No suprice that the phase shift was the same at 20Hz before and after recap. That's just what capacitors do, they delay the signal (introduce phase shift) at lower frequencies. Maybe that's why they are more pleasing to listen to... At 0 Hz the phase shift is supposed to be 90 degree if I remember correctly.
Nice job enjoyed the repair I bet you wish you had a distortion analyzer, I too wish I had one, bet it would have been very useful in this situation. I calibrated a ton of them in the military but never owned one. To me it’s one of those tools that sits around not being used much until a job like this pops up.
Really nice see the old analog scope getting some love. That’s the first time I recall seeing that on your channel. Thank you for overhaulin’ my 2216, upgrading the transistors, and diffusing the LED’s. I can’t wait to hear it in person.
A few months ago, I bought my first digital scope. Now, admittedly, it was an inexpensive one - about $300. But it was supposed to be a "50MHz" scope, and that should be more than enough for any audio work. The dang thing would NOT show an eye pattern for adjusting CD players. Absolutely would not. It even had trouble locking onto audio waveforms. I sold it and wen back to my 40-year-old CRT scope. I had already given my other CRT scope to my apprentice. Glad I still had my backup scope!
I bought warm led fuse lights for my marantz setup. I have the 2220b and the 3200/112/140 separate, and I bought these lights, they are del, warm white, but have opaque white shell for better diffusion, they are few dollars more, but they look like the original one, without the heat obviously.
@ScottGrammer I have 2 scope, a Hitachi VT-211 for audio work, it's only 20mhz and another one, that goes to 150mhz for alignment. Both analog. I have them since the 90s, bought used. You can find similar ones used easily for a reasonable price.
Marantz make good stuff, but they often have mistakes in the service manual. Pioneer is also guilty of this. Good to see someone else working for a change 👌 Edit: I always clean the glue and verify if the legs on any parts have been corroded by the glue, because it happens. It's look like some kind of contact glue, and it's sometimes hard to remove, I use MEK flux cleaner to remove it.
Excellent repair. As always. To improve the bass tightness, i put a 1uf filmcap in parallel on the output caps. This improves speed and tightness quite a bit. I love the (right) way you test the performance of the amp with the scope. Not sure i like the backlighting as it is now. Thanks for the video, this is how things should be done. I.M.H.O. I also had to220 driver transistors fail on low hfe on a au 11000 restoration. This kind of faillure is becoming more common. I use a metrix transistor tester which does hfe on different current settings. Very usefull Cheers from the Netherlands.