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Creek Destiny amplifier issues

Discussion in 'd.i.y.' started by Ant, Jun 10, 2019.

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  1. Ant

    Ant pfm Member

    Hi, I have a Creek Destiny Amplifier which was working fine, but now a couple of minutes after powering up there's a relay switching sound and the speaker protection steps in, the speaker channel (A/B) and input selector LED's turn red and the amp becomes completely unresponsive leaving only the power button active.

    I initially though there was an issue with my speakers, but swapping to various speaker and cables made no difference at all.

    The amp doesn't even need to have any speakers/cables/source connected or selected to enter protection mode.

    The Destiny does have some history, and has been back to Creek for 'refurbishment' by Mike himself - there's a sticker on the main board saying so. Just by removing the lid It's pretty obvious one channels entire pre & power has been completely replaced. After searching many forums in hope of a diagnostic test procedure, nothing came up other than one guy who had exactly the same issue as me, and although his amplifier was inside the warranty term, he had an incredibly difficult time with Creek to get the amp repaired, received the amp back after quite a considerable cost to himself and sold it on to recover the cost.

    My amp was purchased pre-owned and advertised as 'refurbished' by Mike Creek himself. I do wonder if my amp is the actual amp that the above guy had many problems with? Regardless, I contacted Creek and I was advised they are still able to service the Destiny, and they seemed aware of the serial number, to which they hinted it may not be cost effective to repair the Destiny compared to replacing the amplifier.

    The amplifier works fine and sounds great up until the speaker protection steps in, and I really would like to get this amp up and running again.

    There is no DC present on the output and the bias seems fine on both channels, the rail voltages and transistors seem in tolerance from what little info I can find. The output relays don't seem to be sticking. I have no idea what the fault is, I can only presume its the speaker protection itself causing the issue. I don't have access to a scope or the knowledge how to use one, so it's pretty basic measurement testing.

    Questions: has anyone had any issues with a Destiny before? Do Creek have any kind of diagnostic code finder? I don't have access to a circuit diagram - Is there a dummys guide present anywhere for fault finding speaker protection problems and output stages please?

    Thanks,
    Ant
     
  2. Jim Audiomisc

    Jim Audiomisc pfm Member

    The best course is probably sending it again to Creek or other repair bod. However: Does the same thing happen if you try using it with no speakers connected? It might be possible to walk yourself though diagnosing if it is simple as the protection circuit operating when it isn't needed. But I know zip about the design of the amp, so someone else may well have better advice.
     
  3. bugbear

    bugbear pfm Member

  4. Jim Audiomisc

    Jim Audiomisc pfm Member

    The tnt page mentions a "sophisticated" protection circuit. TBH I'm not a fan of active protection circuits as the more 'sophisticated' they get, the more likely they might be to needlessly panic. As per another thread, this may depend on the exact choice of the combination of speakers, cable type, and cable length. So I'm wondering if something else has altered which your experiments haven't 'corrected'.

    How long does the amp work for, and do the output devices get hot even when you've not played loud music?

    I also have an old-fashioned hesitation about power fets being keen to burst into HF oscillations. Which all takes me back to my earier comments. Need a circuit diagram, though, to say much more, not having seen the actual circuit, etc.
     
  5. Ant

    Ant pfm Member

    Thank you for your replies. The amp fails with various speakers and cables connected, although it doesn't require any speakers/cables/source connected or any particular input selected to enter protection mode, and the time it errors after power up varies. I thought it had fixed itself after around 5 minutes of listening yesterday morning, then it failed, where as last night it was less than a minute. I have searched for the circuit with no luck, hoping someone here may be able to point me in the direction of an archived diagram.
     
  6. Jim Audiomisc

    Jim Audiomisc pfm Member

    There are various experiments you could try - e.g. putting it into a plastic bag in the fridge for a few hours. Then take it out, turn it on, and see if it works for longer when cold. However in the end it looks like you need to send it to Creek or a repair bod who knows or can reverse-engineer the circuitry, etc. Like you I find it annoying when diagrams seem to be regarded as 'trade secrets'. I came into audio at a time when companies felt delighted to give people diagrams and not treat them as if they contained magic incantations some other wizard might 'steal'.
     
  7. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    What with no diagram, the compact one board layout of the main amp board, a dubious history of previous repairs and possibly worse of all the use of a microprocessor which is likely involved in monitoring of fault conditions it is probably beyond economic repair. I repair amps, but due to the above issues it would likely be a bigger bill than from Creek who no doubt have the service info and still suggested it would be uneconomical.
    One possibility to try would be http://www.ant-audio.co.uk/index.php?cat=post&qry=about Alex designed some of the Creek amps but is involved mainly with tape these days so may not do repairs... and will likely say it's beyond economic repair if he does!
     
  8. S-Man

    S-Man Kinkless Tetrode Admirer

    There could well be no DC on the output because the protection relay is doing its job!!

    You need to measure the DC on the amplifier output side of the relays before and after the fault occurs.
     
  9. Jim Audiomisc

    Jim Audiomisc pfm Member

    FWIW In the past I've found Alex very helpful, etc. But I assume the Destiny is after his time with Creek.

    For me, though, this illustrates why I feel it should be expected and the norm for circuit diagrams, etc, to be available. Otherwise, what happens to complex designed that become 'classics' when the makers have long gone. Bad for audio, and bad from a 'green' perspective.
     
  10. Jim Audiomisc

    Jim Audiomisc pfm Member

    It depends on if there is eithe a slow dc 'drift' or ab abrupt jump. The problem is that knowing nothing about the details of the design all anyone can do is guess or experiment.
     
  11. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    There are two sides to the story when it comes to IP of schematics etc. A big manufacturer will probably consider repairs a burden that they must carry out for good will reasons and of course as part of the guarantee.

    As someone who does repairs for a living it's a pain when I can't get them of course, but when I have schematics that are not in the public domain I have an advantage if I keep it to myself... eg I worked for Alchemist Products and Musical Fidelity and have lots of specialised info on these in the little grey cells but also a certain amount of schematics... now there are not that many repair outfits that specialise in expensive hi fi gear anyway so when someone wants an Alchemist or MF amp servicing there's a good chance the work will come my way and it is not in my interests to make it easier either for DIYers to fix stuff themselves or for rival repairers to get the business!

    If we're talking say a Ford Mondeo wiring diagram then there are so many people with the info and so many actual Mondeos that the repair is pretty generic and will usually go to the nearest or cheapest garage.... all the Ferrari repairs will probably go to one guy who has the service info no one else has;)
     
  12. S-Man

    S-Man Kinkless Tetrode Admirer

    If it's a slow drift then it's easy to measure on a DVM (which I assume the OP has, because he seemed to be able to measure zero offset on the amp o/p), if it's an abrupt jump and it stays there, then it's also easy to measure. If it's an abrubt jump then returns to following the music then it's a signal and the op would hear it through his speakers.

    You don't have to know much about the design to put your DVM probes between the 0V output and one of the output emitter resistors. You can swap between AC and DC on the DVM and see the amp working (AC) or going wrong (DC).
    Of course this assumes a follower o/p stage with emitter/source resistors, but this can be checked with the continuity tester of the DVM or will be very apparent if the resistor voltage is near one of the supply rails.
    It's all basic fault finding, made much easier because the amp works at first.
     
  13. Ant

    Ant pfm Member

    Thank you all for your advice and suggestions.

    I tested for DC between the output inductor and 0V on the both channels and there's around 12mV for anywhere between 30 seconds to 3 minutes when initially working.

    DC then rises (drops?) from 12mV on the Right channel to around -900mV over approximately 1 second then the protection relays switch, and the DC continues to rise (drop?) to -4.9V over a further 2 seconds, then the amp shuts itself down completely.

    Excuse my ignorance if this points at an obvious fault.
     
  14. david ellwood

    david ellwood Kirabosi Kognoscente

    It certainly sounds like it’s a fault with the amplifier and the protection is doing it’s job fine
     
    bugbear likes this.
  15. Jim Audiomisc

    Jim Audiomisc pfm Member

    I can quite understand why you and others do so.

    Yet it might well be in your interest if other repair people/makers *didn't* behave in that way. That would allow you to compete with them on a wider range of items than the range you'd be opening up in exchange. Thus you're actually acting to conspire with them against owners who might also benefit by a wider choice or even simple factors like finding a more local repair bod they can get to know.

    It could also promote the abilty of some repair bods to be able to offer 'fixes' for common problems as their individual way to prevent a common problem from recurring, etc.

    Given the politicals views I've seen you give, you might reflect on this... :)

    However for me, the primary responsibilty here resides with the makers. It should be *their* policy to make data available to people who can make use of it. They spawn the situation to which you react.

    Consider also what happens when you and they are no longer in business. How will owners then get repairs? How will any future researcher/historian be able to assess what was acheived, etc?
     
  16. Jim Audiomisc

    Jim Audiomisc pfm Member

    You omitted one of the possibilities I had in mind.

    A quick jump which the protection circuit detected and blocked from ever appearing at the actual output terminals. i.e. removed from the terminals before the DVM could register it as a reading.
     
  17. Jim Audiomisc

    Jim Audiomisc pfm Member

    Yes, that does look like a fault with the amp not the protection. Possibly something like a leaky capacitor. Trip back to Creek recommended unless you prefer an alternative repair bod.

    Seems odd to suggest it, but try monitoring the selected *input* sockets for any dc in much the same way as you checked the output.
     
  18. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    It's one thing to be altruistic when you are doing well financially and hence giving away free info will have little or no impact on being able to put food on the table, and quite another when you earn very little. My politics reflect my attitude towards big companies, PLC's, governments etc screwing over "the little guy" without remorse and giving no quarter. I don't expect say a self employed plumber to tell me how to fix my own boiler and give me factory service info helping me to do it!

    I really appreciate your site, it's a wonderful resource and I fully agree that historical technical info must me archived, info on it has helped in a few repairs even. However, my getting or not getting just one repair job in on a more obscure MF or Alchemist amp can, in a bad month, literally mean I do or do not have the money to pay the phone bill, for example, that month... I'm not about to voluntarily make this financial thin ice even thinner:)

    If you look around the web you will find a few schematics for common MF amps, some came from me and on the A1 there is already much info on a site by Mark Hennessy, and diagrams plus info I provided. You could copy this, or, as it's there anyway, I would be willing to give you your own copy for your site if you have ethical issues over cutting and pasting what's already there.
     
  19. Jim Audiomisc

    Jim Audiomisc pfm Member

    Arkless: Yes, I do understand, and your POV makes sense given the situation you and others are in. However it's perhaps a a shame that 'SME' level repair people/companies don't have an equivalent of a 'union' to make it beneficial for them *all* to pool such info.

    That would be a way to preserve it *and* give you and the others involved the advantage of actually gaining more useful info than you contribute. Potential for common interest and mutual advantage, not altruism. But, again, I can understand why this *doesn't* happen, and of course it would bring in a risk of a 'cartel' which might then exclude others, so be unfair. Hence your POV makes sense given where we are now.

    I'll search for the Hennessy site and see what I can find. In terms of UKHHSoc accepting/using info. On the one side there are some IPR concerns for some types of material. On the other there is a question of determining when information is correct. That's a reason for really wishing *makers* would release info as that helps to ensure it is reliable.
     
    Arkless Electronics likes this.
  20. Jim Audiomisc

    Jim Audiomisc pfm Member

    FWIW This has also reminded me of one aspect of an age which is sadly long-past. I've recalled the old journals like ERT which published technical details for all the retailers and traders to use. Shame there is nothing like that now as it fostered the sharing of info by makers, etc.
     

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