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Creek Destiny amplifier issues

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

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  1. Jim Audiomisc

    Jim Audiomisc pfm Member

    I've used the form on Mark's website to send him an email. Hopefully, I'll get a reply. From some of the drawings on his site it looks like the one hand-drawn MF schematic UKHHSoc have came from him, probably via an indirect route! (I can't recall when or where I got it.) If noting else, this may help to 'verify' what he have if he replies and can advise. Fingers crossed... :)
     
  2. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Indeed. I recall brown hardback books coming out with all the radio sets from say 1947-49 and these were updated every few years.
    Audio Research famously used to publish entire schematics and parts lists for all amplifiers at the back of the owners manuals... which enabled me to build a SP8 clone (just the phono stage) about 30 years ago... I've still got it.
     
  3. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    All the MF diagrams from this time are hand drawn. Fairly neatly, using a ruler etc, but still look hand drawn to me.
    You know it's so long ago I'm not sure what exactly I supplied now I think about it... certainly some info and I corrected a few mistakes but not sure if I just gave the info so he could correct the diagrams he had already made probably from reverse engineering it...

    Anyway, as I said, the A1 being in the public domain anyway I can supply you with the circuit diagram if you wish.
     
  4. bugbear

    bugbear pfm Member

    They came out every year - I saw one at a car boot recently, and bought it as a gift for my ex-radio-ham and TV repair technician brother in law.

    I forget the name of the publisher.

    EDIT; this sort of thing;

    https://archive.org/details/RadioTelevisionServicing1968-1969Models/page/n7

    BugBear
     
    Arkless Electronics likes this.
  5. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    That's the ones yep.... A mate of mine has probably 20 years worth of them. IIRC that 68-69 one would be one of the last... There was a magazine, "Television" maybe that still had headlines like "We service the new Philips chassis this month. Full diagrams included" that certainly went on during the VHS video recorder era and included circuits etc for these. I doubt it's still going...
     
  6. Jim Audiomisc

    Jim Audiomisc pfm Member

    The only MF diagram UKHHSoc have at present is the A1 hand-drawn one linked to

    http://ukhhsoc.torrens.org/makers/MusicalFidelity/index.html

    Is that the same? I can't recall how we got it. A problem with such things is to determine 'provenance' and 'validity', as future researchers/historians are bound to wonder about that.

    Diverting slightly, the thread you began giving details about MF also makes me feel that UKHHSoc should really collect info about what various people in the business have done. As yet we only have a few examples. One being Watkinson's notes for the 'course' have gave to QUAD about Audio CD. Another being the 'advertising archeology papers' I wrote. Again, the people involved in designing, making, etc, the kit should really have their stories collected.
     
  7. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Ah that's not what I have but after a quick check over it seems correct. The only foible I can see is a cap in the riaa marked 628 which should be 6n8. There are a few other discrepancies which are likely production changes and either value will do OK. I suspect that diagram has been reverse engineered from an actual production unit and probably a later one and may well reflect reality better than the diagram I have, which is a photocopy and has quite a bit of that grey/black speckling etc one often used to get from photocopy machines.
    R6, 11 are shown as 1M8 on my diagram and 3M7 (eh? not a real value!) on yours. These set the quiescent current and we used to fit normally 3M3 IIRC but would sometimes up these to 4M7 if a unit was particularly hot and this could well be the intended value here and 3M7 is a typo. With the use of the low noise 2SA1016 in the phono section rather than ZTX753 which used to be used I reckon this is a late example that has been reverse engineered.
     
  8. Jim Audiomisc

    Jim Audiomisc pfm Member

    One of the areas where info is lost tends to be wrt 'versions' of a design. From my own experience I know there were many more than 3 'versions' of the Amstrong 600 units. Yet only three versions of the circuit diagrams were printed and distributed. Most changes were, of course, minor. But others made a fair bit of difference to the operation. Alas, all the old revision sheets, etc, got skipped. :-/ Again, this could be a real source of confusion in the future.

    I'd welcome any alternate forms of a diagram you would he happy to let us have. You can send it via the drop form on http://ukhhsoc.torrens.org/upload.html. When something is sent the server sends me an email and I can get it. I can then add it as an alternative to the website.
     
  9. Jim Audiomisc

    Jim Audiomisc pfm Member

    Mark has now emailed me and I've replied to him. Thanks for suggesting that! :)

    Having replied to him, one point I made in my email made me think it worth repeating here.

    This is that although UKHHSoc is most 'known' for the public website we *do* also collect info which is kept *confidential* for one reason or another. This is usually because of copyright. But is also sometimes because the source wants for it to remain confidential and not shared generally.

    The *primary* purpose of UKHHSoc is to collect and collate information for future historians and museum curation. Although the members aren't particularly 'active' they include at least one Uni researcher and a Museum curator. The point being that we can help to ensure that info is not 'lost' by holding a few distributed copies by such a group of members.

    So not *everything* we have is on the public website. We prefer if it can be public. But preserving copies in confidence helps avoid the risk that info is lost when a single person pops their clogs.

    Hence we would be happy to take info on the basis that it is only shared by UKHHSoc members and not made public, if that is required by the donor. It is the worry that info (and recollections by those who were present at the time of events) will be lost that is our main driver.
     

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