Monoprice Monolith THX 887 Balance Headphone Amp: New Champ?

[graz_lag]

Can I look forward to monoprice cheques as well as topping cheques?

The summer is almost gone, otherwise these cheques would have been of the cabriolet type ...

 

[Veri]

Now I hope Topping will release an excellent DX7 pro soon to match it.

Early in-house measurements are promising indeed.

 

[imagidominc]

As a proud owner of the Massdrop THX 789 (I'm listening to it right now, it's my favorite piece of gear I've ever owned), I'm so happy to see an opportunity for more people to enjoy this quality product! It's amazing that the guys at THX managed to top their previous record, as the Massdrop THX 789 was already an A+. Whether you get the Monolith or the Massdrop version, you are getting the best performance in the game, and as Amir said, "Buy one and be happy forever."

 

[sbsj]

The fact they went unavailable almost immediately doesn’t make me confident.

May be in due time it will always be available just like the Monolith Thx 788 portable and desktop versions.

 

[Labjr]

"buy once and you are done "

Yeah done until the next one comes out!

The next one should be a state of the art DAC (ES9038PRO or AK4499 chipset) with THX amp in one box under $500. Maybe add an option for a stepped attenuator.

 

[RichB]

This is their press release:

Amongst various offerings, Monoprice will highlight the following products at CEDIA this year:

• Monolith Home Theater Processor ($3,999.99)
o A 16-channel processor engineered to deliver a higher level of sound. This processor boasts the most modern technology in multichannel surround sound with Dolby Atmos and DTS: X decoding, advanced room correction with Dirac Live, the latest generation AKM4493 DACs, and plenty of inputs for all sources. Coming Winter 2019.

November 15'th is the current ETA reported on AVS and now posted on the Monoprice website.
Winter 2019 is only a 10 day window

- Rich

 

[amirm]

@amirm any chance of measuring the dimensions of this thing? Nothing on the Monoprice website.

Sure:

22 centimeters wide (8.66 inches)
20.7 centimeters deep (8.15 inches)
5 centimeters high (including feet) (1.97 inches)

The depth is excluding the connectors and volume control. Inclusive of those is about 23 centimeters deep (9.06 inches).

 

[amirm]

Someone had asked about gain settings:

Gain 1: -9.8 dB (nominal -10 dB)
Gain 2: 0 dB
Gain 3: 10.6 dB (nominal 10 dB)

 

[amirm]

As with THX AAA 789, Gain 3 clips with over 2.7 volts or so input on XLR connection.

 

[Schackmannen]

Someone had asked about gain settings:

Gain 1: -9.8 dB (nominal -10 dB)
Gain 2: 0 dB
Gain 3: 10.6 dB (nominal 10 dB)

Thanks, and the channel imbalance test was done in high gain right?

 

[amirm]

As requested, here is a level matched comparison of the Massdrop/Drop THX AAA 789 versus Monoprice Monolith THX 887 using medium gain:

First, the Drop 789:

Now Monolith 887:

Distortion is reduced by about 4 dB. Noise dominates though and likely is limited with my analyzer. Still difference is about 1.1 to 1.3 dB in SINAD.

 

[amirm]

By the way, they both ship with the identical external power supply (same type, brand, model, etc.).

 

[amirm]

Thanks, and the channel imbalance test was done in high gain right?

It has been a few days so don't quite remember. Regardless, gain stage doesn't matter because that graph is relative dB (0 = max volume).

 

[astr0b0y]

• Monolith Home Theater Processor ($3,999.99)
o A 16-channel processor engineered to deliver a higher level of sound. This processor boasts the most modern technology in multichannel surround sound with Dolby Atmos and DTS: X decoding, advanced room correction with Dirac Live, the latest generation AKM4493 DACs, and plenty of inputs for all sources. Coming Winter 2019.

This hopefully is available for your testing once close to release @amirm . If Monoprice's attention to detail that was applied to this headphone amp translates in a similar fashion to the home theatre processor you may have a top spot for other to aim for.

 

[Schackmannen]

It has been a few days so don't quite remember. Regardless, gain stage doesn't matter because that graph is relative dB (0 = max volume).

So realistically you only have 50 dB of reduction of the input voltage if you use low gain before the channel balance goes to shit? Feels like that's not good enough but I guess you can always pair it with a DAC that has easily changable volume control and it will be fine.

 

[Labjr]

I think the Monoprice amp looks nicer.

 

[amirm]

Someone asked about noise level differences. Instead of using the noise meter, I decided to run an FFT to show the spectrum which is more meaningful:

As we see, the Drop 789 and Monolith 887 are close but the latter is definitely lower noise.

Neither approaches the Audio Precision APx555 though which is good news as far as ability to continue to analyze these state of the art devices.

What is great about all three is absence of anything but noise. No extra spikes of any kind is visible despite the extremely low measurement noise floor (the top of the graph is -90 dB).

 

[amirm]

I am going to park the unit and move on to other reviews.....

 

[neutralguy]

If you haven't put it away yet, with its 4w max output, do you mind testing it with 8ohm speaker output?

 

[neutralguy]

This is one of the top questions on the monoprice site: https://www.monoprice.com/product?p_id=39359