1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Where we are now: The site is back up and running! The character set encoding issue has been fixed so old posts should now look ok. I am currently working on themes/skins etc and I will be deleting the temporary green skin very soon as it has many issues. I will do a very quick variation on the stock blue skin first just to get a light-grey background and san-serif font, and I will set this as default. Later this week I will hopefully add a professional third-party skin in pfm colours (life is way too short to do this crap myself, and I've found one I really like than needs next to no tweaking). We are getting there slowly...
    Dismiss Notice
  3. May I please request people check and update their email address if it is out if date. I ask as I’m getting countless bounce errors as the server fails to send notifications through etc. I’ll eventually figure out how to send these to a black hole somewhere, but it makes sense to address it at source as quite a few folk are obviously not getting the thread and conversations notifications they have set in their preferences.
    Dismiss Notice
  4. Things you need to know about the new ‘Conversations’ PM system:

    a) DO NOT REPLY TO THE NOTIFICATION EMAIL! I get them, not the intended recipient. I get a lot of them and I do not want them! It is just a notification, log into the site and reply from there.

    b) To delete old conversations use the ‘Leave conversation’ option. This is just delete by another name.
    Dismiss Notice

diyAudio group buy Paradise R3 phono stage boards

Discussion in 'd.i.y.' started by Markus S, Aug 9, 2012.

  1. sq225917

    sq225917 situation engineer


    Chilly pm ynwoan for panels.
     
  2. Avinunca

    Avinunca pfm Member

    Thanks guys. I will get some appropriate resistors.
     
  3. 337alant

    337alant Negatively Biased

    Si
    Do you know if it makes any difference as I did my Power supply with CRCLC not CLCRC ?.

    Alan
     
  4. sq225917

    sq225917 situation engineer

    I've never measured it but it's nearly always done that way.
     
  5. sq225917

    sq225917 situation engineer

    Try the 20 watt Caddock t220 package parts, easy to heatsink
     
  6. slawekt

    slawekt pfm Member

    Simulate it in PSU Designer software
     
  7. Avinunca

    Avinunca pfm Member


    Just checked my voltages so that I can order some new dropper resistors. The +V are both +26.7V which I assume is fine. The -V however are both -32V. Is it normal to have less current demand on the negative rails?
     
  8. sq225917

    sq225917 situation engineer

    Nope. If you are running Calvin's, disconnect them and measure the rails before the shunt reg. If voltages become even your Calvin's are bad, if they don't your shunt reg is bad.

    Watch how long it takes the led strings to light up on the sides of the boards, they should come up together, within half a second of each other.

    Of course you could have a short elsewhere on the board.
     
  9. Avinunca

    Avinunca pfm Member

    It's odd that I have the same conditions on both boards. Shunt op voltages are ok. I bought these amp/psu boards completed. What is the normal current consumption (inc Calvin boards)? I'm wondering which are correct - the + rails or the -rails. Will try to discon the Calvins.
     
  10. Avinunca

    Avinunca pfm Member

    Quick check of currents before disconnecting - negative supplies 174ma and positive supplies 218ma. Positive rail leds illuminate fractionally faster. Shunt outputs are around 18.5V
     
  11. sq225917

    sq225917 situation engineer

    Are you using Calvins output boards?
     
  12. Avinunca

    Avinunca pfm Member

  13. sq225917

    sq225917 situation engineer

    How did yoy zero them?
     
  14. Avinunca

    Avinunca pfm Member

    Although I have a set of boards to build, this phono amp I bought completed - or so I thought. I built the pre-regs. I've PM'd the seller querying the mismatch.
     
  15. sq225917

    sq225917 situation engineer

    Matching all the parts and doing all the set on test stuff is where the magic lies.

    Disconnect signal in out from the Calvins.
    Fit a 100K resistor into the empty slot.
    Adjust shunt trimpot to get equal voltage then adjust Calvin trim pot until voltages match and yhe led strings light up equally.
    This takes a few go rounds.
    Then remove the 100K and reattach signal wires and it'll be golden.

    I imagine there's a lot of part dialled in Paradises out there.
     
  16. chiily

    chiily PFM Special Builder

    Si,

    When you say, ",,,then adjust Calvin trim pot until voltages match..", where on the Calvin's are you measuring the voltage(s)?

    Ta
     
  17. sq225917

    sq225917 situation engineer

    Across the Top left and second resistors down on the right. Think it's the 22r, I'd have to check the schematic.
     
  18. sq225917

    sq225917 situation engineer

    I'll open mine tomorrow and check
     
  19. Avinunca

    Avinunca pfm Member

    Simon, I have prepared one of my Calvin boards for adjustment .
     
  20. sq225917

    sq225917 situation engineer

    I get 93mv and 93.5mv across those two resistors, r6and r11, the 2.2ohm parts.. Each time you redial the calvin board you'll need to adjust the trim pots on the main board. Eventually it should all even out.
     

Share This Page