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Question 1 out of 2 speakers not working when connected to PC via AMP

chiken

Junior Member
Jan 10, 2021
2
0
6
Hey everyone. So during these past months I began using some music hardware that had been lying around my house, pretty much unused for literal decades, and now I'm looking into creating a simple audio setup (with a turn table) for my small room.

First of all, let me list all the hardware I have at the moment:
  1. 2X 30W Lenco passive speakers
  2. Lenco MINI-001 Power AMP + integrated CD/USB player
  3. Micro Seiki DD24 turn table
Basically what I want to do is have at least 1 of the 2 speakers connected to the Power AMP, which will receive input from my PC via RCA to AUX cable and from the turn table, after it's connected to a pre - AMP that is.

Unfortunately though I only have an AUX to triple RCA cable (red, white, yellow) lying around. I thought it shouldn't be a problem, so I just used the red and white RCA cables, connected them to the AMP just like in this image and connected the AUX end of the cable to my PC, first in the green line port of the MOBO and then to the normal 3.5mm headphone jack port.

Unfortunately though, after connecting both speakers to the power AMP, only one of them worked and played the audio from the PC. I tried lots of things such as completely removing the CD/USB unit and connecting the RCA cables from the PC to the INPUT port of the amplifier. Of course I tried lots of things from Windows settings as well, but the problem persisted. Only the left speaker would play.

I was also able to replicate the same exact problem by using a YAMAHA RX-V367 AMP and another computer and the speakers are working just fine, so it's probably a Windows problem.
So yeah, I would appreciate a lot if someone could help me solve this :)

Additionally, 2 last things. Does anyone have any suggestions on basically the best pre - amp I can buy for my turn table for under 35 dollars or so? I'm located in Europe and these are the ones I've been considering:
  1. https://www.amazon.es/dp/B000H2BC4E
  2. https://www.amazon.de/dp/B07BKYL88W
  3. https://www.amazon.fr/dp/B07YZKFD1V
  4. https://www.amazon.de/dp/B087Q96WDS
Finally, since I want to have both my PC and turn table connected to the AMP, is it possible I could buy 2 RCA splitters (like these: https://www.amazon.de/-/en/Sienoc-Adapter-Connector-Splitter-Adaptor/dp/B0141XSMN8/ref=sr_1_3?dchild=1&keywords=rca-splitter&qid=1610182986&sr=8-3 ), connect them to the 2 AUX INPUT ports of the CD/USB unit and then connect the PC and pre - amp outputs to the splitter inputs?

And if such a method works, out of curiosity, what would happen if both the PC and turn table played audio at the same time? Would the AMP prioritize one of the two inputs or something like that?

Sorry for the large post and thank you so much in advance.

I have replaced your preamp links with ones that have the referral tags removed. We do not allow those.
administrator allisolm
 
Last edited by a moderator:

mindless1

Diamond Member
Aug 11, 2001
5,641
535
126
You know exactly what you mean, and I can guess that I might know what you mean, or there might be something getting lost in translation.

Whatever your adapter cable is, to use two channels you only need a single 3.5mm stereo plug (which has one tip connection and two ring connections) going to what is usually a red and a white RCA plug. Whatever else you have connected to the PC, disconnect it temporarily as some motherboard/card audio devices will switch around what the sockets do based on what they detect is connected.

Do you have a multimeter? It could be handy to use one to see where the audio signal is stopping. With audio playing, you will have a near line-out signal level from the computer. This will be roughly 1 volt AC. Since audio (unless it's a continuous tone) has fluctuating voltage levels, do not be concerned with exact voltage, just that you see a voltage in roughly a 1V magnitude.

If you have fiddled with your computer audio driver, control-panel settings, you might want to go back through those and try to reset everything to defaults because the default normally causes the headphone out to work... but I could be wrong!

I can't help with the preamp, don't have a turntable hooked up nor your specific model nor have any experience with the ones you linked.

You should not use a splitter for two inputs to an amp. Depending on how the outputs from your two sources are designed, it could do funny things like drag the signal down, and with both playing simultaneously it would both do that, and combine the signals, not the amp somehow choosing which to use. That is impossible with analog audio.

Since your amp does not have multiple inputs that are switched with buttons or logic, you'd want a manual A/B switch box to toggle between the two different input sources. I was going to link an example on ebay but I've finding it difficult to use the right search keywords to just find a simple, inexpensive switch rather than something fancier and more expensive than you need. For what it is, you should be able to find one for $2-3 delivered from China on ebay.

Anyway, here's an example of one I found that is more than the minimal functionality needed, costs more to be *fancy*:

You could instead build this yourself. All you need is a three pole, dual throw switch (or multiple switches to achieve all three poles, the three being Left, Right, and Ground for each input) wired to the RCA jacks, assuming you want RCA rather than 3.5mm stereo jacks which is also an option.

Here's other examples, and the second one has more inputs than you need and also video in and out but you could just leave the video disconnected.


There has to be a simple, inexpensive A/B audio switch box out there somewhere if you want to spend the time to find it, maybe on Aliexpress.
 
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chiken

Junior Member
Jan 10, 2021
2
0
6
You know exactly what you mean, and I can guess that I might know what you mean, or there might be something getting lost in translation.

Whatever your adapter cable is, to use two channels you only need a single 3.5mm stereo plug (which has one tip connection and two ring connections) going to what is usually a red and a white RCA plug. Whatever else you have connected to the PC, disconnect it temporarily as some motherboard/card audio devices will switch around what the sockets do based on what they detect is connected.

Do you have a multimeter? It could be handy to use one to see where the audio signal is stopping. With audio playing, you will have a near line-out signal level from the computer. This will be roughly 1 volt AC. Since audio (unless it's a continuous tone) has fluctuating voltage levels, do not be concerned with exact voltage, just that you see a voltage in roughly a 1V magnitude.

If you have fiddled with your computer audio driver, control-panel settings, you might want to go back through those and try to reset everything to defaults because the default normally causes the headphone out to work... but I could be wrong!

I can't help with the preamp, don't have a turntable hooked up nor your specific model nor have any experience with the ones you linked.

You should not use a splitter for two inputs to an amp. Depending on how the outputs from your two sources are designed, it could do funny things like drag the signal down, and with both playing simultaneously it would both do that, and combine the signals, not the amp somehow choosing which to use. That is impossible with analog audio.

Since your amp does not have multiple inputs that are switched with buttons or logic, you'd want a manual A/B switch box to toggle between the two different input sources. I was going to link an example on ebay but I've finding it difficult to use the right search keywords to just find a simple, inexpensive switch rather than something fancier and more expensive than you need. For what it is, you should be able to find one for $2-3 delivered from China on ebay.

Anyway, here's an example of one I found that is more than the minimal functionality needed, costs more to be *fancy*:

You could instead build this yourself. All you need is a three pole, dual throw switch (or multiple switches to achieve all three poles, the three being Left, Right, and Ground for each input) wired to the RCA jacks, assuming you want RCA rather than 3.5mm stereo jacks which is also an option.

Here's other examples, and the second one has more inputs than you need and also video in and out but you could just leave the video disconnected.


There has to be a simple, inexpensive A/B audio switch box out there somewhere if you want to spend the time to find it, maybe on Aliexpress.
Thanks for the reply. I'm going to purchase a dual RCA to AUX cable, reset all Windows Sound Settings and buy a cheap A/B audio switch box for the two inputs. I'm going to update the thread if the problem doesn't get fixed after I get the new cable :)
 

Dranoche

Senior member
Jul 6, 2009
206
25
91
The TRRS cable you currently have probably has video instead of the second audio channel on the first ring. Putting the yellow plug in place of the red might work. I would still buy the correct cable though.
 
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