What gives with QC/Design?

[The Dude]

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?

[rjb]

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

[g1]

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.

[The Dude]

If I had gotten that damn smart, I'd be doing something else entirely- something that paid much better.
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[The Dude]

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.

[J M Fahey]

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

[loudthud]

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.

[J M Fahey]

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

[Roberto]

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).

[Leo_Gnardo]

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.

[nsubulysses]

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"

[nsubulysses]

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


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

[nsubulysses]

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.

[Leo_Gnardo]

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?

[Justin Thomas]

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