Some nice transformers are made by Indel in Poland. Have used these with very good results. For 2X GU50 in PP, the TGL40/001 would suit you good, and for 4X in PPP, TGL60/001 or 002 are fine. The later for 4 ohms load, the others for 8 ohms. The tube GU50 needs about 4-5 kohm in PP, and about 2,5 kohm in PPP. In Europe it is convinient to buy these transformers from Transfer Multisort Elektronik - Electronic components, and they have powertransformers also. Here are some schematics also:
Röhren-Verstärker mit der LS 50 (GU 50)
Röhren-Verstärker mit der LS 50 (GU 50)
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More from Poland:
TTG-KT88PP - Tube output transformer [4kOhm] 2xKT88 / 2x300B Push-pull or similar - Shop Toroidy.pl
Also available from TME:
TTG-KT88PP TOROIDY - Transformer: speaker | TME - Electronic components
I have tested several of the types from this manufacturer and can recommend for hifi amplifiers.
TTG-KT88PP - Tube output transformer [4kOhm] 2xKT88 / 2x300B Push-pull or similar - Shop Toroidy.pl
Also available from TME:
TTG-KT88PP TOROIDY - Transformer: speaker | TME - Electronic components
I have tested several of the types from this manufacturer and can recommend for hifi amplifiers.
If you are in the UK or near by, I always use Majestic Transformers, Poole, Dorset. Tell them what you want, any impedances and special trappings etc, it is designed and made for you. Exactly as you require. Even has your own part number on it!
Electrical Transfomers & Electrical Transformer Manufacturer UK
Electrical Transfomers & Electrical Transformer Manufacturer UK
Wavebourn was your Amp running on BAF?- have read and seen pics- now i wait for some
clips.
Here is what E. Rössler has build a Grommes with different Tubes. The VB408 is never
to get since years.
Gegentakt-Verstärker in AB-Betrieb fuer GU 50
clips.
Here is what E. Rössler has build a Grommes with different Tubes. The VB408 is never
to get since years.
Gegentakt-Verstärker in AB-Betrieb fuer GU 50
Yes, but it was not a GU-50 amp.
Attachments
SMPS
Do you mean my amp? No, made completely in my garage.
I have a similar 813 amp too, but GK-71 are more powerful. And yes, thanks to local feedback around output tubes it was driving Fritz speakers elegantly!
Ah, SMPS- elegant solution.
I only have build with given schematics- little SE Amps with PCL86; EL34(6P3S/-E; 6AS7;KT-88.
Since last year i swapped back to ss builds.
The bigger Tube Animals with HIGH Voltage makes me a bit scary, but much liked by optical view.
Nice to read that it is enjoying 'partnership' Fritz Speaker and the GK-71.
Have to watch more back in Valve Tube.
Where is FLT now- find a solution, any ideas?
I only have build with given schematics- little SE Amps with PCL86; EL34(6P3S/-E; 6AS7;KT-88.
Since last year i swapped back to ss builds.
The bigger Tube Animals with HIGH Voltage makes me a bit scary, but much liked by optical view.
Nice to read that it is enjoying 'partnership' Fritz Speaker and the GK-71.
Have to watch more back in Valve Tube.
Where is FLT now- find a solution, any ideas?
Well, it depends on the plate supply voltage, see here, page 9. E/FL152 and GU50 can be considered as equivalents, as both are sucessors of WWII RL12P50 and LS50 of TELEFUNKEN fame.
Best regards!
an EL34 uni Amp
I have build a EL34 with EF86 SE last winter.
Also tested with 6P3S(-E) and 6P7S(oktal to 807- for lower Plate Voltage)
For use 6P7S you must change two wires on socket, one to Anodecap.
It has a slightly +6db high and low pass correction- and worked super.
The best it has a bias point via little lamp.
With all this tests at last i have a bad grounding contact and seems one OPT
is failed- 6P7S only one channel- the other is sending piping tone to speaker-
that's bad.
All info you find here.
Funk - u. Fernmeldetechnik
I have build a EL34 with EF86 SE last winter.
Also tested with 6P3S(-E) and 6P7S(oktal to 807- for lower Plate Voltage)
For use 6P7S you must change two wires on socket, one to Anodecap.
It has a slightly +6db high and low pass correction- and worked super.
The best it has a bias point via little lamp.
With all this tests at last i have a bad grounding contact and seems one OPT
is failed- 6P7S only one channel- the other is sending piping tone to speaker-
that's bad.
All info you find here.
Funk - u. Fernmeldetechnik
Attachments
Well, plate voltage and load impedance depend on power/distortions ratio that you prefer. LS-50 was designed for mobile operations, with low filament power. It can't deliver as the result adequate current on low anode voltages.
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I received an answer from Mr. Ogonowski yesterday. Very quick, very interesting.
80W or 100W; normal EI core and amorphous C-core. Of course amorphous core
costs more than standard iron...
Now it is my decision...
I dont think that one can hear any difference between 80 and 100W.
Wavebourns pyramid has 80W and it should be enough to make your
neighbours angry.
As for amorphous core: price is about tree times the standard core iron.
I know it is worth it, but right now it is a bit too much.
80W or 100W; normal EI core and amorphous C-core. Of course amorphous core
costs more than standard iron...
Now it is my decision...
I dont think that one can hear any difference between 80 and 100W.
Wavebourns pyramid has 80W and it should be enough to make your
neighbours angry.
As for amorphous core: price is about tree times the standard core iron.
I know it is worth it, but right now it is a bit too much.
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