La Radiotechniques Ptt2s Pre Amplifier

La Radiotechniques Ptt2s or Bas Pre amplifer.

* Pre Amplifier tube is La Radiotechniques Ptt2s run in RC coupling
* Rectifier tube is Telefunken AZ1 Mesh anode
* Filarment of Ptt2s is DC regulate by LM317 and filter by commond mode choke
Sound is very good , excellent detail not smooth as #26 but more exciting and handle all kind of music.


>>> currently using SIF Ptt2s tip glass sound smoother than RT Ptt2s , for Valvo Ba and Siemens Bas they are very difficult to handle hum still need more experimental.

Remark: Picture show experimental tube is Valvo Aa , using same chassis and design some different in specicifation but sound is very close .

Arcturus 126 Pre Amplifier

This #26 Pre Amplifier is original design by Mr. Jim de Kort ( www.vt52.com ).

* Pre ampplifier tube is Arcturus 126 run in LC coupling.
* Anode choke is Lundahl LL1667 270H 15mA
* Rectifier tube is Arcturus 82 Mercury vapor type
* Filarment of 126 is 2 stage regulate using LM317T

Sound is very smooth and natural sound , very very little hum ( lucky me ) but not to exciting sound . Good for vocal song if you like female jazz this is one you looking for.

RCA VT64 SE

RCA VT64 ( 800 ) 10W Class A2 Single End Amplifier

Here are RCA VT64 or 800 Triode Transmitting tube in Single end class A2 amplifier.

* Driver tube is 2 stage anode follower , 1 stage is Hytron VT232 ( E1148 ) and 2 stage is RCA 2C22 ( 7193 )
* Interstage transformer is Lundahl LL1671 5K:5K 30mA
* Output tube is RCA VT64 fixed bias to 22mA 380V at plate
* Output transfomer is Hashimoto H-20-3.5U at 3.5K primary
* Rectify tube is RCA 866A half wave rectifier mercury vapor type

Sound >>>>> poor project , only very nice looking but some problem in driver design and interstage problem make the sound to distort at 1.5W level so the sound is lack of high , mid is not clear ..... need to modification

La Radiotechniques R120 SE

RT R120 drive by STC CV1988

La Radiotechniques R120 2W Single End Amplifier

* Driver tube is Parallel STC CV-1988 ( British military version of 6SN7GTA )
* Output tube is La Radiotechniques R120 Indirect heat Triode run at 60mA 250V
* Output transfomer is Local custom made M6 EI at 2.5K primary
* Rectify tube is Telefunken AZ12

Sound is very smooth sound , this is single end sound , great mid sound . Good for vocal song specaily female vocal.

RT R120 drive by STC ML-6

After I try some other driver tube so now I using STC ML-6 and found that it's match and produce the very good sound , more dynamic and very good in detail , high and specially bass is very good. This is the configuration that I like very much.

*** R120 is known as IDHT version of 2A3 but it have very uniques sound not like 2A3 ***

6C33C-B SE ( Nobu Shishido version )

Ulyanov 6C33C-B 15W Single end Amplifier
Tribute to great Japanease Tube Diyers Mr.Nobu Shishido is my 6C33C-B that using his circuit.
* Driver tube is 2 stage direct coupling Mullard CV-1988 ( British military version of 6SN7 ) replacing his original version 12AXZ7 and 12BH7
* Output tube is Ulyanov 6C33C-B run at 120mA 200V Ua
* Output transfomer is Local custom made M4 EI core at 600 Ohms Primary
* Rectify by solid state cicuit

Sound is very good , Not bad in detail , buetiful high tone and a ton of bass . This is audiophile sound tube amplifier.

Telefunken EL156 SE

Telefunken EL156 10W Single End Amplifier
* Driver tube is Telefunken C3m run in Triode mode at 13mA and Ua 150V
* Output tube is Telefunken EL156 run in Triode mode at 80mA and 440V at plate
* Output transfomer is Hashimoto H-20-3.5U at 3.5K primary
* Rectify tube is Telefunken EZ150 full wave rectify

Sound is Very good , Not bad in low but very good ih high , detail is also excellent and smooth sound but not as sweet as real Triode tube. Good for all kind of music.

Siemens F2A PP

Here are Siemens F2A 12.5W Push Pull Amplifier
* Driver tube is parallel Telefunken EF12K ( low microphonics version of EF12 ) run at 2mA and Ua at 160V.
* Phase splitter is PSA-2N autofomer from Electraprint.
* Output tube is Siemens F2A push pull in triode mode run at 60mA and 425V plate-to-plate.
* Output transformer is Partridge TK-8102 5K primary
* Rectify tube is Valvo AZ50

Sound is wonderful , the punch of the sound is it trademark , high and low is very good , less smooth than normal SE amp but if you like rock music this is the one you looking for.