How to Pass a little time ...cont

Discussion in 'DIY' started by dBel84, Oct 22, 2018.

  1. dBel84

    dBel84 Friend

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    3,302
    Trophy Points:
    113
    upload_2023-5-27_11-32-59.png
     
  2. dasman66

    dasman66 Self proclaimed lazy ass - friend

    Pyrate Contributor
    Joined:
    Mar 13, 2018
    Likes Received:
    2,540
    Trophy Points:
    113
    Location:
    nowhere and everywhere
    Looking at the first pic, I never would have guessed the chassis was cobbled together bits. Amazing what people with talent can do...
     
    • Like Like x 1
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List
  3. dBel84

    dBel84 Friend

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    3,302
    Trophy Points:
    113
    I think this is going to be the last solid state amplifier I build, I would have stopped with the one I use currently but I started collecting the parts for this amp prior to COVID and the pandemic put a damper on the development and availability of this amp which is what I had intended to build all along – my current amp, the balanced M2OPS was a very pleasant accident and I have been very happy with its performance. The amp in question is a derivative of the PASS XA25 – called the XA252SIT – it is the creation of the crazy ZenMod, naturally inspired by NPs design. It is a beefy 40W class A amp - full details available here ( link ) - I am building the SIT version with the industrial TH51s

    upload_2024-1-1_15-42-26.png

    I picked up the output devices a very long time ago – they are now virtually unobtanium , and have picked up parts as I saw them over the past few years. Dual 12A 24VAC transformers for a full dual mono implementation. Mosfet switched output protection for very quick shutdown in case of failure and to protect my speakers ( I used the same boards in my F4 - they are very well designed, not cheap but significantly cheaper than a new pair of speakers). A slow start and timed startup board to support both latching and momentary power switches. I picked up 8 beer can capacitors ( 50V 56000uF ) with the idea of building a CRC supply filter but they were massive and filled the entire chassis , so I switched gears to using a mosfet regulator for both positive and negative rails.

    I had planned to build this one in a prefabbed chassis as a “keeper” amp , but my plans may be thwarted by the massive heat dissipation requirements of the output devices.


    I picked up a non-working Sumo Andromeda II that was quickly filled by building the power supply

    upload_2024-1-1_15-31-53.png

    upload_2024-1-1_15-32-16.png

    All rails settle to + and – 33VDC which is perfect for the circuit.


    These are the heatsinks I had originally bought for the amp and have put them next to the original andromeda sinks for comparison.

    upload_2024-1-1_15-32-38.png

    And in relation to the chassis and power supply.

    upload_2024-1-1_15-32-58.png


    A long way to go , I thought I might have had more time over the holidays but family time was a priority and there are many a cold night ahead as we nestle down for winter in the midwest.

    I have a few implementation decisions to make but this will evolve as I complete the amp itself and start to test just how hot these heatsinks get. This beast is going to weigh in close to 60lbs with these beefy heatsinks , so need to think about the practicalities too.

    ..dB
     
    • Like Like x 11
    • Epic Epic x 7
    • heart heart x 1
    • List
  4. sp33ls

    sp33ls Friend

    Pyrate Contributor
    Joined:
    Oct 24, 2018
    Likes Received:
    170
    Trophy Points:
    33
    Location:
    PNW
    I'm still debating on building this amp, despite having no time to do so and already having built a wonderful SissySIT with the THF-51S (highly recommend this design from Zen Mod!)
    PXL_20220919_181803292.jpg

    I'm halfway through a Wolverine (ultra-low THD;Class A/B) build, which is essentially a wire with gain project; and, I really don't need more amps, but the XA252 SIT looks awesome.

    Stoked to see your progress and read any impressions you may be willing to share.
     
  5. dBel84

    dBel84 Friend

    Pyrate
    Joined:
    Sep 27, 2015
    Likes Received:
    3,302
    Trophy Points:
    113
    I very nearly picked up the wolverine boards but i always gravitate back to Class A , hence the XA252 - I will compare to Sissy when done
     
  6. Pancakes

    Pancakes Friend

    Pyrate Contributor
    Joined:
    Aug 13, 2020
    Likes Received:
    1,442
    Trophy Points:
    93
    Location:
    Atl
    Curious about your thoughts on the Wolverine when you're done. I have the boards and silicon but that's about it right now.
     
    • Agreed, ditto, +1 Agreed, ditto, +1 x 1
    • List

Share This Page