GUEST ARTICLE

DESCRIPTIONS OF VARIOUS EL-84 TUBES Our thanks for this month's guest article on EL-84 tubes goes to Mike Zaite of DR. Z AMPS. - John Grimm (Vintage Music)

DESCRIPTIONS OF VARIOUS EL-84 TUBES
EL-84’s have been used in many guitar amps through the years, most notably VOX’s, but other manufactures have also found the sweet sound of 84’s a great sound prescription for lower powered combo amps. Gibson’s RVT-79 is an excellent example of pairs of 84’s used in stereo, driving a Jensen 10-inch speaker per side. Marshall’s rare 18 and 20 watt 84 driven head’s are highly sought after for studio use, and WEM Dominators are leading the new British invasion, used by such groups as Oasis. Even Fender experimented with 84’s 30 plus years ago, using them in a version of the Tremolux. With the advent of lower powered tube amps becoming in vogue, the logical choice for many designers was the EL-84. Many players are not as familiar with 84’s , as say 6V6’s or 6L6’s the American standard output tubes. With their availability, low cost, and great musical distortion I feel 84’s will be used well into next decade to power guitar amps, I will attempt to explain the variations of 84’s manufactured by different tube companies.
SOVTEK EL-84 (standard grade ) - These tubes are affectionately called STOVE-TOPS, due to their low plate and screen voltage requirements. They aren’t as rugged as some 84’s, but have a warm, thick, clean sound and a very focused distortion. Top to bottom they are well balanced with a very transparent mid-range response. As I stated earlier, if installed into a properly designed circuit, (ie. plates and screen voltages under 320 volts ) they will last many hours. Great Blues tone, nice sustain with moderate attack.
SOVTEK EL-84M ( Military Grade ) - Not designed for audio applications, will handle higher voltages in a poorly designed amp, but sound flabby on the low-end, with splattered distortion. Wattage is increased by use of these tubes, but at the cost of tone.
TESLA EL-84 - Strong, long lasting, and powerful tube, a drop in replacement for HI-FI amps using the rare and discontinued 7189. Increased output power will be noticed when using this tube. Its strengths are its lower mid and bass response, very punchy, but be careful of its top-end -very transient and edgy. Again when used in properly designed circuit, this tube excels in head room and balls. Great rock tone, punchy , with strong attack..
EI EL-84’s - Unfortunately these tubes are very inconsistent and prone to premature failures. I say unfortunately because a good matched quad sounds fantastic. Copied after the Amperex 84, they stay together when overdriven with a great dimensional sound. Their poor QA makes me shy away from using them in my amps. Full bodied and versatile, sound much like a good 6V6.
-Mike Zaite
Mike can be reached at:

DR. Z AMPS
7523 Grand Division
Cleveland,Ohio.44125
USA
Phone 216-429-2922
Fax 216-581-7577
DR Z's web site is a recommended visit click here
His E-Mail is DRZ@icgroup.net
Here's some previous month's guest articles guitar tone by CyberMonk and Mr. Keen's Tube Faq