EEVblog #354 – CityRail PA Amp Teardown

Teardown Tuesday
Forum Topic HERE
What’s inside an Sydney CityRail Train PA Amplifier.
And an extensive tutorial on the design of the power amplifier system from the designer himself, Doug Ford:

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  1. Top-notch. Just top-notch!

    Not that the previous teardowns were bad, but having a designer of a circuit present his design was something completely unexpected. Thanks, Dave. And thank you, mr. Ford!

  2. That was great having the original designer talk about it! Its a shame more equipment doesnt come with its designer in the box hehe.

    And damn that thing got toasted from the cleaning solution drip. reminded me of a few weeks back when my MCU light switch outside thats running off 230V and the rain got in the electrical box so made it arc all over it(Luckuly fuse blew pretty soon).

  3. That episode was a act of class. Mr. Ford’s structure of explanation, design priorities analysis, memory and hindsight lessons, carried the engineering messages across 100%
    Dave proves to be quite good a technical host BTW, obviously paying attention, helping the flow, asking short to the point questions that most would think of asking, making it interesting but not stealing the guest’s main role.

  4. IMHO this is the best video you have ever put out. Big respect to Doug Ford.

  5. Blimey. Fascinating. Years and years of experience in one hour of video. Excellent

  6. I’ve always wondered why the announcements sound like they’re coming through a mailing tube full of gravel.

  7. Just incredible, great insight thanks to Doug Ford

  8. Fantastic!

    Small point of order – The main problem with the Millennium trains was that they were the first in Sydney with AC drive systems. All the recent signalling equipment uses AC overlays and Time Domain Reflection that travel along the tracks, which are also used for the traction return current (1.5kVDC) – As you can guess there were a few teething problems! But since then they have been by far the most reliable trains in Sydney.

  9. Excellent video; congratulations!
    The insights of the original developer are absolutely priceless, as any teardown leaves us with a lot more guesses than certainties about the constraints and options available during a particular project design.

    I particularly loved the explanation behind the choice of not using a micro-controller in the design. This is a great example that shows younger developers that software-based designs are not everything.

    Discrete analog design is a real art. Congratulations to Doug for providing his insights to an excellent design and for Dave for providing the rare opportunity to peek into a product with such great depth.

  10. To quote Dave… “I love it…. yeah!”
    One question…. why 25/50kHz for signalling?

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