AUDIOPHONICS MPA-S250NC left and right channel reversed

[Fralle87]

So I just got this and to make left and right separation I actually have to put the left hand speakers into the right hand output of the amp. I am guessing this is not normal behavior and that my amp must be faulty right?

Already tried another preamp to see if the fault was there but same result.

 

[DVDdoug]

No, it's not normal. Try plugging-in just the left input and the sound should come-out of the left speaker (or vice versa).

 

[Fralle87]

Plugging in the left speaker makes the sound come out of the left speaker and vice versa. But when trying a left-right speaker test Track it is still reversed. What does this mean?

 

[DVDdoug]

But when trying a left-right speaker test Track it is still reversed. What does this mean?

It means it's something else in the "chain". You'll have to test one thing at a time. Or the test recording is wrong.

If there is a TRS connection (a stereo connection with one plug like a headphone) anywhere in the audio chain, the cable might be wired wrong.

 

[Fralle87]

It means it's something else in the "chain". You'll have to test one thing at a time. Or the test recording is wrong.

If there is a TRS connection (a stereo connection with one plug like a headphone) anywhere in the audio chain, the cable might be wired wrong.

Hmmm. Like a trigger?

 

[Fralle87]

Tried to take out the trigger but it did nothing. I tried several left and right test tracks with the same result.

 

[Fralle87]

And now I took the entire chain out by just plugging in a tape deck with output volume control directly to the power amp. Did a left and right test tape and it is still reversed. Scratching my head here.

 

[raindance]

And now I took the entire chain out by just plugging in a tape deck with output volume control directly to the power amp. Did a left and right test tape and it is still reversed. Scratching my head here.

The input or connectors are reversed. Simply swap one set.

 

[Fralle87]

The input or connectors are reversed. Simply swap one set.

Thats what I thought to before trying using only the left speaker connector and vice versa. Doing that the sound indeed came from the left speaker - but doing the speaker test tracks it was still off.

Anyway reversing the connectors does get rid of the problem completely. And there is no real harm in doing this right?

 

[rolfrander]

maybe you can post a picture of the connections on the back of your amp and it will be easier to confirm our understanding of the issue.

 

[Fralle87]

I will do that as soon as I get home.

While on the subject: Does anybody know the dimension or better spare part number for the O-ring on the feet of these units? They are very loose and I already lost one.

 

[Ropeburn]

First, try the surefire method: plug in only one speaker, say, left, and also plug in only one channel of the source to the corresponding input (also left). Does it play? It's correct. Does it play from the other, right speaker output? It's reversed internally.

Also make sure you're plugging things correctly in the first place. Left is left and right is right looking from the front. It's also labelled that way. If you look from the back, left is right and right is left! Unlikely mistake, but it happens.

If all that is correct and it's still playing to the right speaker output from the left input and vice versa, the internal wiring is reversed. But fear not, that's an easy fix.

If you open up the device (disclaimer: only do it if you know what you're doing and take proper precautions), you'll see this:

This may look a little different if you have the RCA version, but the same principles apply.

Circled green is the inputs, labelled as Ch1 and Ch2, red is the speaker outputs labelled as LS1 and LS2. Check whether both go to the same connectors on the back correspondingly. If the left input goes to Ch1 for example, then LS1 must go to the left speaker output.

Fun fact: if we want to be picky, this is done "wrong" on my specimen. Left is Ch2 while it should be Ch1 - convention is that left is Ch1. But the speakers are also reversed, so overall it's correct again.

Check this on yours. If these are really reversed, you can simply swap the plugs circled in green, and that was it.

 

[Fralle87]

First, try the surefire method: plug in only one speaker, say, left, and also plug in only one channel of the source to the corresponding input (also left). Does it play? It's correct. Does it play from the other, right speaker output? It's reversed internally.

Also make sure you're plugging things correctly in the first place. Left is left and right is right looking from the front. It's also labelled that way. If you look from the back, left is right and right is left! Unlikely mistake, but it happens.

If all that is correct and it's still playing to the right speaker output from the left input and vice versa, the internal wiring is reversed. But fear not, that's an easy fix.

If you open up the device (disclaimer: only do it if you know what you're doing and take proper precautions), you'll see this:

View attachment 395082

This may look a little different if you have the RCA version, but the same principles apply.

Circled green is the inputs, labelled as Ch1 and Ch2, red is the speaker outputs labelled as LS1 and LS2. Check whether both go to the same connectors on the back correspondingly. If the left input goes to Ch1 for example, then LS1 must go to the left speaker output.

Fun fact: if we want to be picky, this is done "wrong" on my specimen. Left is Ch2 while it should be Ch1 - convention is that left is Ch1. But the speakers are also reversed, so overall it's correct again.

Check this on yours. If these are really reversed, you can simply swap the plugs circled in green, and that was it.

I tried this and sure enough the sound came from the other speaker when doing this, so it is reversed internally then.

Since I am not used to doing this and can't say that I know what I'm doing I guess it is better to create a ticket and send it back.

 

[Ropeburn]

I tried this and sure enough the sound came from the other speaker when doing this, so it is reversed internally then.

Since I am not used to doing this and can't say that I know what I'm doing I guess it is better to create a ticket and send it back.

Alright. It really is reversed then. And yes, if you're unsure and not used to opening up devices, be safe and let the manufacturer handle it.

 

[Fralle87]

Alright. It really is reversed then. And yes, if you're unsure and not used to opening up devices, be safe and let the manufacturer handle it.

Thank you for being so helpful.

This might be a real stupid question, but that's how you learn right?

There is no harm or degrade in SW just swapping channels by using left RCA in Right input or just swapping speaker cables for that matter right?

That way I can still enjoy music while waiting for Audiophinics to respond.

Also do you know if there is replacement O-rings to buy for these feet? Already lost one and it's only been a week...

 

[Ropeburn]

Thank you for being so helpful.

This might be a real stupid question, but that's how you learn right?

There is no harm or degrade in SW just swapping channels by using left RCA in Right input or just swapping speaker cables for that matter right?

That way I can still enjoy music while waiting for Audiophinics to respond.

Also do you know if there is replacement O-rings to buy for these feet? Already lost one and it's only been a week...

Of course you can simply swap the left and right RCA plugs to have it play correctly. There's no harm in that.

As for the O-Rings, simply ask Audiophonics for the size. These appear to be standard parts you can get anywhere.

 

[raindance]

Thats what I thought to before trying using only the left speaker connector and vice versa. Doing that the sound indeed came from the left speaker - but doing the speaker test tracks it was still off.

Anyway reversing the connectors does get rid of the problem completely. And there is no real harm in doing this right?

No harm at all. It is just a labelling issue.

 

[rolfrander]

The amplifier doesn't really care about "left" and "right", there is just two independent channels, how you connect them is irrelevant to the amplification. The usual way of labelling (of most equipment, not just amplifiers) is "left" and "right" when looked from the front to give you a more tidy cable management (avoiding crossing speaker-cables)

 

[Fralle87]

First, try the surefire method: plug in only one speaker, say, left, and also plug in only one channel of the source to the corresponding input (also left). Does it play? It's correct. Does it play from the other, right speaker output? It's reversed internally.

Also make sure you're plugging things correctly in the first place. Left is left and right is right looking from the front. It's also labelled that way. If you look from the back, left is right and right is left! Unlikely mistake, but it happens.

If all that is correct and it's still playing to the right speaker output from the left input and vice versa, the internal wiring is reversed. But fear not, that's an easy fix.

If you open up the device (disclaimer: only do it if you know what you're doing and take proper precautions), you'll see this:

View attachment 395082

This may look a little different if you have the RCA version, but the same principles apply.

Circled green is the inputs, labelled as Ch1 and Ch2, red is the speaker outputs labelled as LS1 and LS2. Check whether both go to the same connectors on the back correspondingly. If the left input goes to Ch1 for example, then LS1 must go to the left speaker output.

Fun fact: if we want to be picky, this is done "wrong" on my specimen. Left is Ch2 while it should be Ch1 - convention is that left is Ch1. But the speakers are also reversed, so overall it's correct again.

Check this on yours. If these are really reversed, you can simply swap the plugs circled in green, and that was it.

I think I will give this a go tomorrow, just for piece of mind and due to the fact that Audiophinics wants me to pay for shipping back and forth. To be honest I think that is kind of lacking in customer support since they actually sent me a unit that's not put together right.

Just to make sure: I should just pull the whole black plastic out of the white socket and change places?

 

[Ropeburn]

I think I will give this a go tomorrow, just for piece of mind and due to the fact that Audiophinics wants me to pay for shipping back and forth. To be honest I think that is kind of lacking in customer support since they actually sent me a unit that's not put together right.

Just to make sure: I should just pull the whole black plastic out of the white socket and change places?

That is unfortunate to hear. If true, it would go against EU regulations, which clearly state that the seller must pay for shipping back and forth in case of a defect that needs repair. Only if the supposed defect turns out to be untrue, the seller can then demand a refund for shipping costs from the buyer - afterwards.

I only just looked this up to make sure. It would be nice if @Audiophonics could reply.