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Monoprice Monolith THX 887 Balance Headphone Amp: New Champ?

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I currently own D90 and Monolith 887 which are connected using short XLR cables. The problem is that in high gain mode 887 has distortion / clipping going on whereas if I connect both devices using RCA cables then there is no clipping / distortion. My guess is that it is due to higher voltage supplied to 887 in XLR mode and it is not designed to sustain that voltage (4v in XLR and 2v in RCA), I am not sure though. Can anyone please confirm this? I can work around this problem by using either RCA cable or by using D90 in preamp mode and lower the volume a bit on D90. Both are not ideal solution as in both cases I am loosing headroom in terms of loudness / volume. The volume is important to me as I am using Hifiman Susvara which requires high gain on 887 to reach good level of listening.
 

Veri

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I currently own D90 and Monolith 887 which are connected using short XLR cables. The problem is that in high gain mode 887 has distortion / clipping going on whereas if I connect both devices using RCA cables then there is no clipping / distortion. My guess is that it is due to higher voltage supplied to 887 in XLR mode and it is not designed to sustain that voltage (4v in XLR and 2v in RCA), I am not sure though. Can anyone please confirm this? I can work around this problem by using either RCA cable or by using D90 in preamp mode and lower the volume a bit on D90. Both are not ideal solution as in both cases I am loosing headroom in terms of loudness / volume. The volume is important to me as I am using Hifiman Susvara which requires high gain on 887 to reach good level of listening.
Both drop 789 and monoprice 887 accept only up to 2.1V input before clipping in high gain (knob setting III). This is documented in the manual. So with balanced 4V input, you will drive it to clipping in the highest gain, except when using an input that is <= 2.1V, solution is to use only middle gain with XLR input, or to lower the output a bit as you indicate :/ (over at Topping A90 thread, a user tested this and found no such clipping in highest gain. So it appears to be a "limit" in the THX amplifying circuit).
Edit: I see you already replied in the A90 discussion so you are already aware of all this.. :)
 
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trl

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I currently own D90 and Monolith 887 which are connected using short XLR cables. The problem is that in high gain mode 887 has distortion / clipping going on whereas if I connect both devices using RCA cables then there is no clipping / distortion. My guess is that it is due to higher voltage supplied to 887 in XLR mode and it is not designed to sustain that voltage
If when using a lower gain the distortions are not there, my guess is that the input stage might distort a bit. Usually, higher gains are for much lower input voltages, like 1V RMS for non-balaced or 2V RMS for balanced operation, while a lower gain is imperative for higher input voltages.

Something similar is happening with the Objective2 headamp: https://www.audiosciencereview.com/...-about-input-gain-headroom.10383/#post-286626, http://nwavguy.blogspot.com/2011/08/o2-details.html?m=1#maximuminput.
 
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Both drop 789 and monoprice 887 accept only up to 2.1V input before clipping in high gain (knob setting III). This is documented in the manual. So with balanced 4V input, you will drive it to clipping in the highest gain, except when using an input that is <= 2.1V, solution is to use only middle gain with XLR input, or to lower the output a bit as you indicate :/ (over at Topping A90 thread, a user tested this and found no such clipping in highest gain. So it appears to be a "limit" in the THX amplifying circuit).
Edit: I see you already replied in the A90 discussion so you are already aware of all this.. :)
Thanks. Yes I saw that post. It was a coincidence that he posted this just when I was looking for the answer to this question.
 

dpippel

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I just got this and have it paired up with the S.M.S.L M200 - DAC mode, balanced in, low gain, listening with a Focal Clear via the balanced out, using the volume pot on the amp. Superb in every way. I know we're all objective here, but I've been comparing this with the S.M.S.L SP200 using the same DAC, and I feel the Monoprice has a wider and deeper soundstage. A bit more three dimensional. Maybe it's that bottomless pit of power? Maybe confirmation bias? ;) This certainly is a clean, transparent, and powerful amp. The SP200 sounds a bit more like I have two speakers strapped to my head, which of course I do. I'm leaning towards keeping the Monoprice even though I prefer the size, stackability, aesthetics, and PRICE of the SP200.

Decisions, decisions.
 
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escalibur

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I just got this and have it paired up with the S.M.S.L M200 - DAC mode, balanced in, low gain, listening with a Focal Clear via the balanced out, using the volume pot on the amp. Superb in every way. I know we're all objective here, but I've been comparing this with the S.M.S.L SP200 using the same DAC, and I feel the Monoprice has a wider and deeper soundstage. A bit more three dimensional. Maybe it's that bottomless pit of power? Maybe confirmation bias? ;) This certainly is a clean, transparent, and powerful amp. The SP200 sounds a bit more like I have two speakers strapped to my head, which of course I do. I'm leaning towards keeping the Monoprice even though I prefer the size, stackability, aesthetics, and PRICE of the SP200.

Decisions, decisions.
Or just get Topping L30 unless you definitely need balanced? :) It costs much less and probably beats both in terms of better measurements if it even matters anymore at these scales.
 

dpippel

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Or just get Topping L30 unless you definitely need balanced? :) It costs much less and probably beats both in terms of better measurements if it even matters anymore at these scales.
The L30 isn't available yet. ;) And yes, I prefer balanced.
 

preload

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Is there any advantage to using the balanced xlr inputs or would the single ended rca inputs be equivalent? Headphones would have balanced cables.
 

Celty

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Is there any advantage to using the balanced xlr inputs or would the single ended rca inputs be equivalent? Headphones would have balanced cables.
XLR vs. Single Ended Inputs: Primarily the advantage of XLR over SE is eliminating the issue of ground loop related noise (if you have any). Makes longer runs less susceptible to noise.

XLR vs. Single Ended Output: Specifically with the THX design of the 887/789, with XLR you of course get the full power available vs. SE.
 

preload

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XLR vs. Single Ended Inputs: Primarily the advantage of XLR over SE is eliminating the issue of ground loop related noise (if you have any). Makes longer runs less susceptible to noise.

XLR vs. Single Ended Output: Specifically with the THX design of the 887/789, with XLR you of course get the full power available vs. SE.
Thanks! I'm not worried about ground loop or induced noise via the input cable, but are you saying that balanced headphones, using the balanced headphone jack, won't be able to receive max power if the SE inputs are used? Why would that be? For a SE input, wouldn't the amp just invert the input signal and send it to the "second" amplifier?
 
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Labjr

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Thanks! I'm not worried about ground loop or induced noise via the input cable, but are you saying that balanced headphones, using the balanced headphone jack, won't be able to receive max power if the SE inputs are used? Why would that be? For a SE input, wouldn't the amp just invert the input signal and send it to the "second" amplifier?
I think he was referring to the SE output.
 

dpippel

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Thanks! I'm not worried about ground loop or induced noise via the input cable, but are you saying that balanced headphones, using the balanced headphone jack, won't be able to receive max power if the SE inputs are used? Why would that be? For a SE input, wouldn't the amp just invert the input signal and send it to the "second" amplifier?
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preload

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Welp, now that @Labjr and @dpippel have clarified that it's the balanced output that differs from the se output, can anyone confirm that the se input and balanced input should be equivalent in the absence of induced or ground loop noise via the cable?
 

ReaderZ

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Welp, now that @Labjr and @dpippel have clarified that it's the balanced output that differs from the se output, can anyone confirm that the se input and balanced input should be equivalent in the absence of induced or ground loop noise via the cable?
There is volume difference, but with 887 or the 789 I would use RCA since with XLR at full output it will clip. For A90 XLR all the way since it seems very prone to noise with RCA. Although personally I am running RCA to A90 with zero issue ATM.
 

dubsubs

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Best place to buy in EU / Germany ?? Would like to cancel the Drop 789 (310usd + 52usd customs to germany prolly) before it drops, if the 887 is actually available out here for 400usd.
 

Veri

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Best place to buy in EU / Germany ?? Would like to cancel the Drop 789 (310usd + 52usd customs to germany prolly) before it drops, if the 887 is actually available out here for 400usd.
The 887 was available from monoprice.eu direct via this link here. It is far more expensive on other reseller sites.
https://www.monoprice.eu/products/m...ne-amplifier-featuring-thx-aaa-887-technology
Unfortunately, the stock management on monoprice.eu is quite bizarre in that it throws a 404 error if the product is currently unavailable. I mailed them about this and they simply answered: "The Monolith THX AAA 887 amplifier is as the moment not available in our EU Stores. It should be back in stock by end of June. Please feel free to check with us again."

Considering we are long past the end of June, I suggest shooting monoprice EU another mail. They are by far the best source to buy from, that is, when they have stock... Alternatively you could look and see if anyone has a used one for sale.. not sure if there are (m)any around :)

Edit: it looks like audiophonics sells it for the same price as monoprice.eu now, which is 399euro. Only difference from what I remember, monoprice had free shipping so you need to add the shipping cost from FR. You cannot buy it for 400usd ... you need to factor in shipping and import charge from USA, try calculating the cost from monoprice.com and you'll be surprised how much the shipping charge is. Intl shipping is expensive, not to mention duties. Unless you hop on a plane and bring the amp with you on the way back, you won't find it anywhere for 400usd I'm afraid.
 
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wplchou88

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I was gonna get the drop 789 at 300 + 30 usd shipping to where i live (have to wait for 4 months) but then amazon has a free shipping thing going on so got this at 400 usd flat! idk if i should feel bad spending 20% more to have the same thing 4 months earlier, but im certainly excited!
 

ReaderZ

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The 887 was available from monoprice.eu direct via this link here. It is far more expensive on other reseller sites.
https://www.monoprice.eu/products/m...ne-amplifier-featuring-thx-aaa-887-technology
Unfortunately, the stock management on monoprice.eu is quite bizarre in that it throws a 404 error if the product is currently unavailable. I mailed them about this and they simply answered: "The Monolith THX AAA 887 amplifier is as the moment not available in our EU Stores. It should be back in stock by end of June. Please feel free to check with us again."

Considering we are long past the end of June, I suggest shooting monoprice EU another mail. They are by far the best source to buy from, that is, when they have stock... Alternatively you could look and see if anyone has a used one for sale.. not sure if there are (m)any around :)

Edit: it looks like audiophonics sells it for the same price as monoprice.eu now, which is 399euro. Only difference from what I remember, monoprice had free shipping so you need to add the shipping cost from FR. You cannot buy it for 400usd ... you need to factor in shipping and import charge from USA, try calculating the cost from monoprice.com and you'll be surprised how much the shipping charge is. Intl shipping is expensive, not to mention duties. Unless you hop on a plane and bring the amp with you on the way back, you won't find it anywhere for 400usd I'm afraid.
I was in similar situation in Canada, I really wanted to buy it but had to pay shipping plus tax, so end up holding out for A90 which costed me about the same. However newegg.ca has it now and it's about CAD $120 less than A90, making it a solid choice now.
 
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