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agedhorse

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Everything posted by agedhorse

  1. Why not have your amp repaired. I would expect that a qualified MarkBass authorized service center would be able to get this taken care of for you.
  2. I have not seen anything that specifically states that the + and - signals are fully isolated from pin This is an essential requirement for use with ANY amp that contains bridged topology.
  3. Yes. The direction is screen printed on the PCB. Use all safety precautions, the PCB does not need to be removed. It’s a double sided board with plated holes so be be gentle.
  4. There is no difference as the Streamliner's speaker outputs are parallel wired from a single output. I suggest a single cable, simpler and just as effective.
  5. Thanks Al, tried to grab the correct page from my phone but obviously didn't get it quite right. Cheers.
  6. I have addressed some of this to the best of my ability in a TalkBass thread. Rather than rehash this here, please take a look at the thread: https://www.talkbass.com/threads/official-mesa-boogie-subway-series-club.1181245/page-1144#post-24825163
  7. Yes, it appears not to be a language misunderstanding, just showing his true personality.
  8. Excuse me, nothing I said was insulting nor was it intended to be. I deal with international customers every day, I am aware that many use translation software that may not translate as accurately as assumed (either to or from anybody’s native language) I simply suggested that this might be an explanation for the miscommunication rather than assume that you were being intentionally disrespectful. The US is a very large country with diverse politics. Many do not find what’s going on in our country acceptable in the slightest. To assume that I (or anybody you talk with from the US) finds it acceptable is a form of casting stereotypes and may very well be wrong. Is this how the forum thinks of all US residents? If so, if he talks for everybody here, I find it very sad.
  9. He mentions a resistor in series with an LED, which means that the discharge rate would be very low and the discharge time very high UNLESS there is an ADDITIONAL resistor (~10 ohm, 10-25W) like I suggested earlier. I suspect that the communication issues here may be due to different native languages. If so, none of this is going to be very helpful.
  10. How are the voltage (tension) the most important? There are many important aspects to the signal path of an amp, and while the voltage is ONE part of this, there are many other important factors in identifying not only where the fault might be located, but also what the fault might be. "Tension" (voltage) doesn't flow, it is a potential. CURRENT flows. Perhaps there is a challenge here with language?
  11. Glad you liked the manual. I wrote it along with a LOT of contribution and detailed editing by a couple of seriously seasoned TalkBass members, one who is a very technically inclined and one who is a journalist, both are solid players. The primary focus of the manual was to provide accurate, detailed information that is useful to players and form a player perspective. These guys started with the WD-800 manual and the response was so overwhelmingly positive that it was a no brainer to continue this way. Writing manuals is unbelievably time consuming, and these guys stepped up to the plate to make it clear and player friendly, especially when describing features that have not been implemented before. Here are links to the WD-800 and TT-800 manuals, they might help those who are interested better understand the amps to determine if they might be a good fit or not. WD-800: https://mesa-boogie.imgix.net/media/User Manuals/070556_Subway_WD800.pdf TT-800: https://mesa-boogie.imgix.net/media/User Manuals/Subway-TT800-web.pdf
  12. Not necessarily true, in that some class D output stages have additional emulation and modeling circuitry as well as damping adjustments and symmetry control at the point the POWER amp begins to overdrive. That said, taking a signal from the speaker output using a conventional direct box is not a safe application. There are ways to do this, but with specialized hardware only.
  13. Yes, I deal with this sort of thing often enough that these warnings (including warnings in the newer owner's manuals) are entirely justified.
  14. That's EXACTLY what is being discussed, and what the OP's situation involved.
  15. External DI's are almost never used to boost the signal level from instrument level to line level. In fact, since the numbers you posted above are incorrect, let's clarify what happens with a typical direct box. For bass guitar: Mic levels are typically in the range of .01V to .1V Instrument levels are typically in the range of .1V to 1V Speaker levels are typically in the range of 10V to 50V A typical DI drops instrument level signal down to mic level (approx. -20dB) and for a DI with a speaker level input, drops the level down to mic level (approx. -40dB). This is (often but not always) done by the use of an step-down audio transformer (in combination with an input pad in the case of a speaker level signal). The transformer also galvanically isolates the signal source from the destination. One very important thing to make note of... in the case of any amplifier that is configured in bridge mode (either externally or as an internal topological design element which is how many class D power amps operate), taking the output from a speaker out is a bad idea because neither the + or - terminals of the speaker output are ground referenced. When connected to a DI, the pin 1 connection becomes tied with the speaker - and results in shorting 1/2 of the output bridge. Also, the resulting fault current (which can be as high as 30 amps on some newer amps) will flow through pin 1, through the snake and into the console's grounding system. Since this grounding system is not designed for high currents, catastrophic damage can result. If this is an expensive console, somebody is going to be unhappy.
  16. The balanced output clips at +2dB peak (-1dBu RMS) maximum, not enough for driving a power amp to rated output in the real world. You will need +4dBu (minimum) plus at least 6dB of headroom to make up for losses relative to real world implementation.
  17. No sir, class D has nothing whatsoever to do with the power supply. It has to do with the topology of the power amp only.
  18. Except that the DI out will not be able to drive the amp to rated output unless it's full line level (ie. nominal +4dBu)
  19. If you understood that this amp is NOT rated for a 4 ohm load in bridge mode, you wouldn't recommend something dangerous to the health of the amp. Bad advice.
  20. With that amp, which I know very well, you are much better off running dual mono.
  21. Except that most bass speakers fail from exceeding their mechanical limits not their thermal limits. The mechanical limits of a speaker can be as low as 1/2 the thermal rating, and when you exceed the mechanical limits you cumulatively cause damage to the suspension components and reduce their lifespan. Also, mechanical power handling decreases as frequency falls below ~100Hz on most speakers. Generally, when you match the amplifier power (in RMS metrics) with the speaker rating (in RMS metrics) you will be reasonably well matched. This is a rule of thumb that’s holds up pretty well in the real world IME.
  22. Line level serial effects loops are often used for different purposes depending on the player. For example, some player use it for connecting a LINE LEVEL processor (compressor, eq) in series with the signal path, some players use it to connect to the send jack to drive a line level input, and some use the effects return as a power amp input, bypassing the onboard preamp. Then again, some players have no need for any of the above and don't use it at all.
  23. Yes, due to the architecture, the DI output (post) is also post master volume. Yes, you can operate the amp without a speaker attached.
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