NuPrime ST-10 ™

Reference LE class power amplifier

The ST-10 amplifier is NuPrime's Reference LE power amplifier for listeners who require a reference-class amplifier at a somewhat lesser power rating of 2 x 150W (8 Ohm). NuPrime’s sonic character stands well apart from – and indeed above – the soft, cushy sound we often associate with most tubed amplification and the dry, clinically 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 sound stage against a backdrop of mile-deep silence.

The “LE” of Reference LE designates near-reference-class performance. The fourth generation (V4 amplifier module) of this patented amplifier design outperforms its predecessor in several aspects:

  • It lowers the noise floor by an astounding 20dB and elevates the output stage to 85% efficiency.
  • Shortened circuit pathways result in a 20% improvement in through-put.
  • Improved reliability in no-load condition and short circuit protection.
  • Increased output current drive capability for low impedance speakers.
  • Increased switching frequency to 600 KHz and an improved musical sampling rate.
  • Improved S/N ratio and dynamic range.
  • New linear power supply with a high-efficiency toroidal transformer. Reduced high-frequency noise and strengthened low-frequency performance.
  • Signal path avoids cross-linking capacitors, thus achieving a frequency response at DC level for pure musical enjoyment.
  • Enhanced even-order harmonic (H2) circuitry resembling the most attractive features of tubed-amp sound without its drawbacks and limitations.

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

Specifications:

Inputs: 2 x RCA Outputs: Five-way binding posts
Power Output: 150W x 2 at 8 Ohms; 150W x 2 @ 4 Ohms Gain: X 28
Input Impedance: 23.5k Ohms Sensitivity: 0.89 V to rated power
THD+N: 0.01% Frequency Response: 0 Hz to 60,000 Hz
S/N Ratio: 110dB at 1W, 10W, 100W Dimensions: 59 mm H x 215.4 mm W x 394 mm D
Weight: 6 kg    

 

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.

Where can I find a Turn-On trigger cable for MCH-K38

It is not included as an accessory. If you need it, please contact your distributor or dealer. You can't use any generic 12V trigger cable.

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

ST-10 Reviews

Product Of The Year award

 

OUR TOP PICKS by The Absolute Sound

"...over the years I’ve reviewed and used plenty of digital power amplifiers from Bel Canto, Wyred4Sound, April Music, and others, and I appreciate what a well-designed model can bring to a system. And it happens that the ST-10 is the best digital power amplifier I’ve heard to date...
 
...Within their product categories the DAC-10H DAC/preamp and ST-10 basic power amplifier are priced at the lower mid-level, yet they both deliver a level of performance that could be considered exemplary regardless of their cost... ", - Steven Stone
 

"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)