Review of Siemens C3m ,Siemens C3g

1 => C3g :

 I tried some C3g  and the sound was very fine to me. I used them in triode and pentode mode. The C3g have 6,3V filaments.

2 => C3g :

You can also take the C3g tube. It has 6,3V filament voltage and 600mA filament current. For me it's the best sounding driver for such an amplifier, if you prefer a pentode in the gainstage.

3=> C3m

>I was puzzled by one recent posting regarding the 300B and 2A3
>sound. In a reply posting Thorsten replied that he NEVER liked
>the sound of 6SN7 driving 300B...

Correct. However only because I DONT like it does not mean it is as such bad. In a different system, with someone else listening to music other than that I listen to the story may be different.

If you like what you have, stick with it, it obviously suits you. And that is EXACTLY what it should do. It doesn't suit me, but I'm not listening to your system... ;-)

If you want to try something use a Siemens C3m as Penthode.... IMHO and with me listening it offers much more clarity, immediacy and much less colorations than any of the usually used Valves (6SN7, 5687, 6SL7) and Circuits (Cascade, SRPP or combinations of both). I even prefer it over a 417A IT coupled to the 300B....

My main "excuse" is simple.... Wester Electric used a Penthode to drive ALL their later SE DHT Amplifers. And these Amplifers are eminently musical and still command ludicrous prices. So obviously they where doing SOMETHING right. So I tried the EL84 as Penthode Driver and liked it a lot.

Then I switched to the cute loctal 20V Heater Siemens C3m (yellow Colour Series = high reliability, close matching for Telecom Service), it's even better.

4 => C3m

My fav. Driver Valves for DHT's nowadays are Penthodes. OPERATED AS PENTHODES.... The EL84 works well, try a 12k Anode Load, 250V Anode Voltage and 140V G2 Voltage, currentdraw about 14mA, +B 420V. The Cathode Resistor is 470 Ohm.

The rare Siemens C3m sounds even better, all resistors apart form the Cathode Resistor remain

5 => C3m

Poweramp is still the 300B SE Job (Fugue/Legacy 300B) with the EL84 Pethode Driver and Valve regged PSU's, very similar to the older JC Verdier unit. At the moment I'm running 2A3 Outputs as these sound better with the Speakers (Hoerning Perikles) I'm testing at the moment for Enjoythemusic.com, normally I like 300B's better, but these
Speakers are rather laid back.

I have on my shelf two pairs of Siemens C3m which I intend to use as new Input/Driver Valves as soon as I get used to the system as it is now. These should be very nice in the Poweramp. Looking at the curves and doing some Math these look as if they could produce an even more Ideal Harmonic Spectrum than the EL84's together with the 300B.

The only problems are the 20V heaters and the Loctal sockets (I have the sockets luckily enough) which will require quite some mechanical changes. Electrically they will drop in for the EL84 with only the Cathode Resistor to change.