agedhorse

This is what starts the urban mythology that caps are "always" the culprit, they always go bad, without digging a little deeper to discover that there are products that last decades without any cap failures. You kind of get what you pay for usually 😉

This is what happens when you buy grossly substandard parts from unauthorized (or non-genuine) supply chains. This is not a capacitor issue, it's a fraud issue.

Yes, 24/7/365 operation is a little different. I have an amp in my shop undergoing aging testing that’s been in operation like this approaching 150,000 hours (that’s about 17 years). The caps still meet the original design specs. By comparison, for an audio amp used 4 hours a day, 5 days a week (high usage for a bass amp), that would be about 150 years… so even if the caps lasted half that long we are still talking about 75 year lifespan. This is quite simplified, but serves to reinforce why replacing caps in amps just because they are a “few” years old borders on the absurd. Or, the design and selection of components is really awful.

Leave the caps alone, age does not mean that there are problems, or that there will be problems. The whole notion of “must recap” is an absurd extrapolation from a little bit of truth.

As a bass guitar driver, it’s very limited. Some of this can be overcome by using multiples of this driver (410 and 810 for example)

Indeed, as have any number of brands of "miracle cure-all" sprays. There is nothing worse than cleaning up all the additional damage caused by the willy-nilly use of such substances by those who received their electronics education via the internet. Also, these sprays can damage plastic components, some plastics (including wire insulation) can become very brittle from exposure to this stuff.

Stan Lawrence is a very competent service professional. He may be a little more expensive than an average technician, but I would also suggest that in this case you get (more than) what you pay for.

Those drivers have some SIMILARITIES to the Beta drivers but may in fact have very different performance and tuning parameters. This is why it was recommended to take the original cabinet dimensions and cut them in half, splitting the port area (same length) between each new cabinet. This way you don't need to know the driver's parameters and are using the work that Ashdown did when designing the original cabinet.

Yes, we both believe being helpful supporting products (and especially when problems arise) is a big part of running a business. It’s part of our culture.

If this was a language translation issue, that's fine but I was addressing exactly what you wrote even if that's not what you thought you wrote. When this kind of thing comes up, and you are using a translation app, recognize that it's possible that your translation is not accurate and when questioned about what you have posted, consider that you could have made the mistake and be respectful in your follow-up responses. I deal with the international community every day, I am very careful how I write responses and how it's possible that they might be mis-interpreted and rarely encounter disrespectful responses unless there is more to the story that I am unaware of. Have a good day.

Yes, that's always his option as well.

I was just responding to YOUR post where you SAID you would share them... did I misunderstand what you wrote?

You are always welcome to disagree with me, but you can probably do so a little more respectfully IMO.

You might have a different perspective on this if you have had your designs appropriated from confidential documentation that was passed on to a competitor against your will. I have, it took money out of my pocket and the companies that produced those products. This may explain our different perspectives. Most modern designs are pretty difficult to reverse engineer without spending considerable effort and cost of doing so. Documentation reduces this cost to do so. Many companies do not release documentation for this reason alone.

Even if the information is not yours to share?

Not quite, unless I read it wrong...

Almost. The power of a square wave is equal to the RMS power of a sine wave and 1/2 the power (.707 x the voltage) of the peak power of a sine wave. Peak power is defined for a sine wave at 2x the RMS power, and when Trace advertised 500 watts peak power, that's exactly the same as 250 watts RMS. It has nothing to do with burst power (which has an entirely different definition and applied primarily to broad band signals). Power RMS is equivalent to the area under the voltage curve x the current curve, and when integrated over time becomes energy.

Yes, for the most part that is incorrect. There may be a trivial difference at very low frequencies due to filter cap time recharge constants, but it will be less than 1/2dB at 30Hz on a properly designed amp and often much better. Note that meters can be inaccurate at very low frequencies, which why special meters are used for broad band audio measurements.

Not necessarily. I'm still measuring the same way today as I did in the 1970's and every product I have designed uses power based on RMS metrics and states THD. For MI applications, especially where the distortion harmonics components may be integrated into the signal in both the preamp and power amp, I have standardized on 10% because after a lot of test player contributed their perceptions, 10% was pretty much the sweet spot where most players liked both the tone and texture. The most common numbers I see for bass amps range from about 5% to 20%, depending on the application. For guitar amps intended to be overdriven as part of their native tone, 10% to 30% is more common. Of course, the amps must be tested and safety certified under these conditions if being honest. For pro audio, the numbers are different of course, and as powers increase the duty cycle factors into the equation. This is most common at very high powered pro audio amps, where after a second or two, the limiting algorithms fold the power back to about 1/2 the rated power and in big powered speakers, the HPF may shift upwards and the crossover points may also shift along with the limiting thresholds. This was all started with Meyer, Renkus Heinz, Apogee and later with JBL, etc. This has allowed maximum performance with minimum damage and warranty claims.

or lost...

Agreed, a false sense of security

Actually, the damage to the older gear tended to be more catastrophic if it falls the same way. Broken parts, bent sheet metal and such is not uncommon when an amp takes a fall, usually the lighter weight gear is easier to repair in that regard. It used to be common for a fall to break the transformer mounting screw(s), causing the transformer to cause collateral damage to whatever initially survived.

Why not a simple splitter Y cable?

Steve1250 - If you are still having issues with your D-800, message me and I will help you get it sorted out. Be sure to let me know where you are located so I get you accurate info.

Or how many (because one is never enough) 😄