The Kenwood KR-6170 “Jumbo” receiver gets a noisy transistor transplant. I explain and demonstrate biasing. I bench test for wattage power and frequency response. The spring reverb gets tamed. And a quick electric guitar demonstration with the receiver’s guitar input. Shot in 4K HDR.
Here are the topics covered and time stamps:
0:00 Introduction
0:11 Recap of Previous Episodes
0:59 Let’s Fix The Noisy Guitar Input
1:11 Noisy 2SC458 Transistors
1:35 KSC1845 Replacement Transistors
1:40 20 dB Amp Boards
2:25 Did That Fix The Problem?
2:50 Bias/Idling Current
3:10 Class AB Output
3:23 Crossover Distortion
3:41 Calculating Bias Current
4:20 Adjusting Bias Trimmers
4:39 Bench Tests With SpectraPLUS Software
4:52 Power/THD Test. How Many Watts?
7:09 Frequency Response Test
7:51 Spring Reverb Lock Fix
8:25 Putting It All Back Together
8:44 Electric Guitar Demonstration
To see all the videos in this series, please click:
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