• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Monoprice Monolith THX 887 Balance Headphone Amp: New Champ?

junk88

Member
Joined
Sep 5, 2019
Messages
46
Likes
4
I'm guessing that the 1/4 single ended out Would
have the same 119 sinad ?
 

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
8,480
Likes
10,432
I'm guessing that the 1/4 single ended out Would
have the same 119 sinad ?
come on man the first graph is annotated with 1/4 out. it's literally right there.
 

Tks

Major Contributor
Joined
Apr 1, 2019
Messages
3,051
Likes
4,883
I just noticed from the pictures that the Monolith THX 787 does not have any vents on top like the 789.
I wonder if it generates less heat?

Heat is probably identical, and as a 789 owner, I can tell you the device generates none that would require vents tbh.. If I could, I'd seal my vents on the 789 to prevent dust falling in there as it's currently doing.
 

Celty

Senior Member
Joined
Nov 4, 2019
Messages
354
Likes
294
Heat is probably identical, and as a 789 owner, I can tell you the device generates none that would require vents tbh.. If I could, I'd seal my vents on the 789 to prevent dust falling in there as it's currently doing.
I agree, my 887 is running cool to the touch, not even warm.
 

joeinabox

Member
Joined
Mar 25, 2019
Messages
7
Likes
1
I‘m opening my THX AAA 887 as I write this. I’m not going to form an Opinion until I get my SMSL SU-8.

could someone tell me if the power button clicks on your amp like the input button does? Please tell me it’s normal that it doesn’t cuz I’m gonna cry if I need to send it back.
 

T.J. Turner

Member
Joined
Jun 6, 2019
Messages
78
Likes
64
Location
San Ysidro, CA
I‘m opening my THX AAA 887 as I write this. I’m not going to form an Opinion until I get my SMSL SU-8.

could someone tell me if the power button clicks on your amp like the input button does? Please tell me it’s normal that it doesn’t cuz I’m gonna cry if I need to send it back.

I'm not sure what you mean by click. There is the audible sound of a relay that clicks about a split second after you press the power switch.
 

wizzman

Member
Joined
Nov 15, 2019
Messages
6
Likes
6
could someone tell me if the power button clicks on your amp like the input button does? Please tell me it’s normal that it doesn’t cuz I’m gonna cry if I need to send it back.
The input button is a mechanical button that locks in and out for the two inputs.

The power button is spring-loaded but does nothing but hit a relay switch when you push it. The position does not lock in and out for on and off. It works just fine but its a rather unsatisfying action. The LED turns red for about 1.5 seconds every time you power it on too which gives you that brief panic moment that you have a check engine light :)

You have nothing to worry about.
 

JohnYang1997

Master Contributor
Technical Expert
Manufacturer
Joined
Dec 28, 2018
Messages
7,017
Likes
16,440
Location
China
Just an FYI, for the 887 we upgraded over 50 internal components to increase performance:

5 Opamps – same opamps as 888 to reduce noise

32 Resistors – Upgraded to reduce noise

12 Capacitors – Upgraded to reduce distortion

I'm glad to see there is interest in the unit!
I wouldn't call changing resistors(using smaller values) being upgrade. But still great improvement for the price.
 

Evgeniy

Active Member
Joined
Aug 10, 2018
Messages
100
Likes
46
Location
Ukraine, Odessa .
Just an FYI, for the 887 we upgraded over 50 internal components to increase performance:
5 Opamps – same opamps as 888 to reduce noise
32 Resistors – Upgraded to reduce noise
12 Capacitors – Upgraded to reduce distortion

887 Amp from site monoprice.com - upgraded version or old ?
 

VeerK

Active Member
Joined
Jan 29, 2019
Messages
240
Likes
305
Location
NYC
Had a blast last night messing around with the 887, need to be careful with the Elex not to push too much, this is a dangerous combo. I’ve gone through so many amps over the years, wish this was out earlier, would have saved so much money.

One thing I’m a hair disappointed with is the noticeable channel imbalance at the lowest volumes, takes a little bit more turning to take care of it. Probably unavoidable with the volume pot, part of the reason I’m eagerly anticipating my M500 to arrive from wherever it is, I need the fully digital volume control.
 

ZeDestructor

Active Member
Joined
Jul 28, 2019
Messages
112
Likes
66
I wouldn't call changing resistors(using smaller values) being upgrade. But still great improvement for the price.

Agreed. To me it seems they upgraded those parts to parts with tighter tolerances in order to achieve the improvement in performance possible/promised by the opa1612.

It's just like dacs in that respect, really: unless you engineer your supporting circuitry around your amazing dac chip correctly, it'll never achieve good performance.
 

Celty

Senior Member
Joined
Nov 4, 2019
Messages
354
Likes
294
Had a blast last night messing around with the 887, need to be careful with the Elex not to push too much, this is a dangerous combo. I’ve gone through so many amps over the years, wish this was out earlier, would have saved so much money.

One thing I’m a hair disappointed with is the noticeable channel imbalance at the lowest volumes, takes a little bit more turning to take care of it. Probably unavoidable with the volume pot, part of the reason I’m eagerly anticipating my M500 to arrive from wherever it is, I need the fully digital volume control.
I've been leaving my 887 volume at around the 2 o'clock position, and adjusting from there with the SU-8 volume control. Works for me, and the remote is handy. Glad you are enjoying yours, it is one purchase for which I don't have a hint of buyer's remorse.
 

mwan

New Member
Joined
Aug 18, 2019
Messages
2
Likes
3
Does anyone have an issue with using gain setting 3 on their 887? I sent an email to Monoprice about my issue.
My Monolith THX AAA 887 amp on gain setting 3 sounds very wrong. To try to describe it, low frequency sounds are extremely distorted and crackling. Extremely noticeable on the song Doin' it Right by Daft Punk. It sounds fine on gain setting 1 and 2. Is my unit defective?
This was their response:
I am really sorry to know that you are having this kind of issue with this item. I honestly do not think your item is defective. I think that your item has no issues. The item offers 3 gain settings (1, 2, an 3). It sets the level of noise and distortion. The higher the gain, the higher amount of noise and distortion you will get. I suggest you to play around these settings to find out which one works best for you.

Gain 3 is basically unusable for me, issue is present with both Pinnacle PX IEMs and Sennheiser HD800 S. The Weeknd - Pray for Me is another song that is unlistenable on gain 3. Gain 1 and 2 sound great, no issues there at all.
 

Celty

Senior Member
Joined
Nov 4, 2019
Messages
354
Likes
294
Does anyone have an issue with using gain setting 3 on their 887? I sent an email to Monoprice about my issue.

This was their response:


Gain 3 is basically unusable for me, issue is present with both Pinnacle PX IEMs and Sennheiser HD800 S. The Weeknd - Pray for Me is another song that is unlistenable on gain 3. Gain 1 and 2 sound great, no issues there at all.
Actually I use gain 3 most of the time with HD6XX and HE4XX with no problems at all.
 

Schackmannen

Active Member
Forum Donor
Joined
Aug 6, 2018
Messages
167
Likes
221
Location
Tucson, Arizona
Does anyone have an issue with using gain setting 3 on their 887? I sent an email to Monoprice about my issue.

This was their response:


Gain 3 is basically unusable for me, issue is present with both Pinnacle PX IEMs and Sennheiser HD800 S. The Weeknd - Pray for Me is another song that is unlistenable on gain 3. Gain 1 and 2 sound great, no issues there at all.
It's possible that you're clipping the amp if your DAC is outputting more than 2 Vrms.
 

mwan

New Member
Joined
Aug 18, 2019
Messages
2
Likes
3
It's possible that you're clipping the amp if your DAC is outputting more than 2 Vrms.
Whoa, thanks, this was the issue. I was using a Topping D70 DAC with XLR output. Your reply prompted me to try a few things:
1. Topping D30 DAC with RCA output fixed the issue.
2. Topping D70 with RCA output also fixed it.
3. Topping D70 with XLR output but turning down the output volume setting to -3.0dB also fixed it.

To help my own understanding, I did some searching in this thread and found this:
The 887 does not come with any printed or downloadable documentation.
Assuming the specs are the same. There is some information from the 789 manual.
  • When using a DAC or source with <2.1 V output, any gain position may be used.
  • When using a DAC or source with >2.1 V output, only use low and medium gain positions, or else the 789 preamp may clip internally
The maximum DAC or Source voltage is 7 Vrms. (+19 dBu) to avoid the 789 preamp clipping.
If using a higher voltage DAC or source, apply a small amount of attenuation (e.g. in the media player) to reduce the maximum source voltage to 7 V / +19 dBu maximum.
I just noticed in the D70 manual that the XLR output is 4Vrms so it all makes sense to me now.

So, nothing wrong with my 887 at all. Thanks!
 
Top Bottom