Kraus KPR 100
The pre power amplifier from Kraus was built in Japan by Cybernet. They came on the market around 1980. The complete system included tuner KTL 100 tape KCD 100, preamplifier KPR 100 and power amplifier KPA 100. There was actually another larger series in the same format, the 200 series. This one even had a system remote control, I saw it myself. The units are solidly built and durable, the pre and power combo here works fine even after 33 years.
The pre : Inputs : Phono MM, Phono MC, Tuner, AUX, Tape 1 ( Monitor ), Tape 2 ( Monitor ). Tape 1 can also be connected via a 5 pin round plug. Pre Out to the power amplifier. Features : Loudness, HI treble filter, LO low filter, direct, controls for bass, mid, treble, balance, volume.
All potentiometers are detent potentiometers, everything is made of metal. The devices were available in silver ( more often )or in black. ( rare )
The power amplifier : 2 pairs of speakers can be connected, unfortunately for the time the usual spring terminals are installed. Furthermore the A / B speaker switching is only done by 2 switches mounted behind the front panel. There is only one thick Matsushita relay in the unit for switch-on delay. The output signal runs from the transistors ( 2 per channel ) to the switches and then back to the output terminals. A special feature is the very nice LED power display. It goes from 0.1 watts to 200 watts into 8 ohms. The display can be switched on in the sensitivity in 2 steps. The amplifier also has a -20 dB volume reduction that can be activated at the push of a button. On the back you will find the connection panel between the large heat sinks. There is the mono stereo switch, also the output signal flows over this switch but also the input signal is switched here. A circuit diagram would give more details.
The inner workings : Inside it's very tight, the monster transformer which is in the cast case takes a lot of space. This is screwed to the rear panel. The power amp has 2 very thick NEC transistors per channel. One black, the other blue. The buffer capacitors have 12000 mF, 56 V.
The sound : These 29.5cm wide and small units can easily rival units from Rotel in terms of sound. Compared to the Onkyo legend A 8780 I would rate this combination even higher. The sound is very airy resolved with enormous impulse power. Bass is abysmally deep and very precise when the Loud button is engaged. Even at high volume the character does not change. The stated 70 watts RMS at 8 ohms should be far exceeded. The power amp is usable as a monoblock, with 140 watts RMS into 8 ohms na if that's nothing. Connect the leftmost and rightmost terminals of pair B, set the BTL switch to mono. This pre power combo really blows my mind in terms of sound and performance. By the way, who has 2 power amplifiers can operate with him Bi Amping, so a preamp and for each speaker a power amplifier.
