Need help from someone whose know about electronics and sound

[DigimonNinja]

I bought some speakers from one of those surround sound type systems from a junk store for about ten dollars. I’m current running the audio from my DVD player through a duel cassette deck to increase the signal strength to the speakers.

Keep in mind that the junk store did not have an amp and I don’t have much money, looking for work. So I decide to modify a portable cassette player to try to amplify the signal strength. Below is a pic what I have done. I have run across a small problem and was wonder if someone can help with a problem.

If I feed directly from the DVD to it and from it to the speaker, the signal is to strong and sounds distorted. If I feed the audio from the dual cassette deck to it, I can turn down the volume and it sound better but there is a hum in the speakers with I turn the portable player up. Does anyone know if I can fix that problem?

Here is a pic of the speakers. They are aiwa speakers.

Note:I'm still new at this and using the very basics I have learn. Plus someone told me to check here for help.

[TheHermit]

you need to look at impedance matching the speakers to the amp inside the casette player this should help with the background noise at volume and may help with your clipping as well. im at work a the mo when i get home ill have a closer look and see if im talking sense or nonsense

[DigimonNinja]

Ok, I don't know where to even look to do " impedance matching the speakers to the amp inside." I know very little in this area. If I did not know you to make XLR or RCA cables, I would have not gotten this far with it.

[DigimonNinja]

Here is a different look at the set up as well as the inside if it will help. I'm also having trouble with one of the channels. For some reason, I keep loosing the signal when I turn the player. I re-did the connection and it still looses it when I turn the player right side up.

[Angablade]

Time to drop that into a project hobby box

[Tarbizkit]

I agree with Hermit that most of the time impedance matching would help, however, when you say that just simply changing the orientation of the device causes you to loose a channel, i am thinking you may have a bad solder connection or a broken component.

[TheHermit]

ok perhaps with a little more info we might be able to get this working for you.

1. I need to know the Impedance value printed on the back of the speakers.

2. How the speakers are connected. i.e. is there a box sitting in the middle.

3. What make / Model is the cassette player

4. a picture of the other side of the board to see your connections

A few things to bear in mind. The cassette player is designed to output to some headphones. the volume for these is Limited and is designed to be low.

to plug external speakers in usually requires that the speakers have some sort of internal amp (this would be the box sitting in the middle)

let me know and ill see if we can come up with something for you

[digip]

Hum can sometimes be a bad ground as well as EMI.

There is also the way in which sometgings are wired and transmits the sound to cancel noise. Like in a guitar with a single coil pickup, you get hum(hence double coils given the name humbuckers), when you use one pickup you get a hum, turn two on and you cancel the hum(inverse of wave cancels each others noise out). If you plug in your input and turn up the volume on the cassette deck(without anything playing in the dvd player) do you still get the hum from just the power alone?

[chateauxtech]

You might just be over driving the amp. See if you can find the op-amp, it should have some kind of heat sink attached, then google the serial number to find a spec sheet.

I found that this type of project is more trouble than its worth. Starting from scratch is better. I built a chipamp last summer. It was a pretty easy project, like legos only with soldering.

[MBP]

turn the input volume down had have the tv turned up. I found when i was running a mp3 to tape in my car the mp3 turned right down with the tape deck turned up sounded 100% better then mp3 up tape down.

[DigimonNinja]

You might just be over driving the amp. See if you can find the op-amp, it should have some kind of heat sink attached, then google the serial number to find a spec sheet.

I found that this type of project is more trouble than its worth. Starting from scratch is better. I built a chipamp last summer. It was a pretty easy project, like legos only with soldering.

I'm looking for a job so I need something to kill my time.

I will get new pics up a little later, I did found why I was loosing one of my channels. The port for the headphones pluged into was not making a good connection with the board.

[DigimonNinja]

turn the input volume down had have the tv turned up. I found when i was running a mp3 to tape in my car the mp3 turned right down with the tape deck turned up sounded 100% better then mp3 up tape down.

That is what I've been doing. Although I have to much of a hum.