Uploaded February 2024 | Updated September 2026, 2 weeks ago
Here’s a Technics SA-510 60WPC receiver from 1983. Features taken to the excess and I’ll summarize some technical aspects. Also has some unnecessary things and perhaps the lessons were learned.
Great looking unit. Discrete transistors but this Technics “New Class A” amp with the ICQ lights bells and whistles behind the scenes may have been unnecessary. Let’s go further.
Many models came out during this model line. Some had STK’s, some had transistor chips like this model. They all had various depths of lights on the faceplate that informed the user what the amp was doing (eye candy).
There’s a preheat circuit and ongoing monitoring via a custom stamped Technics Computer Drive chip. Until the amp blows and the lights STILL indicate that all is OK!! Even with fully blown STK chips!! Or the discretes!! And the thermal monitor does not stop to prevent damage - it’s just a light and monitor.
Best stated, it’s an “on the fly” bias which adjusts the audio as you increase the volume. So as you crank, the bass and distortion reduces. You can’t really overdrive it and run it like a standard amp from the era. So, if you’re like me, and you wanna push the amp, it automatically reduces your bass and audio whether you want to or not, there’s no bypass.
Just like a GM car Delco tape deck stereo in the late 80s - loud full sound until you increased volume and the fun went away as it lowered the bass at increased volumes.
Love Technics for this strange approach. It performs well but is a little silly. But, wasn’t everything crazy in the 80s? Cocaine, anyone?
Good looking unit with true digital tuning and an analog meter representation of your frequency for those converting from analog.
Low filter for turntable rumble - love it!
Multiple tape inputs - love it!
Automatic impedance detection circuit which changes on the fly between dual pair 8/4 ohm speakers - love it!
Oddball tuner VFD - love it!
Technical: These units get hot. There is a daughter board for the ICQ circuit where two specific transistors have weak/dry joints cause DC and the protection circuit to engage. #1 reaaon for failure.
After a solder reflow throughout and re-bias (about 30% off), it’s making the wife mad tonight. Which means, it’s performing well. Pushing my HPM-100’s.
if you watch the video at the end, I have a second unit under repair on the bench as I speak - and I’ll be throwing it on eBay soon. On the unit being repaired, that dry solder translstor problem caused a downstream issue that took out a regulator and 2 diodea. I have an OEM parts from the 80s, from China, enroute.
Have a great weekend and go Chiefs (I’m not specifically a fan, but was born in Kansas City, MO).
Here’s a Technics SA-510 60WPC receiver from 1983. Features taken to the excess and I’ll summarize some technical aspects. Also has some unnecessary things and perhaps the lessons were learned.
Great looking unit. Discrete transistors but this Technics “New Class A” amp with the ICQ lights bells and whistles behind the scenes may have been unnecessary. Let’s go further.
Many models came out during this model line. Some had STK’s, some had transistor chips like this model. They all had various depths of lights on the faceplate that informed the user what the amp was doing (eye candy).
There’s a preheat circuit and ongoing monitoring via a custom stamped Technics Computer Drive chip. Until the amp blows and the lights STILL indicate that all is OK!! Even with fully blown STK chips!! Or the discretes!! And the thermal monitor does not stop to prevent damage - it’s just a light and monitor.
Best stated, it’s an “on the fly” bias which adjusts the audio as you increase the volume. So as you crank, the bass and distortion reduces. You can’t really overdrive it and run it like a standard amp from the era. So, if you’re like me, and you wanna push the amp, it automatically reduces your bass and audio whether you want to or not, there’s no bypass.
Just like a GM car Delco tape deck stereo in the late 80s - loud full sound until you increased volume and the fun went away as it lowered the bass at increased volumes.
Love Technics for this strange approach. It performs well but is a little silly. But, wasn’t everything crazy in the 80s? Cocaine, anyone?
Good looking unit with true digital tuning and an analog meter representation of your frequency for those converting from analog.
Low filter for turntable rumble - love it!
Multiple tape inputs - love it!
Automatic impedance detection circuit which changes on the fly between dual pair 8/4 ohm speakers - love it!
Oddball tuner VFD - love it!
Technical: These units get hot. There is a daughter board for the ICQ circuit where two specific transistors have weak/dry joints cause DC and the protection circuit to engage. #1 reaaon for failure.
After a solder reflow throughout and re-bias (about 30% off), it’s making the wife mad tonight. Which means, it’s performing well. Pushing my HPM-100’s.
if you watch the video at the end, I have a second unit under repair on the bench as I speak - and I’ll be throwing it on eBay soon. On the unit being repaired, that dry solder translstor problem caused a downstream issue that took out a regulator and 2 diodea. I have an OEM parts from the 80s, from China, enroute.
Have a great weekend and go Chiefs (I’m not specifically a fan, but was born in Kansas City, MO).
