Monoprice Monolith THX 887 Balance Headphone Amp: New Champ?

[bequietjk]

I can't wait for the 887. Dear lord.

 

[DubbyMcDubs]

Worth getting if I already own an Atom? Is the move to balanced worth it? Not experiencing any ground loop issues.

 

[ZeDestructor]

Worth getting if I already own an Atom? Is the move to balanced worth it? Not experiencing any ground loop issues.

Only if you have headphones you want to put even more power into thanks to the balanced output. If you have no plans to get balanced headphones or stick to efficient headphones, the Atom is just fine and doesn't need upgrading.

 

[ayane]

Worth getting if I already own an Atom? Is the move to balanced worth it? Not experiencing any ground loop issues.

There are not really many reasons to go after the 887 if you already have an Atom. The only main reason would be if you want higher power output. The 887 doesn't come with balanced pre-amp outputs, so it's not better than the Atom in that regard at all.

XLR headphone outputs only offer a better electrical connection (lower contact resistance/no short on plugging in devices/lower crosstalk) than the TRS jack, but this is an advantage of XLR connections, not of differential outputs. Using a differential output to drive transducers increases total power, but it also increases noise power, so there aren't tangible SNR improvements. In fact, differential outputs will have a higher output impedance, which can *reduce* SNR. Excepting electrostatic transducers, headphones can't be "balanced" because it doesn't not matter what the ground reference is at the transducer; they are driven by the voltage across the two terminals and nothing else.

 

[wadec22]

Worth getting if I already own an Atom? Is the move to balanced worth it? Not experiencing any ground loop issues.

not really. i'm probably getting one but not for any really good reasons and certainly none that are a good value propostiion.

I keep a lot of heapdhones around and regularly use probably 4 of them. I want the convenience of the 1/8" jack that I know I would use regularly, XLR as an option (even though I'll probably not use it) and I really like the looks. Currently I have the 788 and the two stacked together I think will be pretty to look at

Love my JDS Labs Atom though and it's not going anywhere. It drives my new Verum 1 very well and some amps struggle to put out the current needed for a 8ohm planar (some have had issues with the 789 with it). Regardless if you pick something new up, I would always keep the JDS around for it's price it is just a super nice unit to have on hand.

 

[Nango]

There are not really many reasons to go after the 887 if you already have an Atom. The only main reason would be if you want higher power output. The 887 doesn't come with balanced pre-amp outputs, so it's not better than the Atom in that regard at all.

XLR headphone outputs only offer a better electrical connection (lower contact resistance/no short on plugging in devices/lower crosstalk) than the TRS jack, but this is an advantage of XLR connections, not of differential outputs. Using a differential output to drive transducers increases total power, but it also increases noise power, so there aren't tangible SNR improvements. In fact, differential outputs will have a higher output impedance, which can *reduce* SNR. Excepting electrostatic transducers, headphones can't be "balanced" because it doesn't not matter what the ground reference is at the transducer; they are driven by the voltage across the two terminals and nothing else.

Actually they are driven by twice (or 4x) the voltage across the terminals. I have never seen any measurements about how this does affect the performance of a given membrane/transducer in direct comparision to regular 2V. I can just say that the sensation of "surround/involving sound" arises instantanely when I listen to my SRH1840 in balanced mode.

But the decisive advantage for balanced driven amp/headphones is the 100% channel decoupling. The german premium mfr Violectric explains on his website, this can quickly become audible with non-balanced circuits. Lamentabely they only explain this in german lanuguage, see: https://www.violectric.de/faq .

 

[wadec22]

Actually they are driven by twice (or 4x) the voltage across the terminals. I have never seen any measurements about how this does affect the performance of a given membrane/transducer. I can just say that the sensation of "surround/involving sound" arises instantanely when I listen to my SRH1840 in balanced mode.

But the decisive advantage for balanced driven amp/headphones is the 100% channel decoupling. The german premium mfr Violectric explains on his website, this can quickly become audible with non-balanced circuits. Lamentabely they only explain this in german lanuguage, see: https://www.violectric.de/faq .

It seems odd to me that someone would want to power a headphone that measures with high THD with XLR. Seems like you are very likely to get higher noise and distortion. Claims of "surround/involving sound" sounds a lot like the propaganda that comes from tube amp aficionados.

No offense, but taking a manufacturer's explanation for tech they sell is not something I think you can rely on. Go look at some of the stuff on the Schitt website for guides and FAQ. Admittedly, I trust Violectric a hell of a lot more than Schitt, but still....

 

[Nango]

No, they also sell single-ended gear, they just explain in general terms, they design and sell both amps. They also do not favour one over the other. They just explain.

 

[wadec22]

No, they also sell single-ended gear, they just explain in general terms, they design and sell both amps. They also do not favour one over the other. They just explain.

I understand they sell both

 

[ayane]

Actually they are driven by twice (or 4x) the voltage across the terminals.

They're driven by twice the voltage, or four times the power. This means four times the noise power as well, and at least twice the output impedance (not to be confused with contact resistance of the XLR jack).

I have never seen any measurements about how this does affect the performance of a given membrane/transducer.

There is no measurement or difference. Unless you are driving electrostatic headphones (which are completely different purely reactive/capacitive loads), headphone transducers work irrespective of whether they are driven "balanced" or single-ended. They only respond to the electrical potential difference across the transducer terminals. This means it does not matter what the ground reference is. Driving with +2 V and - 2 V is identical to driving with 0 and +4 V or +2 V and +6 V.

I can just say that the sensation of "surround/involving sound" arises instantanely when I listen to my SRH1840 in balanced mode.

That's uncontrolled anecdotal information. If you can really hear a difference in a blind test, it means that the output stage of your amp (and possibly the entire amp itself) is poorly designed or poorly matched for your headphones. Again, simply having a high output impedance when driving a non-resistive load can change the sound of the transducers. Balanced output doubles the output impedance. Please see nwavguy's explanation of damping factor.

But the decisive advantage for balanced driven amp/headphones is the 100% channel decoupling

You're forgetting about parasitic capacitance. Even if the two channels have different grounding planes, there will still be crosstalk because any piece of metal will behave like an antenna, even if ever so slightly. A well-designed amplifier can bring the crosstalk down to - 140 dB or lower, like the Benchmark HPA4, not 100%. Most amplifiers are a few orders of magnitude worse.

 

[graz_lag]

There are not really many reasons to go after the 887 if you already have an Atom. The only main reason would be if you want higher power output. The 887 doesn't come with balanced pre-amp outputs, so it's not better than the Atom in that regard at all.

XLR headphone outputs only offer a better electrical connection (lower contact resistance/no short on plugging in devices/lower crosstalk) than the TRS jack, but this is an advantage of XLR connections, not of differential outputs. Using a differential output to drive transducers increases total power, but it also increases noise power, so there aren't tangible SNR improvements. In fact, differential outputs will have a higher output impedance, which can *reduce* SNR. Excepting electrostatic transducers, headphones can't be "balanced" because it doesn't not matter what the ground reference is at the transducer; they are driven by the voltage across the two terminals and nothing else.

That's one of the most clear / simple explanation I ever read on the topic.
Thank you so much!

 

[Julf]

There is no measurement or difference. Unless you are driving electrostatic headphones (which are completely different purely reactive/capacitive loads), headphone transducers work irrespective of whether they are driven "balanced" or single-ended. They only respond to the electrical potential difference across the transducer terminals. This means it does not matter what the ground reference is. Driving with +2 V and - 2 V is identical to driving with 0 and +4 V or +2 V and +6 V.

This! It is surprising how so few people seem to understand even the basics of how electricity actually works. Sad reflection on the educational system...

 

[mocenigo]

No shipping to EU??? Wtf...

Where did you read that? Monoprice ships to EU.

 

[Nango]

Balanced output doubles the output impedance.

Z-Out is for balanced 0.03 and 10 and 120 Ohm for SE. Doubling the noise is generally not an issue, it widely depends on which kind of music you are listening to. Not saying that I even detect audible or disturbing noise.

...., it means that the output stage of your amp (and possibly the entire amp itself) is poorly designed or poorly matched for your headphones.

So, when is an amp a poor match with the phone, how do you measure this or how do you determine this?

 

[ayane]

Sad reflection on the educational system...

I'm part of the education system; trying to do whatever I can to make a difference =)

So, when is an amp a poor match with the phone, how do you measure this or how do you determine this?

Typically, a damping factor of 10 or higher will result in the best frequency response from the headphones. Measuring output impedance is simple; it can be calculated by measuring the voltage across the two terminals without any load, then comparing that to the voltage across the terminals with a headphone plugged in. It's a good idea to measure the voltage at various different frequencies if the impedance curve of the headphones is not flat, or if the nominal impedance frequency of the headphone is unknown (which is typically the case; most manufacturers list the nominal impedance but do not specify the impedance curve).

Doubling the noise is generally not an issue, it widely depends on which kind of music you are listening to.

That's a fair point. The SNR of the amp will far exceed the dynamic range of most music.

 

[Rem]

Interesting... I was considering the 789 and this came up. Does anyone think this could drive an HE-6?

 

[JohnYang1997]

Interesting... I was considering the 789 and this came up. Does anyone think this could drive an HE-6?

Unless you want your ears bleed, easily.

 

[dannylin]

Conclusions
I did not think it would be possible to build a mid-priced headphone amplifier and beat the Massdrop THX AAA 789. It is clear that the Monolith team managed to go against the tide and produce even a better headphone amplifier. Both subjectively and objectively, the "Monolith by Monoprice THX AAA Balanced Headphone Amplifier featuring THX AAA 887 Technology" (yes that is the official name) beats the Massdrop offering. Mind you, there is not much room left to squeeze one up there but they did. It is like beating the world record holder in Olympics.

Needless to say, it is my absolute pleasure to recommend the Monolith THX AAA Balanced headphone amplifier. It delighted me to see a company dedicated to absolute excellence and full transparency to our sources and content. This is a type of product you buy once and you are done. It made me happy just testing it!

I guess the difference between the Massdrop THX AAA 789 and the Monolith THX AAA 887 is minimal.
Massdrop THX AAA 789 is still one of the best mid-priced headphone amplifiers in the market and is still highly competitive!

The thing that we learn from Amir's review is that (1) it is good to see another company striving to bring an even competitive one. (2) that brings us a hope to see any other future product releases from Monolith!

 

[JohnYang1997]

I guess the difference between the Massdrop THX AAA 789 and the Monolith THX AAA 887 is minimal.
Massdrop THX AAA 789 is still one of the best mid-priced headphone amplifiers in the market and is still highly competitive!

The thing that we learn from Amir's review is that (1) it is good to see another company striving to bring an even competitive one. (2) that brings us a hope to see any other future product releases from Monolith!

One thing to notice the dash board on 789 was tested on 600ohm. So distortion performance is likely to be the same. Main difference is the improved noise performance which is basically nothing because the improvement is done in the gain stage, so unless it's near full volume setting there isn't a difference. At real world usage it's negligible.

 

[solderdude]

If you can really hear a difference in a blind test, it means that the output stage of your amp (and possibly the entire amp itself) is poorly designed or poorly matched for your headphones.

Or the single ended common returnwire in the different headphone cables is of unusually high resistance.

Personally I think the 6dB level difference is more likely to be the cause of the subjective found differences.
Takes a very special AB box or 2 similar amps to properly test this.

The SRH1840 has little to no reaction to higher output resistances b.t.w. other than the obvious level differences.

I have to say your technical knowledge in these matters is unusually high for someone with your work background.