Monolith by Monoprice THX AAA Balanced Headphone Amplifier featuring THX AAA 887 Technology
Product # 39359
$399.99
Qty: 1
$399.99
Qty: 2-9
$399.99
Qty: 10-19
$399.99
Qty: 20-49
$399.99
Qty: 50+
$399.99
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Questions and Answers
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Browse 84 questions
Browse 84 questions
and 116 answers
Does the pass through output both the XLR and RCA inputs or just the RCA?
Chris W
on Nov 27, 2019
BEST ANSWER: The pass through RCA outputs only function with signals from the RCA inputs. Signals from the XLR inputs will not pass through to the RCA pass through output.
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- Bryce U on Nov 27, 2019
- Purchased on Nov 13, 2019
BEST ANSWER: The pass through RCA outputs only function with signals from the RCA inputs. Signals from the XLR inputs will not pass through to the RCA pass through output.
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- Bryce U on Nov 27, 2019
- Purchased on Nov 13, 2019
It outputs on everything at once (so you can listen to 3 different headphones at once if you desire)
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- Jonathan H on Nov 27, 2019
- Purchased on Nov 13, 2019
Confirmed, when balanced XLR inputs are used, no output to the RCA.
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- Mark S on Nov 27, 2019
- Purchased on Nov 20, 2019
There's just one pair of RCA pass through output.
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- New User U on Dec 5, 2019
- Purchased on Nov 13, 2019
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I heard this runs a bit hot, how long can this stay on in use before recommending to switch this off?
New User U
on Feb 11, 2020
BEST ANSWER: I use this amp with a Topping D90 on top as my office rig. It's on and running at least 8-10 hours per day. It doesn't seem to get very hot. I have no concerns about running it all day.
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- CHIP H on Feb 12, 2020
- Purchased on Jan 18, 2020
BEST ANSWER: I use this amp with a Topping D90 on top as my office rig. It's on and running at least 8-10 hours per day. It doesn't seem to get very hot. I have no concerns about running it all day.
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- CHIP H on Feb 12, 2020
- Purchased on Jan 18, 2020
It will stay on as long as it can detect a signal from your DAC. If it doesn't notice a signal, it will turn off automatically after a set amount of time
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- Argenis D Chavez H on Feb 11, 2020
- Purchased on Jan 28, 2020
That wasn't the question, it was whether this would have any detrimental effects to the AMP if left on IN USE for a long period of time.
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- New User U on Feb 11, 2020
Actually it runs very cool.I leave mine on and it’s barely above ambient room temp even after long listening sessions.
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- B E on Feb 11, 2020
- Purchased on Jan 14, 2020
∞ It is a class D amp so it runs _very_ cool. By default it powers itself off after no signal is detected.
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- Lance S on Feb 13, 2020
- Purchased on Dec 20, 2019
I run my planars off of this amp for long listening sessions and it never runs hot.
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- Tim R on Feb 11, 2020
- Purchased on Dec 28, 2019
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Does the pass through have THX?
A shopper
on Feb 20, 2020
BEST ANSWER: Simple answer; no. The pass-through is not passing through the THX amplification section.
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- Bryce U on Feb 20, 2020
- Purchased on Nov 13, 2019
BEST ANSWER: Simple answer; no. The pass-through is not passing through the THX amplification section.
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- Bryce U on Feb 20, 2020
- Purchased on Nov 13, 2019
I would say no. The pass through is only for the RCA inputs. The volume knob has no effect on the pass-through output. I believe it completely skips the THX/amplification circuitry.
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- Stephen on Feb 21, 2020
- Purchased on Nov 13, 2019
No. It wouldn't be a pass through if it was intended to do anything besides pass a signal, like a wire.
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- Andrew L on Feb 20, 2020
- Purchased on Nov 13, 2019
No. It just passes whatever analog signal your DAC is outputting. Zero processing.
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- Mark K on Feb 21, 2020
- Purchased on Nov 13, 2019
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What is the difference between this and Product # 24459 (https://www.monoprice.com/product?p_id=24459)?
Gleb K
on Apr 7, 2020
BEST ANSWER: The biggest difference would be that #24459 also includes a DAC (Digital to Analog converter.) The other difference is #39359 uses a slightly updated THX module, the 887 ans as opposed to the 788 pm the #24459. Lastly, the #39359 has buttons for gain as well as an output specifically designed for use with IEMS.
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- Scott B on Apr 7, 2020
- Purchased on Nov 19, 2019
BEST ANSWER: The biggest difference would be that #24459 also includes a DAC (Digital to Analog converter.) The other difference is #39359 uses a slightly updated THX module, the 887 ans as opposed to the 788 pm the #24459. Lastly, the #39359 has buttons for gain as well as an output specifically designed for use with IEMS.
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- Inaccurate
- Scott B on Apr 7, 2020
- Purchased on Nov 19, 2019
There are a lot of differences, but the primary difference is that one is simply an amplifier and nothing else, and the other is an amplifier, a DAC, and a digital signal processor.
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- Nelson D. C on Apr 9, 2020
- Purchased on Nov 18, 2019
The one you linked has a DAC built into it, as this one does not. As far as I know, you cannot bypass the DAC, so if you want to experiment with DACs get this one.
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- Jeff K on Apr 7, 2020
- Purchased on Nov 19, 2019
This one is just an amp. The other one is DAC and Amp in one
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- Matthew F on Apr 7, 2020
- Purchased on Nov 14, 2019
The 887 is pure amplifier the other one has a dac too
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- krikour m on Apr 7, 2020
- Purchased on Nov 14, 2019
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Should I turn the amp on/off with headphones plugged in or should I first unplug the headphones before turning the unit off?
New User U
on Jan 20, 2020
BEST ANSWER: I've cycled the power on this amp while listening with moderately efficient headphones (99 dB SPL/mW) and head no clicks, pops or other noise as the power goes on and off. Given that experience, there is likely no need to unplug ordinary headphones when powering the unit on or off. The story may be different with highly sensitive IEMs so YMMV.
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- Michael S on Jan 22, 2020
- Purchased on Nov 14, 2019
BEST ANSWER: I've cycled the power on this amp while listening with moderately efficient headphones (99 dB SPL/mW) and head no clicks, pops or other noise as the power goes on and off. Given that experience, there is likely no need to unplug ordinary headphones when powering the unit on or off. The story may be different with highly sensitive IEMs so YMMV.
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- Michael S on Jan 22, 2020
- Purchased on Nov 14, 2019
It's always good practice before turning on to turn volume down all the way then turn on amp wait for say 30 seconds then plug in headphones. Then carefully play music and slowly turn up volume. To shut down stop music then turn down volume unplug headphones then turn off amp.
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- Alexander D on Jan 20, 2020
- Purchased on Nov 24, 2019
For basically all amps, it's good practice to always (1) plug in the headphones AFTER turning the amp ON and (2) unplug the headphones BEFORE turning the amp OFF. Before either, however, be sure to turn the VOLUME knob all the way down.
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- James S on Jan 20, 2020
- Purchased on Nov 14, 2019
No difference. There is no sound (click) during on off
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- PAOLO B on Jan 21, 2020
- Purchased on Dec 3, 2019
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Can this be used as a power amp for headphones with a DAC that has volume control and balanced out?
A shopper
on Feb 24, 2020
BEST ANSWER: Yes. Using a Topping DX7 Pro with balanced out and volume control with Sennheiser HD500’s.
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- Robert W on Feb 24, 2020
- Purchased on Nov 20, 2019
BEST ANSWER: Yes. Using a Topping DX7 Pro with balanced out and volume control with Sennheiser HD500’s.
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- Robert W on Feb 24, 2020
- Purchased on Nov 20, 2019
Yes. If your DAC has digital volume control, you might find that you get better results setting your dac to a fixed output with no attenuation and then using the volume control on this amp. Generally, digital volume control will reduce your dynamic range. This amp rocks. I use it with an RME ADI-2 DAC fs set to 0dBu attenuation.
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- jtstep on Feb 24, 2020
- Purchased on Nov 17, 2019
You can certainly do so. I feed mine with the balanced output of a Schiit Bifrost 2 DAC,. and it works beautifully. There is no fixed output selection for this headphone amp, so while you can easily use it with a DAC having a digital volume control, you'll still be sending the signal through the amp's volume pot.
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- Michael S on Feb 24, 2020
- Purchased on Nov 14, 2019
It could, but you should probably use a DAC without a volume control. The potentiometer actually degrades the sound quality to some extent.
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- James S on Feb 24, 2020
- Purchased on Nov 14, 2019
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Is this enough to power the seinheiser HD800S headphones? Which has a 300ohms impedance.
New User U
on Jul 14, 2020
BEST ANSWER: I found this amp was not powerful enough for Focal dynamic headphones at 55-80 Ohms. Although this amp was my favourite for a long time, closest to perfect I had ever experienced... It took me a long time to realize a more powerful amp was what I needed to get a nice tonal balance in the low-end. That said, you may be completely happy with it driving HD800S.
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- Daniel van V on Jul 14, 2020
- Purchased on Dec 4, 2019
BEST ANSWER: I found this amp was not powerful enough for Focal dynamic headphones at 55-80 Ohms. Although this amp was my favourite for a long time, closest to perfect I had ever experienced... It took me a long time to realize a more powerful amp was what I needed to get a nice tonal balance in the low-end. That said, you may be completely happy with it driving HD800S.
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- Daniel van V on Jul 14, 2020
- Purchased on Dec 4, 2019
Yes, this amplifier has more than enough power for an HD800S, or pretty much almost any headphone, with very, very few exceptions.
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- Nelson D. C on Jul 16, 2020
- Purchased on Nov 18, 2019
Yes. More than enough. I have the HD800 and use it regularly with the Monolith 887 and Topping D90 in balanced mode.
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- James S on Jul 14, 2020
- Purchased on Nov 14, 2019
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Is this amp good enough to power the HD800s headphones?
New User U
on Jul 14, 2020
BEST ANSWER: This is, of course, a subjective question. But I'm using mine with a Hifiman HE1000v2, a ZMF Auteur, an Audeze LCD3, and a Focal Utopia at various times, along with a Chotd Qutest DAC, all connected with pure silver cables. The results are outstanding by my reckoning. This amp is great value for money, and in my view showcases high end headphones outstandingly, provided the other elements in your signal chain don't limit your results.
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- Robert S on Jul 14, 2020
- Purchased on Feb 10, 2020
BEST ANSWER: This is, of course, a subjective question. But I'm using mine with a Hifiman HE1000v2, a ZMF Auteur, an Audeze LCD3, and a Focal Utopia at various times, along with a Chotd Qutest DAC, all connected with pure silver cables. The results are outstanding by my reckoning. This amp is great value for money, and in my view showcases high end headphones outstandingly, provided the other elements in your signal chain don't limit your results.
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- Robert S on Jul 14, 2020
- Purchased on Feb 10, 2020
Rest assured that this amp will easily power the Sennheiser HD800s headphones.
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- MARK E on Jul 14, 2020
- Purchased on Jan 21, 2020
Yes I used it with an hd800. Plenty of power.
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- Marcos K on Jul 17, 2020
- Purchased on Jan 30, 2020
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Can this be used as a pre amp with active speakers?
A shopper
on Sep 10, 2019
BEST ANSWER: Yes, you can utilize the pass through output.
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- New User U Staff on Sep 10, 2019
BEST ANSWER: Yes, you can utilize the pass through output.
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- New User U Staff on Sep 10, 2019
Volume knob on the amp has no impact on the pass through output so you will have to control volume either at the source or after the amp.
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- Mark S on Nov 27, 2019
- Purchased on Nov 20, 2019
No. There is no line level output that utilizes the preamp. Using "pass through" does not utilize the preamp and is no different than leaving this unit out of the signal chain to your powered monitors.
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- New User U on May 30, 2020
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When the volume is all the way down on this amp, I still hear sound from the headphones on the balanced output. Is that normal?
Mason L
on Apr 14, 2020
BEST ANSWER: It should not happen. This is not normal. It might be due to other things in your setup like the DAC outputs that are used and whether they are increasing the gain of the output signal etc. There can be other factors as well.
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- Muhammad M on Apr 22, 2020
- Purchased on Dec 28, 2019
BEST ANSWER: It should not happen. This is not normal. It might be due to other things in your setup like the DAC outputs that are used and whether they are increasing the gain of the output signal etc. There can be other factors as well.
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- Muhammad M on Apr 22, 2020
- Purchased on Dec 28, 2019
This happens when the amp is on it's highest gain setting (3). A good rule of thumb is to use the lowest gain setting that still allows you to get your desired sound level. High gain also raises the amps noise floor.
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- MARK E on Apr 15, 2020
- Purchased on Jan 21, 2020
Not for me, I don't hear any sound. Even if the volume is up. I am using balanced cables as well.
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- David T on Apr 14, 2020
- Purchased on Feb 4, 2020
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Your description says XLR , 1/4" and 3.5mm INPUTS. I don't see those . I think you really mean OUTPUTS?
A shopper
on Jun 6, 2020
BEST ANSWER: This is correct. Theres one balanced pair (XLR) input, and one single-ended (RCA) input. The outputs are the XLR-4, 1/4" and 3.5 mm headphone jacks, and the single ended (RCA) passthrough output pair. The volume control has no effect on the passthrough output.
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- Stephen on Jun 6, 2020
- Purchased on Nov 13, 2019
BEST ANSWER: This is correct. Theres one balanced pair (XLR) input, and one single-ended (RCA) input. The outputs are the XLR-4, 1/4" and 3.5 mm headphone jacks, and the single ended (RCA) passthrough output pair. The volume control has no effect on the passthrough output.
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- Stephen on Jun 6, 2020
- Purchased on Nov 13, 2019
Correct. The 887 has 3.5mm, 1/4", and 4-pin XLR outputs. There are only XLR and RCA inputs.
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- Bryce U on Jun 6, 2020
- Purchased on Nov 13, 2019
You are correct. They are outputs for your phones.
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- Paul l on Jun 6, 2020
- Purchased on Nov 13, 2019
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My DAC is single ended only. If I run single ended in, does the balanced headphone output still work and if so, does it still provide more power than the single ended headphone output or would it be the same amount of power as the SE output?
A shopper
on Oct 20, 2020
BEST ANSWER: Yes. The Amp can output via the balanced 4-pin XLR output using either the RCA single-ended input or the XLR balanced input. Yes the power output from the XLR output will be more than the SE outputs of the Amp.
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- Bryce U on Oct 20, 2020
- Purchased on Nov 13, 2019
BEST ANSWER: Yes. The Amp can output via the balanced 4-pin XLR output using either the RCA single-ended input or the XLR balanced input. Yes the power output from the XLR output will be more than the SE outputs of the Amp.
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- Bryce U on Oct 20, 2020
- Purchased on Nov 13, 2019
Yes I have 2 DACs and use them together. It is very convenient to switch inputs with button on front. With the same headphones, volume is the same.
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- Igor D on Oct 20, 2020
- Purchased on Nov 13, 2019
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is this amp fully balanced input to output?
Eric F
on Nov 5, 2020
BEST ANSWER: I don't believe it perfectly balanced but it far exceeds anything in its price range performing 2-3X its price.
Check out the detailed audio science review and measurements for the Monoprice 887
Check out the detailed audio science review and measurements for the Monoprice 887
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- Naran P on Nov 5, 2020
- Purchased on Nov 19, 2019
BEST ANSWER: I don't believe it perfectly balanced but it far exceeds anything in its price range performing 2-3X its price.
Check out the detailed audio science review and measurements for the Monoprice 887
Check out the detailed audio science review and measurements for the Monoprice 887
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- Naran P on Nov 5, 2020
- Purchased on Nov 19, 2019
No, it is not fully balanced. It has balanced inputs and XLR output, but the internal circuitry is not balanced.
That being said, it is a fantastic sounding amplifier, especially for the money.
That being said, it is a fantastic sounding amplifier, especially for the money.
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- Nelson D. C on Nov 5, 2020
- Purchased on Nov 18, 2019
"Fully" is open to interpretation. There's a single THX stereo module that works as a bridge to split power to each channel. As far as I'm concerned, it's fully balanced.
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- James S on Nov 5, 2020
- Purchased on Nov 14, 2019
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What's the dimensions and weight?
A shopper
on Sep 10, 2019
BEST ANSWER: 8.66"W x 8.15"D x 1.97"H Approx 3.5lbs
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- New User U Staff on Sep 10, 2019
BEST ANSWER: 8.66"W x 8.15"D x 1.97"H Approx 3.5lbs
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- New User U Staff on Sep 10, 2019
I put the measurements at the end of the review thread on Audio Science Review.
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- Amir M on Sep 10, 2019
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Can this be used as a pre amp with active speakers?
F R
on Sep 10, 2019
BEST ANSWER: Yes, you can use the unbalanced pass through output to the active speaker.
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- New User U Staff on Sep 10, 2019
Pass Through means volume is not adjustable?
- Reply
- New User U on Nov 14, 2019
BEST ANSWER: Yes, you can use the unbalanced pass through output to the active speaker.
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- Inaccurate
- New User U Staff on Sep 10, 2019
Pass Through means volume is not adjustable?
- Reply
- New User U on Nov 14, 2019
No, it doesn't function as a proper preamp with volume control. The previous user answered incorrectly. You can only passthrough the RCA signal, but you would still need a proper preamp for active speakers.
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- Andrew G on Jul 13, 2020
- Purchased on Nov 13, 2019
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Are the full specification out yet since they are not on this page?
A shopper
on Sep 13, 2019
Thank you for your question.
There would be specs available once the item is available for sale.
There would be specs available once the item is available for sale.
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- Tyler C Staff on Sep 17, 2019
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Noticibly absent from the description is the inclusion of Dirac II which the desktop 789 dac amp includes. Is this because the full specs haven't yet been published or because this model won't include this functionality?
A C
on Sep 23, 2019
BEST ANSWER: This model will not have this functionality.
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- New User U Staff on Sep 23, 2019
BEST ANSWER: This model will not have this functionality.
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- New User U Staff on Sep 23, 2019
The 789 does not include dirac. It is amplifier only, Dirac is implemented in DAC
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- New User U on Jun 23, 2020
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Are there any products in the pipeline that will use a matching chassis to the 887? This is one of the sleekest and best looking chassis I’ve ever seen.
A shopper
on Dec 20, 2019
BEST ANSWER: We have another THX Amp + DAC that is in stock currently that uses the same chassis.
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- New User U Staff on Dec 20, 2019
BEST ANSWER: We have another THX Amp + DAC that is in stock currently that uses the same chassis.
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- New User U Staff on Dec 20, 2019
Don't know, there's enough room for DAC. If they can come close to or tie the measured performance of the ESS9038pro based Matrix XSabre Pro MQA DAC than I would buy that combo for my computer desk. It's amazing that this $400 hpa ties for 1st place in measured performance of the $3000 Benchmark HPA4!
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- Jon C on Dec 20, 2019
- Purchased on Dec 13, 2019
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balanced SNR in dB?
A shopper
on Feb 26, 2020
BEST ANSWER: I myself have no means of measuring that. I saw a review online that stated the SNR to measure at 123db. I believe Monoprice claims it to be even higher. Another reviewer on YouTube opined that the SNR is so low that the difference between balanced and unbalanced is not audible. I know that with no audio playing I can turn the volume to the maximum and not hear a hint of noise.
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- Robert S on Feb 26, 2020
- Purchased on Feb 10, 2020
BEST ANSWER: I myself have no means of measuring that. I saw a review online that stated the SNR to measure at 123db. I believe Monoprice claims it to be even higher. Another reviewer on YouTube opined that the SNR is so low that the difference between balanced and unbalanced is not audible. I know that with no audio playing I can turn the volume to the maximum and not hear a hint of noise.
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- Robert S on Feb 26, 2020
- Purchased on Feb 10, 2020
It should be around 123 db. Check out the Audio Science Review for more info.
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- Ben K on Feb 26, 2020
- Purchased on Feb 6, 2020
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Can I connect my turntable preamp to this headphone amp with rca cables and use the balanced output?
A shopper
on Jul 13, 2020
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Seeing it can output almost 4 W of power. How low impedances can it power? Will I be able to run my 8 ohm speakers from this?
A shopper
on Sep 10, 2019
BEST ANSWER: It is not designed for this purpose, which is why there aren't any binding posts to hook up speakers.
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- New User U Staff on Sep 10, 2019
BEST ANSWER: It is not designed for this purpose, which is why there aren't any binding posts to hook up speakers.
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- New User U Staff on Sep 10, 2019
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A simple question that I shouldn’t have to ask, what are the specs?
A shopper
on Sep 10, 2019
BEST ANSWER: Simple answer: They are now live on the site.
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- New User U Staff on Oct 24, 2019
BEST ANSWER: Simple answer: They are now live on the site.
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- New User U Staff on Oct 24, 2019
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how long is the warranty?
A shopper
on Sep 10, 2019
BEST ANSWER: Thank you for your question.
This item would have a three year warranty.
This item would have a three year warranty.
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- Tyler C Staff on Sep 10, 2019
BEST ANSWER: Thank you for your question.
This item would have a three year warranty.
This item would have a three year warranty.
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- Tyler C Staff on Sep 10, 2019
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will it have the 887 number on the front like i saw on a reviewers picture? if so i would suggest to leave it out or move it to a better place with better font similar to the thx logo font for a cleaner look
A shopper
on Sep 11, 2019
BEST ANSWER: The 887 is getting removed from the unit and it was only on a handful of early units. It will look like the images on our site.
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- New User U Staff on Sep 11, 2019
BEST ANSWER: The 887 is getting removed from the unit and it was only on a handful of early units. It will look like the images on our site.
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- New User U Staff on Sep 11, 2019
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EU availability anytime soon?
A shopper
on Sep 11, 2019
BEST ANSWER: Thank you for your question.
It would be best to sign up for our newsletter at the bottom of our site to receive updates on new items.
It would be best to sign up for our newsletter at the bottom of our site to receive updates on new items.
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- Tyler C Staff on Sep 18, 2019
BEST ANSWER: Thank you for your question.
It would be best to sign up for our newsletter at the bottom of our site to receive updates on new items.
It would be best to sign up for our newsletter at the bottom of our site to receive updates on new items.
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- Tyler C Staff on Sep 18, 2019
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What is the minimum impedance earphones that is safe to use with? I ask this because I have earphone with balanced driver that has impedance of 8 .
A shopper
on Sep 11, 2019
BEST ANSWER: 12 Ohms is the minimum impedance for full range usage.
Or if you restrict the output to < 4V pk, then the unit can tolerate 8 Ohms minimum.
Or if you restrict the output to < 4V pk, then the unit can tolerate 8 Ohms minimum.
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- Andrew M on Nov 15, 2019
BEST ANSWER: 12 Ohms is the minimum impedance for full range usage.
Or if you restrict the output to < 4V pk, then the unit can tolerate 8 Ohms minimum.
Or if you restrict the output to < 4V pk, then the unit can tolerate 8 Ohms minimum.
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- Andrew M on Nov 15, 2019
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Will there be an updated version of the Monolith THX DAC/AMP (788) that will utilize this new THX technology (887) in the near future?
Christopher H
on Sep 11, 2019
BEST ANSWER: Question was answered elsewhere in the Q&As: "No, there will not be one in the near future." - New User U (Staff)
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- Christopher H on Jan 7, 2020
BEST ANSWER: Question was answered elsewhere in the Q&As: "No, there will not be one in the near future." - New User U (Staff)
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- Christopher H on Jan 7, 2020
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Is the RCA pass output fixed or variable?
A shopper
on Sep 17, 2019
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What does the bypass, timed off switch on the back do?
A shopper
on Sep 18, 2019
BEST ANSWER: Switch up: After a few hours without audio, the unit will turn off to conserve power.
Switch down: The unit will not automatically turn off.
Switch down: The unit will not automatically turn off.
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- Inaccurate
- Andrew M on Nov 15, 2019
BEST ANSWER: Switch up: After a few hours without audio, the unit will turn off to conserve power.
Switch down: The unit will not automatically turn off.
Switch down: The unit will not automatically turn off.
- Reply
- Inaccurate
- Andrew M on Nov 15, 2019
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Hi there, are the speakers muted while using headphones? Like, when you plug in headphones speakers are muted automatically?
Milos T
on Oct 9, 2019
BEST ANSWER: This is not an amplifier for speakers.
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- New User U Staff on Oct 10, 2019
Yes, I am aware of that. I just presumed this would have pre-out so I can control the volume on my desktop speakers, most headphone amps have it.
They're asking what happens to the passthrough outputs when a headphone is plugged in. Many headphone amplifiers with passthroughs will mute the passthrough when headphones are plugged in and we want to know if this device does that.
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- New User U on Oct 19, 2019
BEST ANSWER: This is not an amplifier for speakers.
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- Inaccurate
- New User U Staff on Oct 10, 2019
Yes, I am aware of that. I just presumed this would have pre-out so I can control the volume on my desktop speakers, most headphone amps have it.
They're asking what happens to the passthrough outputs when a headphone is plugged in. Many headphone amplifiers with passthroughs will mute the passthrough when headphones are plugged in and we want to know if this device does that.
- Reply (1)
- New User U on Oct 19, 2019
Vote for the best answer above!
Reviews
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Rated 5 out of 5
THX AAA 887 is da bomb
Inaudible noise floor, conveys micro details, ample power with balanced out for Sennheiser 6xx headphones
Very affordable for quality this high
Very affordable for quality this high
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Rated 5 out of 5
10stars
Awesome and powerful, clean amp. Driving my 6xx on balanced cables like a charm and with authority!
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Rated 5 out of 5
Balanced Headphone Amp with 3 Gain Settings is Stellar Performer
This headphone amp is not only reasonably priced, it’s a stellar, balanced performer. I have a very good amp with an independent headphone output and this Monoprice unit outperforms it in spades. Gain selection is perfect and balanced output is a game changer. I added a basic EQ to dial in my cans and I couldn’t be more pleased. You can’t go wrong with this headphone amp.

Added Aug 31, 2020
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Rated 5 out of 5
Eargasms!
Very satisfied with my purchase. A step up from my Schiit Jotunheim with a cleaner more precise presentation of my music. Not night & day but definitely noticeable. Note: it’s teamed with SMSL’s M500 (balanced) & Sennheiser HD600 & Drop HD6XX.
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Rated 5 out of 5
Great little thing...
Works great with my Sennheiser HD700 and Pro-Ject Pre Box S2 Digital

Added Jun 18, 2020
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Rated 5 out of 5
Get this over the Drop THX
Superb amp that's basically perfect according to AudioScienceReview. Makes my HD6XX sound wonderful combined with my SMSL Sanskrit 10th Mk II DAC.
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Rated 5 out of 5
Delighted
So far this AMP paired with anything I paired it with is fantastic! It's it's so transparent that I could clearly tell the difference between different DACs.
I'm pretty sure I'll stick to it for the next 5-10 years until there is (or maybe not) a new Revolution in sound quality and clarity (maybe it's already irrelevant)
The price is higher than for the Drop THX 789 though (for basically the same performance), but the feel of the Monoprice (look and build) is worth every penny over the Drop THX 789.
At this point, I wonder what can be done to improve sound even further but I guess there will be a new revolution in the future like an integrated physical equalizer built into the same form factor or maybe something that enhances further the soundstage; who knows?
I'm pretty sure I'll stick to it for the next 5-10 years until there is (or maybe not) a new Revolution in sound quality and clarity (maybe it's already irrelevant)
The price is higher than for the Drop THX 789 though (for basically the same performance), but the feel of the Monoprice (look and build) is worth every penny over the Drop THX 789.
At this point, I wonder what can be done to improve sound even further but I guess there will be a new revolution in the future like an integrated physical equalizer built into the same form factor or maybe something that enhances further the soundstage; who knows?
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Rated 5 out of 5
Sound quality and everything else about this headphone amp is utterly amazing.
I'm using the balanced XLR output to my Aeon 2 Closed headphones from Dan Clark Audio. Input is currently unbalanced RCA from an iFi iDSD Micro BL, which works well enough, but I'll be replacing that with balanced input from a Topping D90 DAC once that unit arrives.
I'm using the balanced XLR output to my Aeon 2 Closed headphones from Dan Clark Audio. Input is currently unbalanced RCA from an iFi iDSD Micro BL, which works well enough, but I'll be replacing that with balanced input from a Topping D90 DAC once that unit arrives.
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Rated 5 out of 5
Impeccable build and sonic quality - Multiple outputs - Minor gripes only
First of all, this headphone amp has a very solid build and can power any headphones, up to the power-hungry Sennheiser HD-800S (with a 300-ohm impedance). It never gets hot either, even after a whole day.
I tested it extensively with a couple of very good headphones, Audeze XC and Hifiman Ananda, and both performed at the top of their capabilities. Sound quality is impeccable, and power feels unlimited.
It's great to have multiple gain levels available, because the Audeze XC produces considerably louder sound when connected to the balanced output compared to Hifiman Ananda. I am changing gain level to compensate for that when switching headphones.
Another great feature: ALL THREE outputs (balanced, 6.4mm, and 3.5mm) work simultaneously. I connected three pairs of headphones, and all of them worked very well together. Ample power available on this amp made it possible. Convenient for testing/comparing various headphones.
Added bonus: Matches my Topping DX-7 Pro Dac/amp perfectly in terms of style and size. (The Monoprice amp is deeper, though, but it doesn't matter aesthetically).
Minor gripes (to stay objective):
1. The documentation is NOT available (checked with Monoprice support). While most functions are self-explanatory, I still cannot understand what the Timed OFF/Bypass switch on the back panel does... The Support doesn't know it either :-).
2. There are no tick marks around the volume rotating knob at all, so you have no idea where you are volume-wise. There is a tiny black-on-black mark on the knob itself, but it's not visible under normal conditions unless you search for it with a flashlight...
3. The button on the right switches input between balanced and RCA, but again, it's unmarked. You figure out that balanced = depressed state experimentally (and there's no doc, as I mentioned).
I tested it extensively with a couple of very good headphones, Audeze XC and Hifiman Ananda, and both performed at the top of their capabilities. Sound quality is impeccable, and power feels unlimited.
It's great to have multiple gain levels available, because the Audeze XC produces considerably louder sound when connected to the balanced output compared to Hifiman Ananda. I am changing gain level to compensate for that when switching headphones.
Another great feature: ALL THREE outputs (balanced, 6.4mm, and 3.5mm) work simultaneously. I connected three pairs of headphones, and all of them worked very well together. Ample power available on this amp made it possible. Convenient for testing/comparing various headphones.
Added bonus: Matches my Topping DX-7 Pro Dac/amp perfectly in terms of style and size. (The Monoprice amp is deeper, though, but it doesn't matter aesthetically).
Minor gripes (to stay objective):
1. The documentation is NOT available (checked with Monoprice support). While most functions are self-explanatory, I still cannot understand what the Timed OFF/Bypass switch on the back panel does... The Support doesn't know it either :-).
2. There are no tick marks around the volume rotating knob at all, so you have no idea where you are volume-wise. There is a tiny black-on-black mark on the knob itself, but it's not visible under normal conditions unless you search for it with a flashlight...
3. The button on the right switches input between balanced and RCA, but again, it's unmarked. You figure out that balanced = depressed state experimentally (and there's no doc, as I mentioned).

Great build quality, impeccable sound. Minor gripes: NO markings on volume control, NO doc at all!
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Rated 5 out of 5
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