Can I output a keyboard thru the speakers on my home stereo?

[BlackenedJustice]

Probably a stupid question. I really like the sound of the speakers, they have great bass response and overall sound. They are Sony speakers my father got with a stereo system in America, around '85-'86. The amp on the stereo isn't that functional anymore, it sometimes sends sound to only one channel, and I have to adjust the amp and change its postition to get it to output to both channels again. This is why I don't usually listen to music on that stereo, but every once in a while, I do, and I'm just blown away by their sound.

 

I'm currently outputing my sound through the internal speakers on my Roland HP103e, mainly because that's the only instrument I play, but I'm soon gonna be getting a Nord C2, when it comes out, and I'm gonna need some decent speakers to play it. I do have a pair of Boss speakers, with 3 inputs each that I could use, but those were also bought in America and as far as I know, I'd have to plug them into a transformer. I do have one of those around, and it's where my D-50 is plugged into, but I think I'll put the Nord C2 in a different room, so that really isn't very practical.

 

So, I realize this may be a stupid question, but so be it.

[Garrafon]

Yes, it can be done. You will need a power source for them (you say the amp is not functional). As long as you match the proper power source, I don't see any significant problem (assuming you are just doing this for your own living room pleasure playing).

[ITGITC]

So, I realize this may be a stupid question, but so be it.

 

 

Oh no, no, no, no. This is NOT a stupid question.

 

I, and many others, have wanted a pair of speakers that would look appropriate in the living room, yet can also used with our keyboards.

 

The problem is that, unless you are careful, you can damage your speakers. Here's how:

 

1. You will like the music you are playing and want to crank it up. Because the dynamics of many sounds are much greater than prerecorded music, you can easily physically damage a woofer by playing a drum sound, an organ sound, or percussive sounds with a great amount of low frequency energy. Although you are careful, this can easily be done in error.

 

The best way to avoid this is to keep the master volume down on the amp/preamp/receiver, always keep the subsonic filter turned on, and never turn the bass EQ knob up high.

 

2. You can fry the tweeters if (for instance) you connect/disconnect the keyboard - or just turn the keyboard on with the volume control of the amp/preamp/receiver up.

 

Although that pop that you hear usually won't damage a PA speaker or keyboard amp speaker, it may indeed kill the very sensitive tweeter in a home stereo system.

 

Do I sound like the voice of experience here?

[Synthoid]

The problem is that, unless you are careful, you can damage your speakers.

 

I think all synths & workstations should come with a warning regarding this matter.

 

[BillWelcome Home Studios]

Ineed, you can damage the speakers, and it is even likely. Unless you listen at pretty low levels.

 

The intermittent output from amps is usually caused by a physical break in connection at one of two places... either the input jack or the output jack.

 

These jacks are often soldered directly to the circuit board, and the physical stress of plugging and unplugging over the years often causes a very small crack in the solder joint where the jack ties into the board. The simple repair is to take a solder gun and reheat the joint. The solder liquifies and re-makes the connection, and you'll probably be good for another 25 years or so.

 

Bill

[BlackenedJustice]

Ineed, you can damage the speakers, and it is even likely. Unless you listen at pretty low levels.

 

The intermittent output from amps is usually caused by a physical break in connection at one of two places... either the input jack or the output jack.

 

These jacks are often soldered directly to the circuit board, and the physical stress of plugging and unplugging over the years often causes a very small crack in the solder joint where the jack ties into the board. The simple repair is to take a solder gun and reheat the joint. The solder liquifies and re-makes the connection, and you'll probably be good for another 25 years or so.

 

Bill

 

I realize it may be a physical break, yet I don't think is either at the input nor the output, because I've experimented with it and realized the problem persists regardless of input used (it has 2 inputs) and after checking with an ohmimeter (or however you call a device that measures electric resistence) on both speakers' outputs, current passes through the outputs to both speakers, so I guess the problem must be internal.

[drawback]

The problem is that, unless you are careful, you can damage your speakers.

 

I think all synths & workstations should come with a warning regarding this matter.

 

 

Like: "Don't Try This At Home?"

 

[Karl Schmeer]

 

Using an organ like a C2 on a set of 24 year old stereo speakers? Noooo, I would not want to do that. Unlike a piano

or guitar, an organ generates constant solid tones. With chords these notes add together to create one large speaker eating tone.

Also, depending on how well the speakers were taken care of I would think the rubber which holds the speaker cone in place would be just about at the end of it's life. Any large sustaining bass notes are just going to push it over the edge.

 

The amp on the stereo isn't that functional anymore, it sometimes sends sound to only one channel, and I have to adjust the amp and change its postition to get it to output to both channels again.

 

A stereo system of this vintage could have many possible issues. You may have already done this but, I would start with brand new speaker wire for one.

When you say adjust, what are you adjusting? controls? Which Ones? Also, please tell me what you mean by position. Are you saying you change the actual physical position of the stereo,or are you talking about the left/right balance control. If moving controls is fixing the problem, this is pointing to the controls needing a good cleaning.

 

ohmimeter (or however you call a device that measures electric resistence) on both speakers' outputs, current passes through the outputs to both

Yes, you are quite correct, this is called an ohmmeter. But something to keep in mind. The vibrations caused by a speaker could easily cause a faulty connection to vibrate loose. This could easily be caused by a faulty component or failed solder joint in the speakers crossover. It might be a good idea to get another amp and see if both speakers are okay before blaming the stereo.

 

Good Luck

- Karl

 

 

 

 

 

 

 

[BlackenedJustice]

I do have another amp, but it's connected to my home theater system, and at this moment it'd be a pain in the ass to disconnect everything from it. But I am positive the problem is in the amp itself. When I say I adjust the stereo and change its position, I'm talking about physically lifting it and twirling it around (only slightly) until the sound comes back on the speaker.

[Karl Schmeer]

Well, Okay that would point to the wire (speaker or input) or as Bill points out, the soldering on the input/output jacks.

Next time instead of moving the stereo try moving the wiring of the non-functioning channel around. You would want to keep the volume level low when doing this BTW. If no change try wiggling the jacks a bit. If this makes no difference, try moving the wire/jacks at the speaker end.

 

- Karl

 

[BlackenedJustice]

I've tried that every single one of my past times. I started it up and played a Doors' album just to make sure, and I confirm that moving the wire and wiggling the jacks doesn't do a thing. Only moving the stereo itself helps. Sometimes even lightly touching it can bring the channel back to life again. This time I was lucky and it didn't collapse many times. I don't know if the problem is triggered by the vibration associated with the sound, but it feels like it doesn't shut the channel down at any specific moment, it's pretty much random.

BTW, here is the stereo in question: http://www.youtube.com/watch?v=nwH-ZGF90_0

The speakers are the original, not the ones the video shows, and I currently have only the EQ and amp connected, neither the AM/FM receiver nor the cassette deck are connected, and I have to say that the lights on the EQ no longer show. I have to control overall response by ear.

This one shows the original speakers:

 

Cheers

 

EDIT: BTW, the Boss monitors are the Boss MA-12. It's been forever since I've played anything through them, and when I did it was my dad's Roland D-50. I really don't know what they sound like these days, but the reviews online seem to be pretty good. The only problem with setting them up is that they, along with the D-50 have American style plugs, and no internal voltage selection.(the Sony stereo is american too, but since it has a voltage selector, I can just set it to 220V and put the plug through a converter) Both the D-50 and Boss monitors would have to be connected to a transformer, which could be a problem, since I think I'll put the C2 in a different room than the D-50 is in. Not to mention that, since the D-50 has to be earthed (is that a word?), it has to be in that specific room, because it's the only one, besides where the fridge and stuff are, that has earthed mains current.

The other option would be to take the D-50 to my country-side house so that I can have a keyboard I can play there, and bring my VST-equipped laptop for some sounds. Then I could either put the C2 where the transformer is set up, or put it in the room I was expecting to put it, dealing with some hum, because of it not being earthed.

[Karl Schmeer]

Sometimes even lightly touching it can bring the channel back to life again.

 

Ahhh, This says a lot, If just touching the stereo sometimes fixes the problem this suggests to me an electrostatic problem.

Is it close to a air vent?

I used to have a Pioneer Stereo very simular to this

(CA 1985). It had digital volume control ( switches instead of pots), I moved it under an air vent and suddenly It would randomly jump up in volume. As far as I could tell, air rushing past the stereo would build up a static charge which would cause eratic behaviour. At the time these stereos were designed everything was going digital, many engineers were just becoming aware of static problems in digital circuit designs. Many things got out the door to consumers before the problems were fully understood. I don't know if it will help but you might try running a wire from the metal chasis to an earth ground. I am guessing your in Europe

and I am not that familure with the electrical wiring in a

residence there. Here in the states you can get a ground from the elctrical socket or any metal water pipe.

This is what finally fixed mine.

 

- Karl

 

 

 

[BlackenedJustice]

It recently moved from my countryside house to here, and it displayed the same symptoms over in the countryside house as it does here. No air vents in my place. I guess that would be and explanation, but since most of the times I have to shake it up lightly and not just touch it goes against that explanation. I will try to connect it to an earth ground, though.

[bloodyMary]

connecting an American electrical device to a 220 volt outlet requires a special adapter device, a transformer. The price depends on required power. I've bought one rated for 15 watt (for a mixing console) for about $5.

 

 

About the amp - it's definately a physical connection problem, might be an output jack, might be some internal connection that came loose. Might be a cracked circuit board (in this case - not much to do).

[BillWelcome Home Studios]

..Might be a cracked circuit board (in this case - not much to do).

 

Two easy fixes... first, try my original suggestion of re-heating the existing joints, maybe adding a touch more solder (be careful!). Second, drill through the trace connections and install jumpers.

 

If the plug/jack connection is not continually made, broken, and remade; then simply doing the reheat thing should work. If you've got to plug and unplug a lot, then it is indeed questionable as to what will be a permanent fix. Putting in a scab and glue to support the board might work, but no way to tell for sure.