I did not actually test it properly with full range passive xo'd speakers, but I would presume that some audible differences are possible, but they are likely very small at the most.
Zobel does not relate to DC offset, it acts as a low pass filter to stabilize the amp driving inductive loads.
XPA-1 has a microprosessor that monitors various fault conditions like short circuit, but I don't know if it monitors DC offset at the output and if it does, what is the amount it accepts before shutting the amp.
Regards,
Legis
I'm just wondering If I should introduce these onto the output to protect the speakers. I have blown a few drivers.
eBay Australia: Buy new & used fashion, electronics & home d?r
also wondering if it will affect the sound
eBay Australia: Buy new & used fashion, electronics & home d?r
also wondering if it will affect the sound
I would say no, it will affect the sound.
It is not the DC that has blown the drivers. There is no excess DC at the output if you have not bypassed the 4,7µF input capacitors (and the amp does not clip). If there is over 20mV, there might be something wrong. My XPA-1s have 1,5mV and 6mV, which are normal figures. Excessive excursion and power will destroy the drivers in normal situations.
How have you blown the drivers? Just turn down the volume when you hear distortion? With some extreme dynamic tracks one should know the limits of one's set before going all in, because there in no warning like distortion (like Tchaikovsky's 1812 with real cannons bottoming the drivers very hard).
Regards,
Legis
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Please do explain more why you think DC protection with relay will affect the sound.
AFAIK all modern amplifiers have some sort of protection and/more delay for DC, and as long as it's a good quality relay that is used sound shouldn't be affected.
That eBay DC protection suggested does look interesting, even if I don't know the relay type, which should be checked for contacts quality.
Well, this circuit supposedly does not add anything active or passive, except the relay contact.
So what we should weigh is whether if that is worth it to keep you safe from a potentially disastrous DC at the output.
This is something I did experience, because I had no DC protection on my previous power amp and it almost fried my woofer. It did not because the woofer was well built, but I'm not sure whether something changed due to the time half the amp supply went through it.
So what we should weigh is whether if that is worth it to keep you safe from a potentially disastrous DC at the output.
This is something I did experience, because I had no DC protection on my previous power amp and it almost fried my woofer. It did not because the woofer was well built, but I'm not sure whether something changed due to the time half the amp supply went through it.
xpa1 mod cap
My xpa1 is ver 07. Original sounds a little compressed and sibilant.
1.Installed 12*22,000 uf 63v per each xpa1 replacing stocked reservoir.
2.Replaced 4.7 uf sounder cap with 15 uf Q5 capacitor bi cap with 0.1 uf k75-10
3.Add 220 uf 100v silmic2 to input stage capacitor 1000 uf 100 v.
The 22,000 uf 63v is fitted perfectly to the board.
Modded amp sounds much better.
Here is few questions
1.Will schottky or fast recovery diodes replacement in rectification input stage and amp stage make difference? All voltage will be a little higher. Will bias be
changed?
2.Schottky or fast recovery ?
My xpa1 is ver 07. Original sounds a little compressed and sibilant.
1.Installed 12*22,000 uf 63v per each xpa1 replacing stocked reservoir.
2.Replaced 4.7 uf sounder cap with 15 uf Q5 capacitor bi cap with 0.1 uf k75-10
3.Add 220 uf 100v silmic2 to input stage capacitor 1000 uf 100 v.
The 22,000 uf 63v is fitted perfectly to the board.
Modded amp sounds much better.
Here is few questions
1.Will schottky or fast recovery diodes replacement in rectification input stage and amp stage make difference? All voltage will be a little higher. Will bias be
changed?
2.Schottky or fast recovery ?
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