Technics SU-8080 Stereo Integrated Amplifier: Restoration

Join me as I tear down and rebuild the vintage Technics SU-8080 Stereo Integrated Amplifier. I chose to replace all electrolytic capacitors, most semiconductors and a couple of other components: For now, I kept the main filter caps, the rectifier diodes, the output transistors and a couple of transistors in the phone stage original. I might rebuild the power supply at some point. This video complements my blog post and as such has no voiceover. Go to the blog post on my website: https://sebastianharnisch.de/ For someone repairing the amplifier, here is a list of replacements I either used or would recommend as a starting point. These are not necessarily the only and maybe not always the best choices, but they worked for me so far. I didn't test the phono preamp though, have no use case for it. Also, both with and without the transistors replaced, the transition from clipping into the normal region was not as clean as I’d like. This behaviour seems to be a bit more pronounced after the transistor replacement. Please also have a look into the component selection yourself and use the information provided at your own risk. Again, for more details I encourage you to have a look at my blog post. Diodes ------------ MA150: 1N4148 MA162: 1N4148 10E1: 1N5393 .. 1N5399 (1N4004 .. 1N4007 might also work, but has a bit weaker ratings than the 10E1) S1RBA20: 4x 1N5393 .. 1N5399 (Requires competent lead bending or an adapter board ;) Diode selection similar to 10E1.) S3V20: BY550-400 .. BY550-1000 (Haven’t done the change myself yet.) Zener: (Edit:) Although I chose BZX85 series, in some and potentially many cases 0.5W Zeners might have been a better choice due to their sharper I-V-curve at low currents. I would recommend to check the service manual and select an appropriate Zener diode for the respective application. Transistors: ------------------- 2SC1567: TTC004B (iirc I used TTC011B’s I had on hand, but TTC004B’s seem to be a better replacement.) 2SA794: TTA004B (iirc I used TTC006B’s I had on hand, but TTA004B’s seem to be a better replacement.) 2SC1328: KSC1845F 2SC1708: KSC1845F 2SA798: 2x KSA992FB (Matched for V_BE and H_FE. Thermal coupling might require heavy contortion ;) High gain FB range is end of life; Alternative: F/FA ranges.) 2SA847: KSA992 2SA564: BC327-40 2SC1913: MJE15032 2SA913: MJE15033 2SC828(A)-R: BC546B (Completely different pinout! Couldn’t verify thermal characteristics, otherwise seemed more similar than all others tested. Thermal behaviour seemed fine in my tests and quite substantial use of the amp.) 2SC1628: KSC3503 (Just went extinct, unfortunately. Haven’t looked for it specifically, but right now I don’t know of a suitable modern replacement.) 2SA722: KSA992 2SA777: KSA1013 2SC1509: KSC2383