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Thread: What gives with QC/Design?

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    Supporting Member The Dude's Avatar
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    What gives with QC/Design?

    I was finishing up some "repairs" today and it occurred to me that recently many of my "repairs" are not so much repairs as re-designs. Bad design engineering? Poor design implementation? Crappy part tolerances? It used to be that when you got in a repair you'd just look for something bad- shorted part, poor solder, dirty contacts, etc. Recently, I've had to add looking for design problems to the list. Anybody else noticing this, or is it just my run of luck?

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    “Yeah, well, you know, that’s just, like, your opinion, man.”

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    Maybe you've gotten so damn smart that you now notice others' screw-ups more than you used to?

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    don't forget the joker g1's Avatar
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    Are they all within some particular age group? I don't see a lot of that issue, but I'm not getting a lot of current stuff either.

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    Supporting Member The Dude's Avatar
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    If I had gotten that damn smart, I'd be doing something else entirely- something that paid much better.
    .

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    Supporting Member The Dude's Avatar
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    Quote Originally Posted by g1 View Post
    Are they all within some particular age group? I don't see a lot of that issue, but I'm not getting a lot of current stuff either.
    A lot of it is the newer reissue stuff. I'm hesitant to hack on a brand, but some guy named Leo started the company. To be fair I've run into similar issues with other manufacturer's current offerings. I'd say most of the problem children have been birthed in the last 10 years or so.

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    Old Timer J M Fahey's Avatar
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    It depends.
    *ANY* new design can show bugs when "out there" on stages or user´s home, not all are caught atb the design lab, no matter how much they try, but eventually, specially by browsing through the warranty list, patterns emerge and cause redesign.

    Any major design you see will show a list of versions, often 5 or 6 (sometimes more) revisions, where parts value is changed, many times seemingly minor changes, other times drastic.

    Eventually they settle on what works, use that experience on new designs and everything goes reasonably well.

    Now on newcomers, label which applies *specially* to "revered old brands" (think VOX, Randall, Acoustic, etc.), they have little experience, or directly ZERO on MI amplifiers, they design them "as if they were Hi Fi amps" and shtf.

    Old brands? ... how come?
    For the simple and very good reason that those are **brands** and nothing else.

    I can understand what happens with a lot of products if I remember brands were bought at auction by a group of Inverstors, they have no clue or experience Manufacturing, even less on the Musical Instrument scene, they are .... uh .... "investors" .... so they typically hire some general purpose "Consulting firm" which best case will have some general purpose Engineer amongst them who will pick some old designs and update them (best case) or find some oriental OEM Electronics maker who will design something "acceptable" and within budget.

    And then we find products which in principle are not exactly *poorly* made, use "whatever everybody else uses" (popular tubes, TL072, LM3886, Accutronics or Belton tanks, Eminence or Celestion speakers, etc.) but look like they were assembled in a DVD player Factory (hint: they ARE ), are anything but impossible to disassemble for Servicing, are mechanically weak in some aspect which does not stand up tp the road or Touring, or ventilation is poor for 4 or 5 hours full blast, etc.

    So we have to partly re-engineer some poorly made feature on risk on repaired product coming back within OUR warranty time which is a time , money and karma loser.

    I was just telling my Son about fake parts which worse than exploding on sight, "work" ... sort of ... long enough to close amp and charge for it, adding some servicing warranty ... and die at customer´s studio or Show ... live , burning us as Techs.

    So I often reengineer amps for safety or sometimes for plain repairability ... using what´s currently available.

    A lot of it is the newer reissue stuff. I'm hesitant to hack on a brand, but some guy named Leo started the company. To be fair I've run into similar issues with other manufacturer's current offerings. I'd say most of the problem children have been birthed in the last 10 years or so.
    Thyat´s what I mentioned above.

    Today "a VOX is not A VOX, a Marshall is not A MARSHALL, an Ampeg is not AN AMPEG" and so on.

    And of course a Bugera or similar never was anyway

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    Supporting Member loudthud's Avatar
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    What I would add to what JM said above, bean counters tend to think all electrical engineers with a degree are equivalent and can get the job done. Naturally they don't want to pay much so they hire someone right out of school with zero experience. Analog design is a lost art and not much time is spent on it in school so mistakes get made. Because budgets are tight and schedules are even tighter, not much time gets spent on a product once it gets to the working stage. And once somebody with a window in his office signs off on it, out the door it goes.

    That's if the design is done in house. If an outside design firm is used, that firm tries to do it for as little as possible and once they get that sign off, they're out of the picture. The parent company doesn't spend enough time to properly evaluate the product before they are forced to say yeah or nay.

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    WARNING! Musical Instrument amplifiers contain lethal voltages and can retain them even when unplugged. Refer service to qualified personel.

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    Old Timer J M Fahey's Avatar
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    I see that all the time on newer designs.

    Just a personal hunch, crazy theory, but I somewhat believe modern designers fear "high voltage" ..... that being anything much higher that the +5V Logic World they have grown in

    So now everybody is using:

    a) bridged amps everywhere , while they should be the exception (say, when you are forced to, such as battery powered equipment) and not the rule.
    Looks like designers fear going much above 28V , and single supply at that.

    If you design your own PSU, which nowadays is usually an SMPS, you design it for any voltage you need and want, period.
    What´s wrong with +/- 40 to 90V rails?

    b) if more power is needed, low voltage bridged amps are still used, but speakers go to ridiculous low impedancen to be able to achieve that, think JBL powered cabinet >>> 1 ohm <<< voice coil woofers ... WTF?

    What´s wrong with 4/8/16 ohm speakers, with emphasis on Industry Standard 8 ohm?

    Lately I see "respected Brand" amps (think Marshall) schematics and think: "this guy is NOT a Musical Instrument Amp designer" even if, as mentioned above, they hold a Degree.

    And many "American Brand" amps wher the schematic looks oh-SO-Korean

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    Juan Manuel Fahey

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    Keeping the privacy rule of this thread on not mentioning the brands, I’ve noticed that with... you know those orange (without the capital O) amps that should be made in UK? The first that were buolt in Far East had really small resistors (even if the schematic showed them as 1 or 2 Watts) that constantly blew up, especially on CFs.
    I remembet something similar with Laney as well (the ones with the smaller logo).

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    Old Timer Leo_Gnardo's Avatar
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    Quote Originally Posted by J M Fahey View Post
    Lately I see "respected Brand" amps (think Marshall) schematics and think: "this guy is NOT a Musical Instrument Amp designer" even if, as mentioned above, they hold a Degree.
    That right there.

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    Something is happening and you don't know what it is, do you Mister Jones?

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    If it is designed by an electrical engineer that has never toured or recorded and then made in a DVD player factory overseas, I'd call that my kinda gear.

    Just joking. The musician has to be just as unseriousness as the brand for it to be "their kind of gear." Like some bedroom rocker or high school kids starting their first band.

    In my experience (I must be among snobs AND serious musicians) Marshall is not a respected brand, or if people like them it's usually with a caveat, like "they haven't made a good amp since the 80s," or something along those lines. "can you please fix my JMP"

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    But hey, seriously, once in a while the boutique big money amps make the cheap stuff actually look desirable. Recent verellen I got in . Quite a load of crap that I would guess cost $2000. Quite disgraceful

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    outsourced class d power amp with their own rigged preamp

    Edit: no idea why the first pic flipped itself upside down. That's the best one

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    Last edited by nsubulysses; 06-23-2018 at 10:05 PM.

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    Also, if a brand does a very bad job, why should their name be protected. YOu are not just being devious slandering some brand for personal vendetta. Their work, which represents them, is very poor. So there is no praise to give and it is not our fault. Their poor work has become our problem.

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    Old Timer Leo_Gnardo's Avatar
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    Quote Originally Posted by nsubulysses View Post
    In my experience (I must be among snobs AND serious musicians) Marshall is not a respected brand, or if people like them it's usually with a caveat, like "they haven't made a good amp since the 80s," or something along those lines. "can you please fix my JMP"
    My muso/tech friends & I started cringing at the new JCM800 series the moment it emerged. The first time, I mean. Now they're considered "classics" by some. There's worse to be had for sure, but it's instructive and amusing to see what eventually becomes "classic." Sears Silvertone? Wards Airline? Alamo? Who knew?

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    Something is happening and you don't know what it is, do you Mister Jones?

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    Quote Originally Posted by nsubulysses View Post
    But hey, seriously, once in a while the boutique big money amps make the cheap stuff actually look desirable. Recent verellen I got in . Quite a load of crap that I would guess cost $2000. Quite disgraceful
    Crappy outsourced class d power amp with their own rigged preamp
    Gee. I build true PTP in recycled organ chassis and look better than that. Lemme guess, they're not riddled with noise, either, right? Mine are usually... sucks for me I guess.
    On another note, first thing I do when I get my hands on a boo-teek amp is open it up & check the guts. 65Amps had a nice interior in the little Ventura...

    Justin

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    Bent Member Chuck H's Avatar
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    Verellen? Hadn't heard of that one. I'm going to look them up now. Should be a hoot now that I've seen the floating, solder reliant joints all over their build and the slip shod layout of a pre made curcuit kludged with their own. I'll bet they make a big noise about "Orange Drop caps!" in their propaganda.

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    "...less ear-friendly but handy for jazz." Leo_Gnardo

    "A pedal, any kind, will not make a Guitar player more dangerous than he already is." J M Fahey

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

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    Old Timer J M Fahey's Avatar
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    You bet.
    Funny thing is that the fully unshielded 1/2 inch away Class D amp right along the high gain preamp will inject all kinds of ... um .... "interesting" signals into it.
    I´d LOVE to scope that preamp

    As a side note, I bet they will win the "Coldest Shop on Earth" prize, since people is shown sitting at a workbench soldering parts while in thick jackets, stacked sweaters and long sleeve flannel shirts, plus woolen caps.
    I´d suggest them to carry a couple soldering irons in their pockets just as extra pocket warmers

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    No, they just cryo-treat all their builds for extra specially aligned crystal lattices in the tube and cap micas. And e gotta make sure all the solder atoms align the same way.

    Justin

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    "... If an older Boogie and classic Marshall had a (clearly illegitimate) child and you baked it in an oven set to clown shit crazy." - Chuck H. -
    "When receiving a shock I emit a strange loud high pitched girlish squeak." - Alex R -
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    Bent Member Chuck H's Avatar
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    Here you go

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    "...less ear-friendly but handy for jazz." Leo_Gnardo

    "A pedal, any kind, will not make a Guitar player more dangerous than he already is." J M Fahey

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

    "A shot gun delivers a force that exceeds the operational range of most systems, such as pumpkins." Antigua

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    "Thermionic Apocalypse" -JT nickb's Avatar
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    Quote Originally Posted by nsubulysses View Post
    But hey, seriously, once in a while the boutique big money amps make the cheap stuff actually look desirable. Recent verellen I got in . Quite a load of crap that I would guess cost $2000. Quite disgraceful

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    outsourced class d power amp with their own rigged preamp

    Edit: no idea why the first pic flipped itself upside down. That's the best one
    Out of curiosity, what was used for a power supply in that?

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    NickB, it is an outsourced class D power supply made by a brand called ICE

    Fahey, yes it seems extremly unstable and oscillating/chirping. If you turn knobs while playing the signal will cut out and then cut back in again, not in a familiar way where there is a hanging-by-a-thread solder connection or dirty pot or something, it seems like some sort of interference or phase cancellation or something. I suggested I should not work on it to try to "right the ship" and the manufacturer should be forced to face their work again and sort it out.

    It's like that story where the carpenter is too lazy so he builds a crappy house then has to live in it.

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    Last edited by nsubulysses; 06-25-2018 at 12:16 AM.

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    When you try to play this amp into a dummy load its a big fuzzy sine wave on the screen and then when you get to a certain volume level it starts chirping and cutting in and out.

    Is this some sort of problem with class D power supply being played into a dummy load, or is it just because the amp is totally unstable and full of weird noise?

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    A class D power supply? Do you mean Class D Power Amp section, or Class D power supply? It sounds like parasitic oscillations to me; I don't think a power "supply" should care what form of load it's plugged into, as its job is to transform voltages and rectify AC into DC.

    I'm confused. Is this one of their "hybrid" ones with a tube preamp & SS power amp?

    I checked out their website.

    Justin

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    "... If an older Boogie and classic Marshall had a (clearly illegitimate) child and you baked it in an oven set to clown shit crazy." - Chuck H. -
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    Lifetime Member Enzo's Avatar
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    The ICE boards are a combination of switching power supply and a class D power amp on one board.

    At least without further information I see no reason to expect the commercial SMPS/power amp of instability rather than the cobble job preamp mess.

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    Sorry I mispoke. yes Class D power AMP and the power supply is a switching supply. It has two power amps so it can do 700W each at 4 ohms. Run it stereo 700W per cab or mono bridged up to 1400W at 4 ohms.

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    Bent Member Chuck H's Avatar
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    Quote Originally Posted by nsubulysses View Post
    Sorry I mispoke. yes Class D power AMP and the power supply is a switching supply. It has two power amps so it can do 700W each at 4 ohms. Run it stereo 700W per cab or mono bridged up to 1400W at 4 ohms.
    OMG! (to use the parlance of our times)

    Having visited the website myself... The other offerings already fly by the seat of their pants. What the hell is THIS monstrosity you have been charged with? It doesn't appear in the companies offerings. It wouldn't surprise me if the designer himself were using service techs to fix/troubleshoot problems in the designs before marketing. This thing sounds like a kludge. I wouldn't touch it.

    JM2C

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    "...less ear-friendly but handy for jazz." Leo_Gnardo

    "A pedal, any kind, will not make a Guitar player more dangerous than he already is." J M Fahey

    "Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas

    "A shot gun delivers a force that exceeds the operational range of most systems, such as pumpkins." Antigua

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    I'm guessing it's the Meatsmoke Hybrid head.

    It's on the website. You not look very hard! :P

    Justin

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    "When receiving a shock I emit a strange loud high pitched girlish squeak." - Alex R -
    "All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -

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    Thanks for bringing this up -- I'm flabbergasted by those pictures, especially after hearing buzz about these amps for a few years now.
    I've used the 700W ICE module, and it's very thoughtfully designed. Seeing the pics, can't blame you for declining the repair.

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