How It's Made - vacuum tubes

when it comes to sound quality audiophiles swear by amplifiers which contain vacuum tubes to boost and modify the electrical signal they were the norm until transistors came along in the 1950s many audio enthusiasts still prefer tube sound which they find warmer richer and more natural [Music] once standard in radios photographs and televisions today you see vacuum tubes only in very high-end audio equipment they come in an array of models designed to perform specific sound enhancing tasks technicians at this Czech factory first wind wire a precise number of revolutions with a very specific degree of tension then they clean the surface and weld it to a support structure this completes the grid one of the tubes main components next technicians take the second main component the cathode and insert it into the grid when the sound signal enters the tube the cathode produces a flow of electrons the grid controls that flow as it travels to the third main component the anode the anodes top-secret black coating increases the effect of the electrons hitting it causing the anode and cathode to have two different voltages both of which are greater than that of the original signal this makes the signal larger and more powerful meaning it amplifies the sound with those three components now assembled into one unit the inside structure of the tube is complete now for the ball which will encase the unit a glassblower skillfully crafts it out of hard laboratory grade glass using a high temperature torch in glass making tools he melts the open end and seals it off then he blows in a bit of air to shape the end into an evenly rounded dome now he mounts the bulb on a lathe to complete the shaping keeping the glass evenly heated he blows in just enough air pressure to keep the ball from collapsing inward when the glass reaches just the right temperature a die presses against it setting the final shape next they mount a glass collar over copper wires clamped into a motorized vise then insert a glass straw called an evacuation port as the vise rotates they heat the collar uniformly with stationary torches using a handheld torch they remove any stretches or runs in the soften and glass when the time is right they activate a die to press the glass into the final shape this completes the stem on which the tubes inside structure sits the wires protruding from the top of the stem connect to the structures terminals [Music] now they put this assembled unit on a turntable and center the bulb over it [Music] as the turntable revolves they heat the bottom of the ball as the glass melts they press it inward fusing it to the stem they remove the excess glass and continue heating to ensure the bottom is fully sealed next they prepare to suction out the air this step is critical to the tubes performance because air molecules hinder the flow of electrons technicians fuse the tubes evacuation port to the glass evacuation line of a vacuum pump the pump then extracts the air through the port at the same time they heat the tube in a pulldown oven this increases pressure inside the tube creating a stronger vacuum next they run an inductive heater over the tube this dislodges damaging impurities enabling the vacuum pump to draw them out they target the stem area with a second inductive heater to draw particles called ions onto the glass permanently so that they can't later damage the two finally they connect the protruding wires to a plastic plug in base there are subtle technical differences between tubes of the same model so the factory tests each tube then matches pairs with similar performance features this ensures though amplifies sound evenly [Music]

Channel: morrisonAV

Views: 531,801

Keywords: How It's Made, vacuum tube, audio equipment, KR Audio

Id: 8n4WVRKkmww

Length: 5min 1sec (301 seconds)

Published: Fri Dec 23 2011

Reddit Comments

[u/TheDanielHolt]

Just when you think they're done, it gets a little more crazy

[u/del_rio]

The sad state of the audiophile community. In the comments, one user gets downvoted below the threshold for asking "...forgive me if i sound ignorant; but why are vacuum tubes even being made? we've had transistors for decades now..."

[u/22travis]

beautiful

[u/sudosudont]

Here are some details about the company featured:

http://www.stereomojo.com/KR%20Audio%20Kronzilla%20SX1%20Mk%20II%20Review/KRAudioKronzillaSX1MkIIAmplifierReview.htm

[u/OJNeg]

Kronzillas are crazy stuff. Specially designed for audio by those guys.

[u/faceman2k12]

Here is a review of the Kronzilla DXL power amp (with the massive T-1610 tubes)

[u/jcwitte]

Wow. I was shaking my head in disbelief the entire length of that video. Amazing!

[u/[deleted]]

Incredible.