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agedhorse

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Everything posted by agedhorse

  1. Note that wiring non-identical cabinets in series will often result is unexpected performance issues because each cabinet's non-identical electrical parameters will interact when wired in series. I do not recommend this.
  2. Only if you are sure that's the cause of the problem. You are 50% likely to be right, but also 50% likely to be wrong.
  3. Yes, should be no problem as long as your expectations are reasonable. I'm sure your neighbors will see to that as well...
  4. The 200ASC module is capable of significantly greater power, the data sheet rating is conservative and does not consider some off sheet applications (specifically duty cycle management). In fact, the same module type is available in a larger version as well, the 200ASC shares very similar performance but without the off sheet enhancements. The power rating that was used by the test lab for CB scheme testing is 290 watts RMS into 4 ohms, there is another off sheet enhancement that brings this value to 310 watts RMS into 4 ohms as well. The larger model contains this last enhancement plus some additional thermal management allowing for 2.7 ohm operation in addition to 4 ohms. Either module will work properly in the Shuttle 3.0. Kiwi's module also has some off-sheet enhancements available, rated at 550 watts RMS into 4 ohms before the enhancements are applied. We actually worked with IcePower on the development of enhancements that were included in their more recent products and we hold a US patent specifically addressing some of these applications. One such enhancement involves the alteration of the current limit curves to better drive sub-nominal impedance loads without impacting operation. Another allowed Genz Benz to be the first company to develop ways for the larger module (used in our 900 watt amp models) to safely drive 4 ohm BTL loads even though the data sheet indicates this is impossible. This too was covered under our patent, and verified as safe by IcePower. Ironically, our competitors jumped on the bandwagon claiming that it was impossible, and that all of our amps would "blow up", when in fact it was entirely possible and the amps were incredibly reliable over many years. Handling factory service and support for all of North America, I typically see only 2 or 3 failed modules a year. In other parts of the world, the most common cause of module failure is the amp set on 115V and being plugged into 230V which is not the fault of the module. I have been designing with IcePower products for about 20 years, starting in the touring pro audio (expensive powered speakers) sector and later with bass and acoustic amp products. Designing with IcePower products when IcePower was young certainly has advantages (including a close working relationship with their engineering team).
  5. I can guarantee 100% that IcePower modules have NEVER been made in China, Hong Kong or Taiwan. This is absolutely fact, I have worked with the company and it’s products for close to 20 years and I have the legal country of origin documents for those models. Counterfeits look the same, they test different and do not meet the same performance, safety and EMC standards. You were lucky your module worked, it’s really just that simple.
  6. Definitely not a cap, not from that fault. Also not fuses. These modules are not designed to be repaired, specifically in the EU where repairs to the power supply would require additional safety testing including hi-pot and residual (leakage) current certification. Most IcePower modules sold out of China are counterfeit. The failure rates are unbelievably high. Sometimes you get lucky, but usually not. The quality of the ones I have seen are abysmal, do net meet many specs and most fail within a couple of days if they power up at all. The Fender sourced modules are guaranteed to be genuine, and are reasonably priced when they are in stock at the Fender-Europe depot.
  7. That is a bad error to make, it damaged the power module because the chassis ground is not the same as any other "ground" in the amp when it comes to current routing. It's ground only for fault currents in order to protect against shock, and that particular accident forced about 30 amps into the protective earth circuit. A Fender authorized service center should have this part in stock or be able to get it from the Fender Europe depot, but I don't recall their part number for it. I have plenty of them in stock in the states as well, but shipping is a bit stiff, and it still needs to be installed by somebody who can fully test the amp for among other things that there's no damage to the safety ground/protective earth.
  8. I would not have been surprised if under a control test (same unit to same unit) players "discovered" a 25% difference from where pure guessing would result. Without control testing, you don't know if your original listening test is valid. Failing a control test is not uncommon, just shows that there is a flaw somewhere in the methodology.
  9. What were the numbers when comparing tube to tube and solid state to solid state... ie. controls? Were they statistically 50-50 or were they skewed as well?
  10. It serves as a control, because if statistically greater than 50-50 is the result, something else is going on. Yes, double-blind testing (including control testing) is an important part of moving technology and designs forward. This is how we rule in or out a particular aspect of a design being the cause/effect of what’s being investigated.
  11. There is a very wide range of output levels that basses can output, which are also affected by setup and playing technique. Likewise, amp designers design amps to handle the wide range of levels in different ways. Some amps are designed with the ability to handle high input levels without overdriving, other amps are designed to overdrive more easily and some amps fall between these extremes. The Shuttles fall in the middle, it might be difficult to overdrive with a low level bass but is also able to handle very hot basses.
  12. On the Shuttle series, the input LED senses input stage overload and also backs up by sensing the post EQ signal, but it's pretty hard to overdrive the eq unless you are doing something very outside the box. The output clip (or limit) LED senses the power amp stage through an adaptive algorithm, it indicates that the output tube overdrive circuit is operating (this begins to come into effect a couple of dB before clipping) and engages an adaptive limiting circuit that adds both compression and harmonics to the tone. There's about 6dB of compliance in this function before power amp clipping occurs. That's a 4:1 power ratio between threshold and clipping, which is quite a large range. Knowing this and the information contained in the manuals, you will better understand how to use the output limiting function. I have attached the manuals for your convenience. Shuttle 6.0 Owners Manual (rev. 3).pdf Shuttle 6.2 Owners Manual.pdf Streamliner 900 Owners Manual.pdf
  13. This is not designed to be used as a crossover, though you could adopt two pedals to make one that is effectively a low pass and one that is effectively a high pass, each with its own eq. LR filter topolopy is not essential for crossovers, as it's essentially a similar topology as a lower Q Butterworth filter alignment. The bigger difference is that for constant power summing the filter's are specified at the -6dB point rather than the 3dB point. In practice, this simply slides the specified filter points apart to result in constant power summing at the crossover point (due to the voltage squared in the power equation). [edit for glaring typo]
  14. Yes, LPF elements are used throughout audio circuit design. Not just for bandwidth limiting but also for stability management reasons.
  15. A dual channel amp can in fact be used to describe a stereo amp and the other way around. It depends on the product.
  16. IIR, the choices are 30Hz and 50Hz, the slope is 18dB/octave. For large bass reflex sub cabinets, the 30Hz HPF works well. For the other applications, 50Hz works well.
  17. An amp properly designed to drive a 2 ohm load will be just as effective as an amp properly designed to drive a 4 ohm load into their respective loads.
  18. The preamp output must be -10dBu nominal then. The sensitivity difference between .775V and 1.16V is insignificant in this context. There are several versions of the SVP, it’s very possible that this is common with all SVP models.
  19. Do you have the level controls all the way up on the power amp?
  20. Unlikely that the tubes/valves have anything to do with the amp going into protect, the tubes/valves have nothing to do with the protect circuit. Most likely cause is an intermittent short in the speaker cable/connectors, a defect in the speaker/crossover like a damaged tweeter or a tweeter that was removed leaving the crossover filters in place, a poorly designed crossover, or serious power issues. The protection circuits are very comprehensive. I rarely see bad stock tubes/valves in the Streamliners, the parts were selected for low noise, low microphonics, middle of the road balanced tone and long life. They are very robust in that circuit and my calculations along with experience now that the amps are over 10 years old are that 7,500 - 10,000 hours is a very reasonable expectation. I have seen amps come through the factory service program with a LOT of hours and 50-75% tube life remaining. I generally recommend leaving stock tubes/valves alone in well engineered products, a lot of effort, evaluation criteria and math modeling/statistics go into the selection of parts used in products that have a long manufacturer's warranty... we (Genz Benz) typically warranted tubes/valves in our bass products for ~1 year and almost never had to replace any after the first 30 day infant mortality period (and even then it was rare). Mesa also warranties their tubes/valves longer than most companies at 6 months. The typical wattanty period for tubes is 30 - 90 days.
  21. Both are quality pieces IMO, and with quality comes reliability.
  22. If you like what the envelope filter does modulating the filter off of the subharmonic noise, that that's the way to do it.
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