PLATINUM TUBES
EM 84 Tuning Indicator Pair (2 Tubes)

EM84 Tuning Indicator (Magic Eye) Ei Pair (2 Tubes)

The EM84 tuning indicator, or magic eye, was used to display the optimum tuning point of a receiver, or the recording level of a tape recorder. The main benefit in reception was for FM radio where the exact tuning point was harder to determine than for AM.

Sensibly equivalent to: 6E3P, 6FG6, CV5434

Can be used with DIY Boards such as:
ebay.com/itm/Magic-Eye-6E2-EM87-6UH6-EM84-Tube-Audio-Indicator-Low-Level-Input-DIY-Board-/331876232557?hash=item4d455d6d6d:g:nDoAAOSw9eVXV~Cx

This valve is in a standard thin glass tube envelope with a phosphor strip on the inside of the glass. The electrode structure is based on a double triode with common cathode. The anode of the second triode is called the target and within the electron stream is a deflector electrode designed to alter the path of the electron beam, it would normally be connected to the anode. In the EM84 the quiescent condition was two green bars, one at each end of the window. As the signal strength increased the bars would elongate and eventually overlap to form a bright green region. The optimum point for tuning was a minimum gap.

No Returns; Will exchange defective tubes free of charge for 60 Days

WHY PLATINUM TUBES?

 

Platinum Tubes  

   Once purchased and received by Platinum Tubes, vacuum tubes undergo exacting quality control measures to further assure reliable, sonically acceptable performance. Power output tubes are first mounted in test fixtures and burned in for 24 hours. This burn-in helps stabilize the internal operating parameters of the tubes before measurements begin. Each power tube is then tested and graded for technical characteristics specified by platinum tubes engineers. Only after a tube successfully passes these exacting challenges is it labeled and put into stock to be sold. Tubes not meeting these criteria are rejected to the supplier or disposed of.

 Average tube life will depend on several parameters: product type, how the product is installed, loudspeaker efficiency, room size and acoustic damping, listening habits or average sound pressure levels, A.C. line stability and purity, and other circumstances. Generally, preamplifier tubes last up to 5,000 hours, while power amplifier output tubes will last up to 3,000 hours. Near the end of their useful sonic life, aging vacuum tubes may degrade the sonic character of the product(s) they are used in. The sound may become somewhat dry and lifeless, with a noticeable decrease in harmonic richness or bloom. Bass response may be diminished, and musical dynamics may flatten out or compress. Toward the very end of their service life, tubes may become noisy, noticeable as a slight rushing sound or rustling noise. It is far better to replace vacuum tubes prior to the end of their service life, before severe sonic degradation or outright failure occurs. Running vacuum tubes into failure may damage to other internal components and cause needless repair expense.

Factors which can shorten tube life include inadequate ventilation, overdriving loudspeakers at continuously high volume levels, severely fluctuating A.C. line conditions (e.g. sagging line voltage during summer peaks of air-conditioning demand), or severe interference pulses or electromagnetic interference.

SHIPPING INFORMATION

U.S.A. $3.00 (USPS Air Mail)

International $15.00 (USPS Air Mail)