Monoprice Monolith THX 887 Balance Headphone Amp: New Champ?

[joeinabox]

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]

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]

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.

 

[joeinabox]

You have nothing to worry about.

Thank you, thank you, thank you!!!

 

[JohnYang1997]

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]

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 ?

 

[ArtemisXCIX]

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

Uh there is no new or updated 887. He was just saying those were the things they did differently from the 789.

 

[VeerK]

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]

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.

 

[pcdinh]

I think that I found my end-game headphone amp

 

[Celty]

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]

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]

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]

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]

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!

 

[Veri]

Yep, >2.1V + gain III will cause clipping.

 

[Celty]

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:

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!

Fantastic! Glad you got it sorted and can now enjoy things. Great to have these forums where folk like Schackmannen can help.

 

[ArtemisXCIX]

It's possible that you're clipping the amp if your DAC is outputting more than 2 Vrms.

Would this issue be a concern when connecting the M500 xlr output to the 887?
Also where do I look to see how much Vrms my dac is outputting?

 

[SoyBean0809]

Would this issue be a concern when connecting the M500 xlr output to the 887?
Also where do I look to see how much Vrms my dac is outputting?

In the M500 review Amir set the volume to 34 and the output is 4.2Vrms, set to max will output 6.8Vrms, so I think there is no need to use high gain on the 887.

 

[Schackmannen]

Would this issue be a concern when connecting the M500 xlr output to the 887?
Also where do I look to see how much Vrms my dac is outputting?

Just use low or medium gain and you won't have to worry about clipping, it should be plenty loud anyways. In general most balanced consumer grade DACs output around 4 Vrms but some do go even higher like the M500, it's usually mentioned in the spec sheet what the highest output voltage is, but otherwise you would have to use something like a multi-meter to measure it.