Audio Preamp???

[psycho]

I use a cheap pair of amplified PC speakers plugged into my MP3 player to listen to music in my electronics workroom. With the speakers turned up all the way and the MP3 player up quite a bit, it is still not very loud.

What I need is more volume on the cheap. If I made a preamp and put it inline between the player and the speakers, would that help? Or should I jest get an amp IC and build an amp and forget about the PC speakers?

How do you normally use the headphone jack to listen with speakers? Or, is this a bad idea to begin with?

Thanks,
Kevin

[MrAl]

Hi,


Yes, it could be that the device needs a boost, or maybe not. Maybe a preamp would boost too much
and cause distortion, so i guess you would have to try it first.

Another idea is to simply pick up a new set of computer speakers, amplified. They are not too
expensive anymore even for a few watts output. You can find them all over the web for a pretty
good price.

I use amplified speakers and headphones, and connect both into the headphone jack on the
computer (one at a time of course) but some amplified speakers have a headphone jack built
in so you can plug into the speakers if you want.

[CeaSaR]

Kevin,

Check your speakers loudness when they are plugged into a computer (volumes maxed), then plug them into
your MP3 player and crank it all the way up. If your MP3 player isn't as loud as the computer, you'll need extra
amplification (I suspect you will).

You can look for an all in one chip solution (LM1458 etc.) or look at these relevant threads:

Mini Amp
Mic Preamp
(Many thanks to all who contributed to them.)

The nice thing about the MiniAmp circuit is that R9 allows for a WIDE range of input levels, <10 mV to >500 mV
for full output.

The Mic Preamp obviously takes Mic level (~ 5 mV) and can put out over 300 mV - adjustable by R1, R2.

Waiting for test results,
CeaSaR

[Bob Scott]

With the speakers turned up all the way and the MP3 player up quite a bit, it is still not very loud.

What I need is more volume on the cheap. If I made a preamp and put it inline between the player and the speakers, would that help? Or should I jest get an amp IC and build an amp and forget about the PC speakers?

How do you normally use the headphone jack to listen with speakers? Or, is this a bad idea to begin with?

Hi Kevin. Yes I too noticed that the newer sound cards don't work well directly connected to speakers, even with all of the various software volume and mixer controls at max.

I connected my sound card's output to the AUX input of an old stereo receiver that a relative gave me. That receiver drives regular old cheap speakers. It is handy this way. The computer output is amplified just fine. HA! These speakers were made before anyone knew about Thiele/Small equations for properly designing speakers.

I can tune the receiver for background music if I want. It is quicker to tune the analog dial than trying to find the station's web URL where you can listen off streaming audio.