1965 Astrosonic 50

[electra225]

I am a tube guy and, to Chris' point, a big V-8 guy to the bone. I wouldn't haul home a solid state "anything" for that reason. I am also a Magnavox type of guy. I will have to admit that Magnavox got their scald right with the electronics on the Astro-Sonic line. When they were still using the old hardwood cabinets held over from the tube days, they were hard to beat at any criteria. Even the lowest Astro-Sonic will outperform the tube models, any of them, even the vaunted 93 series. But, to Brett's point, Magnavox lost their way with cabinetry. They let Zenith and even lowly RCA sneak up on them when it came to cabinets. Most of the cabinets from approx. 1966 on suffered from unfortunate styling. I've also learned that a fuel-injected, turbocharged and intercooled 122 cubic inch four cylinder can put you back in the seat better then the best 400+ cid V-8 ever built.....

Let's also remember we are all friends here.

[Motorola minion]

Yes, to clarify my point on Astrosonics:
1- Always worth cleaning pots and verifying fidelity with a known good source into the preamp via tape input, this may be all!
2- If in #1 above sound is just slightly distorted or not right, STOP unless you can trace it to a bad speaker - rare.
3- #2 lesson has been repeated a few times, even after a recapping and voltage checks, you need transistors - usually not worth it!
4- Keep a good chassis/speakers if you part out, because eventually a Scandinavian Mag Astro may turn up empty someday.

Other SS models:
1-Fisher is great if not high hours, but after 1967 don't bother, they did not get better
2-RCA - rarely had a transistor issue, good bet into the 70s.
3-Motorola - never seen a SS model in the wild, I welcome opinions
4-Sylvania-Zenith-Admiral used good transistors BUT high hours is evident in some
5- Silvertone, Airline, Bradford, anybrand,- always a gamble on SS, so test it per astrosonic #1 above

Very very few tube consoles I have seen would be scrap material unless cabinet is trashed, tubes always respond 100% to a recapping and TLC

[William]

Thanks, Dave. I really appreciate the advice, and your years of experience will with just about everything known to man pertaining to vintage audio stuff.

Question Dave, but to anyone on the forum that might know. You mentioned that RCA was good for transistors, but what years did they use germanium transistors? Or did they start out using silicon. I guess what I am really asking is, what transistors were used in my Grandparents RCA Home Theater pictured in my Avatar? And do you still have the one like mine that you picked up a while back?

Thanks,
Bill

[Motorola minion]

Thanks, Dave. I really appreciate the advice, and your years of experience will with just about everything known to man pertaining to vintage audio stuff.

Question Dave, but to anyone on the forum that might know. You mentioned that RCA was good for transistors, but what years did they use germanium transistors? Or did they start out using silicon. I guess what I am really asking is, what transistors were used in my Grandparents RCA Home Theater pictured in my Avatar? And do you still have the one like mine that you picked up a while back?

Thanks,
Bill

Yes indeed, I still have the Brandywine. One day Ill find a place for it, the TV part is one of RCA's best tube designs. RCA started manufacturing transistors using Germanium as all others did. While silicon was the driver of technological advances through the 1960s, home entertainment equipment seemed to lag behind getting on the Si express.

The advent of transistor's use in television was mostly of the silicon variety. RCA TVs transitioned to all SS in early 1970s, which accelerated a trend away from Germanium. Very rapidly, silicon transistors were standard in radios, record players etc.

Just last night, while finishing a 1969 Zenith "circle of sound" record player, I replaced an OEM RCA transistor that was noisy with volume turnt down. The amp in this player used a silicon for first stage preamp, germanium for second stage and interstage transformer driver transistors and Sanyo-sourced Germanium output transistors like ones from RCA that Zenith and Maganvox had been using since 1964!

What frustrates servicing a germanium-based piece of equipment is vanishing availability of THESE suitable replacements - NTE 102 for AF, NTE 160 for RF and NTE121/2N2148 for output push-pull.

Side note: In my Pontiac garage sit 3 huge 1967-9 TOTL SS consoles (Zenith Z966 RCA VJT76 Sylvania SC919) that may be junk , but I don't know it until taking that first step of discovery.

[William]

Dave, are you saying that my Brandywine\ and yours, has germanium, silicon, or a mix of both in the audio circuits?

Bill