gorgon53 said:
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.
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
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
gorgon53 said:
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.
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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