I believe more my hears than data manuals.....6N3P gives very clear, limpid, detail sound, but 5670 is better....I used like prestage in my 2 ampl. with amazing tubes for sounds 4P1L and 30P1S.
I had the 6N3P-EV in an amp, I think they are not as lively as the 6N2P-EV to be honest, but it sounded OK as a pre-amp.
The biggest issue with them is the neat but totally non-standard pinout, meaning that trying another tube in there required the heater and one triode rewiring. A pain, frankly when the 6N1p, 6N2p, 6N23p, 6N6p etc all have the same base and close are the regular ECC8 series (bar the heater tap/shield).
The biggest issue with them is the neat but totally non-standard pinout, meaning that trying another tube in there required the heater and one triode rewiring. A pain, frankly when the 6N1p, 6N2p, 6N23p, 6N6p etc all have the same base and close are the regular ECC8 series (bar the heater tap/shield).
6Н3П may be quite good for an input stage for a phone RIAA corrector. High linearity is not required from it due to very low signal levels, while microphonic effect may be low. The best ever tubes I tried for mic inputs were rugged military UHF triodes for centimeter wavelengths. However, 6N3P was designed for not so high frequencies, but on frequencies so high vibration of electrodes would cause unwanted effect of modulation of internal capacitances.
Do you mean the ceramic planar triodes(6S17K,6S45K,GS-4V) or the lighthouse type like 6S9D ? I have thought of using these for mic amps.
Exactly.
The problem with some of them is cathode & filament common ring, so negative feedback on cathodes is very problematic.
The problem with some of them is cathode & filament common ring, so negative feedback on cathodes is very problematic.
I remember seeing a Russian circuit using 6S17K. I could not figure out how the tube was biased at all; there was a 1 ohm resistor on the cathode if I remember correctly. Maybe it biased itself in some way? I know the electrode spacing is very close in these UHF tubes and am sure fantastic precision goes into their manufacture. I suppose 6S9D might be the easiest to use.
Biasing may be simple: if 0.5A goes through the filament 1 Ohm would cause 0.5V drop, so 6.8 of pristine clean filament powering voltage would be applied between grid and cathode. It may be a battery power. I used 2.7 Ohm resistor if I remember tight and a cellphone battery when experimented with them.
But if I have at least 8 mic pres, do I need to power each filament from a separate battery?
6С9Д would require much higher anode voltage, I'm afraid.
But if I have at least 8 mic pres, do I need to power each filament from a separate battery?
6С9Д would require much higher anode voltage, I'm afraid.
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6n3p & 5670
Neither 6N3P-EV nor 5670 are noisy or microphonic on 96 dB speakers.
5670s look nicer being small (less than half the height of EL84) and bright with green lettering ...
I have tried combinations of 6N3P-EV & GE JAN 5670 driving EL84s made by Telam, Ei, Tungsram & GE and they both sound good but seem to have 'preferences' when it comes to power tubes. I eventually paired 6N3Ps with Telam EL84s, while 5670 go better with 'Western' EL84 types.
Neither 6N3P-EV nor 5670 are noisy or microphonic on 96 dB speakers.
5670s look nicer being small (less than half the height of EL84) and bright with green lettering ...
Ah yes, I see! Thank you. Maybe a nice clean current source would be a good way ?
Well, a Quad of Ruskie tubes just arrived today...And they are clearly etched 6H2P-EB, P as in Pi... These are Dual Triodes, and here's the fun part...They are now Burning-In in my 3 Tube 6DJ8 Phono Amp. And so far, they sound Pretty Nice. For now I'm just running 2 of them in the Phono Section with a Sylvania 6DJ8 on Output. The neat thing is that these are 300v tubes being run on 125v B+ at 3ma and 2v Bias. I'll have to listen a lot more tonight, but for now I can say that they Sound Good and are Quieter then the 6N23Ps that they replaced.
It is a very happy coincidence that your input stage for 6N23P was actually designed optimally for 6N2P: 125V on anode, 2V bias, and 3 mA current! 😉
Congratulations!
Initially they were used often in microphone preamps and magnetic head amplifiers for tape recorders. Very quiet tubes.
Congratulations!
Initially they were used often in microphone preamps and magnetic head amplifiers for tape recorders. Very quiet tubes.
Not only that, but the 6H2P is a 6AX7 that can be used as a 6DJ8 or a 12AX7 by running its Heaters in series if your using 2 or 4 of them.
Oh, one other thing...Is a 6H2P also a 6N2P?
Oh, one other thing...Is a 6H2P also a 6N2P?
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These wacky Russian/Roman transliterations are confusing the hell out of me.
FYI: Windows users can use the built-in "Character Map" software (Start menu> Accessories> System Tools) to select and paste the proper Unicode glyphs into this forum. That would be nice. Just sayin.
(I'm sure there's something similar on Mac and Linux machines.)
I've attached a cheat-sheet I created for myself a while ago. Don't trust it entirely, it's probably full of mistakes; but it helps. 🙄
..Todd
FYI: Windows users can use the built-in "Character Map" software (Start menu> Accessories> System Tools) to select and paste the proper Unicode glyphs into this forum. That would be nice. Just sayin.
(I'm sure there's something similar on Mac and Linux machines.)
I've attached a cheat-sheet I created for myself a while ago. Don't trust it entirely, it's probably full of mistakes; but it helps. 🙄
..Todd
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Here's a quick update..From what I can tell, the 6H2P's work well in the first stage of a Phono Amp. They have less hiss then the 6N23p's and the 6DJ8's..But, if you use two of them in the Phono Stage they seem to have less Mids, you will get more Bass. It seems to sound the best with just having one as the first tube feeding a 6N23P for the Phono Section and having that power a 6DJ8 for the output..
They work well as the first stage of an integrated amp too!
I have a feedback-free one driving a [6N23P SRPP + GU50 SEP w/37dB FB] stage driving my OPT and it does sound very good indeed.
The 6DJ8 is a good output tube as it has lots of drive (i.e. low impedance). One day I'll need to check my operating points for those tubes actually - too busy using them. The SRPP is about 400V total with a 1k cathodes, I think the 6N2P is running on 47k/1k from 350V. Must get it into the lab when more capacitors turn up!
If you have the first stage feeding a passive Riaa, using 2 is halving the rp, is altering the source resistance which is normally part of Riaa's calculated Z, hence the aberrations. They are nicely quiet in a phono's first stage its my experience too. I used the -EV suffix.
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