs and Cardas CCGR speaker posts are high-fidelity.

     

    It’s really simple to put the money where your mouth is.

  4. 54 minutes ago, Jeffrey D. Medwin said:

    Spade terminals are superior to banana plugs, if you didn't know that. 

     

    I beg to differ but in my opinion, spade terminals are not superior to banana plugs!

     

    I have known to trip over the my speaker wires with such force that the spade terminals either ripped right off the wires or damaged the terminal block on my speakers.

     

    With banana plugs, my speaker wires just pop right off the speakers and I just plug them right back.  I have always use banana plugs forever and no wires have ever been damage from their usage.

     

    Any wires attach semi-permanent to speakers are prone to damage when being tripped over.

    • Like 2
  5. On 7/25/2019 at 3:09 PM, codewritinfool said:

    I don't give my real name unless I do business with someone.  Nickname is "code".

     

    I attempted to try out for a local production of Jesus Christ Superstar for the role of John, but they never called me in for an audition:

     

    IMG-1060.png

     

    I like the long hair.

    • Like 3
  6. I got this little phono preamp at a local church thrift store a couple weeks ago for $25.  It seemed to be new.

     

    I have not have a chance to hook it up.  I have read about this phono preamp online.  Some of the reviews are pretty positive.

     

    Have anyone here personally listen to this phono preamp?  Can anyone give me an impression?

     

    Little Bear Phono Preamp.jpeg

  7. erik2A3, there is absolutely no misunderstanding on your part and I understand it perfectly.

     

    I have to say that after having read many of your posts, I would say that you are an extremely knowledgable person when deal with with these type of amps.  I have a lot of respect for you and when you say something, I listen carefully.  Your explanation of these resistors in my Moondogs and what need to be done are very clear and I understand it well.  Thanks again for taking your time to explain the issue to me.

    • Like 1
  8. 5 hours ago, erik2A3 said:

    Hi Blackbird,

     

    Apologies to begin with here, but the person who worked on your Moondogs (and from the looks of it did a good job), is NOT correct about resistor values.  R13 is actually composed of a parallel pair, which on the parts list will be shown as resistor A and resistor B.  However, you will also see that they have the same resistor reference number as related to the schematic.  Parallel resistors will double the power-handling ability of that particular part of the circuit, but the value of resistance will be reduced -- just as two 8ohm speakers connected in parallel will reflect a new nominal impedance of 4 ohms.  Connected in series, those same speakers would double the impedance load to 16 ohms.  Resistors are the same.

     

    So.  Had R13 been in another position in the circuit, such as the heater supply, the value would have been much more critical.  As you mentioned above, the amps sound good to you.  However, it would be wise, in my view, to correct this situation - and it's an easy fix: the present 1.8kohm power resistor can stay exactly where it is (no need to remove it).  Get an additional 1.8k ohm resistor of the same kind and power rating, place it on top of or along side the one that's already there, join corresponding leads, crimp, and solder.  Clip excess lead, and that's it.

     

    So glad you were able to get a pair of these fine amplifiers! :)

     

    Oh, I meant to say it would be very easy to conclude the resistor values were incorrect if one were not familiar with the particular amp circuit in question.  So, this is absolutely NOT saying anything against the tech!

     

    I poked around a bit and found the following regarding Moondog parts layout.  I was going to dig out my old Moondog manual, so this link saved lots of time.  R14 was shown twice, so is a typo.

     

    http://i-vol.com/welbourne_labs_moondog_2A3/moondog_info.htm

     

    IMPORTANT:  I see I completely forgot to mention that the same is true for R10!  This is much more critical to the circuit since R10 forms the cathode/filament bias resistor.  There is heavy current going through this area, and it's important to make sure, Blackbird, that the resistors used have BOTH the correct value (2K) and power rating.  I am nearly finished repairing a pair of Welborne Laurel mono blocks for a friend, and used a 50 watt chassis-mount resistor in this place for better heat dissipation.  So once more for R10:  IF THE TECH USED A SINGLE 2K POWER RESISTOR FOR R10, HAVE HIM ADD ANOTHER ONE IN PARALLEL WITH IT FOR A FINAL VALUE OF Ik.

     

    Thanks, erik2A3.

     

    As you know I am not good with a solder, I will talk to my technician to see when I can send them back for him to make the modification.

    • Like 1
  9. 20 hours ago, oldtimer said:

    It doesn't exist because of stupidity either.

     

    Just because I said "The moon landing was a fictional work!", I am being stupid?

     

    I see your logic.

     

    Dictionary

    stu·pid
    adjective
    1. 
    having or showing a great lack of intelligence or common sense.
    synonyms: unintelligent, ignorant, dense, brainless, mindless, foolish, dull-witted, dull, slow-witted, witless, slow, simpleminded, empty-headed, vacuous, vapid, halfwitted, idiotic, moronic, imbecile, obtuse, doltish...
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