agedhorse

There were 2 versions of the NeoX 212 cabinet. The original version used a custom Eminence driver and the NX2 version used a custom Faital driver. While the low frequency parameters are reasonably close, the mid voicing parameters are different as the goals for the cabinet line evolved.

I can be general, but correct I can't get specific because these techniques are in fact still used in commercial products being designed today. One of the biggest challenges with any driver is balancing the desired characteristics with their side effects or negative attributes. Sometimes, this works in the designer's favor, but often they can conflict. The critical part of this is correctly identifying the attributes you wish to exploit and those you wish to minimize. It's easier said than done of course, and sometimes, it's simply an impossible set of compromises and a different approach in needed. One characteristic that's VERY important to bass players is the midrange voicing, and how that voicing integrates with the tweeter. This is also heavily influenced by the polar pattern of the driver which is governed in part by the diameter of the driver but also by the cone/dust cap shape, material. Another characteristic is how well the driver tunes in the desired cabinet size. Different choices of soft parts results in different parameters that can make a driver more or less friendly to a particular range of cabinet sizes. This means that if the goal is a smaller than average cabinet size, TS parameters may be adjusted through the selection or tailoring of soft part properties. Another property that a designer can address is what happens to the VC as it enters and exits the non-linear portion of the magnetic field and the shape of the magnetic field fringe is shaped, specifically the ends of the VC, and how the inductance and the VC current interact with the fringed fields. Note that the fields are often not perfectly symmetric, this can become a blessing or a curse depending on the goals and the component parts. Xmax is something that comes up a lot in LF driver discussions, there are different definitions, sometimes different goals and sometimes different mechanisms depending on what parameter the designer is more concerned with. For example, it's possible to design a driver with more robust mechanical suspension parts than the basic Xmax might suggest depending of the characteristics of the fringe field performance, as well as long term ageing and mechanical reliability metrics. While the AES power rating standard is a 2 hour "must survive" test, I typically use a 200 hour "must survive" test because the companies I design for have longer warranty periods and the customers of those products typically have greater expectations. This is just a little bit about what goes into designing a driver.

To clarify this often propagated and unsubstantiated "rumor", the Genz Benz products did not use a stock 12PR300. The soft parts were customized for our design goals with the stock metalwork. The difference is significant and for our goals worth the effort and cost of customization.

Message me and I will help you sort it out. If the job isn't done right, you can indeed end up with a mess. I do not have any replacement PCBs left, ironically in all the years I have serviced these amps, I have never needed a replacement board but I have seen plenty damaged from failed repair attempts that would have been a simple, inexpensive job for a QUALIFIED tech. They are a double sided PCB with plated holes, damage the plating and you have a problem. Due to chronic issues with blue LEDs from what were well qualified suppliers/brands, we moved to using CREE parts due to their much higher overall reliability (of course they cost more too, but that wasn't the reason we used the parts we did use, CREE didn't have this part available until years after the amp was designed.)

Yes, All of ICEPower’s modules going back almost 20 years by now are still in current production and available to authorized manufacturer’s service centers.

There are many parts that are no longer available as the manufacturers of such parts discontinue them and there are no other sources. The most common parts are pots, jacks, switches, relays, and some opto-electronics, plus many lateral and vertical MOSFETs (though for some applications there are still some reasonable substitutes but they don;t work in all applications). Beware of counterfeits however, especially semiconductors. The world is awash with counterfeit MOSFETs, most aren't even the type that they are labeled (lateral in particular). From a company that supports their products, replacement class D modules are often reasonably priced. Not are they generally impractical to repair, the act of repairing them invalidates their safety certifications because they are a specially certified part (reinforced insulation between the primary and everything else) and must be tested for compliance after the repair. The European manufacturers of these modules are quite clear about this and won't even repair them at the factory. It's a bit like rewinding a transformer, if you can't certify it (properly), it can't legally be used in a repair for the same reason. It's treated as an integrated component. The EU is more strict about this than most regions.

Or, they had inventory from orders placed months ago and you were lucky to find them.

I spend some time each day tracking down parts and production schedules that have been upended by one thing or another related to this matter. Just as a glimpse into the manufacturing world, here's the availability of SMT resistors from a large supplier of parts for all industries (including ours): https://www.trustedparts.com/en/search/tt-electronics/M55342K12B I have had nightmares less scary than this.

Yes, it’s a very real thing.

No, a class D amp can reproduce DC if the designer wished it to, just like a class AB amp. In fact a class D amp generally has higher performance at low frequencies. The HPF has to be designed into the amp, the same as for any amp.

This is basically what has driven most companies down this path, it the consumer won't buy it because of price alone, then price will become the overwhelming driving factor.

Everybody shares responsibility, and for many, many reasons.

Everywhere in the world is having these problems. For slightly different reasons, but no region is unaffected.

The problems are global, not related to our side of the pond. We have European manufacturers that can not build components for exactly the same reasons we can’t… unavailability of raw materials and component parts. This has nothing to do with our side of the pond. Transformer vendors (of line frequency parts) today can’t get materials in production quantities without long delays. Lamination steel of all grades, bobbins, terminals, insulation tubing/tapes and TCOs are all impacted. This has nothing to do with our side of the pond. Transformers “wound” in back street shops are not an option for real manufacturers because for the EU market, they MUST be designed, certified, constructed and tested to YOUR EU safety standards. The factories must also be inspected at least quarterly by a nationally recognized test lab inspector.This has nothing to do with our side of the pond. Currently that would be IEC 62368, it’s a European standard, and it’s not optional. All power and output transformers must comply. The shop must be registered as an approved manufacturer by the NRTL that’s responsible for certification of compliance. This has nothing to do with our side of the pond Test labs globally, including in the EU, are backed up with extremely long lead times. This has nothing to do with our side of the pond. Regarding tubes/valves, there were as many western European manufacturers of tubes as US manufacturers back in the day. Now, there are no US or western European manufacturers, they are all built in eastern Europe and Asia. This has nothing to do with our side of the pond. The global shipping industry is heavily impacted. We are experiencing very long delays and prices that are ~10x higher than before. This includes products originating from the EU as well. We use a lot of European components and materials, we struggle with delays due to our European partners inability to source materials, shortage of labor and shipping. This has nothing to do with our side of the pond. This is a global issue, it’s almost certain that delays and shortages will continue for maybe even a year or two at this point as manufacturers work through their back orders. This has nothing to do with our side of the pond.

The commonality of parts is not just a recent thing, it goes back 50+ years to the use of common tubes/valves, semiconductors, pots/switches, knobs, etc. There are commonly accepted architecture based on years and years of development and then refinement, architectures that didn't work out get dropped by the wayside and the successful architectures live on. Every designer has their own take on several basic power amp architectures for example. Every day, and sometimes in the middle of the night in a bad dream that seemingly won't end.

Yeah, too bad it took them forty-something years (and tens of thousands of amps) to "fail". Plenty of pro bassists used them as well.

The protective earth ground is never lifted from the chassis, it’s not allowed (via a switch or otherwise) under any code for a class 1 safety certified device in any region that I am aware of. Lifting circuit ground is different, though generally goes hand in hand with transformer isolation on unbalanced applications (including ABY boxes).

Erm, no it’s not. A DI takes an unbalanced ground referenced signal and balances it. It also floats the signal from ground. It requires a TS input cable, not TRS. that amp has the balancing circuitry built into the amp, so all that’s needed is a TRS to XLR male adapter cable.

This is what you want, the terminations are standard.

No idea, I never saw that. Peavey used a black MEK glue that was really tough and hard. Usually the aluminum fractured at the edge of the dust cap where it became the lip that fit over the top edge of the bobbin. Once it stated cracking, the fracture would travel and the dust cap would kind of come apart. It's possible that Peavey used a different glue for the European market, the MEK glue was quite toxic and for the most part it's been phased out in the favor on more advanced adhesives. At one point, the industry tried CA adhesives, they didn't work all that well until new formulations came into being, and now some manufacturers use UV cure adhesives. Also, at one point, Peavey used a one piece dust cap/bobbin assembly, that was also problematic and expensive to form. These also fractured right at the edge:

Where the joint at the cone neck fails, if you do an analysis of the failure you will find that the glue itself was fine but the paper of the cone neck itself fails. This was before the industry recognized the need for reinforcing the cone necks in higher powered speakers, especially those with shallow cone profiles. Other manufacturers encountered the same thing, and one of my projects was the development of revised cones with reinforced necks for drivers that we had originally used throughout the company I worked for at the time. The surround separating from the basket is more likely a production problem rather than a glue problem, this is also something that every manufacturer has to deal with. The dust cap separating from the cone is also likely a production problem since the glue used for that bond was completely different from the other glues. Back then, there were 3 different adhesives used. There were also issues with the aluminum dust cap fatiguing and actually fracturing around the glue line because the MEK glue was so hard and there was too aggressive heat treatment of the aluminum. This too was an industry wide issue, and one reason why manufacturers moved away from aluminum dust caps. They must be very thin (IIRC it's about 0.003" (0.07mm) aluminum and it must be very stiff, therefore it must be heat treated to a high degree which makes it vulnerable to stress cracking. Even JBL had some issues over the years, and they were the first to successfully perfect the process.

It's possible that there's a bit of magnetic debris stuck in the gap, or just as common would be bits of deteriorating foam from the magnet structure vent. To remedy this, two different methods are used depending on what the problem is. 1. Magnetic debris requires the use of folded over masking tape (sticky side out), and patiently running around the gap. It may take 5 or 6 iterations of doing this before it's clean. 2. Foam residue requires the use of a business card type paper stock, wet it with mineral spirits, and run that around the gap again and again, changing cards as needed. It may take a dozen iterations of this before it['s clean. Also, very gently clean the inside and outside of the voice coil to remove any foam debris that may have melted to the surfaces. I have never heard of the defective glue issue, nor have I seen it, and I serviced a lot of BW drivers (both in and out of warranty). The assembly is generally very well done. IF you need to buy a replacement basket, be sure to use the same part number that was originally used with the motor, there are some newer baskets that are not fully compatible with the old motors. They may physically fit (sort-of), but the power handling is no greater and the sensitivity ends up being significantly lower. You can always email Peavey support to verify that your basket and motor are compatible. IIRC, there were 3 different motor series.

Generally it has to do with timing issues, but with the protect LED on, it sounds like either something g else, or multiple problems simultaneously.

The lube residue is a very thin, almost microscopic layer. The D-5 is a 5% solution of Deoxit (red) and 95% carrier. If you were to place one drop on the surface and then remove 95%, you can see how little we are talking about.

There's noting inherently wrong with SMPS, they just require a lot more knowledge, skill and test equipment to repair. It's a trade-off for smaller size and weight and greater performance. Because SMPS (not unlike transformers) area custom product, there's only so much support available when the parts are no longer available. This is one reason why we went with the more expensive ICEPower platform, they build these by the tens of thousands because they are used by other bass amp manufacturers and in other industries as well. This means that the parts are stocked by many more sources. Without being able to identify what exactly is not working properly, it's hard to suggest a solution.