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TheCow
Stranger
Registered: 10/28/02
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Help with making an audio amp
#4387655 - 07/09/05 06:34 PM (18 years, 8 months ago) |
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Hey, for my bass, I couldnt afford an amp, so I am going to make one. Now all that I want, is to be able to plug headphones into it, I dont to make the actual speaker. But I have a few questions. Does anyone know the frequency range of a bass. As to cut down on distortion, I am going to have a second order butterworth low pass filter, at 20 hz I guess. And a high pass at whatever frequency is the highest. I am going to have gain stages obviously to up the voltage, so does anyone know on average how much voltage comes out of the bass amp? I cant imagine very much. Also what about harmonics, if I play a harmonic at the seventh fret, it sounds a lot higher, is this a higher frequency, or does it just sound like that. I am going to use opamps I guess for this. I dont think I will get too much distortion, should be pretty clean. And for a volume knob, on my last gain stage, I am going to have a trimpot resistor to control the gain that I want. Anyone have any suggestions for me? Or does this sound about right.
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automan
blasted chipmunk
Registered: 09/18/03
Posts: 8,272
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Re: Help with making an audio amp [Re: TheCow]
#4387781 - 07/09/05 07:28 PM (18 years, 8 months ago) |
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is your bass active or passive?
-------------------- No, no, you're not thinking, you're just being logical. ~ Niels Bohr
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debianlinux
Myconerd - DBK
Registered: 12/09/02
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Re: Help with making an audio amp [Re: TheCow]
#4388254 - 07/09/05 10:36 PM (18 years, 8 months ago) |
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Quote:
TheCow said: Anyone have any suggestions for me?
LM386. Get an oscilloscope.
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TheCow
Stranger
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Re: Help with making an audio amp [Re: debianlinux]
#4388552 - 07/09/05 11:50 PM (18 years, 8 months ago) |
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Ah I should have pointed that out, it will be passive. Yea I was gonna use lm386's, good ol dual op-amps.
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metasin
Stranger
Registered: 10/12/04
Posts: 972
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Re: Help with making an audio amp [Re: debianlinux]
#4392514 - 07/11/05 01:13 PM (18 years, 8 months ago) |
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Quote:
debianlinux said:
Quote:
TheCow said: Anyone have any suggestions for me?
LM386. Get an oscilloscope.
or soundforge or cool edit
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BloodNOil
Captain Zeep
Registered: 10/08/03
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Re: Help with making an audio amp [Re: TheCow]
#4392613 - 07/11/05 01:45 PM (18 years, 8 months ago) |
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Quote:
TheCow said: Ah I should have pointed that out, it will be passive. Yea I was gonna use lm386's, good ol dual op-amps.
I built one of those in wood shop. heh... I used cheap-ass coils too close to each other, and so my crossover was tuned entirely wrong (not that I had any hope without an oscilloscope), but it kind of worked.
-------------------- It's like a koala bear crapped a rainbow in my brain!
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TheCow
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Re: Help with making an audio amp [Re: BloodNOil]
#4393395 - 07/11/05 06:11 PM (18 years, 8 months ago) |
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I am going to be doing this with no oscilloscope. But I know how to design it to fit the correct frequencies and amplification, with bass boosting, and such like that. Also I have a circuit program on my computer, so that I can sort of test it out from there. As long as I build it correctly from my diagram I should be good to go.
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automan
blasted chipmunk
Registered: 09/18/03
Posts: 8,272
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Re: Help with making an audio amp [Re: TheCow]
#4395829 - 07/12/05 12:50 PM (18 years, 8 months ago) |
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is this for home or car? what will the loudspeaker design be? i suggest a nearfield line array for the mids and tweets. the secret is to be able to drive the mids low enough without distortion to get below the audible range for an average human... which is around 600Hz. everything below that should be direct to the bass drivers because it is just for feeling, not hearing. by having the crossover frequency just out of the range of human ears, it gives a better illusion of a live performance, which is what good hifi strives for.
-------------------- No, no, you're not thinking, you're just being logical. ~ Niels Bohr
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debianlinux
Myconerd - DBK
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Re: Help with making an audio amp [Re: automan]
#4397350 - 07/12/05 07:33 PM (18 years, 8 months ago) |
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er, it's for a headphone practice amp.
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TheCow
Stranger
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Re: Help with making an audio amp [Re: debianlinux]
#4397544 - 07/12/05 08:25 PM (18 years, 8 months ago) |
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yea just for a headphone amp. But what do you mean frequencies below 600 hz are just for feeling. You can hear an A 440 note quite easily.
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automan
blasted chipmunk
Registered: 09/18/03
Posts: 8,272
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Re: Help with making an audio amp [Re: TheCow]
#4398110 - 07/12/05 11:13 PM (18 years, 8 months ago) |
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*60Hz, heh. DAMN YOU PINKY FINGER!!!!.
-------------------- No, no, you're not thinking, you're just being logical. ~ Niels Bohr
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outerwave
shuffler ofmortal coils...
Registered: 01/12/06
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Re: Help with making an audio amp [Re: TheCow]
#5356303 - 03/02/06 03:58 AM (18 years, 1 month ago) |
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well, i realize this thread is a little old, but i pay my way as a recording engineer...
in mixing it is standard practice to chop the lows off of bass instruments. drums, etc. since the lowest note played may be 62Hz, the content at 20-50 Hz tends to be rumble, and the amp or stereo trying to play the track 'blows it's wad' trying to recreat this low freqs that most speakers cannot reproduce anyway. by cutting rid of the rumber, suddenly the amp has more juice for the fundementals, like 62Hz, and it now 'feels' like there is more bass...
as far as a headphone amp, try:
http://tangentsoft.net/audio/cmoy-tutorial/
i've built a few of these, from radioshack parts, and from ridiculously high end ones. for 15 bucks and a soldering iron, and a 9v battery, you get a simple headphone amp that will stirfry your brain. huge improvment over say an ipod or discman, suddenly shitty headphones can do alot more with the excess power.
-------------------- take care, outerwave
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