The NuPrime MCH-K38 Multi Channel Amplifier

A Reference LE Class Multi-Channel Amplifier

The NuPrime MCH-K38 is a Reference LE class multi-channel amplifier designed for uncompromising home theater and music listening. With its quality parts throughout and an advanced 550kHz switching amplifier operation, the MCH-K38 delivers a full 210 watts into 4 and 8 Ohms per channel. Each pair of output channels can be bridged to double the power to 400W at 4 and 8 Ohms. The NuPrime MCH-K38 comes with 8 sets of RCA and true balanced XLR inputs. A self-resonant design, the amp’s 550 kHz PWM switching frequency constantly adjusts to the input signal, output current demands, and loudspeaker impedance variations. Exemplary speed, accuracy and exquisite dynamics nicely describes NuPrime's signature sound.

The MCH-K38 amplifier is derived from the ULCAM (Ultra Linear Class A Module)+Class D design first introduced in IDA-8. By joining a powerful high impedance single-ended amplifier circuit in the preamp stage with a well integrated Class-D power stage, the MCH-K38’s rich tube-like sound and tremendous speed is sure to impress audio enthusiasts. By utilizing a 1000W power supply and CMA capacitor array, the MCH-K38 fully exploits the Class A+D design’s ability to deliver massive amounts of power and speed when needed by a single or multi channels.

The NuPrime Sound

  • Vast soundstage
  • Wide, lightning-fast dynamics
  • Ultra-low distortion and noise
  • Music emerges from a pristine background, with delicate details and nuances intact

In summary, NuPrime’s sonic character stands well apart from – and indeed above – the soft, cushy sound we often associate with most tubed amplification or the dry, edgy sound we often associate with solid-state and switching technology. Rarely does an amp achieve an ideal balance of richly textured timbres and harmonics, bottom-end authority, startling dynamics, exquisite low-level detail, and a fully revealed, fully dimensional soundstage against a backdrop of mile-deep silence.

Specifications:

Inputs: RCA: Un-Balanced input x 8 XLR: Balanced input x 8  
Outputs: Stereo Speaker Out x 8 Mono Speaker Out x 4  
Power: 8 X 210W at 4 & 8 Ohms / 4 X 400W @ 4 & 8 Ohms. MCH-K38 is able to maintain the same power rating at 8 Ohms due to a large power supply. Standby power: 115V/230V at 40W with all 8 channels turned on. 22W with 2 channels turned on.
Gain: x 22 THD+N: 0.02% (Stereo) / 0.01% (Mono)
Input Impedance: 47k Ohms Frequency Response: 10Hz to 50kHz
Signal to Noise Ratio: 80dB at 1W, 10W, 100W    
Worldwide AC voltage: (115 VAC / 230 VAC) AC Fuse: Slow-blow, 7A, 250VAC
Dimension: 430.3 mm W x 378.7 mm D x 98.55 mm H (including feet)    
Weight: 14.5 kg Color: Black
Power On Trigger Cable: Use any 3.5mm male to male stereo audio cable    
Warranty: 2 Years    

Back Panel

The back panel of NuPrime MCH-K38 consists 4 sets of stereo amplifier output modules. Each set can also be bridged into a mono amplifier making NuPrime MCH-K38 versatile when comes to channel selections. This feature enables MCH-K38 capable of supporting 8 channels (all set to stereo), 7 channels (1 set to mono 3 set to stereo), 6 channels (2 set to mono 2 set to stereo), 5 channels (3 set to mono 1 set to stereo), and 4 channels (all set to mono).

  1. Choose either RCA or XLR input and make sure the switch is properly selected.
  2. Be sure the switch is selected to Stereo.
  3. Be sure the cables are securely connected to the desire input connectors.
  4. Connect the speaker cables to output terminals. Note: The top row is positive and bottom row is negative.

  1. Choose either RCA or XLR connection and make sure the switch is properly selected.
  2. Be sure the switch is selected to Mono.
  3. Be sure the cables are securely connected to the desire input connectors. Please connect to the connectors in white color. Gray connectors do not work in Mono mode.
  4. Connect the speaker cables to output terminals.

MCH-K38 Remote Control Code

Customer can purchase the optional Remote Control or use a Programmable Remote to control MCH-K38.

000Eh // POWER ON
0010h // POWER OFF
0004h // CH 1
001Ch // CH 2
0000h // CH 3
0002h // CH 4
0003h // CH 5
0006h // CH 6
000Ch // CH 7
0005h // CH 8

Frequently Asked Questions

MCH-K38 front panel buttons and LED lights

The buttons on the front panel are toggle on/off switch. 

Power button:  Red means Standby and Green means power on.  No Light means AC power switch off.

Channel 1 ~ 8, Red light means the source is set to XLR and Green means the source is set to RCA.  No Light means the channel is turn off.

The light in between 1 & 2, 3 & 4, 5 & 6, and 7 & 8 are Mono indicators.  Red light also means the source is set to XLR and Green means the source is set to RCA.  No Light means the channel is turn off.  The mono channel can be toggled on/off with channel 2, 4, 6, & 8. 

Please make sure to press the buttons to turn on the channels.  Since our stereo lights are very small LED on the button top, so it might be easy to miss if its put inside the rack.

What some of the amps have the same power rating at 8 and 4 Ohms ?

There is two side to a coin. The truth is that the amp is capable of more power than the spec suggested. So if 4 and 8 Ohms are specified at 100Wx2, that means the power supply is a 200W PSU. And we are extremely conservative about our power rating (we provide conservative RMS rating, not peak power). A customer reported 180W for IDA-8 because he is using just one channel to do the measurement. So, if IDA-8 is in a bigger case, and we put in a 300W PSU, you will see a higher rating. In reality, you get more than 100W per channel from the 200W PSU, because not both channels are driven at the same time.

Why don't we put in a bigger PSU? Each model is designed for specific product position and adding more power will certainly increase the cost and size of the product.

Can the amplifier's speaker terminals be used as source inputs (e.g. to REL Subwoofer) ?

In some applications, the speaker outputs from the power amplifier are used as source signals for devices such as REL sub woofer. For such application, usually the receiving devices should have DC offset blocking capability because some amplifier by design has floating ground (DC offset) on the speaker outputs. 

The following models have no DC offset on the amplifier speaker outputs and the negative terminal is also the ground:

NuPrime STA-9, MCH-K38, IDA-16

The following models' speaker outputs can not be connected directly to sub woofer input:

NuPrime Reference 20, ST-10, IDA-8

What kind of trigger cable can be used for your products?

When a device has a 12V trigger input, it is designed to be turned on when a 12V is detected. You can use any standard male to male 3.5mm (3-pin type) cable.

 
"I have Audience 2+2 in a stereo system in the bedroom, they have been powered by Cary Audio and Parasound multi channels. Due to the weight and only stereo need i sold the Cary and Parasound for the Nuprime ST-10. I was cautious as i have hated my previous experiments with class d amps such as rotel, pioneer and wyred4sound, all cold and lifeless, boring and flat. The ST-10 was a revelation, sweet, very detailed, tight, extended and bouncy, it had life and was a joyful match with the 2+2's, i cannot remember a more enjoyable sound in 30 years, especially for the money, and the mids are incredible. In my main system i needed to replace my hernia weighted Cary 7 channel, so with my positive experience with the ST-10 I plumped for the MCH-K38 at half the weight of the Cary and hoping it would come close to the exceptional ST-10. The MCH-K38 will be used in a 5.1 system driving Audience 4+4's when they arrive from the factory. In 5.1 mode the first 4 channels will be bridged and that is how i compared it to the ST-10, not only did it equal the ST-10 but in bridged mode bettered it. Same family signature but just with a more effortless control, more open, less restrained and detailed, I am extremely surprised and very happy, what a combination made in heaven, the Audience and the Nuprime .... rock on ….", - ZAPHOD2012 (audiocircle.com)