Vacuum Tubes

Black Diamond Series Vacuum Tubes

TELEFUNKEN vacuum tubes have been the benchmark of excellence in all audio applications, both production and reproduction, for many decades. This rich history continues with the introduction of new production tubes from TELEFUNKEN Elektroakustik, in partnership with JJ Tubes from the Carpathian Mountains of Cadca in Slovakia.

Each tube is meticulously measured for all critical parameters of performance including transconductance, gain, noise, and microphonics. All TELEFUNKEN branded tubes are hand picked to be the best examples of Eastern European construction in the proud tradition with which the name TELEFUNKEN Elektroakustik has become synonymous.

In addition to the rigorous testing procedure, all new production TELEFUNKEN tubes are cryogenically treated to ensure durability, and subjected to an extended burn-in period to ensure superior stability. The tubes are re-measured subsequent to burn-in in order to guarantee that only the best, lowest noise tubes are offered for purchase through your TELEFUNKEN Elektroakustik reseller.

ECC83-TK (12AX7)

Developed by RCA and released in September of 1947, the 12AX7 is a high gain / low noise tube that is the most popular tube used in input / inter-stage audio amplifiers. The dual triode design makes the 12AX7 compact, relatively inexpensive, and produces a high quality full frequency response....

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The ECC82 is a dual triode vacuum tube with medium gain and low noise characteristics, making it ideal for hi-fi audio equipment and instrument amplification. Commonly used as a low-noise line amplifier, driver, and phase inverter in push-pull amplifier circuits, it can replace an ECC81/12AX7....

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E88CC-TK (6922)

Also known as the 6922, the E88CC was originally targeted for test equipment and radar. The E88CC has medium gain, low noise and is a favorite for tight sounding audio input stages. There are some that will argue that the E88CC is the best sounding input tube ever designed....

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The EL-34 is smaller in diameter and taller than the 6L6, but it runs on a higher plate voltage, which gives the EL-34 its unique output stage properties. The EL-34 is a high output pentode tube as opposed to other output tubes like the 6L6 and the 6550, which are beam tetrode tubes....

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Originally designed for the output stages of audio frequency amplifiers, the EL-84 can deliver up to 17 watts. Commonly found in smaller guitar amps, this pentode tube can really deliver. In many ways it is similar to the EL-34 but without the output "horse power"....

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The 6L6 was developed more than 70 years ago as the first power tetrode. It produced 19 watts of power, and was the first "beam power tube". The 6L6 was first developed as an alternative to the high output pentode designs, which Phillips had under patent at the time....

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Originally released in 1937 by RCA, the 6V6 is a beam-power tetrode vacuum tube ideal for use in hi-fi audio equipment and music instrument amplifiers. The 6V6 has been used in popular guitar amplifiers such as the Fender Champ, Princeton Reverb, and Deluxe Reverb for decades....

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Tung-Sol developed the 6550 in 1955 for use as a servo amplifier and in industrial applications. Based on the 6L6, the 6550 was designed to have more gain than the 6L6, and better stability....

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The KT88-TK is a beam-power tetrode that shares similar applications as the 6L6 and EL34, and is one of the largest tubes in its class. Originally introduced by GEC in 1956, it became competition for the American-made 6550, but with the ability to handle a much higher plate voltage of up to 800....

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The GZ-34 isn't a very talked about tube, but it is one of the most common rectifier tubes found in audio, especially in guitar amps. Rectifier tubes were some of the very first tubes to be invented since their purpose is one of the first requirements in electronic and audio design....

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What is the difference between Black Diamond Series vacuum tubes and the JJ-branded tubes?

The TELEFUNKEN Black Diamond Series tubes are built in the JJ Electronic Factory in Eastern Europe based on their existing models. The Black Diamond Series tubes go through an extensive multi-tier testing and quality control process, as well as a cryogenic treatment in the USA to ensure they are the best representation of European made tubes. Each vacuum tube is burned in for 24 hours, tested for all critical parameters, cryogenically treated, and tested a final time. TELEFUNKEN Elektroakustik guarantees this by branding them with the legendary diamond logo.

What is the cryogenic treatment process?

After the initial 24-hour burn-in process, the Black Diamond Series tubes are placed into a cryogenic processor where a computerized system gradually cools them from ambient temperature to -300 °F (-184 °C), where it remains for 24 hours until slowly returning to room temperature.

What sonic differences will you notice with cryogenically treated vacuum tubes?

The cryogenic process is done for a number of benefits, both sonically and constructional. Cryogenically treated vacuum tubes have a lowered noise floor, less microphonics, expanded dynamic range with more tonal depth, and a more consistent tone for a longer lifespan. In guitar amps, Black Diamond Series vacuum tubes have more harmonic content and improved saturation, which results in a richer tonal quality and deeper overdrive character.

What effect does the cryogenic process have on improving the construction of Black Diamond Series tubes?

The cryogenic freeze process plays a key role in treating and strengthening the tube's internal metal construction. By bringing the tubes to these extremely low temperature conditions, the stresses of the internal metal structure from the high temperature manufacturing process are reduced and settled. This strengthens the construction as a whole. The cryogenic process also aligns the grain structure of the carbon in the metal to be more uniform, which yields a more efficient system with lower operating temperatures, longer life, and improved electron flow. The results are tubes with superior durability and stability. Preamp tubes offer expanded dynamics and a richer tone, while the power tubes are more stable and efficient.

What are the benefits of burning in vacuum tubes?

All Black Diamond Series vacuum tubes are burned in for a 24-hour period at real world voltages. One of the major benefits of burning in is to heat the cathode and remove any impurities or unevenness on the cathode coating. The cathode is the element in the tube that is heated and releases electrons. By burning the tube in, it reduces any popping, static sounds and erratic behavior. This is proven to benefit the vacuum tube's lifespan and durability.

What is the significance of the black ink on the new Black Diamond Series tubes?

TELEFUNKEN's Black Diamond Series tubes have been screen printed with black ink to clearly differentiate them from the original, white inked diamond-based TELEFUNKEN tubes, originally produced in Germany in the early and mid 20th century.

Can these Black Diamond Series tubes be used in TELEFUNKEN Elektroakustik microphones?

Black Diamond Series tubes have been developed for the Musical Instrument and Hi-Fi Audio markets and are excellent for use in applications like guitar amps, preamplifiers and power amplifiers. None of these tubes are currently used in TELEFUNKEN Elektroakustik microphone production.

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