NEWS: monolith amp with Hypex amplification!

[Descartes]

Here is the dilemma I am doing a 9.4.6 system and requires at least two 8 channels amplifiers plus 4 subs, a blu-ray player, streaming device, and a projector!

So I need to find out how much current each piece of equipment is drawing from the wall

 

[dumpingg]

depending on the volume you listen and speaker sensitivity every situation may be different. You can spend a few dollars and try and measure the load your devices are pulling.

watt meter

 

[Descartes]

depending on the volume you listen and speaker sensitivity every situation may be different. You can spend a few dollars and try and measure the load your devices are pulling.

watt meter

I already have a watt meter but I don’t have have all the electronic equipment yet!

 

[Descartes]

Ya, I thought that one was going to be using the 122mp modules due to the 8x100w rating, not the 252mp's that it does use. That is just $350 more than the buckeye 8 channel 252mp offering. I would still personally lean towards buckeye, but I can definitely see the appeal to buying this for only $350 more for everything extra you get.

5 year warranty is worth something

 

[dumpingg]

Descartes,
I hooked up my watt meter to my M8125X M8250X. I guess I am really not stressing it at all in my setup. I am using the M8125X M8250X to power my 7 speakers of Center (magnepan MMG-C), Rear Left/Right Back surrounds (Mirage Omni 60) and 4 Ceiling speakers (mirage omnisat). 80hz to 100hz sub crossover settings on most of the speakers. 8th channel of amplification is empty.

The M8125X M8250X surges to 1.35Amps on powerup as it cycles up the Hypex boards. Then idles to .88Amps. With music and movies it barely rises above idle .88Amps in my setup. I tried changing the Yamaha surround mode to 9 channel stereo to force more content to all of the surround speakers. But again the watt meter barely moved again.

Obviously putting the M8125X M8250X on fronts or subwoofer duty would be better and a more stressful test, but that is not my setup and a bit too much work to make happen. Sorry I could not give you better data, but this was a quick and dirty test for you.

oops, edit 2.0 I missed typed the model number. I have the M8125X.

 

[Descartes]

Descartes,
I hooked up my watt meter to my M8250X. I guess I am really not stressing it at all in my setup. I am using the M8250X to power my 7 speakers of Center (magnepan MMG-C), Rear Left/Right Back surrounds (Mirage Omni 60) and 4 Ceiling speakers (mirage omnisat). 80hz to 100hz sub crossover settings on most of the speakers. 8th channel of amplification is empty.

The M8250X surges to 1.35Amps on powerup as it cycles up the Hypex boards. Then idles to .88Amps. With music and movies it barely rises above idle .88Amps in my setup. I tried changing the Yamaha surround mode to 9 channel stereo to force more content to all of the surround speakers. But again the watt meter barely moved again.

Obvisously putting the M8250X on fronts or subwoofer duty would be better and a more stressful test, but that is not my setup and a bit too much work to make happen. Sorry I could not give you better data, but this was a quick and dirty test for you.

Thank you this is a lot more helpful than the response I got from Monoprice!
Do you have it plugged using both cords or just one?

 

[dumpingg]

Thank you this is a lot more helpful than the response I got from Monoprice!
Do you have it plugged using both cords or just one?

ooops... I misstyped my model number. I went back and edited my post to M8125X

 

[Descartes]

ooops... I misstyped my model number. I went back and edited my post to M8125X

Great that’s the one I am looking at or Buckeye not decided yet

 

[jimk1963]

Descartes,
I hooked up my watt meter to my M8125X M8250X. I guess I am really not stressing it at all in my setup. I am using the M8125X M8250X to power my 7 speakers of Center (magnepan MMG-C), Rear Left/Right Back surrounds (Mirage Omni 60) and 4 Ceiling speakers (mirage omnisat). 80hz to 100hz sub crossover settings on most of the speakers. 8th channel of amplification is empty.

The M8125X M8250X surges to 1.35Amps on powerup as it cycles up the Hypex boards. Then idles to .88Amps. With music and movies it barely rises above idle .88Amps in my setup. I tried changing the Yamaha surround mode to 9 channel stereo to force more content to all of the surround speakers. But again the watt meter barely moved again.

Obviously putting the M8125X M8250X on fronts or subwoofer duty would be better and a more stressful test, but that is not my setup and a bit too much work to make happen. Sorry I could not give you better data, but this was a quick and dirty test for you.

oops, edit 2.0 I missed typed the model number. I have the M8125X.

Double checking - did you mean 0.88 Watts? (and 1.35 Watts?) If you're measuring from the wall, 0.88 Amps x 110VAC = nearly 100 Watts consumption without any audio input. Please confirm. At 100W idle, I would think the amp feels pretty warm all the time.

 

[jimk1963]

Double checking - did you mean 0.88 Watts? (and 1.35 Watts?) If you're measuring from the wall, 0.88 Amps x 110VAC = nearly 100 Watts consumption without any audio input. Please confirm. At 100W idle, I would think the amp feels pretty warm all the time.

I'd also add that 100W Idle is awful behavior for a modern day amp. It's been asked before by others, really wish Amir would add PAE, IDLE and STANDBY power consumption to his analyses. It seems to be one of the last "who cares" specs for the audio purists, but it directly relates to thermals and wasted energy usage. Some of us would find that data very helpful, and in theory it would eventually wake up these companies to design in better standby circuits at a minimum. It's not rocket science, just a little cost they don't want to add.

 

[dumpingg]

My Watt meter was set to measure amps. The .88amps is powered up but with no music playing.

 

[jimk1963]

My Watt meter was set to measure amps. The .88amps is powered up but with no music playing.

Thanks for confirming. There are 4 NC252MP modules in the 8125X, so I guess that means each module idles at 0.22A, or about 24W if I assume 110VAC. The NC252MP data sheet specifies 8.5W "Idle Losses" for the SMPS and 3.5W/channel (7W total) for the amps, 15.5W total. So there is a bit of additional power consumption beyond these it appears. Looked at the NC502MP, it specifies 17W SMPS + 4.8W/CH (9.6W total) = 26.6W. So the Monolith 8250X must run around 120W IDLE, maybe a bit more. The NCx500 data sheet is coy, only mentions amplifier idle losses (5.3W/CH). But I did find this in a PR:

And another new technique implemented in this new module series is a differential idle current. Meaning, the module will run in a much lower idle current when it can and will only switch to a higher idle current when performance is needed. This technique results in a lot less heat dissipation. Without going into detail, we can already confirm that the idle losses are 20% lower compared to the NC500 OEM."

The NC500 is spec'd at 8.5W+6.5W=15W idle losses, so the NCx500 should come in around 12-13W idle power I suppose.

 

[dumpingg]

Thanks for confirming. There are 4 NC252MP modules in the 8125X, so I guess that means each module idles at 0.22A, or about 24W if I assume 110VAC. The NC252MP data sheet specifies 8.5W "Idle Losses" for the SMPS and 3.5W/channel (7W total) for the amps, 15.5W total. So there is a bit of additional power consumption beyond these it appears. Looked at the NC502MP, it specifies 17W SMPS + 4.8W/CH (9.6W total) = 26.6W. So the Monolith 8250X must run around 120W IDLE, maybe a bit more. The NCx500 data sheet is coy, only mentions amplifier idle losses (5.3W/CH). But I did find this in a PR:

And another new technique implemented in this new module series is a differential idle current. Meaning, the module will run in a much lower idle current when it can and will only switch to a higher idle current when performance is needed. This technique results in a lot less heat dissipation. Without going into detail, we can already confirm that the idle losses are 20% lower compared to the NC500 OEM."

The NC500 is spec'd at 8.5W+6.5W=15W idle losses, so the NCx500 should come in around 12-13W idle power I suppose.

some additional data on my M8125X from my watt meter.
.58 Power Factor at idle (powered on, no music playing)
60 watts at idle
106 VA at idle
.88 amps at idle (same as listed in previous post)

After the M8125X has been on for a few minutes and warms up, those idle numbers drop a little. .85Amps and 58 watts and 103 VA.

 

[Descartes]

some additional data on my M8125X from my watt meter.
.58 Power Factor at idle (powered on, no music playing)
60 watts at idle
106 VA at idle
.88 amps at idle (same as listed in previous post)

After the M8125X has been on for a few minutes and warms up, those idle numbers drop a little. .85Amps and 58 watts and 103 VA.

And when playing an action movie

 

[jimk1963]

Anyone having issues with channel drop-out using the Monolith M8250X (or M8125X)? Running a Cinema 40 + 8250X. About 10-30 minutes into programming, one or more channels will stop entirely. Sometimes only the CC, sometimes 5 or 6 channels. The 8250X runs very hot, my first suspicion was a heat-related issue as both AVR/Amp are in a cabinet w/ fan ventilation. But even placing the 8250X in open air, I'm occasionally getting this drop-out. I purchased a second 8250X and it does exactly the same thing. Ran the AVR speaker test tones a couple of times when the system was in this bad state, with mixed results: in one occurrence, all channels outputted the noise fine, even though program audio was still dead on 5 channels; in a second instance, only one channel outputted the noise, all others were silent. This led me to conclude the AVR is the culprit. Returing the Cinema 40 today for a swap, will give it one more try. Frustrating.

 

[jimk1963]

Anyone having issues with channel drop-out using the Monolith M8250X (or M8125X)? Running a Cinema 40 + 8250X. About 10-30 minutes into programming, one or more channels will stop entirely. Sometimes only the CC, sometimes 5 or 6 channels. The 8250X runs very hot, my first suspicion was a heat-related issue as both AVR/Amp are in a cabinet w/ fan ventilation. But even placing the 8250X in open air, I'm occasionally getting this drop-out. I purchased a second 8250X and it does exactly the same thing. Ran the AVR speaker test tones a couple of times when the system was in this bad state, with mixed results: in one occurrence, all channels outputted the noise fine, even though program audio was still dead on 5 channels; in a second instance, only one channel outputted the noise, all others were silent. This led me to conclude the AVR is the culprit. Returing the Cinema 40 today for a swap, will give it one more try. Frustrating.

Replaced my Cinema 40, it exhibited a similar issue as the original. With this unit, the audio begins dropping out for only a second or two, does that for maybe 30 seconds, then audio drops out completely. Performed a factory reset after saving the config. Reloaded the config and audio hasn't dropped out since.

Thermals on this 8250X are nuts - using my T9 fan (AC Infinity), temps rise to about 120F on this amp, in a cabinet with a large open slot on top (17x4 inches). The T9 is running at med-high speed for any decent listening volumes.

 

[jimk1963]

some additional data on my M8125X from my watt meter.
.58 Power Factor at idle (powered on, no music playing)
60 watts at idle
106 VA at idle
.88 amps at idle (same as listed in previous post)

After the M8125X has been on for a few minutes and warms up, those idle numbers drop a little. .85Amps and 58 watts and 103 VA.

Returned the Monoliths, will search for a more efficient solution. Posted this on AVS:

Re: NC502MP Power Consumption, wondering how it will compare to the NCx series:

NC502MP Datasheet:
3.3 Main SMPS: Idle Losses = 17W (4 of these per 8-channel amp)
3.4 Ncore Amplifier Specifications: Idle Losses = 4.8W per Channel

So when powered on, no audio running (or very low volume), the 8-channel total power consumption is: 17W(4) + 8(4.8W/CH) = 106W

Using a watt meter on two different Monolith M8250X units:
.54 PF
97W at Idle
178VA at Idle
1.48A at Idle

This explains why this amp runs so hot, even when just idling. Basically a 100W light bulb.

In Standby (12V trigger low), draw is negligible, works as expected.

NC252MP Datasheet:
3.3 Main SMPS: Idle Losses = 8.5W (4 of these per 8-channel amp)
3.4 Ncore Amplifier Specifications: Idle Losses = 3.5W per Channel

Idle Power = 8.5(4) + 8(3.5W/CH) = 62W

Comparing to your results:
Some additional data on my M8125X from my watt meter.
.58 Power Factor at idle (powered on, no music playing)
60 watts at idle
106 VA at idle
.88 amps at idle (same as listed in previous post)

These numbers seem to agree pretty well. So how about the NCx500 OEM Datasheet?

NCx500 OEM Datasheet:
Main SMPS: N/A, module requires external power supply
2.4 NCx500 OEM Amplifier Specifications: Idle Losses = 5.3W/CH (typical) --> slightly worse than the NC502MP amplifier stages

So for the Buckeye 3-CH amp, with custom Micro-Audio SMPS, what can we expect overall?

i.e., : Main SMPS Idle Losses + 3(5.3W/CH) = 16W + SMPS Idle Losses = How Much Total Idle Losses?

Not unhappy with the 100W idle consumption of this M8250X 8-channel amp. Pretty much defeats the purpose of bothering with Class-D to improve thermals/efficiency when paired with my Cinema 40. As these sit in a cabinet, running two AC Infinity T9's all the time just adds to the noise/hassle. Looking for a more efficient solution, thinking that the Buckeye 3-CH NCx500 amp plus Cinema 40 for the 4 surrounds may be a better solution. Asked Dylan for some Idle power consumption estimates, awaiting an update.

 

[Descartes]

The power draw of an amplifier varies with the sensitivity and impedance of your speakers and how loud you like to listen. Under normal listening conditions you should have no issues. Also a 15 amp breaker is not going to trip the very instant that 15A goes through it. There is a time/current curve that has to be met before trip takes place.

If your intent is to place load resistors on all eight channels and run each up to full load using a signal generator (like Amir would), then all bets are off and there is a good chance that you'll trip your 15A breaker.

I'm using the 8250 amplifier (only five channels though) with relatively low sensitivity (87 dB) speakers and at concert levels I've has no issues.

My speakers are 4ohm and 85db sensitivity! I am looking at a 9.4.6 system.

 

[exm]

As also posted on AVS:

I am considering the Monoprice M8125x to power my Kef R8 Metas (rated at 25 - 150W@4ohms). Right now I have 6 powered by a Marantz MM8807, so I would get this amp to use 8 R8 Meta's. These are configured as height speakers, so I think the power of these is more than sufficient.
However, I can't find the measurements into 4-ohm with all channels driven (strange if you ask me). From the specs:

Measurements into 8‑ohm Loads
FTC Full Bandwidth (20Hz ~ 20kHz) Output Power	100W (All Channels Driven)

Measurements into 4‑ohm Loads
FTC Full Bandwidth (20Hz ~ 20kHz) Output Power	175W (4 Channels Driven)

So what are the measurements into 4-ohms with all channels driven?

 

[Jdunk54nl]

As also posted on AVS:

I am considering the Monoprice M8125x to power my Kef R8 Metas (rated at 25 - 150W@4ohms). Right now I have 6 powered by a Marantz MM8807, so I would get this amp to use 8 R8 Meta's. These are configured as height speakers, so I think the power of these is more than sufficient.
However, I can't find the measurements into 4-ohm with all channels driven (strange if you ask me). From the specs:

Measurements into 8‑ohm Loads
FTC Full Bandwidth (20Hz ~ 20kHz) Output Power	100W (All Channels Driven)

Measurements into 4‑ohm Loads
FTC Full Bandwidth (20Hz ~ 20kHz) Output Power	175W (4 Channels Driven)

So what are the measurements into 4-ohms with all channels driven?

Each module has its own power supply in these amps. So power available is solely based on your wall power availability. If you have adequate wall power available, the. It could produce all the rated on all channels driven.