Hypex Nilai500DIY Amplifier Review

[LucreciaBorgia]

There is no XLR out of the Denon : It is a pure single ended AV receiver
I personally think AV receiver should be used only for home theatre system, not for a high quality stereo set up

 

[Buckeye Amps]

There is no XLR out of the Denon : It is a pure single ended AV receiver

Yes, which is why OP is using RCA to XLR Cables (which work perfectly fine for the preouts on the Denon)

 

[Thecaptain3737]

Do you have a regular XLR cable you can try connecting to the Nilai side to see if the same behavior happens (with the other XLR end not connected to anything obviously)?

Also, just to double check, when you try the RCA to XLR cables with the RCA end left unplugged it isn't touching or grounding to anything accidentally right?

Unfortunately I do not have an fully balanced cable to try. I'll work on getting a pair.

Just tried unplugging the RCA end again to be sure it wasn't accidentally touching anything. Still getting popping, but also seems to be accompanied by a buzz (pop buzz...pop buzz...). At least this was in the case in the 1 amp. Tried the same with the other amp and didn't hear the buzz but still getting pop, pop...pop, pop. Also neither didn't seem to stop after 30 seconds this time when left unplugged at the RCA end.

Appreciate the quick responses!

 

[Buckeye Amps]

Unfortunately I do not have an fully balanced cable to try. I'll work on getting a pair.

Just tried unplugging the RCA end again to be sure it wasn't accidentally touching anything. Still getting popping, but also seems to be accompanied by a buzz (pop buzz...pop buzz...). At least this was in the case in the 1 amp. Tried the same with the other amp and didn't hear the buzz but still getting pop, pop...pop, pop. Also neither didn't seem to stop after 30 seconds this time when left unplugged at the RCA end.

Appreciate the quick responses!

Were these DIY build or bought prebuilt from someone?

 

[Thecaptain3737]

Were these DIY build or bought prebuilt from someone?

Diy build.

 

[Buckeye Amps]

Diy build.

Have you double checked to make sure all proper grounding internally was done? (especially for the XLR connections)

 

[Sokel]

Unfortunately I do not have an fully balanced cable to try. I'll work on getting a pair.

Just tried unplugging the RCA end again to be sure it wasn't accidentally touching anything. Still getting popping, but also seems to be accompanied by a buzz (pop buzz...pop buzz...). At least this was in the case in the 1 amp. Tried the same with the other amp and didn't hear the buzz but still getting pop, pop...pop, pop. Also neither didn't seem to stop after 30 seconds this time when left unplugged at the RCA end.

Appreciate the quick responses!

Any close proximity to routers, cheap LEDs (or their PSU) , screens, etc?
Did you try plugging them to another "silent" location?

Does mains grounding doing ok?

 

[Thecaptain3737]

Have you double checked to make sure all proper grounding internally was done? (especially for the XLR connections)

Double checked and all the conn actions look good. Just looks like a ribbon cable for the xlr.

 

[Thecaptain3737]

Any close proximity to routers, cheap LEDs (or their PSU) , screens, etc?
Did you try plugging them to another "silent" location?

Does mains grounding doing ok?

No, in a stand rack on a shelf by themselves. If the xlr isn't plugged in at all and I turn the amps on it is silent at my speakers.

 

[Sokel]

Double checked and all the conn actions look good. Just looks like a ribbon cable for the xlr.

I would twist and not coil the cables at the left.

I would also redo the binding post soldering using a generous amount of good flux but that's irrelevant to the crackling.

 

[AkodoGilador]

 

[antcollinet]

Double checked and all the conn actions look good. Just looks like a ribbon cable for the xlr.

I think @Buckeye Amps was referring to the build of the cable, not the amp. At least that is how I read it.

 

[Thecaptain3737]

I think @Buckeye Amps was referring to the build of the cable, not the amp. At least that is how I read it.

Ah, I see. Yes, just double checked the cable and the connections look good there as well.

 

[antcollinet]

Ah, I see. Yes, just double checked the cable and the connections look good there as well.

Could you describe how you've wired it. There's more than one way to skin a cat when it comes to RCA to XLR connections.

 

[Thecaptain3737]

Could you describe how you've wired it. There's more than one way to skin a cat when it comes to RCA to XLR connections.

So I didn't make the cables. I bought these cables pre wired. I've tried 3 different cables as I dove down this rabbit hole. 1st was a wbc RCA to xlr which left pin 3 unattached. 2nd was a blue jeans cable which connected pins 1 and 3 on the xlr side to ground. Lastly I purchased a set of the buckeye cables which use star quad cable and connect pin 2 to center RCA and pins 1 and 3 to the RCA ground with all 3 pins on the xlr pins separately connected.

 

[stefanovesa]

is this one? In my RCA to XLR this worked fine.

 

[antcollinet]

So I didn't make the cables. I bought these cables pre wired. I've tried 3 different cables as I dove down this rabbit hole. 1st was a wbc RCA to xlr which left pin 3 unattached. 2nd was a blue jeans cable which connected pins 1 and 3 on the xlr side to ground. Lastly I purchased a set of the buckeye cables which use star quad cable and connect pin 2 to center RCA and pins 1 and 3 to the RCA ground with all 3 pins on the xlr pins separately connected.

The last one is the one to use. I've no idea why you are getting the popping. I suspect a fault somewhere.

 

[FERCSA]

So I didn't make the cables. I bought these cables pre wired. I've tried 3 different cables as I dove down this rabbit hole. 1st was a wbc RCA to xlr which left pin 3 unattached. 2nd was a blue jeans cable which connected pins 1 and 3 on the xlr side to ground. Lastly I purchased a set of the buckeye cables which use star quad cable and connect pin 2 to center RCA and pins 1 and 3 to the RCA ground with all 3 pins on the xlr pins separately connected.

I had the same popping with a commercial XLR-XLR cable I bought a few years ago and the wiring was wrong there.

These passive RCA-XLR cables can cause the same symptoms and honestly the best way is an active converter. I would advise to go through this and rewire it if necessary: PDF (check: 4b, 6)

 

[Thecaptain3737]

is this one? In my RCA to XLR this worked fine.

View attachment 510008

Yep. That's the one I currently have connected up. Same issue though.

 

[antcollinet]

These passive RCA-XLR cables can cause the same symptoms and honestly the best way is an active converter. I would advise to go through this and rewire it if necessary: PDF (check: 4b, 6)

That's the one I currently have connected up. Same issue though.

6 is for XLR output to RCA Input and is not the reverse which you need. Apart from anything else it references female XLR. It is not even suitable for most XLR outputs - only transformer coupled ones, since it connects negative output to ground at the RCA end. It will work for RCA to XLR, if you replace the female connector with male, but is not optimum.

For RCA to XLR, ideally you want pseudo balanced : 17, but with shield also connected to the RCA shield.


But @FERCSA that is an excellent document - thanks for linking it.