Vintage Tube Gear Priced Insane Now

Can you believe it, those darned Toulouse-Lautrec paintings sell for over ten million dollars now? When he lived at the cat house, you could buy one for the cost of a good meal.

And my buddies spend a couple of hundred on a bottle of old wine. None of that old grape juice for me. I want my wine fresh in an undented box. What is in these guys minds?

As the owner of some very coveted vintage gear, I should be happy that most of my gear has substantially increased in value since I purchased it.  Still, it is abit sad that others might be squeezed out from owning stuff that remains terrific sounding after all these years.

Vintage gear needs quality coupling caps and best tubes to sound great.

With tube gear, there is nothing we know today that was not known 70 years ago.  It comes down to quality of the parts and the skill of the builder in voicing the component.  Foremost in importance is the output transformer, followed by the coupling cap and then all the rest of the components.  Depending on the kind of sound one seeks, it may not be the case that modern components are better.  Whether it is the case of cost cutting or a lost art, many of the best sounding transformers are vintage.  Likewise, many prefer the sound of older caps even though they don’t measure as well (not as tight tolerances, higher ESR, slower slew rates, etc.).  Even resistors matter and I know builders who prefer old carbon composition resistors over the latest offerings with ultra tight tolerances.

IMHO, making vintage gear reliable involves a lot more than coupling caps and tubes.

Much vintage tube gear contains carbon comp resistors which are hygroscopically reactive, and when they go out of spec, rather counterintuitively, they increase in resistance. So all carbon comp resistors should be checked. Sometimes, they can be oven baked to get them back in range.

The next problem is usually line voltage, which at my place runs around 122V. Most vintage gear is designed to run at 115-117V, so this should be addressed if ones line voltage is high. A bucking transformer, variac, or even a couple of thermistors in series should knock down the voltage.

And if the vintage tube gear is stereo, a fair amount of it will have PECs in it. They can last forever, or they can go tomorrow. I replace most of them with discrete circuits, YMMV.

And common selenium, or "top hat" diodes, suck and release toxic gas if they give up the ghost, so they should be replaced with modern diodes. The problem here is that modern diodes are more efficient and the downstream voltage will rise, necessitating a dropping resistor.

And back in the day, tubes were cheap, so much vintage gear runs the output tubes hard. A problem that is exacerbated by higher line voltages. Especially if using new production output tubes, bias voltage will need to be adjusted, some vintage gear does not allow bias adjustment, so a work around needs to be installed.