This
page's real name is 6N6P CLUB
INTRODUCTION TO 6N6P
First some facts: 6H6(Pi) is written in CYRYLLIC alphabet. That's why
sometimes you can find the same tube written in latin which spells 6N6P.
To my knowledge this tube has been produced only in Soviet Union (the
oldest sample I found was from 1974, the newest from 89.)
It is a genuine Soviet design, unlike most of their tubes which they
copied from the West all the time. The closest equivalent is the
Ecc182, E182CC although the pinout is different, .
We do not want to use the impulse variant 6N6P-i later named 6N30P. We
want the good old 6N6P only.
ARG, which could use any tube they wanted, I mean ANY Soviet tube, uses
6H6P
in all their designs and in all stages except output ;-)
There was eve an abandoned plan to make a small amp with 6H6P as power
tube
working in paralell into
an output transformer as an AMPLIFIER. Ala TdParavicini's V12. Having
said that the 6H6P can produce over 8 Watts of output power (from both
halves together) and swing as much
as 450 V. Compare it to 3 W from 6922/6DJ8/ECC tubes.
Oliver and Hardy -
ECC82 and 6H6P
This tube can work at incredibly low voltages, i.e it is used in an
input stage of a transistor (hybrid) amp with same power supply as for
the output FET minus 50 V DC. It is possible in SRPP config upside
down. But the main
differenciator is current: It can take such big current, that would fry
other tubes dead. So it is excellent as a driver for power tubes like
845, 300B or 6C33C.
6N6P Pinout
The general type is NOVAL (meaning with 9 pins) and the pinout is
identical to many western novals like 6dj8, 6922, ecc88.
The parameters
are comparable to ECC99-E182CC-12BH4.
Like almost all novals, this tube is a dual triode meaning phisically
two triodes packed side by side in one glass bottle.
To reduce
cross-talk (i.e in stereo applications) they added a scereen between
halves.
Screen in tubes 6N6P
There are two sub-groups of noval tubes: with screen and without.
The first group to which belongs most of the western novals, like
ECC82, 81, 83, etc. has the following pinout (clockwise from the
bottom side)
Anode1, Grid1, Cathode1, heaterA, HeaterA (joined), Anode2, Grid2,
Cathode2, heaterB. It has no screen (dividing the A and B
halves of the tube.)
The 6H6P has a different pinout , just like 6DJ8, 9622, E88CC, 6H30,
6H41P, etc.
Anode1, Grid1, Cathode1, heaterA, heaterB, Anode2, Grid2, Cathode2,
SCREEN.
The screen is usually grounded.
POSSIBLE
CONVERSION TO 6N6P
In modifications of existing gear, first thing to look for is wether
the 4 th and 5th
pins
of the heaters are joined - this means first camp as described above .
If they
are separate - this is "6H6P camp".
To modify the
i.e. ECC82 circuit to work with 6H6P - first cut
the traces or wires joining pins 4 and 5, and cut the trace or wire
leading to pin 9. Move the heating current from 9 to 5, keepingt the 4
as it was. So current will flow from pin 4 to 5 instead of from 4,5 to
9.
ALL DRAWINGS ARE HERE
Second difference is heater (filiament) current. Almost all smal novals
consume 300 mA 6,3 V (ac or dc - does not matter). Our tube is a
supertube and is double in lenght and has triple the electron emission
surface. Hence it needs MORE power to heat the emmission area on the
cathode. It needs
twice the current and namely - nominal current is 750 mA @ 6,3 V (dc or
ac does not matter).
So what do we do about the heater current during upgrade?
There are many possible scenarios.
Generally, most designs have big safety margins of specs. Isn't
high-end all about OVER-SPECIFYING circuits? You can just hope
that
the device (amp, preamp) will tollerate 350 mA more. It usually will.
There are two possible scenarios
- if IT WON'T:
A: if the heater was a regulated DC type, the regulator will
burn.
Regulator is a three legged chip usually standing upright and with sink
of some sort - own heatsing (radiator) or screwed to the chassis. In
this case you buy a 1 euro chip with higher specs, like
instead
of 7806 type - 78S06 (6 Volts, former is 0,5 A and latter 1,5 A).
Use
larger sink if possible.
B: if heater was AC type (which can be easily checked by a meter)
then it is fed directly from the transformer's secondary winding or
even a separate transformer which is a better situation. The
transformer is unlikely to burn the heater secondary, but it may start
to buzz and overheat slightly. In such case it is time to install a
separate transformer.
If there are two tubes in the circuit - it is very easy. We change the
heater supply from 2 paralell 6,3 V to a series 12,6 V. For this we use
a halogen lamp transformer from the shop or any other transformer
with minimum 10 VA and the secondary from the range between 12
and 13 V AC. We run it like this: one wire to tube 1 leg 4, then a
small jumper from tube 1 leg 5 to tube 2 leg 4, and from tube 2 leg 5
to the transformer (second wire). We adjust the voltage by a 3
watt resistors- ranging from 0,5 to 2 ohms. In most gear there is a
room to add such transformer. It can be fed directly from AC socket
without the main AC switch so the tubes will stay always warm and live
longer. Plus the product will sound well immediately after switching
it on, without the warm-up period.
A better option is to rectify the cirtcuit - meaning converting it to
DC type. We just add a diode bridge (100 V / 4A or higher) It costs 1
Euro. We connect ac-ac to the transformer, and + / - to the capacitor
(CRC filter) and then plus and minus to the two tubes - just like on
the schematics of the lampizator:
We adjust the voltage to be 12,6 DC on the last capacitor when tubes
are connected, by testing various resistors - the R (5W-1 Ohm or close
value).
6N6P
SONIC
IMPROVEMENT
The 6H6P will inevitably sound better than any other small tube, with a
reservation that whenever VERY HIGH GAIN is needed, 6N6P does not have
high gain. Usually this is not a problem and one can accept it and
enjoy it with medium gain.
For 6922 and 6DJ8 the improvement is so big it is beyond discussion.
The main difference is that the sound becomes so easy, it FLOWS, it is
liquid, open, spacious, rock solid, and very very natural. At the same
time, in the first day or so, some people call the new sound "lazy". I
do not agree but they get used to the nature of 6H6P and after - wild
horses cant drag people away from the new sound.
The biggest and quickest improvement is over 6H30P - the tube
popularized by BAT and its creator mr. Khomenko. He raves that 6H30 is
a supertube, but in my opinion it is very coarse, hard and glassy by
comparison. I hate 6H30 in circuits which I tried, including my own BAT
VK-D5SE cd player. Anyone having BAT gear should immediately give 6H6P
a try without any other circuit mods. You will be surprised.
I can not really comment about the exotic NOS tubes from the first
league like the Telefunken and Siemens from 1950's and 60's which cost
over 100 Euro a pop
and are inconsistent in results. I guess the real exotica can get close
or really better the 6H6P in asymptotic way and then it becomes a
personal taste issue.
What I can guarantee - is that "my" love tube will easily outperform
each and every new noval tube there is.
The price of 6H6P in Poland (ebay.pl) is around 2,5 Euro and they are
consistently perfect (I never had a rejected unit) and last forever (I
never witnessed this tube die. I guess it lasts up to 10 years).
I guided some audiophiles to exchange all their small tubes
in all BAT setup - cd, preamp and monos - and they were quite shocked
how much better the system sounded. In their own description -the
upgrade seemed twice as expensive (meaning as if they swapped
their 20 000 USD system for a 40 000 USD one).
Recent upgrade of a Copland preamp changed this nice machine from a
hi-fi to high end. And so on and so on.
Next on my agenda is a conversion of Shanling
CD Player
from 6922 to
6H6P and then from tube triode cathode follower buffer to a true
lampizator status.
A DISCLAIMER_ THE 6N6P IS NOT SUITABLE
FOR LAMPIZATORS WORKING DIRECTLY WITH CURRENT OUTPUT DAC CHIPS LIKE
TDA1541A.
For the I-out DAC types allways use
6N2P!
Story
from Soren about 6N6 upgrade in Copland
Datasheet
of 6N6P
Other datasheets
Interesting page
in Polish
EXAMPLE
CIRCUIT 1 - anode follower triode
EXAMPLE
CIRCUIT 2 - cathode follower triode buffer
EXAMPLE
CIRCUIT 3 - SRPP lampizator totem-pole
One shop with
the tube:
http://www.thetubestore.com/ru-6h6p.html
November 12, 2006
6N*P family tubes from Soviet Union
In july 2008 I decided to add the brothers and sisters of the mighty
6H6P -
The brother tube 6N1P (DATASHEET)
and the sister 6N2P (DATASHEET)
Goddamnit, I hope that drunk Russian soldiers already sold all spare
tubes from their military reserves to audiophiles and in case someone
in Kremlin or a drunk General in the Dalnyi Vostok nuke base pushes the
red button, NOTHING will happen. Only silence will respond. Because all
missles will be dead without the tubes. And the tubes will be
singing Ella Fitzgerald all over the World.
Anyway,
6 stands for heater voltage 6,3 V, N stands for noval (I think)
and P stands for Palcevaya - it is a "small finger type" as opposed to
old big octals. C in the end means stiekliennaya - Glass envelope. and
the number after N is the modell number. We already know the 6, lets
meet the 1 and 2.
6N1P
The beauty of this tube is that is pin-compatible with not only 6N6P,
but also with ECC 88, E88cc, 6DJ8, and 6922 popular tubes. The sound of
6N1 is more crisp and energetic than the sound of 6N6P and it is more
easy and natural than that of the ECC 88, E88cc, 6DJ8, and 6922.
Another interesting feature is that it has been designed to be
electrically identical to the most popular audio tube of all times -
the American 6SN7GT.
Yes, the datasheet says - it is a drop in replacement for all 6SN7
circuits (except base of course ;-)
So when designing new circuits we can be immediately familiar
with the behaviour of the 6N1P tube.
Usually - in amplifiers - I would use 6N1P as input amplifier and the
6N6P as driver (high current !!!)
The amplification factor is circa 20 and I really like the sound
from this tube used as lampizator with I out dacs, that is UNTILL I
FOUND THE 6N2P !!!!!!!!
It is worth noting that 6N1P tube has three variants:
standard,6N1P, long life - 6N1P-EB, and the impulse - 6N1P BU
(Wi). The middle is the one to have, or at least the first, but NOT the
impulse type.
OTK
Otbor tiehneecheskovo kachiestva - quality controll level - they used
the stamp OTK followed by a number. The lower number the better. The
zero is if I am not mistaken the best. Zero was strictly
military; one - also military but not for nukes, and so on. I
would like to read more about this aspect one day.
Just don't forget that in the Soviet times for producing a faulty tube
the worker could face 10 years in siberian labour camp in minus 50
degrees without gloves. These times were not funny at all.
6N2P
Discovery of this tube was a shock for me. Nothing prepared me for such
leap in quality. When designing my best hot-rodded superdac SATCH TUBED, I
was researching alternative tubes and I found in the very end the
one which thrashed them all - 6N2P.
It looks like typical small noval, but the SOUND !!!!! What a
revelation. Everyone whom I subjected to test drive of 6N2P in their
own gear commented that this can't be true. Such is the quality leap.
This tube is somewhat similar to ECC83 but beats it in quality hands
down.
The very high amplification factor of 6N2P (100) predistines it to
working with small input signals, such as from I OUT DACS. and in
circuits with very high load impedance - like another tube grid.
Yes, the tube 6N2p is IDEALLY suited to work especially with the Wold's
best DAC chips - TDA1540, TDA1541A, TDA1541A/S1, TDA1541A/S2,
AD1862, AD1865, PCM58, PCM63, PCM1702, PCM1704 and PCM1794.
This tube is absolutely not recommended to make lampizators for the U
out DACs like the best of this kind CS4397, CS4398, AD1855, TDA1549,
and Wolfson WM8740 and WM8741
For these DAC types - use LAMPIZATOR with 6N6P tube (6H6Pi).
THE BEST SCHEMATICS OF THE 6N2P Lampizator and TDA DAC
DATASHEET OF 6N2P
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