FS: Headphone tube amplifier "NoName"

Discussion in 'Closed (Archived) Sales' started by Zampotech, Jun 9, 2019.

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  1. Zampotech

    Zampotech Friend

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    Dear friend

    Sell experimental tube amplifier for headphones. The amplifier used tube 6Z51P in triode mode.

    [​IMG]

    [​IMG]

    [​IMG]

    There are speaker connectors at the back. But they are not used.

    Its feature:
    - A complete lack of separation of the capacitors
    - The shortest path for the sound.
    - In the output transformers two types of transformer steel are used to improve the performance


    Main parameters:
    The output impedance of the amplifier - 6 ohms.
    The output voltage is 2.2 Vp
    Noise is not defined. Less than-80dB, below my voltmeter's measurement limit.


    The disadvantage of the amplifier - it can not provide a very high volume.

    Cost $230+shipping. Two spare tubes will be added to the amplifier.


    I would appreciate criticism and comments.

    PS Sorry, forgot to prefix FS. Don't know how to fix:eek:
     
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  2. Dzerh

    Dzerh Friend

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    hmm, try to look at it from a potential buyer perspective - "I just made something I can't even measure and describe properly, please review it for me for $300." I, personally, don't find it too tempting.
    If you are planning to continue improving the amp and then make them in small batches would SBAF tour be a better option?
     
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  3. Zampotech

    Zampotech Friend

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    Very good question. I'll have to show you my underwear:oops:

    Transformers to me the firm in the city of Veliky Novgorod made. Аt the time of manufacture of the amplifier in the firm quit the old winder. When you order this transformer firm said that such transformator to make impossible.

    The amplifier froze in the state of the prototype. He's 5 years old.:D
     
  4. Zampotech

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    I will try to show in the photo the reason for the manufacture of this amplifier in a single copy.

    The first photo shows the output transformers. It can be seen that the core is made of two different types of transformer steel. In the photo they are black gray and green.

    [​IMG]

    The black and gray core is standard transformer steel.

    Green core is an unknown to me experimental or special transformer steel.

    The transformer from two different grades of steel turned out to be small and with good technical parameters.

    For comparison, I will show the dimensions of the transformer with a standard transformer steel with almost similar parameters.

    [​IMG]

    The manufacturer of transformers refused to produce such small-sized transformers ( the technician who made these transformers are retired) , so this amplifier was forced to turn out exclusive.
     
  5. Dzerh

    Dzerh Friend

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    So, practically, it is one of a kind collector's item of unknown quality.
     
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  6. Zampotech

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    You're right. Now this amplifier for all is "black cat in a black bag"

    This amplifier has a virtue that is rare in other amplifiers. It has no capacitors in the audio path. And accordingly there is no distortion associated with capacitors.

    Another option is possible. I can refer this amplifier to a reputable SBAF member for testing. In case of negative feedback, this amplifier will remain in the SBAF Museum (if there is one).

    In case of positive testing, it is possible to produce a small number of such amplifiers (of course in a different design and other transformers) for distribution among SBAF members who wish to purchase such a club amplifier.
     
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  7. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    So, how loud will it play, exactly, with a high impedance dynamic?
     
  8. Lyander

    Lyander Too sensitive for SBAF

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    There seems to be an abundance of novel amplifiers at the moment.

    Yay.

    I do think sending it over to trusted ears and getting feedback for a limited production run might be excellent. If nothing else, it's a way to get feedback on the design for future reference!
     
  9. Zampotech

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    There will be 4 points on the 5 point volume scale: very quiet, quiet, medium, loud, very loud

    But there is a reserve of power.. The power of the tube allows you to cover the entire volume range. You only need a little in the future to change the parameters of the transformer.
     
  10. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    I would be interested in testing it and providing feedback if you go this route. Budget too tight to buy outright, but I’m curious enough.
     
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  11. Zampotech

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    OK. Write to PM your address
     
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