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    Coupling cap options for SP14

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    ramon68

    Posts : 87
    Join date : 2009-04-12
    Age : 76
    Location : naples fl

    Coupling cap options for SP14

    Post by ramon68 on Fri Apr 26, 2013 12:20 pm

    I'm in process of putting together an SP14 and I'm looking at Ampohm PIO aluminum foil output coupling caps.
    Does anyone have experience with these? Or other suggestions for affordable premium coupling caps?
    Thanks.

    stewdan

    Posts : 161
    Join date : 2010-03-07
    Age : 78
    Location : Houston Texas

    Re: Coupling cap options for SP14

    Post by stewdan on Fri Apr 26, 2013 1:26 pm

    Hi -- If my memory is correct, on one of Roy's SP14 pages or one of his pictures he used Russian PIOs (K40-Y's) as a choice in caps. They are definitely affordable. The only drawback is the breakin time and the relative size of the cap with respect to the PCBs hole spacing.

    ramon68

    Posts : 87
    Join date : 2009-04-12
    Age : 76
    Location : naples fl

    Re: Coupling cap options for SP14

    Post by ramon68 on Fri Apr 26, 2013 1:54 pm

    I'm not that concerned about cap size. There are pics on the forum of SP14s with enormous caps mounted off board.
    I just want to know what people's ears tell them about different coupling caps.The reviews I've read of the Ampohms
    are very enthusiastic.

    stewdan

    Posts : 161
    Join date : 2010-03-07
    Age : 78
    Location : Houston Texas

    Re: Coupling cap options for SP14

    Post by stewdan on Fri Apr 26, 2013 6:30 pm

    Hi Again -- well I use K40Y's in my Dynaco Amps. If I had to describe their sound, it would be neutral, IMHO, since they don't color the sound. I do like how they sound in my VTA ST70, my VTA MkIIIs and in Bob's M-125 Amps. Cost is between $5 and $10, which allows me to buy a group of them and match them.

    ramon68

    Posts : 87
    Join date : 2009-04-12
    Age : 76
    Location : naples fl

    Re: Coupling cap options for SP14

    Post by ramon68 on Fri Apr 26, 2013 8:55 pm

    The only Russian PIOs I see on ebay lately are of values of .1 uF or less. The coupling cap in the SP14 is .33uF.
    Where are those sourced?

    DarthBubba

    Posts : 81
    Join date : 2012-05-05

    Re: Coupling cap options for SP14

    Post by DarthBubba on Fri Apr 26, 2013 9:26 pm

    ramon68 wrote:The only Russian PIOs I see on ebay lately are of values of .1 uF or less. The coupling cap in the SP14 is .33uF.
    Where are those sourced?

    What voltage is needed? Not necessarily the voltage printed on the cap, but what working voltage is required. People are always using 400v caps in circuits where the plate voltage it sees from the source tube is 125v and the grid it goes to is nearly zero volts. A 200 volt cap would work there.

    ramon68

    Posts : 87
    Join date : 2009-04-12
    Age : 76
    Location : naples fl

    Re: Coupling cap options for SP14

    Post by ramon68 on Fri Apr 26, 2013 10:18 pm

    The coupling caps (C3 on the board) are 400 volt Sonicaps. I bought the board completed. As to what voltage is needed,
    you'll have to ask Roy. I know nothing about circuit design.

    corndog71

    Posts : 451
    Join date : 2013-03-19
    Location : It can get windy here

    Re: Coupling cap options for SP14

    Post by corndog71 on Fri Apr 26, 2013 11:33 pm

    The Sonicap Gen 1 caps are pretty neutral. They're not bad but I prefer Clarity Cap MR series in a line stage. They're more expensive but vastly more resolving. Alternatively, a warmer yet still detailed sound can be achieved with Clarity Cap ESA series.

    Zimmer64

    Posts : 113
    Join date : 2013-01-29
    Age : 52
    Location : Switzerland

    Re: Coupling cap options for SP14

    Post by Zimmer64 on Sat Apr 27, 2013 7:16 am

    I agree with corndog71 re the Clarity MR caps. I have upgraded my bottlehead quicky with them. The level of detail is really great.
    In my VTA ST-70 I use the russion PIO, that Bob offers as an upgrade. I have not compared those to anything else, but am also really happy with them.

    Best

    Michael

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