Pionee SG-9800 temperatures

[A B]

Hi everyone, i observed my Pioneer sg-9800 eq runs a little hot during use. All voltages are fine according to the service manual, but on the radiators i measure 65-70C the two Hitachi HA ic's are running at 45C in the nearby. The two 1/2W resistors between the radiators and the main filtering capacitors reach 80C degrees.
The unit runs well, no distortions on the scope and the thermal paste was renewed.
Are the above temperatures normal, how hot/cold runs your units?

 

[aldena007]

The SG9800 runs at 25W and the temps you measured aren't outlandish. Whether or not they are "Normal" is hard to say. If you are not seeing obvious heat discoloration on the circuit boards and the unit appears to be working I would not worry about it. Some of the Pioneer non switching amps/receivers are quite notorious for high heat issues but the SG-9800 does not seem to have any history of this.

 

[Blue Shadow]

The heat sinks are there because they are keeping those two transistors cool.
The two resistors are mounted above the board because they run warm by design.

Seems the units is working fine. Larger heat sinks are available for the transistors and the resistors could have heat sinks added or swap for higher wattage which will handle the heat better, but the unit seems to. Be working just fine, why mess with it?

Pics of the guts at this link showing the right side of the unit with the items A B is discussing.

Pioneer SG-9800 12-Band Stereo Equalizer

Specifications: Output Level: 1V (7.5V Max) Gain +/- 0dB Frequency Response: 5Hz - 100kHz Signal To Noise Ratio: 92dB Total Harmonic Distortion: 0.02% Control Range: +/- 10dB Frequency Bands: 16, 32, 64, 125, 250, 500, 1k, 2k, 4k, 8k, 16k, 32kHz Semiconductors: 27x IC, 2x FET, 14x Transistors...

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