New DIY Altoids Tin Amp - The Class A "Wintergreen Handwarmer" by xrk971

  1. xrk971
  2. gwompki
    @xrk971 I know you mentioned having a set of KZ ZS5. I got them recently as well and was wondering what cap configuration you were using in the PCA with these. The ZS5 seems to be lacking a bit of dynamics with the amp in stock form. Guessing that is due to their very low impedence.
     
  3. stellarelephant
    For driving very low impedance I think you'll want the largest 16V output caps possible, and you might want to tune bias a little higher.

    Here is my 63mA build, newly outfitted for passive cooling.:floatsmile: I painted the inside of the lid for heat transfer. Thanks for the link to the tiny heat sinks, Funch!
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    xrk971 likes this.
  4. xrk971
    Gwompki,
    I am currently using 1000uF Panasonic FR's and they sound fine relative to dynamics. I need to build a new one with dual 1000uF OSCONs and see if better. In testing, they almost as powerful as full a size headphone on a desktop amp. I can't have my iPhone volume above 70% with PCA on full volume playing some jazz with drums. The drums are very dynamic. The highs are superb with a super tweeter actually sticking into the ear tube. Did you get the upgraded gold cable? That's what I am using - have not even bothered to use stock black vinyl cables.
     
  5. gwompki
    Thanks XRK and stellarelephant. I do have a set of 1000uF panasonic FR that I will try to swap in and see. I will also try tuning the bias a bit to see what that does. Looking forward to trying them out!

    I did not get the upgraded cable for the ZS5 as I heard the only benefit was less microphonics. If you think its a worthy upgrade though I will give it a shot eventually.
     
  6. stellarelephant
    Gwompki,
    Another thought on maximizing performance with those 16 ohm IEMs... I know you were using the EBL batteries. If you want to quickly test the effects of increasing bias before changing resistors, swap in some fresh alkaline batteries and see if you can hear a difference. 18v vs 16.5v.
     
  7. xrk971
    Good idea StellarE! I like simple things that you can try right away with minimum cost/effort. Actually, I always ship my amps preloaded with a set of alkalines to let the customer enjoy right away and to verify that it works. Most people don't have rechargeables on hand.
     
  8. gwompki
    Alright think I discovered the reason for the big discrepancy in the sound between my new build and my first one. I have swapped out quite a few caps on the output now and I think what it came down to is the whole time was I had the polarity backwards when using electrolytics. Doh! The low end has returned to my new build and with the 1000uF caps it is quite a fire breather.

    Time for even more tweaking! :)
     
  9. xrk971
    Glad you found the cause. The caps become a dead short when backwards and you are lucky it did not blow up.
     
  10. gwompki
    :O! That's terrible...I had been listening quite a bit that way. I'm not 100% sure I had them backwards, but I kept feeling the low end was lacking and when I put the latest round in the bass definitely returned in a big way.
     

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