Some questions regarding issues with my new Monolith 7 X 200 amp

[lovinthehd]

I'm still waiting for that time where connecting any pair of speakers to a different amp I notice a particular difference outside of higher spl capabilities (and I've been through many combinations)...altho you could perhaps use some dsp to mimic some additional ambience (or just a simple surround mode). Not even sure what "alive' means in this context outside of cues built into the recording....

 

[Ledformyhead]

Well in regards to the humming it looks like I've determined the issue by some detective work. It turns out it was the damn electric candles in the windows of the room the home theater is in. Should anyone have a similar issue with their amp and that amp is on the same circuit as these damn candles.....unplug them and you'll likely find the issue is gone.

In regards to the performance issue of the amp itself.....miraculously yesterday (before resolving the hum issue) "came alive" (using that on purpose for some on here) and sonically the amp is now much more dynamic in regards to bass response and the brightness of the mids and highs is now much more natural, clean and accurate. Maybe the damn thing understood I was considering sending it back and figured it better get its act straight! That's a joke for those who can't recognize them. I've never really been much of a believer in break in periods (especially on electronics) but my mind may have changed there. The amp has had about a 2 week period of "breaking in" and now the performance is where I expected it to be from the start. Odd and somewhat coincidental but a reality none the less.

The wife is pissed she lost her candles but that just gives me the excuse I needed to run a dedicated 20 amp line to the home theater.....something I wanted to do anyway. Then I should be able to plug in the damn candles again and have no issue.

The only small issue left is something not discussed before....the trigger switch I'm connecting the amp to on my AVR is not turning on the amp. As a matter of fact when the trigger cable is connected the amp won't power up at all, even by pressing the power switch on the front of the amp. The Elite 701 has many options to choose from to lable the trigger use for....none of which are an external amp of course. With that said I chose "AUX" and I think the issue may be that I don't have the amp grounded to anything currently. Am going to try and hook up a ground to the phono ground on my AVR tomorrow or the next day to see if that resolves that issue. Anyone have any issues there to share?

That aside, if all remains the same.....and I expect nothing less now.....I'm keeping it and I'm going to enjoy the hell out of it.

 

[Kleinst]

Congrats on figuring it out. I have had no issues with my trigger cable from my Denon (before that Sony). Not sure what to tell you on that one.

 

[lovinthehd]

The only small issue left is something not discussed before....the trigger switch I'm connecting the amp to on my AVR is not turning on the amp. As a matter of fact when the trigger cable is connected the amp won't power up at all, even by pressing the power switch on the front of the amp. The Elite 701 has many options to choose from to lable the trigger use for....none of which are an external amp of course. With that said I chose "AUX" and I think the issue may be that I don't have the amp grounded to anything currently. Am going to try and hook up a ground to the phono ground on my AVR tomorrow or the next day to see if that resolves that issue. Anyone have any issues there to share?

Looking at your advanced manual its got several pages of setup for the triggers, yikes. It's interesting that your A/B trigger outputs have different mA ratings (100 for A, 25 for B)....but it does seem you could set it to trigger your amp on use of one or a variety of inputs or hdmi ports....but it sucks as it looks like the default value is off (had to look at my avr and my trigger default value is on....). Link to basic/advanced manual if you need https://intl.pioneer-audiovisual.com/manuals/docs/SN29402400_612.pdf

 

[PENG]

Hum is not normal and if no other devices hum on the same circuit I would contact Monoprice and tell them why the unit is defective and ask for a return shipping label.

I think they would accept that argument if it is a grounding related issue, but if it was like what I have experienced with mine, that is harmonics related then they would most likely claim innocent. The thing about the harmonic related issue is that it may in fact not affect other audio devices plugged into the same circuit.

In my case it only affected the Halo amp, I could plug my Bryston, Marantz, or any other amp into the same circuit (even the exactly outlet) and they would be fine. It also only set up the resonance (quite sure of that) when that particular humidifier was on a specific speed, low speed iirc. Harmonic resonance are like that in nature, everything has to be right for it to happen, I have experienced such things at work a few times, one time we had to spent a lot of money to hire a consultant to design and install a detuning harmonic filter (mostly the 5th harmonic in that case) system to a severe vibration of a 6000 h.p. dc drive system, that harmonic filter had to be installed right at the source, the 13,800 V (the low voltage side) side of the big power supply transformer (30 MVA) for the whole plant. I am not sure if this is the case for the OP, but it is easy to eliminate the possibility if he did what I suggested.

Edit, just realized the OP ledformyhead had found the culprit, the candles. So I would assume those candles are dimmable. If so, then it is "harmonic resonance/or something similar for sure", and to everyone, it is always going to be something variable, like dimming, speed etc., that would get you in such trouble that may only affect certain devices in the circuit. For amps, it would be more likely with the larger amps that have a lot of big caps in the power supply.

 

[Ledformyhead]

I think they would accept that argument if it is a grounding related issue, but if it was like what I have experienced with mine, that is harmonics related then they would most likely claim innocent. The thing about the harmonic related issue is that it may in fact not affect other audio devices plugged into the same circuit.

In my case it only affected the Halo amp, I could plug my Bryston, Marantz, or any other amp into the same circuit (even the exactly outlet) and they would be fine. It also only set up the resonance (quite sure of that) when that particular humidifier was on a specific speed, low speed iirc. Harmonic resonance are like that in nature, everything has to be right for it to happen, I have experienced such things at work a few times, one time we had to spent a lot of money to hire a consultant to design and install a detuning harmonic filter (mostly the 5th harmonic in that case) system to a severe vibration of a 6000 h.p. dc drive system, that harmonic filter had to be installed right at the source, the 13,800 V (the low voltage side) side of the big power supply transformer (30 MVA) for the whole plant. I am not sure if this is the case for the OP, but it is easy to eliminate the possibility if he did what I suggested.

Edit, just realized the OP ledformyhead had found the culprit, the candles. So I would assume those candles are dimmable. If so, then it is "harmonic resonance/or something similar for sure", and to everyone, it is always going to be something variable, like dimming, speed etc., that would get you in such trouble that may only affect certain devices in the circuit. For amps, it would be more likely with the larger amps that have a lot of big caps in the power supply.

The candles are not dimmable but they have a sensor to turn them on when the light outside dims, they also flicker. Not sure any of that is why I have the issue.....I just know when I unplugged them the hum went completely away. So the why in the end is not so important....just happy the hum is now gone.

Also a little suprised that the Emotiva CMX2 AC filter and DC offset conditioner didn't prevent this....but it may go to what you were saying.

Thanks for the feedback!

 

[PENG]

The candles are not dimmable but they have a sensor to turn them on when the light outside dims, they also flicker. Not sure any of that is why I have the issue.....I just know when I unplugged them the hum went completely away. So the why in the end is not so important....just happy the hum is now gone.

Also a little suprised that the Emotiva CMX2 AC filter and DC offset conditioner didn't prevent this....but it may go to what you were saying.

Thanks for the feedback!

"flicker", dimmer, variable speed sort of things would do it. DC offset killers just kill/lower offset, won't too anything to detune the harmonic resonance.

 

[Ledformyhead]

Looking at your advanced manual its got several pages of setup for the triggers, yikes. It's interesting that your A/B trigger outputs have different mA ratings (100 for A, 25 for B)....but it does seem you could set it to trigger your amp on use of one or a variety of inputs or hdmi ports....but it sucks as it looks like the default value is off (had to look at my avr and my trigger default value is on....). Link to basic/advanced manual if you need https://intl.pioneer-audiovisual.com/manuals/docs/SN29402400_612.pdf

Well after contacting both Monoprice (and insisting on someone well versed in the Monolith line.....turns out he really wasn't) and Pioneer in regards to the trigger issue, neither could solve the issue. The Pioneer rep who seemed pretty knowlegable on my AVR was stumped and thought in the end it was either a bad trigger cable or possible defective trigger input on the amp or possibly a defective output on the Pioneer. I switched from Trigger A to Trigger B with no fix to the issue.

So in the end on my own I tried a resolution I read somewhere on a Pioneer forum "I think" and instead of just enabling "AUX" in the now connected B trigger section I enabled the whole damn list of choices in the B Trigger which means in the end you set them all to "MAIN". Thought it didn't make sense to have to do all that but I'll be damned if it didn't fix the issue! Now all is working well trigger wise.

In talking with the Pioneer rep he asked me where I purchased the AVR 701 and I told him Accessories4less. He immediately said that my unit must be a refurbished unit......to which I stated ummmm, no it better not be because it was sold to me as NEW. Led me to contact A4Less and verify it WAS NEW and they did....as the rep there stated "Brand New" and said the Pioneer reps are sometimes incorrect in what they state. "Of course" this got me to thinking how can I verify it is NOT refurbished other than an assurance from A4Less? I realize I could call back Pioneer and give them a serial number and they likely could tell me but does anyone know for sure what to look for......and fyi, already checked the shipping box for any notations about refurbed and nothing there.

 

[mazersteven]

I highly doubt Accessories4less would lie and tarnish their reputation.

 

[Ledformyhead]

I highly doubt Accessories4less would lie and tarnish their reputation.

I don't know if that is sarcasm or not......I've seen folks that are very happy with their purchases from them and others irrate. Most issues seemed to be based around returns.....which is not applicable to me.

I'm happy with my purchase......only thing that would change that is if it turns out to be a refurb.

 

[mazersteven]

Not sarcasm. I'm sure there are unhappy people but the Happy People far outweigh the unhappy ones

 

[lovinthehd]

I don't know if that is sarcasm or not......I've seen folks that are very happy with their purchases from them and others irrate. Most issues seemed to be based around returns.....which is not applicable to me.

I'm happy with my purchase......only thing that would change that is if it turns out to be a refurb.

A great part of what they sell are refurbs. It is clearly stated per item. Whether it was refurb or not should have nothing to do with functionality like the Pioneer "rep" seemed to say.....

 

[Ledformyhead]

A great part of what they sell are refurbs. It is clearly stated per item. Whether it was refurb or not should have nothing to do with functionality like the Pioneer "rep" seemed to say.....

The rep was not suggesting nor am I that the question of the refurb vs new was causing my issue. He simply mentioned it in passing after I told him where I bought it.

When I purchased the item it was clearly labeled as NEW and I even pressed a rep at A4Less on the phone as to if it was a refurb / B stock item or open box, etc.....he assured me it was new, unopened. And when it arrived everything looked to confirm that. They supposedly purchased 100 new 701's on a special buy....at that point the 701 was already being replaced by the 704.

I'm sure it was sold to me correctly......that Pioneer rep just got in my head with the suggestion that all Pioneer products sold there were refurbs "as far as he knew".

 

[Ledformyhead]

Something disturbing happened this evening while simply toggling through some home menu audio settings on the SC-LX701. Wasn't cranking any volume at all and reached over to my stand next to my seating area and turned on a simple lamp (now keep in mind this "may" simply be a coincidence) and when I turned on the lamp a BIG POP sounded and my 701 AND the Monolith amp shut down immediately. Thought I may have popped a breaker but realized immediately that wasn't the case because everything else on the circuit was still functioning....just the amp and AVR went dead. Freaked me out. Neither would power back up until I disconnected the trigger cable from the amp and then it powered back up but the 701 remained dead in the water. Had to get behind the Entertainment Center and unplug the AVR and and then plug it back in and it came back on. Nothing seems to have been damaged upon checking things but it sure scared me and pissed me off! Near as I can tell the POP likely came from the AVR because it was the only one of the two (the amp being the other) that needed to be unplugged and then plugged back in before coming back to life.

Earlier in the day I realized that the trigger activation needed only the "TV" set to "MAIN" in the trigger set up for the trigger to function so I turned off all the other component selections (fyi, when I first hooked up the 701 months ago to my Sony Master series OLED it has always powered on when I turn on the TV, so this is likely why I only needed the "TV" component option set to on or "MAIN" for the AVR to trigger the Monolith amp on)......again this may be a coincidence that the POP and shutdown came somewhat soon after but for now to be safe I have the trigger cable unplugged not knowing if that was the issue in part or not.

Any idea as to what may have caused this scare????? I realize I may be asking a bit much here but had to ask.

 

[mazersteven]

I think you need to Step Away from the Electronics and get yourself one of these where you shouldn't be able to Hurt yourself or the gear

 

[Ledformyhead]

I think you need to Step Away from the Electronics and get yourself one of these where you shouldn't be able to Hurt yourself or the gear

View attachment 43168

Ha! I think I'll stick with what I have and try and figure things out. That's the first "POP!" I've ever had from any of my electronics over the many years. Maybe those "demon harmonic resonances" in that circuit just decided to mess with me. Seriously though......really would like to figure it out.....I realize I may not be able to though.

Was planning on getting an electrician in here to run a 20 amp line for the HT components....specifically the amp. If and when he gets here maybe he can answer my questions.

 

[Ledformyhead]

Ha! I think I'll stick with what I have and try and figure things out. That's the first "POP!" I've ever had from any of my electronics over the many years. Maybe those "demon harmonic resonances" in that circuit just decided to mess with me. Seriously though......really would like to figure it out.....I realize I may not be able to though.

Was planning on getting an electrician in here to run a 20 amp line for the HT components....specifically the amp. If and when he gets here maybe he can answer my questions.

I think you need to Step Away from the Electronics and get yourself one of these where you shouldn't be able to Hurt yourself or the gear

View attachment 43168

Well as I researched it back with the wife......"I think" I may know what happened. Bought her a new electronic foot massager for Christmas. She was running that while all this happened. I figure with that now on the same circuit and somehow turning on the lamp sent a surge of some sort through the sysytem, not enough to pop the breaker but enough to trip the protection circuits on the AVR and the Amp.

Having an electrician come in for a quote to run a new dedicated 20 amp line and will ask him if he thinks this could have been the issue.....basically too much stuff running on this circuit and creating voltage issues. We shall see. Just VERY thankful that it didn't damage the components.

 

[KEW]

Late to the party!
@PENG , can you think of any reason that removing the candles and eliminating the hum might have done something to also audibly change the performance/sound of the amplification?
I suppose that the hum might have just been "stepping on" your "new amp joy" such that you were not in a state of mind to hear positive attributes (I say this because I find my perceptions can readily be changed by small factors such as anticipation, excitement, fatigue, etc - that is why I am a firm believer in a direct and quick A-B comparison).

 

[PENG]

Late to the party!
@PENG , can you think of any reason that removing the candles and eliminating the hum might have done something to also audibly change the performance/sound of the amplification?
I suppose that the hum might have just been "stepping on" your "new amp joy" such that you were not in a state of mind to hear positive attributes (I say this because I find my perceptions can readily be changed by small factors such as anticipation, excitement, fatigue, etc - that is why I am a firm believer in a direct and quick A-B comparison).

First of all, I know nothing about flickering candles and have never owned one. I suspect it would, or say, might cause harmonic issues with some amplifier's power supplies especially the big class AB power amps because:

- Logically speaking (by logical deduction only because I really don't know how they work for sure), the flickering effect is likely done using the same principle as how dimmers are done, because flicker=rapid on/off, except the on/off has to be quick to create the flickering effect.

- If my logical deduction is right, or sort of right, then the chance it would cause trouble may be worse than dimmers, again, depending on exactly how it work (design/circuitry) and the demand current.

- Large class AB power amps typically have more blocking/storage capacitance.

So under the "right", or "wrong" if you prefer to call it, it is conceivable that some sort of harmonic resonance that could be triggered by the harmonics in the power supply to the amp's transformer and the capacitive current drawn by the rectifier on the secondary side of the transformer.

If and when the cause of the noise (hum, rattling kind of noise) is due to harmonic resonance, you can hear it from several feet away so you can safely say it will affect sound quality, without getting into any detailed analysis.