Are Class D's Disposable?

[agedhorse]

Talking of perspective, are you currently working on any non class D amps?

Yes, I still work on most Genz Benz GBE and NeoPak series amps (which are also very reliable).

I find that both the Shuttle and GBE series have almost the same normalized reliability numbers, therefore the reliability is independent of amp class.

 

[baxter_x]

Yes, I still work on most Genz Benz GBE and NeoPak series amps (which are also very reliable).

Do you mean you are currently working on some new GB stuffs?

 

[agedhorse]

Do you mean you are currently working on some new GB stuffs?

No, I am repairing legacy class AB amps that I originally designed. There is no reliability difference between those and their class D replacements.

 

[steve_rolfeca]

It seems that component supply for repairs is getting to be an issue now, and this is not strictly Class D-related.

Our local (London, Ontario, Canada) repair place is having to substitute or combine components in order to get certain values, switch to less desirable brands, or make larger minimum orders in order to stay in business. This is not unique to a particular supplier, as they are finding the same issues with all the major parts warehouses.

Back to the original topic: The same shop has had my Class D G-K MB200 for months. I took it in because I'm not equipped to deal with surface-mount stuff. The little guy was rock-solid reliable, until the LED ring stopped progressing from red to blue during startup. When you try to turn it on, it stalls on an intermediate purple color.

No nasty noises, no smoke, no speaker damage, but no audio either...

G-K advised the shop that a daughterboard in the MB200 is a common point of failure. Sounds like it's not a big deal to replace, but the part is backordered.

I don't know if this is related to the way production was relocated to China at one point, but G-K apparently advised them that they are struggling to find parts to cover warranty repairs.

There's apparently no timeline on when they will have parts available for off-warranty repairs like mine.

My sound is very much built around G-K's unique sound and EQ at this point. The MB200 is perfect for the grab-and-go stuff that dominates my workload these days, and I used to feel confident about taking it places where I wouldn't want to take my MBFusion.

I do NOT want to go on another endless hunt for something else to replace it, but I certainly don't want to take chances on another G-K product if they don't even have a secure parts supply for warranty work.

It doesn't help that the price of the MB200 has gone up by about 50% since I bought it...

 

[fdeck]

Based only on relatively small scale electronics projects, I've learned that the component shortage is not limited to stuff made in China, or to high tech components like semiconductors.

And a single tiny part can bring down a production line, especially if substitutions have to go through an approval and testing process.

 

[seamonkey]

It seems that component supply for repairs is getting to be an issue now, and this is not strictly Class D-related.

There's a glut in some industries while there's a shortage in others.

 

[msb]

When my MB200 was in the shop I looked at replacements and decided that another MB200 was all I wanted. It’s my practice rig. The ICE chip was replaced and the fan was fixed. I suspect the fan might have had something to do with the chip failing.
Since I got’er back she’s been running perfectly for several hours a day. No more pink ring of doom!

 

[fdeck]

Once while on a plane flight, I noticed that the jet engines have some marking on the hub of the intake fan so it's possible to visually confirm that they're spinning. I've always worried about fans on amps, because they're mechanical. So I put a dot of white paint on each fan so I can see at a glance that it's working. Of course if it's a multi speed fan like on the GK, it won't spool up unless the amp is getting pushed a bit. But in warm weather or at higher output levels, it'd better be turning.

 

[S-Bigbottom]

I don't know if this is related to the way production was relocated to China at one point, but G-K apparently advised them that they are struggling to find parts to cover warranty repairs.

They have not been manufacturing in China for 10 or so years. This has nothing to do with any current situations.

 

[Mark Reccord]

I recently spent nearly a month revising a board design because I had to substitute 50% of the parts on it because of supply shortages. And then in the two days between me vetting the BOM to make sure everything was in stock and the PO being issued for the parts, one major component went from stock of 25000 to stock of 0 at the only major vendor that had them. We had to go through a broker to get some at more than 3x the price. Oddly enough, the broker had the same number in stock as the vendor did a couple of days prior. Hmm...

It's really challenging times in electronics.

 

[Passinwind]

I recently spent nearly a month revising a board design because I had to substitute 50% of the parts on it because of supply shortages. And then in the two days between me vetting the BOM to make sure everything was in stock and the PO being issued for the parts, one major component went from stock of 25000 to stock of 0 at the only major vendor that had them. We had to go through a broker to get some at more than 3x the price. Oddly enough, the broker had the same number in stock as the vendor did a couple of days prior. Hmm...

It's really challenging times in electronics.

No kidding. I was just quoted $15 a part on some commodity pots that run less than a buck normally. Yeah, no thanks.

 

[Paul New]

This is an old thread, but I'm asking the original question again. Are Class Ds consumable products now?

My 5 year old GK is dead, again, and now GK is only doing warranty repairs. Does anyone know a tech I can ship the head to for eval and repair?

 

[agedhorse]

Give GK a call and ask them for the names of authorized service centers in your area.

 

[steve_rolfeca]

This is an old thread, but I'm asking the original question again. Are Class Ds consumable products now?

My 5 year old GK is dead, again, and now GK is only doing warranty repairs. Does anyone know a tech I can ship the head to for eval and repair?

Probably not helpful given that I'm up here in the frozen north and you're in Alabama, but a little followup on my broken MB200 (well over a decade old...):
- The amp sat in a local London, Ontario repair shop for about a year.
- They hired a new (younger) tech, and he decided to take a second look at it.
- He discovered a couple of small, surface-mount resistors that had popped. They were partially hidden under a blob of glue, which is probably why the first guy went down a rabbit hole trying to source a replacement board from G-K.

A couple of bucks in commonly-available parts, and it's been solid as a rock ever since. Sounds just as good as it did from new.

 

[NitroBobby]

This is an old thread, but I'm asking the original question again. Are Class Ds consumable products now?

My 5 year old GK is dead, again, and now GK is only doing warranty repairs. Does anyone know a tech I can ship the head to for eval and repair?

On GK's site, (Gallien-Krueger Bass Amplifiers) at the top right hand corner there is a drop down menu for "Support". In that drop-down, there is a tab labeled "Authorized Service Centers". You enter your location and it provides you with the locations near you.

Using Birmingham as a search, it looks like there's only one authorized GK repair shop in AL. It's in Madison. There are 2 near Atlanta as well.

Pretty slim pickins out there for GK authorized locations. You should be able to ship to them, i would think.

Good luck
kgb

 

[agedhorse]

Shipping class d amp chassis is not too bad, I deal with this every day.

 

[Paul New]

On GK's site, (Gallien-Krueger Bass Amplifiers) at the top right hand corner there is a drop down menu for "Support". In that drop-down, there is a tab labeled "Authorized Service Centers". You enter your location and it provides you with the locations near you.

Using Birmingham as a search, it looks like there's only one authorized GK repair shop in AL. It's in Madison. There are 2 near Atlanta as well.

Pretty slim pickins out there for GK authorized locations. You should be able to ship to them, i would think.

Good luck
kgb

I shipped the chassis to Stockton. They are treating it as if it were still under warranty.

 

[Paul New]

Probably not helpful given that I'm up here in the frozen north and you're in Alabama, but a little followup on my broken MB200 (well over a decade old...):
- The amp sat in a local London, Ontario repair shop for about a year.
- They hired a new (younger) tech, and he decided to take a second look at it.
- He discovered a couple of small, surface-mount resistors that had popped. They were partially hidden under a blob of glue, which is probably why the first guy went down a rabbit hole trying to source a replacement board from G-K.

A couple of bucks in commonly-available parts, and it's been solid as a rock ever since. Sounds just as good as it did from new.

The first time it failed, the problem was just an open resistor, and I assume that they replaced the resistor and didn’t try to find the issue that caused the failure. This time I think they will look everything over. I imagine that it’s something simple.

 

[fdeck]

This is an old thread, but I'm asking the original question again. Are Class Ds consumable products now?

I believe not. I have older amps that are Class-AB. They would face the same issue if the maker doesn't service out-of-warranty gear.

I've done repairs on my own Class-D amps, but I'm qualified to do so. I haven't needed or attempted to diagnose a power amp module, and would replace one outright if it came to that. Earlier, I mentioned in this thread that module-level repairs are a consequence of both miniaturization and specialization of components. When I was growing up, a storefront TV repair shop could stock most of the components needed for repairing any set worth repairing. Today, the major electronic component distributors list millions of part numbers.

In my view, repairability has more to do with business decisions made by gear makers, than with design specifics. One business decision is how reliable the gear needs to be in the first place.

 

[Paul New]

I believe not. I have older amps that are Class-AB. They would face the same issue if the maker doesn't service out-of-warranty gear.

I've done repairs on my own Class-D amps, but I'm qualified to do so. I haven't needed or attempted to diagnose a power amp module, and would replace one outright if it came to that. Earlier, I mentioned in this thread that module-level repairs are a consequence of both miniaturization and specialization of components. When I was growing up, a storefront TV repair shop could stock most of the components needed for repairing any set worth repairing. Today, the major electronic component distributors list millions of part numbers.

In my view, repairability has more to do with business decisions made by gear makers, than with design specifics. One business decision is how reliable the gear needs to be in the first place.

Before i retired from the nuke plant a few years ago, we spec'd out new essential equipment, battery chargers and inverters, using tech from the 80s. Reliability and reparability were the issues.