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Hi ya. Need a phono input adapter

Discussion in 'Tech talk' started by MikeBoombox, Feb 3, 2017.

  1. MikeBoombox

    MikeBoombox Member

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  2. Boodokhan

    Boodokhan Well-Known Member

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    What is phono input adaptor? Is it something like a pre-amp?
     
  3. Longman

    Longman Well-Known Member S2G Supporter

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    It should be easy enough to get one. I looked on Ebay and there were 199 listings.

    Looked on Amazon and there were loads as well e.g

    https://www.amazon.co.uk/d/5fv/Av-l...8&qid=1486282256&sr=8-2&keywords=phono+preamp

    To answer Boodokhans question, yes it is a preamp specially made for connecting a turntable pick up to a line level input as you would use for a Compact Disc player etc. The output from a cartridge is lower and has a special RIAA equalisation curve

    https://en.wikipedia.org/wiki/RIAA_equalization

    Don't confuse Phono plugs (which seem to get used for all sorts of things including digital signals) with Phono Inputs which is what they were originally designed for back in the 1940s.

    The good news is that it only needs a transistor and a few passive components to make a mono RIAA pre-amp.

    Until CD completely took over any Hi Fi amp would have a suitable circuit built in.

    Some cheap turntables, especially the ones you can buy nowadays, tend to have a preamp built in
    so you can plug them straight into the line input of a Bluetooth speaker, soundbar or similar.
    You can usually switch it out in case you have a real phono input available on your Hi-Fi

    Despite usually only having one external input some Boomboxes have a switch that can make the input suitable for line level or phono level. I have an Akai (I can't remember the number as it is in the loft) that can do this.

    As for which one to buy, that is a discussion for the Audiophiles. Just on Amazon prices range from £13 to £3000 !!!!
     
  4. MikeBoombox

    MikeBoombox Member

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    This device reduces the phono inputs which are very strong & creates that disturbing distortions our boomboxes hate. I have a boombox that has phono input only so using this device I can plug my IPhone & sounds nice and clear just like Aux. One end plugs in the phono & the other to the IPhone & Whalla.
     

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  5. MikeBoombox

    MikeBoombox Member

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    I had this device. I lost it. I wish I can find so I can buy at least 2.
     
  6. MikeBoombox

    MikeBoombox Member

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    Hi Longman, I think the device u showed us is for turntable to run them through auxiliary. Is to increase the signals on auxiliary. I can be wrong.
     
  7. transwave5

    transwave5 Member

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    Its an adapter to phono not a phono preamp.
    This is the reverse of the "phono preamp"
    so no battery or power is required.
     
    Last edited: Feb 5, 2017
  8. MikeBoombox

    MikeBoombox Member

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    Yes Transwave that is correct.
    Where I find this?
     
  9. transwave5

    transwave5 Member

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    Last edited: Feb 5, 2017
  10. MikeBoombox

    MikeBoombox Member

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    Awesome. I'll work on it. Thanks a million man.
     
  11. Nickfish

    Nickfish Member

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    I have been using these ready made attenuators for years but have found that sometimes the attenuated level is too low and that i have to crank the boombox it's connected to way too high to get a reasonable listening level. Would anyone know how to make this either a little bit less attenuated or variable? I did find someone selling home-made variable attenuators on Ebay a couple of years ago and i bought one but while it gave the levels i needed, it sounded awful! I think the components that were used were sub-standard.
    I would of thought that an enterprising clever person on here might be able to make a variable attenuator that does not colour the sound and sell one to each of us!
    Anyone?
     
  12. Northerner

    Northerner Well-Known Member

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    I bought a variable homemade looking one and it was terrible. I bought several of the MCM ones when they seemed to be running out...I use these and find them good :)
     
  13. Longman

    Longman Well-Known Member S2G Supporter

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    Thanks for the explaining what the box does. If I had looked more carefully "Line Level to Phono Input Adapter" is written on the picture on the box.

    I had a look at the Akai and was wrong about that as well. I guess I was using it with my Sound Burger which has a built in amplifier.
    My Sharp GF555 does have separate inputs for line and phono.

    Back to attenuators I had to build one when I was in lodgings and wanted to run a CD player though the DIN socket on my Sony CFS45L.
    Sometime in the future I need to build one to run a line level input into a camcorder.

    Here is a technical article on their design http://www.uneeda-audio.com/pads/

    Doing reverse RIAA would be more complicated though.
     

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