Great Unknown Valve Amps? Number of useful vintage industrial, HI-FI and some DIY schematics, shown here are researched after the WW2 until mid sixties. No brand names, just schematics well known and some manufactured only in Eastern Europe. Some scans are from manufacturers blueprints so don't mind the quality.


Short description
Schematics Parts lists
3W single ended amp. /EL 41/  se_3W.gif  se3_part.gif
 Single ended 6 W amp. /EL 6/ se_6w.gif  
 Push-pull integrated 10 W /EL 41/ pp_i10w.gif pp10part.gif
Push-pull 10 W /6V6/  pp_10w.gif  
Push-pull 8 W /ELL 1/ pp_8w.gif  
Push-pull /auto phase inverter -EL 3/ pp_ampsd.gif  
Push-pull triodes amp 6B5/6N6G /without feedback/ pp_20nnf.gif  
 Hi-Fi class B? 100 W PP - 2 x EL 34 at the max limiting values pp_hf100w.gif  pp100prt.gif
 PP - Hi-Fi 35 W, 2 x EL 34  pp_hf35w.gif pp35part.gif
 PP - 70 W, Hi-Fi 4 x EL 34 pp_hf70w.gif



 Integrated PP 6L6 amp 50 Watt pp_i50w.gif  
 Integrated PP 6L6 amp 55 Watt pp_i55w.gif  
 30 Watt Integrated PP 6L6G amp  pp_m30w.gif  
 Public address PP 6P3/6L6 amp 25 Watt industrial production - Mono 25  pp_pu25.gif  

 UU 600 W - public address 600 Watt Industrial - power stage - all triodes M 470

Public Address - 600 Watt driver stage UU 600 W P27-500 triodes

Public Address - 600 Watt preamp stage UU 600 W




Two channel amplifier /PP and SE/ with 1000 Hz crossover - EL 84 /6P14P Russian/ Crystal 104  pp_se84.gif  
 Simple stereo SE - 1xEL84 per channel se1_84st.gif  

 Class A - PP El 84 - 5 Watt /first described by P. Baxandall/.

Preamp for the above.




 Paralleled push-pull /Circlotron/ EL 84

/6P14P/ - 12 Watt

 SE integrated EL 84 seg_iel84.gif  

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Some schematics may use old, rare or exotic vacuum tubes.

Schematics presented here may contain errors and omissions - no responsibilities is taken

for accidental losses or damages caused by using the above schematics-use it at your own risk.

!!! WARNING: LETHAL VOLTAGES - tube schematics are usually working with high voltages

Experiments with high-voltage tube equipment by non-qualified person could cause death or injury.

All experiments and DIY are at your own risk. Know What You Are Doing before getting started.

No responsibility is to be held in any such case against System 11 Ltd and their owners

© 2002 All right reserved by their authors, portions and comments copyrighted by © P.G.Doynov