Monoprice has been releasing a lot of speakers and subwoofers recently (for more information, check out the links below) and the one thing missing from their rapidly growing pantry has been power amplifiers. Becoming a source for everything can simplify the process for consumers and the strategy has worked for brands like Emotiva — but that doesn’t negate the need for everything to be good and reliable.
Consumers value reliability and that’s where Emotiva has done really well over the years. They have focused on reliability, performance, and price; something that isn’t always the case with every high-end brand.
With that in mind, Monoprice is offering up two new high-end power amplifiers under their Monolith brand name (8125X, 8250X). These amps are not only designed to complement Monolith speakers, but other loudspeakers you may have or are considering.
What a Power Amplifier Is
The purpose of a power amplifier is to supply power and transfer audio signals to one or more speakers. However, It doesn’t have the extra features and connections you often find on a home theater receiver, such as a radio, input source switching, and audio/video (AV) processing. The only control you typically find on a power amplifier (apart from a power switch) is a primary gain control, which is analogous to volume.
Power Amplifiers come in a variety of channel configurations, from a single channel (aka Monoblock) that powers just one speaker, two-channel (stereo), or multi-channel (typically 3, 5, or 7 channels) for home theater applications.
However, to use a power amplifier, a separate preamp or AV preamp/processor is required to get audio signals from content sources to the power amplifier (more on this later in this article).
The AV preamp/processor decodes or processes audio source signals and passes the signals to the power amp, which, in turn, sends the signals to the speakers. The signals are passed in analog form via line outputs using RCA-type connections or, in some higher-end preamp/power amplifier combinations, XLR connections.
Tip: When a separate power amplifier and preamp/processor are used in an audio/home theater setup instead of a receiver, they are referred to as “Separates“.
Features The Monolith 8125X/8250X Amps Share
Tip: The rest of this article refers to more techie info. Check on the provided links for more details on what they mean. Another source that will help is Understanding Amplifier Power Output Specifications.
Getting back to the Monoporice Monolith 8125X and 8250X here are the core features both amps share.
- Amplifier Type: Class D using Hypex Amplifier Modules
- Inputs: Balanced XLR (8)
- Number of Channels: 8
- Input Impedance: 47K ohms
- Gain Range: 25.7dB
- Frequency Response at Rated Output: 20Hz – 20kHZ (+ or – .05dB
- Signal to Noise Ratio: “A Weighted” Better than 115dB below rated FTC Power.
Tip: Neither amp provides a gain control – All gain/volume adjustment must be performed by a connected preamp/av processor.
Measurements for Both Amps When Using 8-ohm speakers
- Total Harmonic Distortion (THD – 20Hz to 20kHz): Less than 0.05% 20Hz to 5kHz & 0.5% 5kHz to 20kHz @ Rated Power output
- Total Harmonic Distortion (THD – 1 kHz): Less than 0.025% at Rated Power Output.
Measurements for Both Amps When Using 4-ohm speakers
- Total Harmonic Distortion (THD – 20Hz to 20kHz): Less than 0.05% 20Hz to 5kHz & 0.5% 5kHz to 20kHz @ Rated Power output.
- Total Harmonic Distortion (THD – 1 kHz): Less than 0.025% at Rated Power Output.
Additional Hypex Module Ratings For Both Amps
- Impedance Load Compatibility: 4 to 16-ohms (this means you can connect 4, 8, or 16-ohm speakers)
- Damping Factor: Greater than 400 from 20Hz to 400Hz
- Crosstalk: Better than -70dB, 200Hz to 20kHz (this means that sound leakage between channels is almost non-existent – unless the audio is mixed across multiple channels)
- Remote Trigger Voltage: 3.3 to 24.0 VDC at 5ma (A Trigger is a remote on/off power function)
- Input Power: 120 VAC
Monolith 8125X
Here are additional specifications related to the 8125X
Additional Measurements for the 8125X When Using 8-ohm Speakers
- Power Output (FTC): 20hz to 20kHz, all channels driven): 100 wpc.
- Input Sensitivity (full rated power): 1.465 volts
Additional Measurements for the 8125X When Using 4-ohm Speakers
- Power Output (FTC): 20hz to 20kHz, 4 channels driven): 175 wpc.
- Input Sensitivity (full rated power): 1.37 volts
Additional Hypex Module Ratings for the 8125X
Power Output at 1 kHz:
- 8-ohm load 1% THD: 150 watts
- 4-ohm load 1% THD: 250 watts
- 2-ohm load 1% THD: 180 watts (current limited)
Chassis Dimenstions (with Binding Posts):5.25 x 17.1 x 12.5-inches (HxWxD)
Net Weight: 28 lbs/12.8 kg
Monolith 8250X
Additional specifications related to the 8250X
Additional Measurements for the 8250X When Using 8-ohm Speakers
- Power Output (FTC): 20hz to 20kHz, all channels driven): 200 wpc.
- Input Sensitivity (full rated power): 2.07 volts
Additional Measurements for the 8250X When Using 4-ohm Speakers
- Power Output (FTC): 20hz to 20kHz, 4 channels driven): 400 wpc.
- Input Sensitivity (full rated power): 2.07 volts
Additional Hypex Module Ratings for the 8250X
Power Output at 1kHZ:
- 8-ohm load 1% THD: 350 watts
- 4-ohm load 1% THD: 500 watts
- 2-ohm load 1% THD: 450 watts (current limited)
Chassis Dimensions (with Binding Posts): 5.25 x17.1 x 14.5-inches (HxWxD)
Net Weight: 35.3 lb/16.1 kg
Monoprice Monolith HTP-1 AV Preamp/Processor
As mentioned previously to provide input sources and control for the amps and whatever speakers you use, you need an additional AV Preamp Processor and a Powered Subwoofer.
The HTP-1 is one option that Monoprice offers that has been in its product line for a while. This unit is a 16-Channel Home Theater Preamp/Processor that includes extensive surround sound decoding and both wired and wireless source connection options.
Here are some additional key features so you can see how the HTP-1 can complement the 8125X and 8250X power amplifiers.
HDMI Connections: HDMI® ver 2.0b (8 inputs and 2 outputs – One output is HDMI ARC/eARC compatible).
Audio‑Only Inputs: Analog stereo RCA (2), digital coaxial (3), digital optical (3), XLR (1),
Audio Outputs:16‑channels balanced XLR line outputs (these can be used to connect to the 8125X and 8250X power amps). Unbalanced stereo analog RCA outputs are included for connection to power amps that don’t have XLR inputs.
Network Connectivity: Ethernet, Wi‑Fi®
Streaming Inputs: Bluetooth® and Roon®
Maximum Video Resolution Pass-Through: 4K@60Hz UHD
Audio Frequency Response: 20Hz ~ 20kHz
Surround Sound Format Support: Dolby Atmos®, Dolby TrueHD™, Dolby Digital®, Dolby Surround®, DTS: X®, DTS Neural: X®, DTS‑HD Master Audio™, Auro‑3D®, Auro‑Matic®
Room Correction/Equalization: Dirac Live® (licensed with HTP‑1 ownership) – Dirac Live Bass Control is also available.
Additional Audio Settings: Bass and Treble tone controls, 16‑band parametric equalizer with independent speaker control on each band.
Dimensions (WHD): 17.1 x 5.7 x 12.0-inches
Price & Availability
The Monolith 8125X (Product Number: 42565) is priced at $1,999.99 at Monoprice.com.
The Monolith 8250X (Product Number: 42564) is priced at $2,999.99 at Monoprice.com.
The Monolith HTP-1 AV Preamp/Processor (Product Number: 37887) is priced at $3,999.99 at Monoprice.com.
More About Monoprice:
Monoprice Announces Monolith THX LCR & Satellite Speakers
Monoprice Monolith Encore Home Theater Speakers Are Very Affordable
Monoprice Monolith Dual Driver THX Ultra M-210 and M-212 Subwoofers
Monoprice Announces Monolith In-Wall Subwoofers
Monoprice Monolith THX Subwoofers Shake the Foundation
Monoprice Shakes Things Up With Two New Massive THX Subwoofers
