Maybe differential inputs on the amp board if bias is off. For sure low level amplifier transistors in tone/pre/phono circuits with lower noise versions, sprinkle in some 1% Dales in the signal path.
He had the right idea with the foam rings cutouts. Must have been rattling really bad & was forced to add the extra brace with the nail-in-the-coffin center screw.
Nice work giving it a heartbeat again.
Im embarking on an aa-1600 soon. Thoughts on replacing the large disk caps on amp board with films?
The 6 axials in it will run a guy $35 for Vishays at mouser, considering to go that route instead of radials.
Tom,
Tough luck on the Bozaks. How would you describe the sound of the Bozak Sonora 201? Do they excel with tube gear?
Ive owned a pair for over a decade, but never got a musing to listened to them yet.
Ive listened to these quite a bit past few years setup in my office. I usually knock paper cone tweeters but this Bose one isnt all too bad, surprises me some times.
The diagram you drew up resembles a “Baker Clamp”. The diodes will hold the collector at around 0.6v, relative to ground. ie: Vce is held (clamped) at 0.6v.
This prevents the transistor from saturating and ensures faster switching. I hold no EE degree, i could be terribly wrong.
Here is an...
I loved playing Sim City on the first MacIntosh compact computer in jr. high, and Street Rod on a IBM in shop class.
Ran Wolfenstein 3d and Leisure Larry when the ‘rents were not around on our TX1000 Tandy computer at home, it had just 2MB RAM.
I have replaced RF/IF, output stage amplifier transistors on many of my old state radios purely for experimental/learning purposes, and was curious if they would perform better. Never once degraded a radio by doing so, and many had improved SQ with lower noise more modern transistors. Favorites...
Those backside resistors look to be in the protection circuit. Kenwoods in that era it was common to see these protection revisions mid production. The circuit design must have gave them problems. I believe there is a service bulletin recently uploaded for this unit regarding revisions on...