Holton Ex Nihilo - Power Mono Blocks

The Ex Nihilo mono block power amplifier was conceived from an idea to produce a no compromise power amplifier that could drive any HiFi loudspeaker in the known world.

To do that we need an amplifier that can drive 2 ohm loads with absolute ease and in doing so it had to do this with the same if not better sound quality that Holton amplifiers are known for all over the world.

The mono block cases have being machined in Europe from no less than 6 x 10mm aluminum plates and 2 x 400mm x 170mm 0.23 degrees-watt heat sinks. With the 14kg 2.5KVA power transformer one mono block amplifier weights in at 35kg per mono block. To minimize and cancel out any acoustic noise from the power transformer a sorbothane suspension system has being employed whereby the 14kg power transformer is placed on its own mezzanine deck which isolates it from the rest of the chassis.

The audio engine printed circuit board is a true mono block construction with the entire power supplies, protection and audio amplifier circuitry built into a 2mm 2 ounce copper gold plate board. The high current power supply feeding the output stage has two high current SMD bridge rectifiers feeding two banks of filter capacitors in total there is no less than 48 low ESR capacitors making a total of 225,000microFarad of filtering and this is just for the output stage of each audio channel.  The input driver stages for each mono block also have there own electronically regulated power supply, this provides extreme electrical isolation from the high current output stage pulses. The two electronic regulators feeding the input driver stages have there own dedicated and isolated secondary winding and bridge rectifier filter bank, providing a well regulated and isolated power supply for the best possible sound quality.

The main audio amplifier uses 12 x 250 Watt dual die lateral MOSFETs in each output stage to transfer the enormous DC reservoir to the loudspeaker load. Output protection is managed by a smart power controller and 120 amp solid state output relay and this in conjunction with a built in DC servo amplifier that manages the direct coupled feedback circuit that keeps the output DC offset to a very low 0.5 millivolts.

The Ex Nihilo amplifiers are true DC direct coupled power amplifiers with no audio capacitor anywhere in the signal path including the feedback network it is truly direct coupled from input to output

Power output from each mono block minimum is 250 watts into 8 ohms, 500 watts into 4 ohms and 850 watts into 2 ohm loads.

To complement these audio behemoths each mono block amplifier is supplied with their own pro audio road case.

Features for the Ex Nihilo Power Mono Block's
  • Mono block configuration
  • DC coupled low global negative feedback circuitry
  • 12 high current dual die lateral power MOSFET output transistors
  • 225,000 microFarad capacitor bank per mono block
  • DC Servo Amp for perfect zero output offset
  • 120 Amp Solid State output protection relay
  • High powered smart power controller
  • Decoupled transformer castings
  • 2mm thick 2 ounce double-sided gold plated printed circuit boards
  • Optimal circuit layout utilizing SMD technology for shortest signal path
  • One 2.5KVA toroidal transformer with inter-winding magnetic shielding
  • Separate power supplies for input driver and output stages
  • Gold-plated Swiss Neutric XLR input sockets
  • 12V remote power trigger for automatic turn-on
  • Supplied with Pro Audio Professional Road Cases
  • Designed and built in Tasmania, Australia
Power Output per channel min continuous rating
250 Watts RMS into 8 Ohms
500 Watts RMS into 4 Ohms
850 Watts RMS into 2 Ohms  
Frequency response
1.5 Hz to 200 kHz -3dB
Signal to Noise Ratio
-110dB SNR Unweighted with respect to full power output
26.8dB Unbalanced Input
32.8dB Balanced Input
Input Impedance
Single ended Input: 20k Ω
Balanced Input: 40K Ω
Input sensitivity
2.0 Volts RMS for full power at 8 ohms, 4 ohms and 2 ohms
 Damping Factor
100hz 8 Ω = 1300
Power Supply Transformer
Custom designed encapsulated 2.5KVA transformer
225,000µf Total power supply filtering per mono block
Input connectors
ETI HC-XTC Phono Pods
Output connectors
ETI Cable Pods Binding Posts
Gold-plated Swiss Neutric XLR input sockets
Outside Dimensions
420mm D x 355mm W x 220mm H
Each Mono Block Only: 35.0 KG; Shipping Weight with road cases 94.0 KG