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davve

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Everything posted by davve

  1. I will order them from mouser. But how to get lower mV´s on the transistors? Trimpots turned all the way down and have 130mV cold. Thanks
  2. Yes I am using OP27. I bought them from ebay, guess not the best source. I bought from a top rated seller. Logo on opamps are Texas Instruments Only difference between opa445 and op27 pins are Don´t know if it matters. opa445 pin 8 NC pin 5 offset trim op27 pin 8 Vos trim pin 5 5 NC And on my KSA5 the 500 ohms trimpots are turned all the way down (clicking) then i have 125mv cold. If i am gonna rise the voltage i need to be able to adjust the mv down even more... Voltage are 21.7 v with op27.
  3. Wich opa445 should i use? i have opa445AP and they wont work in my psu. I have tested two pairs of them, and psu is dead with them. Thanks
  4. Heatsink temps are around 50-60C, so it´s normal. Have question about the trimpots. Trimpots (500ohm) is turned all the way down (clicking) to get 105mv (hot) . Can´t get any lower mv, are they just for if you to run higher mv? Cause no need for adjustment then. Thanks
  5. Thanks for mention the 15024 and 15025, i had swapped them around. Now i have 21.8v + and 21.8v - stable voltage ? Amp is working great, and sounds good. Is it normal for the 15024 and 15025 to run very hot?
  6. Yes, and have changed the mpsa06 and mpsa56. Checked so every pin is correct. Don´t know what is wrong ?
  7. I have checked all the resistors. U3 and U4 have 3.5v between anode and chatode. And D1 and D2 have 12.9v across them.
  8. Thanks for the help. I have started up the PSU and i have 35V DC on the output. + - 70V DC together. Should be 21 + 21 -? All resistors are correct. RAW 35V DC is just over the rectifier? not on the output? If i understand correct?
  9. My apology then for using the krell thread. I have read the thread and was just wondering if there been some changes. Cause 10k or 1k input for the op27 is some diffrence. Perhaps i like to solder?
  10. I bought my kit from the link below, it is your version? But i was wondering, on the board it says 2x 10k ohms resistors and 2x 1k ohm resistors. But i got 4x 10k ohm resistors. https://www.ebay.com/itm/Power-supply-board-for-KG-version-KSA5-headphone-amp-PSU-DIY-kit-and-finished/122365758658?hash=item1c7d914cc2:m:mfcUM96JgKu8Wbo08L6PZFw
  11. I was wondering if it is okay to use 47pf or 100pf instead of the 33pf's. Thanks
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