Thanks for posting this video. I imagine most of these old Dynaco amps that were built as kits by novices have similar problems. Looking forward to more of your videos.
Whew, not only a cold joint (if just a single one...) but look at that discombobulated rat's nest of cables! Someone did a real sloppy job assembling it.
I always wondered how much can these Dynacos be improved by switching out the old components for new ones but just keeping the same amp design. Like the pre-amp transistors and stuff
Not sure… surprisingly many of the transistors in this thing are still for sale today like the tip31/32 and even the outputs. Once I was all done, it put out the rated 30w at 8 ohms with 0.06% THD+N left ch and 0.04 right ch, at 1khz. Which was well below what the manual said was acceptable
Look into a sencore lc75 capacitor analyzer for testing caps leakage and lcr. Up to 600vdc on the leakage test. In my experience, replacing all the electrolytics in old gear is par for the course.
Interesting video. If you could do a channel intro video that would be great. Is this a hobby you have? Do you fix all kinds of audio equipment? Car stereos? Very curious about what you do! Thanks!
Thanks, good idea. I'm still getting the hang of recording etc. Yeah just a hobby. I've always been interested in electronics to a degree but in the last few years I've had a bunch of (somewhat expensive) things fail on me, which I was determined to repair, and then I really started getting into it. I have done some car audio, like a Rockford fosgate 360.6 amp, a pioneer avh-x2700bs that had a bad ram chip, a 1968 camaro radio, and most recently a harman/kardon amp from a buick lucerne (which are surprisingly expensive to find used). I'm mostly interested in 70s-90's home HiFi repairs, power amps, recievers, tuners, etc. I'll work on just about anything though, if I think I can repair it
I couldn’t notice it. However I had just repaired the amp boards after a catastrophic failure, so I wanted to resolve it for two reasons: 1. I provide a printout of various as measured specs after the repair, compared to the factory specs in the manual - and there was a huge discrepancy between the two channels 2. I don’t want it coming back ;)
