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Old 6th November 2009, 09:39 PM   #11
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Exactly what I'm looking for, I can buy some of these tubes, really cheap and NOS!
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Old 7th November 2009, 02:04 AM   #12
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EL86 is a low voltage, high current tube and will go into runaway with a screen above 250V and it certainly doesn't like a plate voltage higher than 300 either.

2 x PL84 will deliver 20 watts clean and 28 watts peak into a 3200 ohm P-P load.

I use EL86 and PL84 a reasonable amount and they are deffinately different animals than the EL84.

Sonically, they sound like baby EL34's, IMO

Cheers!
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Old 7th November 2009, 11:37 AM   #13
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Default Pl84

they cannot deliver that power, clean or not clean, its below 20W. thats a fact. the output transformer takes its toll as well. plate dissipation still is 12W.
or, the measuremnts / calculations were totally wrong to come to this result.
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Old 7th November 2009, 12:03 PM   #14
davorin is online now davorin  Croatia
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Yes pair of EL86 can give 23W in my guitar amp (Ua=265V, Ug2=225Vstab., Ug1=-24V, Ra-a=5Kohm, THD<2%/20W/1kHz, phase splitter-LTP with 6J6WGT and pre-amp with Russian 6H2P-EV), very clean and dynamic, and the same pair of tubes work more than 5 years.
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File Type: jpg 6CW5-EL86-a.jpg (93.3 KB, 407 views)
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Old 7th November 2009, 12:45 PM   #15
davorin is online now davorin  Croatia
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I have some pictures when build amp., but not schematic diagram in electronic form. 6CW5 and EL86 are the same tube, and I used pair of EL86 tubes ("EI"-"Elektronska industrija"-Nis/1989y.). Output transformer is with M85b iron (Prim=4x450w, Sec4/8=52+20w), and main transformer(EI96-12cmcm) have 205Vac/0,4A HV-sec., 30Vac/0,04A bias sec. and 6,3Vac/3A.
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Old 7th November 2009, 07:28 PM   #16
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Default El86

you may see on a datasheet, after 17W OP with EL86 is not any clean power, its way up over 10% THD. if the tubes run over their specified data some extra power maybe available.. if your testinstrument reads the RMS of the Voltage including the harmonics!!! it may look that there is more power available. 2% at 23W is not possible with this tube even at an Rp so low which can give higher power with more THD. If you measure at a speaker this may seem something reasonable bcc. it has its own EMF, but measure at an resistor may give a different value. we have tested this all in the 1960's already. your datasheet makes no difference to the data presented by philps or mullard. also in your point of operation must be some crossover distortion, which is very ugl for the ear. ( at least in HiFi terms!
but as for guitar a player, things in sound look completely different, you maybe happy with your acoustical results! if there is a differens of some watt to the datasheet of 3dB ( means double or half the power) , barely no one can notice that. human ear....
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Old 7th November 2009, 07:34 PM   #17
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Default forgotten

by the way: Ei tubes have been nice sometimes, we loved them, if the QC in the factory did a good job. to my personal, i regret, that they are closed. as far as my info goes. western electric / telefunken have something in mind with them. many of the old tooling etc is still available they answered to me, including ECL86 which is way better than ECL82, for audio. i wish, they can find a way back into vacuum tube business.! i myself was some time with telefunken and there is a link to Ei as you may know.
happy playing!
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Old 7th November 2009, 10:04 PM   #18
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Quote:
Originally Posted by tubesteve View Post
they cannot deliver that power, clean or not clean, its below 20W. thats a fact. the output transformer takes its toll as well. plate dissipation still is 12W.
or, the measuremnts / calculations were totally wrong to come to this result.
I'm not the only one to come to this conclusion.

Stop reading datasheets and start building. Then you'll see for yourself

Cheers!
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Old 8th November 2009, 12:21 AM   #19
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I must say I'm pretty interested on this thread, always wanted info about Pl84's. I thought its max plate voltage was 200V...
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Old 8th November 2009, 08:05 AM   #20
Arnulf is offline Arnulf  Europe
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With some 175V quiescent (which looks like a reasonable operating point) you're bound to end up way higher than 200V on peaks so that can't be the case.
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