These sit in different size classes, so this is not a straight ranking comparison. The Monoprice Monolith THX AAA 788 ranks #25 of 53 DAC and headphone amp combos by measured performance; the Monoprice Monolith THX AAA 887 ranks #7 of 30 headphone amplifiers by measured performance.
What the Monoprice Monolith THX AAA 788 does well: Audio Science Review measured a SINAD of 107 dB, so noise and distortion stay well below audibility in normal listening. The catch: Discontinued, so it is mainly found used.
Why pick the Monoprice Monolith THX AAA 887: Audio Science Review measured a SINAD of 119 dB, so its noise and distortion are inaudible and it is effectively transparent. The catch: Discontinued, so it is mainly found used.
One note: the Monoprice Monolith THX AAA 788 is no longer sold new, but at #25 of 53 DAC and headphone amp combos by measured performance it still outranks most current models, so used is worth considering.
Buy the Monoprice Monolith THX AAA 788 for a DAC and headphone amp combos, or the Monoprice Monolith THX AAA 887 for a headphone amplifiers instead.
Looking for alternatives? See the complete Headphone Amps and DACs rankings.
Specifications Side By Side
| Monoprice Monolith THX AAA 788 | Monoprice Monolith THX AAA 887 | |
|---|---|---|
| Price | Discontinued | Discontinued |
| Ranked | #25 of 53 in DAC and Headphone Amp Combos | #7 of 30 in Headphone Amplifiers |
| Device Type | DAC and headphone amp | Headphone amp |
| SINAD | 107 dB (measured by Audio Science Review) | 119 dB (measured by Audio Science Review) |
| Output Power (32 ohms) | 3,120 mW | 6,000 mW |
| Output Power (300 ohms) | 580 mW | 700 mW |
| Headphone Outputs | 6.35 mm, 4-pin XLR | 6.35 mm, 3.5 mm, 4-pin XLR |
| Balanced Output | Yes | Yes |
| Inputs | USB, optical, coaxial, AES, XLR, RCA | RCA, XLR |
| Outputs | RCA | - |
| DAC Chip | 2 x AK4493 | - |
| Volume Control | Digital | - |
| Dimensions | 8.7” x 2” x 7.8” (221 x 51 x 198 mm) | - |
Related Amp and DAC Comparisons
More top alternatives to Monoprice Monolith THX AAA 887:
- Topping A30 Pro vs Topping A90 Discrete
- Topping A70 Pro vs Topping A90 Discrete
- Schiit Midgard vs Topping A90 Discrete
- SMSL VMV P2 vs Topping A90 Discrete
- Topping A90 Discrete vs Tom Christiansen Audio HPA-1
Prices on this page were last checked October 12, 2026 at 4:13 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Amps and DACs In Full
Monoprice Monolith THX AAA 788 Discontinued eBay
Pros: Audio Science Review measured a SINAD of 107 dB, so noise and distortion stay well below audibility in normal listening. A rated 3,120 mW into 32 ohms is enough for nearly any headphone, including hard to drive planars, with 580 mW into 300 ohms for high impedance models. It offers balanced outputs and USB, optical, coaxial, AES, XLR, RCA inputs.
Cons: Discontinued, so it is mainly found used.
Full Monoprice Monolith THX AAA 788 review and specifications →
| Released | 2018 (8 years ago) |
|---|---|
| Balanced Output | Yes |
| DAC Chip | 2 x AK4493 |
| Device Type | DAC and headphone amp |
| Dimensions | 8.7” x 2” x 7.8” (221 x 51 x 198 mm) |
| Headphone Outputs | 6.35 mm, 4-pin XLR |
| Inputs | USB, optical, coaxial, AES, XLR, RCA |
| Output Power (300 ohms) | 580 mW |
| Output Power (32 ohms) | 3,120 mW |
| Outputs | RCA |
| SINAD | 107 dB (measured by Audio Science Review) |
| Volume Control | Digital |
- Reviews, Comparisons and Sound Samples
Monoprice Monolith THX AAA 887 Discontinued eBay
Pros: Audio Science Review measured a SINAD of 119 dB, so its noise and distortion are inaudible and it is effectively transparent. A rated 6,000 mW into 32 ohms is enough for nearly any headphone, including hard to drive planars, with 700 mW into 300 ohms for high impedance models. It offers balanced outputs and RCA, XLR inputs.
Cons: Discontinued, so it is mainly found used. It has no built in DAC, so it needs a separate DAC or source with a line output.
Full Monoprice Monolith THX AAA 887 review and specifications →
| Released | 2019 (7 years ago) |
|---|---|
| Balanced Output | Yes |
| Device Type | Headphone amp |
| Headphone Outputs | 6.35 mm, 3.5 mm, 4-pin XLR |
| Inputs | RCA, XLR |
| Output Power (300 ohms) | 700 mW |
| Output Power (32 ohms) | 6,000 mW |
| SINAD | 119 dB (measured by Audio Science Review) |
- Reviews, Comparisons and Sound Samples