Due to improper installation of my left speaker, the left output burned out. Now I have the problem of not being able to find the MN25 and MP25 germanium transistors, which are internal numbers used only by Pioneer and not a commercial number or model, making them harder to find. Could someone help me with this?
| Type | Stereo power amplifier | ||||
| Circuit system | First stage differential current mirror load 3-stage Darlington Parallel push-pull pure complimentary service OCL circuit Class-AB Operation, DC Amplifier Configuration | ||||
| Effective output (both channel drive) |
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| Harmonic distortion factor (5 Hz to 30 kHz, 8 Ω) | Effective power : 0.01% At 60W output : 0.01% 0.007% at 1W output | ||||
| Intermodulation distortion factor (50 Hz : 7 kHz = 4 : 1, 8 Ω) | Effective power : 0.006% 60W output : 0.005% 0.005% at 1W output | ||||
| Output Bandwidth (IHF, both channel drives) | 5 Hz to 45 kHz (Distortion Factor 0.01%) 5 Hz ~ 100 kHz (Distortion Factor 0.05%) | ||||
| Frequency characteristic | 5 Hz ~ 200 kHz + 0 -1dB at 1W Output | ||||
| Input terminal | Input : 1V/50k Ω | ||||
| Output terminal | Speaker : 4 Ω ~ 16 Ω | ||||
| Damping factor | 100 (20 Hz ~ 20 kHz, 8 Ω) | ||||
| Signal-to-noise ratio (IHF, A-network, short circuit) | 120dB | ||||
| Channel separation | 1kHz:105dB 100kHz:70dB | ||||
| Semiconductor used | Transistor : 55 Diode, other : 53 pcs | ||||
| Power supply voltage | 100 V, 50Hz/60Hz | ||||
| Power consumption | 280W (Electrical Appliance and Material Control Law) | ||||
| Maximum Power Consumption | 800W | ||||
| External dimensions | Width 420x Height 153x Depth 370 mm | ||||
| Weight | 22.5kg |
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Looks too new to be Germanium outputs. At 120 watts and one pair, really improbable. Mind you, Pioneer wasn't above over-reporting output power either.
What year was it made in? Can you confirm the model number?
Back in the 1970's, a Nikko Alpha II was rated at 120 watts per channel and used the 2SD555 and 2SB600 outputs, one pair of each. Normally at that power you would see 4 outputs per channel. Of course they were silicon, high power transistors.
What year was it made in? Can you confirm the model number?
Back in the 1970's, a Nikko Alpha II was rated at 120 watts per channel and used the 2SD555 and 2SB600 outputs, one pair of each. Normally at that power you would see 4 outputs per channel. Of course they were silicon, high power transistors.