gorgon53 said:I even got data on 6l6 where it is rated at only 18W anodepower
(depends on the operationconditions and live-expectations)
Right.
6P3S-E (so called long live version) was rated for 5W of output power only.
gorgon53 said:There was also a type P50, a offspring off the LS50 used in early Telefunken television sets
After the war Telefunken simplified construction and made EL152.
They were also ray pentodes, cheaper construction, but anyway they were expensive because they were as well ray pentodes. Ray tetrodes are cheaper, that's why they won evolution, but ray pentodes sound much better. They are more linear.

btw, 6L6 is very old, only AFTER RCA adopted the "Kinkless Tetrode" =KT design from english MOV the 6L6 was a sucess and serious competer for Philips EL34, Marconi went on improving theyr own KT serie and gave us the KT 88 we know today
withg almost zero secundaryemission from the plate of a beampowertetrode there is no need for a supressergrid, so, pentodes are only of advantage IF you have the grids not aligned
Btw, if any of you guys ever come across a EL3010, grab it, from a enginers point of view it is the best tube ever made. I could not say anything about the sound of it, I used it back in the 60th in a broadbandamplifier (8W, 500Hz-500kHz, +-10%) for a EG-meter
gorgon53 said:Btw, if any of you guys ever come across a EL3010, grab it, from a enginers point of view it is the best tube ever made. I could not say anything about the sound of it, I used it back in the 60th in a broadbandamplifier (8W, 500Hz-500kHz, +-10%) for a EG-meter
Hmmm.... Thank you... Overprised EL34 vs underprised GU-50? I choose the last one.

and Waveborn, your advice to me to READ Datasheets more carefully isnt justyfied, I WROTE DATASHEETS...long time ago....
and I cannot look up everything I once did...I just try to remember s good s I can....
and I cannot look up everything I once did...I just try to remember s good s I can....
gorgon53 said:and Waveborn, your advice to me to READ Datasheets more carefully isnt justyfied, I WROTE DATASHEETS...long time ago....
and I cannot look up everything I once did...I just try to remember s good s I can....
Indeed you have quite good memory!
Thank you for interesting discussion!
I have to go now, to install equipment that includes GU-50 stereo vocal amp for today's concert!

Had to look up some of my datacollection on one of the last, and certainly best ever allround-pentode (optimized for Rf and Af) developed by Telefunken, a absolute MASTERPIECE of german enineering and manufacturing skill back in the 60th
(just before Transistors wiped finally out any further investments into Tube-developement)
EL 3010
Messwerte: Grenzwerte:
Uf 6.3V/12.6V Uao 2000 V
If 2.2A/1.1A Ua 900 V
Ua 350V Qa 35 W
Ug2 160V Qg2 5.5 W
Ia 100mA +-15% Qg1 0.1 W
Ig2 13mA (max16mA) Ik 0.35A
S 50mA/V +-9 Iksp 1.5 A
Ug +15V
Rk 200 ohm
Röhrenausfallsrate 0,15% pro 1000 stunden Betriebszeit
mindestens 10000 Stunden Betriebszeit ueber 100 Röhren gemittelt
Enge Toleranzen
Stoss und Vibrationsfestigkeit
Zwischenschichfreie Spezialkathode
(just before Transistors wiped finally out any further investments into Tube-developement)
EL 3010
Messwerte: Grenzwerte:
Uf 6.3V/12.6V Uao 2000 V
If 2.2A/1.1A Ua 900 V
Ua 350V Qa 35 W
Ug2 160V Qg2 5.5 W
Ia 100mA +-15% Qg1 0.1 W
Ig2 13mA (max16mA) Ik 0.35A
S 50mA/V +-9 Iksp 1.5 A
Ug +15V
Rk 200 ohm
Röhrenausfallsrate 0,15% pro 1000 stunden Betriebszeit
mindestens 10000 Stunden Betriebszeit ueber 100 Röhren gemittelt
Enge Toleranzen
Stoss und Vibrationsfestigkeit
Zwischenschichfreie Spezialkathode
50 mA/V means input capacitance like MOSFET, right? 😎
Anyway, indeed it is impressive tube. Probably, I would swap GU-50 on it, however if prices would be comparable.
Anyway, indeed it is impressive tube. Probably, I would swap GU-50 on it, however if prices would be comparable.

Wavebourne, dont be silly, I used this tube with a E88CC as the driver, in application needing 8W+-10%, between 500Hz 500kHz!!!
2 of those tubes can giv you 12W at 1% thd
100 5%
120 10%
you can get 120W with a Uin of 10Veff into a Ce of 50pF
2 of those tubes can giv you 12W at 1% thd
100 5%
120 10%
you can get 120W with a Uin of 10Veff into a Ce of 50pF
Wavebourne, tell me how you squeezed out 120W from those GU50?
Telefunken wasnt able to do that with theyr LS50 wich is rated for use by the Luftwaffe, or RL12P35 with its to 35W derated anodepower for use by the Wehrmact or the 40W rated civilian version EL152, all seem to be electrically the same tube (exept for theyr ratings and sockets)
digged out my old Telefunken Databooks and checked
Best what Telefunken was able to get out from a pair of EL152 was 85W, a bit more than 90W could be achieved with some gridcurrent.
This at 1000V on the anodes and 360V on g2 and a supricingly low Rg of only 25kohm.
Offcourse you had only a Ce of 14.5pF wich isnt much of a achievment with a tube that offers a steepness of only 4mA/V
Telefunken wasnt able to do that with theyr LS50 wich is rated for use by the Luftwaffe, or RL12P35 with its to 35W derated anodepower for use by the Wehrmact or the 40W rated civilian version EL152, all seem to be electrically the same tube (exept for theyr ratings and sockets)
digged out my old Telefunken Databooks and checked
Best what Telefunken was able to get out from a pair of EL152 was 85W, a bit more than 90W could be achieved with some gridcurrent.
This at 1000V on the anodes and 360V on g2 and a supricingly low Rg of only 25kohm.
Offcourse you had only a Ce of 14.5pF wich isnt much of a achievment with a tube that offers a steepness of only 4mA/V
Hey
I can se that EL3010 cost a lot of money
There are 5 pcs at Ebay.de Price €1000.
That is a lot of money
Benny
I can se that EL3010 cost a lot of money
There are 5 pcs at Ebay.de Price €1000.




That is a lot of money
Benny
gorgon53 said:Wavebourne, tell me how you squeezed out 120W from those GU50?
Actually, I did not squeeze.
I experimented, what if to replace 4x6L6 by 2xGU-50. I expected to get the same 80W per channel. I rearranged a power supply to get 375+375V instead of 375V. I used 300V regulated to power phase splitter and screen grids. However, GU-50 specifications require no more than 250V on grids, but I decided to experiment and see if they surwive. They actually did, no glow. When I measured max output power I got about 120W on 1 KHz frequency. Then I measured output power of my 4x6L6 prototype and indeed got about 80W. For 6L6 version I used 4K guitar transformers, for GU-50 version I used 6K guitar transformer. I need this amps for vocal and acoustic guitars, so transformers satisfy me absolutely. For home theater I have an isobaric low-Q horn subwoofer powered by bridged 800W transistor amp, so I need frequencies only from 80 Herz from a stereo amp, it is more than plenty, so guitar transformers fit perfectly.
Conclusions: Soviet GU-50 can be used like Telefunken LS50 despite specs require more relaxed applications. They are amazing tubes and I love them. I recently bought hundred of such tubes, now going to sell on ePay all sweep ray tetrodes I bought before, like 6LW6 and similar.
gorgon53 said:
Best what Telefunken was able to get out from a pair of EL152 was 85W, a bit more than 90W could be achieved with some gridcurrent.
This at 1000V on the anodes and 360V on g2 and a supricingly low Rg of only 25kohm.
Offcourse you had only a Ce of 14.5pF wich isnt much of a achievment with a tube that offers a steepness of only 4mA/V
Hmmm...
Attachments
Hojvaelde said:Hey
I can se that EL3010 cost a lot of money
There are 5 pcs at Ebay.de Price €1000.![]()
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That is a lot of money
...or a big box of GU-50 tubes.
😀
Hi wavebourne
Yes those EL3010 are expensive, if I remember correctly the last time I asked for a offer for this tubes (sometimes in the 70th) Telefunken asked sometging that equalled a month salary for a pair, they always have been very very expensive but in some measuringequippement-application they are despite of this a good choice, other choice would have been 4 E55L instead of 1 EL3010 wich wasnt exatly cheap either
will get back later, gotta run now
tc
Yes those EL3010 are expensive, if I remember correctly the last time I asked for a offer for this tubes (sometimes in the 70th) Telefunken asked sometging that equalled a month salary for a pair, they always have been very very expensive but in some measuringequippement-application they are despite of this a good choice, other choice would have been 4 E55L instead of 1 EL3010 wich wasnt exatly cheap either
will get back later, gotta run now
tc
Hi Benny
cool that you could find those tubes, I looked out for them very often, thougth maybe nobody knows them and if I am lucky I could get some cheap, lol
well, cheaper than 200bucka a piece ;o)
200 is to xpensive 4 audio, offcourse a OTL would safe some money that otherwise would have to be wasted on outputtransformers but still....is to expensive....and even 5(4) of those would not be nearly enough...better to use a box of E55L then, lol
cool that you could find those tubes, I looked out for them very often, thougth maybe nobody knows them and if I am lucky I could get some cheap, lol
well, cheaper than 200bucka a piece ;o)
200 is to xpensive 4 audio, offcourse a OTL would safe some money that otherwise would have to be wasted on outputtransformers but still....is to expensive....and even 5(4) of those would not be nearly enough...better to use a box of E55L then, lol
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