Computer-Amplifier connection
EDY19, Sun Sept 10 2006, 07:29PMI'm trying to connect my computer headphone output to my bass guitar amplifier, and I'm having trouble with crackly sound. The input impedance of the amplifier is either 1Mhom or 200k, depending on whether I use the passive or active input, whereas normal headphone impedance is closer to 50 ohms which is what the computer wants to be "seeing". Would this be a problem? Lastly, the computer outputs stereo, which i need to convert to mono. I have a cord I made that connects the left and right chanels via a 1k resistor on each, and where the two resistors are connected, thats where the output is connected to. And the two grounds are connected as well. Suggestions? Do I need a matching transformer of some sort?
Re: Computer-Amplifier connection
Carbon_Rod, Sun Sept 10 2006, 10:54PM
Not sure what type of amp you have -- but you may have already over-driven the inputs.
There are fried tube amps that get their start by people who plug-in home brew stuff.
Good luck,
Carbon_Rod, Sun Sept 10 2006, 10:54PM
Not sure what type of amp you have -- but you may have already over-driven the inputs.
There are fried tube amps that get their start by people who plug-in home brew stuff.
Good luck,
Re: Computer-Amplifier connection
Steve Conner, Sun Sept 10 2006, 11:13PM
I can't see anything wrong with the way you've wired it up, That's how I'd have done it. Maybe your computer output is too loud and it's overdriving the amp? Try connecting a 47 ohm resistor between the node where the two 1k's join and ground, that will attenuate it by 20dB. And/or try the active input since that might well have less gain.
Carbon_rod: When I was younger I tried to get a more distorted sound from my guitar amp. So I plugged my guitar into the phono pickup input of an old stereo and plugged the speaker output of the stereo into the input of the amp. That sounded quite distorted but I still wanted more. So I took an output transformer from a dead tube amp (that I failed to fix) and used it backwards to step the speaker output up. That sounded great for 10 seconds till it fried the front end of the guitar amp and then gave me an electric shock when I touched it.
Steve Conner, Sun Sept 10 2006, 11:13PM
I can't see anything wrong with the way you've wired it up, That's how I'd have done it. Maybe your computer output is too loud and it's overdriving the amp? Try connecting a 47 ohm resistor between the node where the two 1k's join and ground, that will attenuate it by 20dB. And/or try the active input since that might well have less gain.
Carbon_rod: When I was younger I tried to get a more distorted sound from my guitar amp. So I plugged my guitar into the phono pickup input of an old stereo and plugged the speaker output of the stereo into the input of the amp. That sounded quite distorted but I still wanted more. So I took an output transformer from a dead tube amp (that I failed to fix) and used it backwards to step the speaker output up. That sounded great for 10 seconds till it fried the front end of the guitar amp and then gave me an electric shock when I touched it.
Re: Computer-Amplifier connection
EDY19, Sun Sept 10 2006, 11:30PM
I always turn the gain on the amplifier all the way down, as well as the volume on the computer, and gradually turn each up so the clip light on the amplifier doesn't light up. And the amplifier is sounding OK. I just wanted to make sure that this was OK for the computer, which i think it is since the input impedance of the amplifier is sooo much greater than that of the computer. There is also a stereo return jack on the back which I have used as an input, which bypasses all of the preamplifier, however I have no idea what the impedance on that is. It works fine with my active bass guitar. Maybe that would be a better choice.
EDY19, Sun Sept 10 2006, 11:30PM
I always turn the gain on the amplifier all the way down, as well as the volume on the computer, and gradually turn each up so the clip light on the amplifier doesn't light up. And the amplifier is sounding OK. I just wanted to make sure that this was OK for the computer, which i think it is since the input impedance of the amplifier is sooo much greater than that of the computer. There is also a stereo return jack on the back which I have used as an input, which bypasses all of the preamplifier, however I have no idea what the impedance on that is. It works fine with my active bass guitar. Maybe that would be a better choice.
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