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Thread: DIY phonostage.

  1. #331
    Join Date: Mar 2017

    Location: Liverpool

    Posts: 24
    I'm Sandro.

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    I am struggling whit remote PSU positive side is oscillating like mad
    I just don't have the skill to cure that Hfe 385 +- 0.5 % 470P 2.7 N and 47 P + 2SK 170 8.5 mA and 365R
    All caps in place 470 uF Panasonic FM and 100 uF 10 uF silmic and crapy 100 uF whit 15 R tracks are so much shorter than original PCB still

  2. #332
    Join Date: Mar 2010

    Location: Sheffield

    Posts: 2,353
    I'm Simon.

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    I boxed this one up today, it's going to Wales.

    I can crack on and finish Jochim's.

    Sandro, what freq is it oscillating at? Have you tried putting the decouplers on the heatsink? 0.47uF film cap direct onto the underside of the board, from the emitter to ground on the PNP and the NPN on the outside of the heatsink. Essentially they do the same job as the electrolytics on the psu input (which knocks put cabel inductance effects) but they're local, and sized to mop up HF in mHz range.



    Show me what you've got.
    Kuzma Stabi/S 12", (LP12-bastard) AC, USB controlled bi-phase Class A regenerator psu. Benz LP, Paradise (phonostage). MB-Pro, Mdac, Muse 200, Yamaha NS1000m

  3. #333
    Join Date: Mar 2017

    Location: Liverpool

    Posts: 24
    I'm Sandro.

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    It is on the remote home brew boards main thing I try to do is to put the heat sink's outside the box
    Will get scope/ pictures later on.
    I have 47P on C B of Q105

    you suggest 47nF on emitter of Q103 and Q203 ?
    Last edited by Bksabath; 24-04-2017 at 06:51.

  4. #334
    Join Date: Dec 2015

    Location: vancouver

    Posts: 602
    I'm danilo.

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    Damn.. but that thing seems to include More parts than a TV set.
    Clearly KISS wasn't a consideration.
    My audio bits: Thorens / diy phono, CD/dvd player(s), diy pre, F6, Tannoy Golds in my boxes / my xovers, and of course all strung together with basic diy Wires
    Lots of Cd's, yet more audio files, a couple of hundred semi worn Lps.

  5. #335
    Join Date: Mar 2010

    Location: Sheffield

    Posts: 2,353
    I'm Simon.

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    Sandro, yup 47n on emitters. If you've got oscillation coming in around 4-7mhz this should mop it up.

    Danilo, I think it's fair to say that sound quality was the only consdieration with the Paradise. ;-)
    Kuzma Stabi/S 12", (LP12-bastard) AC, USB controlled bi-phase Class A regenerator psu. Benz LP, Paradise (phonostage). MB-Pro, Mdac, Muse 200, Yamaha NS1000m

  6. #336
    Join Date: Mar 2017

    Location: Liverpool

    Posts: 24
    I'm Sandro.

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    Sorry no pictures
    I messed up the boards ...
    I am not going to give up but loads of things going on Moving home soon
    That 47n on emitters would point out problems whit the long tracks on the PCB maybe?
    Agree whit Simon the R2 I built was populated in a rush before all the little tweaks where put in place and it did sound really good I am taking 10 times more building a second one
    As mentioned I got a fair bit going on so slight change of plan for now I am going to stick to building a standard R3 version whit all the little tweaks
    Master plan has not changed it just going to take a little bit more time
    The Paradise is better than most already but I am sure that it could be even better

  7. #337
    Join Date: Mar 2017

    Location: Liverpool

    Posts: 24
    I'm Sandro.

    Default

    WP_20170428_15_54_42_Pro.jpgGot same presents today (no not really about 140) just a few resistors for the RIAA
    Well worth it for R2 Paradise IMO
    R3 is going to be super
    May be not comercialy viable certainly I would like to listen to the Luxman 4K plus and compare
    Any fellow nutter In Liverpool
    I know there must be one or 2 considering that Shieffield got probably more than 30

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