Monolith 8250x 8 Channel Amp

[PENG]

Should we be concerned on these if driving from an AVR with:
Input Sensitivity for Full Rated Power 2.07 volts

And a relatively low gain compared to the Monolith 7x?

I'll keep my big heavy ugly A/B

You shouldn't be concerned unless you happen to have some previous Yamaha AVRs that may shutdown at pre out voltage below 2 V. Most AVRs measured at Audioholics and ASR managed to output more than 2 Volts, some could do it at lower distortions than others. 25.7 dB gain is not bad at all, well suited for AVRs such as Denon, Marantz, Yamaha (the new models), Anthem, Onkyo, Arcam's etc.

 

[PENG]

I can see that some of the posters here seem interested on the SINAD/THD+N specs that in most cases don't correlate well with perceived sound quality. Still if you are interested, below is linked to the results of over 500 amplifiers including power amp, integrated amp, and receivers.

Not that many integrated amps did poorly, even much worse than the low cost Yamaha WXA50.

5 W into 4 ohms were chosen as the measurement point for a couple of good reasons.

Amplifier SINAD list ASR + 3rd parties - Google Sheets

 

[Samwise]

The good thing about Monolith is that they let you see their bench test results. SINAD looks very decent, if measured on ASR, it would likely do about 93 dB, similar to ATI's. It will be tough to find too many class AB amps that could do better in distortions and noise at the below $3,000 price point. If I need a 8X200 W amp, the 8250 would have been my top choice based on the specs, test results and the 5 year warranty.

Doesn't the ATI have a 98 db SINAD? How would you say this compares to Monoprice's own Monolith 7x? I know it is class AB, but it has better THD and SNR with similar wattage and one less channel. Trying to decide which would between these two for my home theater. Thanks!

 

[everettT]

Doesn't the ATI have a 98 db SINAD? How would you say this compares to Monoprice's own Monolith 7x? I know it is class AB, but it has better THD and SNR with similar wattage and one less channel. Trying to decide which would between these two for my home theater. Thanks!

99, and it's their class D version we're discussing. It uses a transformer instead of a switch mode power supply, which brings down the SINAD a couple of points. You in almost every scenario wouldn't know the difference between the two.

 

[Samwise]

99, and it's their class D version we're discussing. It uses a transformer instead of a switch mode power supply, which brings down the SINAD a couple of points. You in almost every scenario wouldn't know the difference between the two.

I was wondering how the monolith 8250x would compare to the monolith 7x. At $3000 I wasn't even considering the 8250x, but now that it is on sale I'm wondering if it would be worth the extra $300. Thanks

 

[everettT]

I was wondering how the monolith 8250x would compare to the monolith 7x. At $3000 I wasn't even considering the 8250x, but now that it is on sale I'm wondering if it would be worth the extra $300. Thanks

I'd take the hypex version personally since you get the extra channel for for the OEM cost of the module with the discount.

 

[everettT]

That's the only drawback to the RENEWED interest in THD+N/SINAD after Stereophile, Home Theater Magazine and others stopped doing the measurements.

We keep on saying that these numbers are INAUDIBLE, but a lot of guys either don't believe it or just ignore it or something.

I've seen many guys based their buying decisions on the highest SINAD numbers/lowest THD+N numbers.

I have said this many times - back when EVERYONE was doing THD+N measurements (before ASR started doing SINAD), I don't recall THIS many people focus so much on SINAD/THD+N numbers.

I think if Amir had just used "THD+N" like everyone else, instead of using the INVERSE of THD+N (SINAD), we might not have this problem.

I think a lot of guys think "SINAD" is the brand new gold standard determining factor for sound quality.

A lot people expect amps to perform like DACs, that's where I think a lot of comes from.

 

[AcuDefTechGuy]

A lot people expect amps to perform like DACs, that's where I think a lot of comes from.

That's another topic right there - some guys think they can hear the difference in DAC with SINAD of 100dB (0.001%) vs 110dB (0.0003%) vs 120dB (0.0001%) vs 130dB (0.00003%), etc.

 

[Nondemo01]

I was wondering how the monolith 8250x would compare to the monolith 7x. At $3000 I wasn't even considering the 8250x, but now that it is on sale I'm wondering if it would be worth the extra $300. Thanks

I bought the Monolith 8250x this week. Should have it by next week. It was a toss up for me between their 7x and this one but this sale price can't be beat. Just gotta decide if you like A/B or Class D. I wanted a one box solution for my 5.2.2 and didn't want the 90+lbs or inefficiency of the toroidal.

 

[Trell]

That's another topic right there - some guys think they can hear the difference in DAC with SINAD of 100dB vs 110dB vs 120dB vs 130dB, etc.

Then there is your claim of 75dB at any distance with me asking: What if the N is dominant in the THD+N.

 

[Samwise]

I bought the Monolith 8250x this week. Should have it by next week. It was a toss up for me between their 7x and this one but this sale price can't be beat. Just gotta decide if you like A/B or Class D. I wanted a one box solution for my 5.2.2 and didn't want the 90+lbs or inefficiency of the toroidal.

Besides the weight and efficiency is there any sonic benefit of the 8250x? At $3000 I can't see why I would get the 8250x, but at this price it looks tempting.

 

[Nondemo01]

Besides the weight and efficiency is there any sonic benefit of the 8250x? At $3000 I can't see why I would get the 8250x, but at this price it looks tempting.

I based my purchase off this review of the Buckeye amps which have the same power supply: https://audiosciencereview.com/forum/index.php?threads/buckeye-nc502mp-review-6-channel-amplifer.27607/

There is a good discussion also regarding the Monoprice branded/ATI implementation of these modules here:

NEWS: monolith amp with Hypex amplification!

It was semi-officially announced during the AV summit by Hobie Sechrest that monoprice's monolith sub-brand will be releasing a new multi channel amplifier with hypex amplification. Take a look.

audiosciencereview.com

 

[Verdinut]

I can see that some of the posters here seem interested on the SINAD/THD+N specs that in most cases don't correlate well with perceived sound quality. Still if you are interested, below is linked to the results of over 500 amplifiers including power amp, integrated amp, and receivers.

Not that many integrated amps did poorly, even much worse than the low cost Yamaha WXA50.

5 W into 4 ohms were chosen as the measurement point for a couple of good reasons.

Amplifier SINAD list ASR + 3rd parties - Google Sheets

This Monolith amp might have a very good SINAD/THD+N figure at 5 W into 4 ohms, but Monoprice publishes a SINAD at 0.5% at rated power between frequencies of 5 kHz to 20 kHz. That's only -46 dB. Is that really acceptable?

 

[Danzilla31]

I can see that some of the posters here seem interested on the SINAD/THD+N specs that in most cases don't correlate well with perceived sound quality. Still if you are interested, below is linked to the results of over 500 amplifiers including power amp, integrated amp, and receivers.

Not that many integrated amps did poorly, even much worse than the low cost Yamaha WXA50.

5 W into 4 ohms were chosen as the measurement point for a couple of good reasons.

Amplifier SINAD list ASR + 3rd parties - Google Sheets

Thank you for bringing this up. Past a certain price point when amplifiers are within they're limits they're will be no difference if performed in a proper blind test. Same as with recievers and pre pros.

None of this is audible.

Now if you have the income and just want to buy the best with specs and performance fine no worries. But it your all about sound quality on a budget it's helpful to know you don't have to do that to get excellent performance from amplifiers that measure less then perfect

 

[PENG]

This Monolith amp might have a very good SINAD/THD+N figure at 5 W into 4 ohms, but Monoprice publishes a SINAD at 0.5% at rated power between frequencies of 5 kHz to 20 kHz. That's only -46 dB. Is that really acceptable?

The test data show much lower than 0.5%. The specs did not say 0.5, it says less than..

 

[Danzilla31]

This Monolith amp might have a very good SINAD/THD+N figure at 5 W into 4 ohms, but Monoprice publishes a SINAD at 0.5% at rated power between frequencies of 5 kHz to 20 kHz. That's only -46 dB. Is that really acceptable?

Rated Power you mean full power all channels driven right? How many of us ever really push our amplifiers to the max in a home theater environment I'm wondering. I've learned over the years I'm using a lot less power than I thought I was usually

 

[Trell]

Sounds like a question for engineers like @PENG.

But again, are you suggesting that if the THD+N is 0.001% and the AVERAGE VOLUME is 75dB in your room from 9 ft distance, that somehow the NOISE can still possibly be AUDIBLE?

My answer is, if the noise is still audible, then THD+N will absolutely NOT be 0.001%.

@PENG can make a better estimate, but if NOISE is audible at 75dB average volume from 9 ft distance, THD+N will be more like 10% or 20%.

You wrote 1% THD+N, at 75 dB, at any distance; not me. I asked: what if noise is the dominant part?

IEM qualifies as “any distance” so a noise dominated SINAD of 1% could very well be audible. If not IEM, how about near field listening?

 

[Verdinut]

Rated Power you mean full power all channels driven right? How many of us ever really push our amplifiers to the max in a home theater environment I'm wondering. I've learned over the years I'm using a lot less power than I thought I was usually

No, the specs figures don't clearly say they are with all channels driven at rated power. You know marketing people don't always specify full details on products if the info is not compulsory. Some companies only specify THD figures at 1 kHz instead of quoting them for the full 20 Hz - 20 kHz range.

I know that on a regular basis I'm not using much power with my HT system. Only once when playing Hans Zimmer's Live in Prague Blu-ray disc, my left and right front channel subs, used as woofers in each cabinet, were getting peaks of over 30 watts each. If you wish to have your sub(s) moving, that BD disc is a good 2017 concert of Zimmer's film music compositions. The Audio tracks are only either LPCM Stereo or Dolby Atmos.

 

[Trell]

I'll make it more simple by taking back what I said about 1% THD+N since I don't see any THD+N measured on ASR that is 1%. Let's say 0.01% THD+N or whatever is the HIGHEST THD+N Amir measured.

You'll make it more simple by not admitting you made an erroneous statement by creating a strawman about ASR measurements? Whatever floats your boat.

 

[Trell]

I made an erroneous statement about ASR measurements? What did I say?

What I recall was saying that all these SINAD measurements are INAUDIBLE unless your golden ears can hear them.

You can read your own posts, for a starter.