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  1. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    the 4.7μ 25V should be alright ... the 100μ 16V ... umm no ... replace with same or higher voltage rating (within reason)
  2. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    so its kinda "ticklish" .... Engineering from thin air, this would prompt a revisit to the NFB loop. Essentially, a power amp is an Op amp on a much larger scale. You'd do well to study them a bit, even try to scratch build a few projects out of them like preamps and the like. one of the basic...
  3. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    Signal in and signal out ... that's excellent. If the thing can track well enough to reproduce a signal, the active components are good. There could still be a sketchy cap in there, but nothing to warrant gutting it. I think it'll be a function of tuning now
  4. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    that describes a power supply issue.
  5. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    yup ... thought something along those lines. In this field, it helps to visualize how things are supposed to work. Transistors, MOSFET or BJT have a set of specs where they are completely on, and completely off. known as saturation and cut off. That whole line of transistors Q608, Q610, Q612...
  6. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    I'm starting to get the vibe that you're kinda new to this sort of thing, but versed enough to try. C614 and C618 are DC blockers so the front end can be devastated and not cause an offset, so we need not look in front of those caps ... yet. That means we can work from there toward output till...
  7. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    You might have mentioned it and I missed it ... did the right side ever work in your testing? I know it sucked the driver in hard at start up and gradually released ... did it function after it "sobered up"?
  8. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    Zeners are used for voltage regulation. you can put 100V across them and it'll read rated voltage ... in your case 8.2. this also lends itself as a protection device ... If we know voltage over say .. 12V will bork the bork, and we anticipate needing only say .. 5V in operation, the 8.2V stone...
  9. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    when you say 613 and 614 are reading differently what are you measuring? Resistance? Voltage? Kinda important as you stated in a previous episode of the amp saga that you had to crank what looks like VR604. Yeah that will swing voltage.
  10. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    zener diodes are interesting devices in that they are often labeled according to rating. it should read 8.2V across it in action. if not, search according to voltage for a replacement
  11. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    check ..... Q614 D610 SOMETHING is borked enough to drag the the OPS to the neg rail. Interestingly, your amp looks to be of a design that's fairly easily scaled, provided you have the power transformer to feed it. Just add OPS pairs, gate and balance resistors. Nice thing about MOSFET amps is...
  12. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    yeah ... the most expensive part is the power transformer. the next are the output transistors, which kinda run the gambit from "wow thats all" on up to "thank you sir may I have another". My home brew solid state guitar amp uses 4 each MJ15003 and MJ15004. Its not quite a 1940's British...
  13. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    that should work, but as I look through a pile of designs ... the next place to look is the VA stage and bias generator. Most seem to have caps large enough to do what you describe ... good news is that the parts are fairly cheap in this part of an amp
  14. VenomBallistics

    Gas diffusion - a question or two

    I had a summer job in a window factory. what I gather so far. The OP wishes to improve the insulating properties of the windows he has... The OP wishes to achieve this while avoiding complications from condensation. If I assume that the product described is more or less equal to plexiglass ...
  15. VenomBallistics

    What are these sections of this power supply?

    A tone stack is the electronic circuit that makes up your tone controls, bass, treble and midrange. Without it you're either cracking teeth, or pumpin' mud. at the very least you should have a tone control. At the bottom of this page is a free calculator that lets you design and tweak these...
  16. VenomBallistics

    What are these sections of this power supply?

    The "Crazy" portion is probably the tone stack. You'll see things ranging from similar to far worse spread across all the various designs . Let me introduce you to the 12AX7. This is a high gain DUAL triode. That is, one tube, two triodes. Thus, the halved segments in the schematics are exactly...
  17. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    Okay ... that's bad. Real bad. basically at power on, its dumping everything the output stage can deliver from the - rail through the speaker. start from the OPS and work back
  18. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    nice empire of dirt ya got there :D I keep a 282iQ in my patch bay. Can you remove the grill from your speakers so that you can observe them at fireup? see if you have a woofer being pushed out or sucked in and held while it wakes up. The light, and probably the noise as well, is due to a...
  19. VenomBallistics

    What are these sections of this power supply?

    excellent. Now , lets look at the amp you have at hand. What you have here seems to be an early Fender Champ clone. this statement includes two terms you might want to evaluate. "Early" as in the front end tube is not exactly plentiful. and "Clone" as in not necessarily accurate. In fact it's...
  20. VenomBallistics

    Adcom 5400 amplifier blowing all fuses

    Jay Saws Flaky Crust .... sold at fine retailers everywhere I'd say give it one more honest and well "preflight checked" try. The fuses may have done their job. Failing this, save the chassis and the power transformer as a host for a full build...
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