| Year | Type Walter Funk, Lauscha | Ref. | Tubes |
| 45+ | Lauschatal GW + Franken GW | La50 | UCH11, UBF11, UCL11, UM11 |
| 45+ | Lauschatal W + Franken W | La50 | ECH11, EBF11, ECL11, EM11, EZ12 |
| 45+ | Neuhaus E853 | La50 | ECH11, EBF11, ECL11, EM11, AZ11 |
| 45+ | Neuhaus U853 | La50 | UCH11, UBF11, UCL11, UM11 |
| 45+ | Werra A 6/653/WKB | La50 | 6SA7, 6SK7, 6SQ7, 6V6, AZ11 |