EL84m
Moderators: pompeiisneaks, Colossal
Re: EL84m
There are to my knowledge 3 basic types of Russian el84's used in guitar amps. The overwhelming majority are the ones in sovtek labeling, a rugged if not optimal sounding version.
The el84m is a mid grade version, it has better bottom and mids, and astonishingly defined and complex upper mids and top end, especilly dirty. There is not a large difference in construction between these two types.
The top grade of Russian el84 I've experrienced is the one labeled (in my ignant interpretation of cyrillic) 6p14p-ev. This one is a different animal, it has a bit of mutant hybrid monster vigor in it's bones. The design is for a low frequency pentode, I'm guessing of the type often used to power servo equipment in aircraft or rockets. That calls for a massive cathode, and this tube has it, a big, thick tube that takes 40 seconds to warm up.
It is rated for 5000 hour use at max plate voltage of 400 volts. Standard el84 plate voltage rating is 300. The plates are physically larger in surface area than just about any el84 I've seen. The glass bottle is thicker and much heavier, I've read that it's leaded glass. Well, the bottles are a bit grayish in the glass color...Pick up a couple of discontinued EI el84's in one hand and a pair of these in the other, the difference in heft is shocking. In the tone department, these are one of my top three fave el84/7189types. Tops for clean headroom with rich thick bottom, full mids, and well represented top end and harmonic content, these tubes are among the fullest, thickest, most wonderfully voiced el84's to play through when diming your amp. I have several hundred hours on a quad in a very hot biased Mesa Boogie Maverick, their plate draw at factory bias fried the PT after a four hour outdoor in the sun city park stage situation. So my tech fabbed out an original design bias control knob for varying the cathode voltage. Those tubes are still in there and sounding like they are just broken in, still tightly matched in current draw with very little individual draw drift over all that time of use. my #2 fave is the German RFT el84, another serious, 7189 voltage rated tube, full and rich in tine like their Siemens labeled el34's. Next comes the Philips family el84's from Mullard and Amperex, astonishing harmonics and maintenance of note clarity.
ummm...Fave el84 type of all time has different pinout, is Bendix 6094, 15 watt rated el84 sized socket and bottle of super thick and high temp rated glass... I have a simple boutique amp with a pair in it biased to approx 70%, second bias pot for bias balance match. Instant Hendrix "Red House" tone with girth that squashes any other 18 watter I've heard like HAD sitting on a whoopeee cushion...
no offense meant there.
The el84m is a mid grade version, it has better bottom and mids, and astonishingly defined and complex upper mids and top end, especilly dirty. There is not a large difference in construction between these two types.
The top grade of Russian el84 I've experrienced is the one labeled (in my ignant interpretation of cyrillic) 6p14p-ev. This one is a different animal, it has a bit of mutant hybrid monster vigor in it's bones. The design is for a low frequency pentode, I'm guessing of the type often used to power servo equipment in aircraft or rockets. That calls for a massive cathode, and this tube has it, a big, thick tube that takes 40 seconds to warm up.
It is rated for 5000 hour use at max plate voltage of 400 volts. Standard el84 plate voltage rating is 300. The plates are physically larger in surface area than just about any el84 I've seen. The glass bottle is thicker and much heavier, I've read that it's leaded glass. Well, the bottles are a bit grayish in the glass color...Pick up a couple of discontinued EI el84's in one hand and a pair of these in the other, the difference in heft is shocking. In the tone department, these are one of my top three fave el84/7189types. Tops for clean headroom with rich thick bottom, full mids, and well represented top end and harmonic content, these tubes are among the fullest, thickest, most wonderfully voiced el84's to play through when diming your amp. I have several hundred hours on a quad in a very hot biased Mesa Boogie Maverick, their plate draw at factory bias fried the PT after a four hour outdoor in the sun city park stage situation. So my tech fabbed out an original design bias control knob for varying the cathode voltage. Those tubes are still in there and sounding like they are just broken in, still tightly matched in current draw with very little individual draw drift over all that time of use. my #2 fave is the German RFT el84, another serious, 7189 voltage rated tube, full and rich in tine like their Siemens labeled el34's. Next comes the Philips family el84's from Mullard and Amperex, astonishing harmonics and maintenance of note clarity.
ummm...Fave el84 type of all time has different pinout, is Bendix 6094, 15 watt rated el84 sized socket and bottle of super thick and high temp rated glass... I have a simple boutique amp with a pair in it biased to approx 70%, second bias pot for bias balance match. Instant Hendrix "Red House" tone with girth that squashes any other 18 watter I've heard like HAD sitting on a whoopeee cushion...
no offense meant there.
