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High Rollers
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Kerry last won the day on May 11

Kerry had the most liked content!

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About Kerry

  • Rank
    High Roller
  • Birthday 06/18/1963

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  • Location
    New York, NY
  • Gender


  • Location
    New York, NY
  • Interests
    Electronics, Drums, Guitar, Golf
  • Occupation
    Management Consultant
  • Headphones
    STAX SR-404, O2 Mk I
  • Headphone Amps
    DIY T2, DIY KGST, DIY DynaT, DIY SS Dynalo Mini
  • Sources
    DIY USB OPUS DAC, Denafrips Ares
  • Other Audio Gear
    Classe CA-200, Magnepan MG-1.5

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  1. They are the Phoenix Mate-N-Lok-2 connectors. They are rated at 600V which is nice.
  2. They're just Nylon R Type Cable Clamp Fasteners. I got my last batch from Amazon. I tend to use 1/8, 3/16 & 1/4" sizes.
  3. In other news, I just got back the analog input board and assembled the amp. The sandwich is 6.2mm thick + bottom components for a total of about 9mm thick. Batteries are about 10mm on top of the input board. Back plate on and plugged into USB-C (charging LED on) Why we did this... Portable music Just analog from my phone at the moment. DAC is up next PS The Weight is 12oz or 340g
  4. Here's the final board I just sent out to get manufactured... I added some more optional parts that help stabilize the current sense circuitry. The board is now 10mm x 58.4mm x 1mm. Parts are ordered, so it's a race to see if Mouser can ship my order before the boards arrive.
  5. The USB-C and battery management chips are crazy insane. It would not be possible to solder with an iron. They both have one or more exposed pads underneath the chips. Here's the USB-C PD controller... Those giant looking resistors on the left of the chip are 0402
  6. The TI chips I'm using for the USB-C and protection/balancer already have a mechanism built in, so I just followed their recommendations. I found some 0603 parts (RT1, RT2 one the board). They are 10K resistance to start and about 4.3K at 50 C. I found new batteries that are 2400mAH that should give a little over 8 hours playing time. Over voltage is 4.2 and minimum discharge voltage is 2.75V. I'm using 4.2V for OV and 3.0V for UV.
  7. I just finished designing this battery protector board. It has a built in balancer to try and keep the cells at the same voltage. I added a thermistor that gets fed up to the battery management on the amp board. This also has it's own thermistor in the middle of the board. I'll set this to about 50 C for both and do some testing once I get this built. The board is 10mm x 56mm.
  8. Kerry


    I watched that about a year ago. It was only subtitles then. I'm looking forward to season 2.
  9. For D24, most people used LTL-4213 on the original builds. In the active batteries, I use a 7V reference and set the current down to .00093mA (3x 260k resistors). That puts about .23W on each resistor. You’d need to adjust the sum of R31, R32 to 14.7k If you’re planning on doing this, I can double check the values.
  10. Thanks. I think I'll pick one up. I've had the amp playing from 9:00 this morning (did I mention it really sounds great ) and batteries were down to 9.8V at 3:20PM. They are not perfectly balanced so one battery is at 3.1V which is below the minimum 3.3V recommended. So looks like I'm getting a little over six hours with these batteries (3x2000mAH). I can look for larger batteries and also play with some optimizations. I've also been running additional 5V and 3.3V supplies for the DAC that consume extra power. They're not needed for just the analog input. The balancer should h
  11. Some more good progress. The amp is up and running I've got two issues on the board, but the amp, power supplies and USB-C PD / battery management are all working great. The wires going to the pot are temporary. There'll be a board for the analog/DAC inputs. The PD chips are small with lots of pins on them. I'm surprised I could solder them Lots of 0402 chips on the right side of the board... Here's the amp running with the battery (I need to have the input board done before I can put the batteries in the chassis). This is with the amp run
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