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Of legacy HIFI gear that is...
I recently took delivery of a Scott LT-112B tuner. Fired it up with the variac and lamp current limiter and all is great.
And it sounds absolutely wonderful, beats all my other tuners both SS and tubed.
And I noticed something about the Scott after operating non-stop for about 6 hours. The tuner is cool as a cucumber. Not even warm anywhere I could detect on the case.
So a 60+ year old tuner sounds great, all original parts, all functions work as designed, assembled from a kit.
It shouldn't, but it does. My theory is that the lack of heat is the key. Nothing kills electronics worse than heat (except maybe for extreme overvoltage or defective component, which are anomalies).
So is heat the numero uno culprit? Therefore we can predict the longevity of pretty much all vintage electronics by how much heat the electronic components have to live with over the unit's lifetime?
Follow Ups:
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The Mind has No Firewall~ U.S. Army War College.
The compact chassis design and layers of "heat shields" (not the tube shields, per se, which are only on the preamp anyway) made for a pretty hot amp after a few hours. Even after getting things tweaked to spec. and running MUCH cooler (e.g., at the PT), the cover over the output tubes gets really really freakin hot and blocks air circulation.
Fwiw, I was once told that all those covers/shields are actually "heat sinks for the tubes." I questioned that but the dude was adamant. Anyone have an opinion on that? I mean, there has to be some radiation off/out for it to truly work as a heat sink, right?
I've read electronics life is cut in half for every 10 degrees C the operating temperature increases. So yup, good thermal design is key to a long life.
There is more than a grain of truth in that statement-
The Precedent Tuner, often cited as one of the Best Ever, had a chassis designed to keep the heat generating bits away from the discriminating bits, in an effort to improve the sensitivity, selectivity and sound quality....
Most failures that I have seen in equipment come from underrated resistors burning up/drifting, or caps suffering from heat/age...
Happy Listening
They also knew a lot about of the correct use of positive temp coefficient capacitors vs negative temp coefficient capacitors where needed. They prevent frequency drift as the unit warms up. Change the RF caps, and you've ruined it.
that's interesting, I did not know that (there's a lot I dont know :)
My one disappointment so far with the tuner is the hiss level in stereo mode. I have not done the "user" alignment steps as described in the manual, maybe that will help.
It's weird to me because I have a 4 element yagi pointed line of sight to my classical station of choice and the signal maxes the strength indicators on my Sony ST-75 and that unit has zero hiss (but it is a bit weak in the bass). But the signal strength shows minimal in the Scott strength meter when connecting the yago via balun to the 300ohm Scott antenna inputs, and the sound using the yagi is unlistenable with hiss.
So I have a typical FM 300ohm dipole oriented line of sight and for mono the sound is fine.
Hum I can probably deal with in my tuners by replacing power supply caps, resoldering ground connections, etc.
But if the alignment per the instruction manual doesn't help, I am probably stuck listening in mono.
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