The Apache, pre-amp/headphone amp, is a fully balanced, input to output, active pre-amp, with a dual mono configuration. Two balanced inputs and two single ended inputs are controlled by four elegant push buttons on the front panel.
The selected input will light, indicating that the input has been activated, and shorts all of the non selected inputs to ground, whether being balanced or single ended. This will insure the purity of the selected input with no cross talk from the other inputs.
As an active, fully balanced pre-amp, the Apache has two active pre-amp outputs, one being balanced and the other being single ended, which are both active at the same time. This will give added control over two power amps, one being balanced the other unbalanced, in two separate locations at the same time.
The Apache is fitted with a balanced four section DACT attenuator which precisely controls the input signal of the four input/gain amps in the Apache. The sound stage is precise and dead center. The added icing to the cake is the three gain selector switch that controls the gain of all the four amps with one flip of the switch. This will give you the flexibility of getting the precise volume needed between those attenuator’s clicks.
The three gains offer a great advantage in the Apache, as they control the level of the signal that is coming into the amp and precisely matches it with the needed output to control either the power amp or the level needed to control the variable headphones impedances and their level of outputs.
Using a low gain, that of two can be very useful to your sensitive IEMs. If you happen to have those custom, expensive phones, now you can use them with the Apache at home besides for portable use. With the Apache, you can now custom wire your expensive IEMs with a balanced cable and listen to them for the first time in balanced mode.
The gain of six is great with all sources that have high output signals and also with those CDs that have high level encoded signals. At the same time it is great when the amp is used in the balanced mode. This mode usually outputs a higher signal level than single ended. This gain is helpful for those who listen with low volumes using high impedance headphones.
The high gain of eleven is useful when your source happens to have a low signal levels. This will boost the signal to the desired level, making it easy to select the right control over the volume between those hard to find clicks of the attenuators. Some power amps need higher gain signals from pre-amps to drive them efficiently. This will help in this situation.
The Apache has selector control over all pre-amp/headphone amp operations. When pre-amp mode has been selected, the Apache grounds all of the inputs and outputs that are not needed in the pre-amp operation to ground. This ensures the entire circuitry to become fully dedicated to the mode that has been selected. All headphones inputs and outputs cease to function and they become dead silent. No signal will be leaking through them and there won’t be any noise leakage. The other way around is also true. When the headphone mode is selected, the pre-amps inputs and outputs are terminated to ground. No signal or noise is present at pre-amp outputs and your power amps are dead silent if connected to the Apache.
The Apache has MUTE function feature. It operates in both pre-amp and headphone amp modes. It simply grounds all signals to ground thus making it a dark silent noiseless environment.
The Apache has no ON/OFF power switch. It is always on. It never generates heat or consumes much power, but is always ready to give you warm and detailed sound with precision control that is common only with expensive tube amps.
The Apache is built on a very solid MIL spec FR4 printed circuit board. It incorporates the best film resistors, with .1% mil spec accuracy, built by DALE, VISHAY. Tantalum caps have been used though out, coupled with film caps for smoothing. The signal lanes and power lanes have been separated from each others with solid ground lanes and patches of grounds to minimize floor noise.
The lay out is very well implemented to give the best performance ever. The left and right channels have full isolation from each other as each has it’s own dedicated power supply. No cross talk ever exists between the two, “four channels”, two for each.
No wires are used in the design of the Apache. The parts lay out are well implemented to do the right function with ease and to look great to the eye. The Apache PC BRD is housed in a beautiful anodized chassis and shielded from RF interferences, thus making the Apache a noiseless pre-amp/headphone amp. The Apache attaches to the DUAL MONO, external power supply via a detachable, shielded low noise, five conductor DC cable.
The DUAL MONO power supply has it’s own external chassis, It incorporate two toroidal transformers, four full wave bridge rectifiers and thousands of MF caps. The four independent voltages are fully and precisely regulated. All parts used are of the highest grade PANASONIC power caps bypassed by film caps for smoothing, on MIL specs printed circuit board. The power supply is designed to serve both worlds of powers, 110-120VAC and the 220-240VAC.
Both the amp and power supply chassis are fitted with precision spikes to minimize vibrations caused by speakers or other surrounding noises.
The amp and the power supply have the same dimensions except that of the height. Twelve inches front, left to right, eight inches front to back Amp’s height 1.75” Power Supply height 2.5”
Input impedance: 50K
Output impedance: headphone amp, 8 – 2K
Frequency Response: 5-100K
Channel separation: Dual mono.
Output signal strength: up to 18 Volts
THD: less than .0002
Hand built in the USA.