Amp to Expand System

[Project SOG]

So you're leaning towards ground loop hum? Might start here https://www.audioholics.com/home-theater-connection/ground-loops-eliminating-system-hum-and-buzz

Thank you for this.

Not sure what you call this or what's happening but I isolated the problem.... I disconnected the trigger and the buzz went away. The only thing is, I would like to use the trigger.

Is it something wrong with the amp or what am I doing wrong?

 

[lovinthehd]

Not sure why that would be a cause, sorry. Might want to post up details about the cable used perhaps....

 

[Project SOG]

Not sure why that would be a cause, sorry. Might want to post up details about the cable used perhaps....

Yeah it's so weird.

I attached the details. If it something with this cable?

 

[lovinthehd]

That appears to be a correct type cable.....unless its faulty or something.

 

[PENG]

Yeah it's so weird.

I attached the details. If it something with this cable?

I don't know how Warren wired the triggers for his amps so it is better you give him a call. I am sure you are not the only one who use RCA to XLR and have the trigger option, so he likely have come across similar complaints from some of his other customers and may have a solution for you.

Some one on AVF did what he did that fixed a similar issue but again, you should talk to Warren first because the AVF guy may have a slightly different situation.

Low level AC hum caused by trigger cable ground loops | AVForums

 

[Project SOG]

I don't know how Warren wired the triggers for his amps so it is better you give him a call. I am sure you are not the only one who use RCA to XLR and have the trigger option, so he likely have come across similar complaints from some of his other customers and may have a solution for you.

Some one on AVF did what he did that fixed a similar issue but again, you should talk to Warren first because the AVF guy may have a slightly different situation.

Low level AC hum caused by trigger cable ground loops | AVForums

@PENG to the rescue!

Quick update, guys. I spoke to Warren and he was trying to help but we couldn't get to the cause of the ground loop happening. But a buddy of mine who knows a bit about electrical work, I had him read the article you sent @PENG and he did exactly that and it fixed the problem. He basically lifted off the ground wire of the trigger cable and the horrible buzz went away. Thank you for that article!

 

[PENG]

@PENG to the rescue!

Quick update, guys. I spoke to Warren and he was trying to help but we couldn't get to the cause of the ground loop happening. But a buddy of mine who knows a bit about electrical work, I had him read the article you sent @PENG and he did exactly that and it fixed the problem. He basically lifted off the ground wire of the trigger cable and the horrible buzz went away. Thank you for that article!

I hope the same would help in your case too. Did you mean your buddy have done it on his own system, have you try that trick to yours yet? Normally I will not suggest disconnecting a ground connection to eliminate group loop noise. In this case I feel comfortable because it is just a trigger cable and the voltage should be only 12 V dc at the most.

 

[PENG]

Have you levelled match the VTV amp with the AVR amps yet? You will find that the level trim for the Hypex amp needs to be increased by about 3 dB, that's because of its lower gain. You can do it manually, without re-running Audyssey/auto setup.

 

[Project SOG]

Have you levelled match the VTV amp with the AVR amps yet? You will find that the level trim for the Hypex amp needs to be increased by about 3 dB, that's because of its lower gain. You can do it manually, without re-running Audyssey/auto setup.

I re-ran Audessey just because I added surrounds.

How do I go about level matching the VTV amp to the AVR's?

 

[lovinthehd]

I re-ran Audessey just because I added surrounds.

How do I go about level matching the VTV amp to the AVR's?

If you ran Audyssey when using the VTV you're good. Or were the surrounds before the amp?

 

[Project SOG]

If you ran Audyssey when using the VTV you're good. Or were the surrounds before the amp?

Yeah I ran Audessey with the amp and with the surrounds. So am I set, or is there something else I should do?

 

[lovinthehd]

Yeah I ran Audessey with the amp and with the surrounds. So am I set, or is there something else I should do?

Nothing to do, you're set.

 

[Project SOG]

Nothing to do, you're set.

Excellent! So is the next step to learn how to use REW?

 

[lovinthehd]

Excellent! So is the next step to learn how to use REW?

Could be....you already get the mic and download it?

 

[PENG]

Yeah I ran Audessey with the amp and with the surrounds. So am I set, or is there something else I should do?

Can you post the trim level settings for the before versus after re-running Audyssey for the LCR channels please?

 

[Project SOG]

Could be....you already get the mic and download it?

Sorry for the late reply. Not sure how I missed this.

Yeah I got the mic and downloaded REW. Have been looking at some videos so hopefully this weekend I can get to it.

 

[Project SOG]

Can you post the trim level settings for the before versus after re-running Audyssey for the LCR channels please?

Hey so sorry for replying late.

I erased all the other graphs I had before in the app because I didn't think I would need it but looking back I should've kept it.

I attached what it looks like now and not sure if it would help or not but my center before re-running Audessey was at -8.5 and now it's at -5.5.

What can be assesed by that?

 

[PENG]

Hey so sorry for replying late.

I erased all the other graphs I had before in the app because I didn't think I would need it but looking back I should've kept it.

I attached what it looks like now and not sure if it would help or not but my center before re-running Audessey was at -8.5 and now it's at -5.5.

What can be assesed by that?

Perfect, good thing you at least remember the trim for the center channel. The results confirms the expected difference by 3 dB because the NC502MP's gain is about 3 dB lower than Denon's internal amps.

It also tells me your AVR can easily drive the NC502MP to its rated output.

 

[Project SOG]

Perfect, good thing you at least remember the trim for the center channel. The results confirms the expected difference by 3 dB because the NC502MP's gain is about 3 dB lower than Denon's internal amps.

It also tells me your AVR can easily drive the NC502MP to its rated output.

Very very cool!

Btw, someone suggested to use REW to level match the speakers to 75db. What's your take on that?

 

[PENG]

Very very cool!

Btw, someone suggested to use REW to level match the speakers to 75db. What's your take on that?

I have never found a need to do that because after running setup the unit always levelled matched to within 0.5 dB. You can check it just to see, it doesn't take long to do. Be sure to place your Umik-1 mic in the same position where you placed the Audyssey mic during setup.