SoundNERD:
yes that's what i'm saying.. even at maximum volume it didn't clip at all... we measured it with an osciloscope.. the curve was perfect..
BUT, it is possible that our schematic didn't allow it to clip.. i'm not sure..
and yes i can post my schematics in a day or two.. there nothing special really, but i'll post'em anyway.
when i say two i mean one for the left channel and one for the right.. stereo, but with the same powersource.
for supply for all the other small circuits in the amp. we used another transformator at 2*6V.
yes that's what i'm saying.. even at maximum volume it didn't clip at all... we measured it with an osciloscope.. the curve was perfect..
BUT, it is possible that our schematic didn't allow it to clip.. i'm not sure..
and yes i can post my schematics in a day or two.. there nothing special really, but i'll post'em anyway.
when i say two i mean one for the left channel and one for the right.. stereo, but with the same powersource.
for supply for all the other small circuits in the amp. we used another transformator at 2*6V.
the lm3886 can handle a voltage off +/-10 - +/-42V..though the maximum peak voltage it can handle is somewhat higher.
Our powersupply peaked over +/-42V often..not very much but anyway. but it went fine anyhow. But, if you use a transformer with a rated voltage of, say +/-42 the actual peaks and max values will be far above what the lm3886 can handle.
I'm sure almost everyone here knows this.. but some seem not to.
By the way, we happened to make a BIG mistake in our construction.. we made a seperate speaker delay unit, which delayed the speaker a while right after we turn the amp on, but also cut the connection to the speaker in the very moment we truned off the amp. The shitty thing with this isn't really the function, but that we forgot to give the two 10000uF caps. a way to empty. So if we truned on the thing, played with it a while and then shut it off, and then suddenly on again all the internal fuses blowed
crap... but it's easily fixed.. either we could make the delay to not work when turning off the amp, so the amp instead off getting quiet just continues to play for 5-10 seconds(and yes it will with those caps), or just give the caps a second way out to GND.
well that's a lot of blabla
Our powersupply peaked over +/-42V often..not very much but anyway. but it went fine anyhow. But, if you use a transformer with a rated voltage of, say +/-42 the actual peaks and max values will be far above what the lm3886 can handle.
I'm sure almost everyone here knows this.. but some seem not to.
By the way, we happened to make a BIG mistake in our construction.. we made a seperate speaker delay unit, which delayed the speaker a while right after we turn the amp on, but also cut the connection to the speaker in the very moment we truned off the amp. The shitty thing with this isn't really the function, but that we forgot to give the two 10000uF caps. a way to empty. So if we truned on the thing, played with it a while and then shut it off, and then suddenly on again all the internal fuses blowed
crap... but it's easily fixed.. either we could make the delay to not work when turning off the amp, so the amp instead off getting quiet just continues to play for 5-10 seconds(and yes it will with those caps), or just give the caps a second way out to GND.well that's a lot of blabla
well gothenburg boy
With a standard inputsignal voltage, in room-temp, at max volume at the amp. it didn't clip at all.. which was measured with an osciloscope. In other words the curve on the oscilator-monitor had a nice shape alla the time and didn't have a flat top(didn't clip). Also the sound was very loud and clear, without noise.
We came a lot closer to clipping using a constant-volume sinus-wave anyway, than with music. Our powersupply-caps. was quite overdimensioned, which can have been a reason for the amp being so hard to get to clip.
And with clip or clipping i here mean that the amp, with the given powersource and input and output load, can't amplifie as much as it should which leads to an output that more and more seems like a square-signal.
please guys, don't take this the wrong way.. i'm not trying to say anything like "oh look at me my amp is the best whawha", the point, if i in this state hasn't forgot it, was to explain for someone, maybe xplod, that it could be a good choice to carefully dimension the power supply to get the best out of his amp. Cause we indeed played very loud with it.. that is with two 4Ohm speakers (in each box 2*1"tweeters and 2*8" basses)..
I had teachers to ask when i built my amp so that was nice, i did it as a part of the class "produktionsanpassad elektronik konstruktion" which in english is something like "electronic construction for production" at the university of Umeå.
With a standard inputsignal voltage, in room-temp, at max volume at the amp. it didn't clip at all.. which was measured with an osciloscope. In other words the curve on the oscilator-monitor had a nice shape alla the time and didn't have a flat top(didn't clip). Also the sound was very loud and clear, without noise.
We came a lot closer to clipping using a constant-volume sinus-wave anyway, than with music. Our powersupply-caps. was quite overdimensioned, which can have been a reason for the amp being so hard to get to clip.
And with clip or clipping i here mean that the amp, with the given powersource and input and output load, can't amplifie as much as it should which leads to an output that more and more seems like a square-signal.
please guys, don't take this the wrong way.. i'm not trying to say anything like "oh look at me my amp is the best whawha", the point, if i in this state hasn't forgot it, was to explain for someone, maybe xplod, that it could be a good choice to carefully dimension the power supply to get the best out of his amp. Cause we indeed played very loud with it.. that is with two 4Ohm speakers (in each box 2*1"tweeters and 2*8" basses)..
I had teachers to ask when i built my amp so that was nice, i did it as a part of the class "produktionsanpassad elektronik konstruktion" which in english is something like "electronic construction for production" at the university of Umeå.
Yes one 4 Ohm speaker at each channel...(we tried without but we came closer with the speakers, we also tried with effect-resistors, but they burned pretty much)GregGC said:
when we raised the into-the-powersupply voltage we disconected the speakers as the sound started to feel like torture.
well i can't post it right now... but it's nothing special really..
Xplod, the schematic you posted at first on this thread, the only things that differ on my amp-circuit is i used a filter before the output to protects speakers from different things that can happen within the amp like self-swinging(själv-svängningar)and also high frequences (very high, damageable for speakers).
Also i didn't use the mute function on the OP at all.
I think the dimensioning between components and power-supply and so on is the most important matter..
Xplod, the schematic you posted at first on this thread, the only things that differ on my amp-circuit is i used a filter before the output to protects speakers from different things that can happen within the amp like self-swinging
(själv-svängningar)and also high frequences (very high, damageable for speakers).Also i didn't use the mute function on the OP at all.
I think the dimensioning between components and power-supply and so on is the most important matter..
ecliptica said:well gothenburg boy
With a standard inputsignal voltage, in room-temp, at max volume at the amp. it didn't clip at all.. which was measured with an osciloscope. In other words the curve on the oscilator-monitor had a nice shape alla the time and didn't have a flat top(didn't clip). Also the sound was very loud and clear, without noise.
We came a lot closer to clipping using a constant-volume sinus-wave anyway, than with music. Our powersupply-caps. was quite overdimensioned, which can have been a reason for the amp being so hard to get to clip.
Clipping does not really depend on what signal you amplify. It's when your input signal is high enough to be amplified to a value higher than the maximum output. Regardless of whether it's sinus or music.
No problem at all. I've done it may times. Clipping is however a bit relative here as the internal protection circuits might do other things before clipping.
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