- Idea & Design by Wim.

This design is also based on the so-called Nishiki Amp design. As donor amplifier an Electrocompaniet AW65 amp is used. It was bought second-hand, though with faulty power stages; both circuits boards had serious damage caused by heat of several transistors. Other, maybe even a bigger problem was that some one tried to repair it, unfortunately not in a professional way. Amplifier was bought for just 50 euros.
The used 6N3P based driverstage is capable of driving the powerstage set to +/-40 VDC to its full potential. At 100 watt output power distortion is only 0.3%, this using no overall feedback.

More about this design using the 6N3P tube based driver section [1.262 KB] .

The Nishiki Amp Mod I

		This Nishiki Amp based Amplifier is using an Elctrocompaniet AW65 housing which was bought for just 50 Euros; amplifier came with faulty / damaged circuit boards. Please click picture for more details.

Inside overall view

		Amplifier is using a single 300VA transformer for 2 channels; BH SlitFoil 15000uF are used as PSU capacitors. Please click picture for more details.

Back view

		Amp is using the original Electrocompagniet heatsinks and housing. The original toriodal mainstransformer is not used, this simply because it is over-powered for this application. Please click picture for more details.

Overview driver board and the 2 power stages

		Driver stage is using a Long-Tail based circuit yielding low distortion and high drive capacity. The 6N3P is used as Long-Tail stage, the 6N1P as cathode follower. On the left bottom the 2 dedicated current sources using a red LED as reference. Coupling capacitors are mounted underneath the driver board; high performance coupling capacitors by ICEL are used. These ICEL are used by some Italian High End manufacterers. Power output stages are using 2SC5200 power transistors. Please click picture for more details. Using the Long-Tail based driver circuit distortion is very low, no overall feedback was used.

Custom-made driver circuit board

		Left bottom: dedicated current sources with their own DC PSU. Right top: MKP decoupling capacitor. Coupling capacitors can not be mounted on this board. Please click picture for more details.