I recently accidently bought some PL 84 tubes. Does anyone have a schematic
for an amplifier using these tubes?
for an amplifier using these tubes?
Pl84
this is the same as the EL86, different heater rating only. you may use this link: http://www.mif.pg.gda.pl/homepages/frank/sheets/030/p/PL84.pdf
this is the same as the EL86, different heater rating only. you may use this link: http://www.mif.pg.gda.pl/homepages/frank/sheets/030/p/PL84.pdf
PL84 is almost the same as EL84 but 15V on heaters, and max plate voltage of 200V. Take an EL84 schematic and stick PL84's! Or just build a class A amp. Take a look at datasheet for data.
Pl84
wrong! bananas are almost like lemons! different operational conditions! different output transformer. please a bit more accuracy in the statements.. a 6l6 is almost the same as an kt88 bcc. similar glass envelope.....
wrong! bananas are almost like lemons! different operational conditions! different output transformer. please a bit more accuracy in the statements.. a 6l6 is almost the same as an kt88 bcc. similar glass envelope.....
Tubesteve is right, EL84 and PL84 are not similar. There are quite a few EL86 designs floating around, refer to one of those (and change heater supply accordingly).
No biggie, it happens to everybody 🙂 This is one of the few tubes where one cannot simply follow the naming convention across different heater series.
More importantly, you didn't mention the credentials of working innards.
Both tubes have specs that are quite different animals. If I went by the envelope/glass shape, this would be fun to see the sparks fly.
richy
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!
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!
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.
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 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.
Attachments
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....
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....
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!
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!
I'm not the only one to come to this conclusion.
Stop reading datasheets and start building. Then you'll see for yourself 😉
Cheers!
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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