• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Russian 6H2p-E??

This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
If the data sheet does not have a figure of noise merit, or equivalent noise resistance, you don't know. In which case presume it is not 'low noise' or "SQ".

The data sheets I've seen on the 6N3P show it as a "low frequency double triode". In this context "low frequency" appears to be 60MHz per note 4 referencing input impdeance Rglk = 14K ohms.

The 6N3P-E data sheet referes to it as "designed to amplify voltage and generate high-frequency oscillations". HF is nominally defined as 3-30MHz, so it borders on VHF.

Define "really a good tube for audio"

I did some measurements of 6N3P compared to 6N1P and found it to be reasonable for audio use. Distortion was only slightly worse for the 6N3P compared to the 6N1P in a common cathode input stage for a SET. The tubes were biased with LEDs and anode load was a current source.

Then again I believe almost all tubes are good for audio use, but this may be highly dependent on the application/circuit for some tubes.
Last edited:
Yes 6N2P is a soviet 6V clone of 12AX7 ( ECC83 seems to be better 6N2P ).

6DJ8 Amperex PQ probably the best triode (used in Tektronix oscilloscopes). Soviet 6N1P very close to 6DJ8. E88CC or 6922 or 6N23P - EV (EV means soviet military quality) are also pretty good, 6922 better then 6N23P.

Conrad Johnson likes 6N30P. EF806 triode strapped also nice, might be the best.

NOS Amperex 6DJ8 pops up on eBay sometimes.
6N3P tubes were never considered to be used in resistive loaded stages. The most common usage was in UHF frontends of FM receivers. Also, they were used in military and railway equipment, always loaded on UHF LC tanks.

6N1P was designed to replace 6N8S (6SN7), 6N2P was designed to replace 6N9S (6SL7)

However, they are smaller, so slightly different.
That's good news as it is common and cheap. When I looked at the data sheet it seemed to me neither quiet enough for input stage nor linear enough for a driver. Where do you use it? 2nd stage of preamp?

I use it in a hybrid amplifier (unity gain output stage with tube providing the voltage amplification, one section per channel). I don't have golden ears or watch music on oscilloscope so it sounds fine to me ;)

If I built the whole thing again I'd use MOSFET input (2N7000) follower in place of BJT, to decrease load of the tube.
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.