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Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Yamariv, Sep 5, 2019.
Which model are you referring to?
Straighten me out here. I’ve been using 6N14Ns to replace EL84s. Wasn’t aware of 6P14Ps. The 6N14N I put in a MAZ38 and a modified Blues Jr.
Correct: The Cyrillic alphabet uses a "pi" symbol for the "p" sound. Since pi isn't a letter in our alphabet, it's often read as "n".
Ok that’s it then.
Yes same tube N or P but there are other end codes like EV and K that are different spec'd versions of the 6N14N's
The 6P14P-EV are supposed to be longer life and more rugged.
Question: Doesn't DR Z use the standard, non ruggedized 6n14n [ same exact tube as the 6p14p] in the Z-Wreck amps? Don't the Z Wrecks have a higher B+ voltage?
I'm not being smart, I honestly want to clear this up and know if they will cook in my Ceriatone clone!
Z has commented that he prefers the sound of 6P14P vs 6P14P-EV. I can’t hear the difference. I have both and use them vs EL84.
BTW if you get or have EL84 tubes with flying saucer getters they are rebranded reflector 6P14P. Just FYI
I had a couple crate VC30's that ran hot cathode biased el84s in a 1x12 combo. That's a harsh environment for power tubes. The tubes were mounted in a cantilever configuration, protruding from the back of the amp towards the speaker, parallel to the ground. You'll never get 5000 hrs out of a set of tubes in that environment.
After trying a couple different brands, I just considered the tubes consumables and replaced with JJs.
I would like to know what the original engineering purpose would have been to bias the output tubes well past max plate dissipation in an AC30. The typical bias resistor in a 2 EL84 amp is 120-130 ohms which can be over dissipation. 4 EL84 amps are usually 60-70 ohms.
Another question, how do NOS Mullard, Tungsram etc fair in durability compared to the Russian 6P14P-EV military tubes?
Is it foolish to spend the high dollars on NOS EL-84's vs Russian EV's when running them hot in a VOX type amp?
My guess is:
"Wow, this amp is only 30 watts? I'm shaking my whole house!!!! I'll buy it now!"
Also, maybe Denney over-biased AC30's because so many players from history thought the AC15 wasn't loud enough. Maybe the original AC15s were much more conservatively rated? Then he goosed the AC30 to snag even more volume (or at this point, smooth compression).
I’ll probably get some flack on this but biasing really hot doesn’t make it louder, it actually costs you power because it’s wasting voltage/current idling. That sags down the power supply before its even being used to amplify. The only reason I could think is to counteract bias excursion under full overdrive. If you play it really hard all the time the tubes are getting a break from excessive dissipation. If you don’t play loud it’s tough on the tubes.
Dr Z uses the Soviet Union Era (Pre 1992) 6n14n Reflektor in his MAZ Jr's from the factory. MAZ Jr's run pretty hot, I happen to have a couple MAZ Jr's, and just finished burning in and measuring a 200ct bulk pack of 1985 6n14n's (standard grade). I took a pair of lower ma and a pair of higher ma to see what they looked like in the MAZ Jr (serial #0001 btw):
60EAA7A5-F506-471F-9D8A-729D090A041F by PerryR posted Oct 9, 2019 at 8:22 PM
4696B8FE-A4EA-4D61-8F77-03C4E8B6B0B0 by PerryR posted Oct 9, 2019 at 8:22 PM
Close to a 10% difference between the lower and higher measuring 6n14n matched pairs.
Its interesting to note that the standard Soviet Union Era 6n14n measures lower ma when compared with ANY other EL84 I have tested. If you bell curve the 6n14n ma measurements the majority fall between 15-19ma (sample size 500). I have measured JJ, GT, Sovtek, EH, EI, Tungsram, NOS Mullard, Siemens, they generally measure in the mid 20's to low 30's under same test parameters.
Its possible that the Soviet Union Era 6n14n may run a touch cooler, depending on the set... particularly if compared with a high measuring set from the new production stuff. I do not get reports of red plating, and I know players are running them in AC30's. Thats not to say they will do fine in an AC30, I haven't personally tested or kept records, though I do know they do fine in my Zwrecks and MAZ amps... and Ken Fischer specifically fingered this tube as the best choice for an AC30 (back when Tungsram, EI, and NOS US were still pretty available).
The one thing i have noticed in combos, and only in combos, over time the vibration can take its toll and develop a lower frequency ring. If you start to notice your combo feeding back, sustaining better, and howling in a good way at high volumes it may one of them 6n14n assisting lol! One of my Zwreck combos with a Germanium Fuzz plugged in would feedback and howl much better than the other, I figured it was just special. But over time I started noticing this lower frequency note overhang, so I plugged the amp into a different speaker and it cleared right up. Thought maybe my combo speaker was having issues.. nope, it was one of the 6n14n. So, Amp heads no problem, for combos.. there is a chance of shorter life due to vibration. Might have to replace a single if the set isn't very old, or just roll with the enhanced sustain.
Those Flying Saucers are the simplest way to identify the standard 6n14n design. The new production may still be made by the same factory, I don't know. What I do know is that Reflektor was a military supplier, and the demise of the Soviet Union in Dec 1991 had huge impact on the Russian Military Industrial Complex. New Sensor leveraged their existing relationship and partnered, and now I think they basically own it. But during that change, the tubes changed, its simple to spot a Soviet Union Era 6n14n (standard), or at least ones that were manufactured with the same parts. Back in the 90's Sovtek, Groove Tubes, even Mojo Tone had the good ones available (with their own branding).
I have 6n14n sets from the 60's, 70's, 80's up to 92'.. they look the same and sound the same.. the 60's may be a touch crisper. The early 90's rebranded stuff was the same as well. But some time during the 90's there was a change in parts (and maybe manufacturing), maybe a parts vendor went under or maybe the parts were military specification that could no longer be produced, who knows, something changed. What I do know is that the quality in the Soviet Union Era 200ct bulk packs I get is excellent, maybe 1 in 400 triggers a fault or wont stabilize. Most drift 10% or so, but after burn in they settle real nice and sound great.
Well, I'll be the Guinea Pig. Put a quad of Tungsram's in my amp, and much prefered the tone of the 6P14P tubes. They have a more brilliant clean tone and more presence. Also the Tungsram pins are too thick. I'm gonna have to retension all the sockets now.Kind of disappointed.