Replacing 6N1P' s with 6922s or 7308s

[singleended40]

Hi Everyone,

I just got a Promitheus Audio Apollo Preamp using a pair of Russian 6n1p tubes as a tube buffer stage for the TVC. I have tried to replace with a pair of RCA 6922s Germany. First thing I noticed one of the 6922 was glaring up then the buzzy noises came out of my VR1 speakers.

I do not know what happened but I have heard both kind of tubes are equivalent except 6N1P has high heater. I like the sound of 6922 and love to roll tubes.

Anyone has had experiences about these tubes please let me know. I thank you and appreciate your time and effort.

Regards,
Tan

[KBK]

The 6N1P (Russian: 6Í1Ï) is a Russian-made miniature 9-pin medium gain double triode vacuum tube intended for use as a line audio amplifier and cathode driver.

Basic data: Uf = 6.3V, If = 600 mA uM = 35 Ia = 7.5 mA S = 4.35 mA/V Pa = 2.2 W

The 6N1P has similar ratings to the 6DJ8 and in the past was sometimes rebranded as such, however, because of the differences between the two types (such as twice as high filament current of an 6N1P and three times smaller S value) it's not suitable as a direct replacement in 6DJ8 applications and vice versa.

A ruggedized/extended ratings version of the tube is designated 6N1P-EV (Russian: 6Í1Ï-ÅÂ)

It has currently found a use as a driver tube in hi-fi tube amplifiers (such as Audio Research models VS55 and VS110) because of its excellent low distortion and low noise characteristics. The tube is being manufactured by "Voshod" plant in Kaluga, Russia (see [1]) and is being distributed in the West under the Sovtek and Svetlana brand names.
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I suggest buying off of ebay from the various Ukranian, Russian, and Belgian, etc folk who have many diferent versions of that tube.

Some are of extreme quality, all being..realtively speaking..military surplus. There are some tubes of that type you might pay as much as $30-50 US each for, if you were to buy them from the usual big name tube re-seller stores. Instead, you will pay $15 or so for 10-20 tubes.

[Sherman]

I don't have the data sheets in front of me but I believe the maximum plate voltage for the 6922 it 150 while for the 6N1P it is 200 (or more?). It is possible the 6N1Ps in your preamp are running near their limit which is too high for the 6922.

You could still make the switch but it would require changing the plate and cathode resistors to values that would allow the lower voltage 6922 to operate within its limit.

[singleended40]

Hi,

I agree with Sherman by changing the values of resistor under tube sockets. Do you know the values of resistor can be used with 6922s normally? Thanks.

Tan

[pchw]

6922 and 6N1P are not identical. It will be more than adding a resistor to drop the plate voltage. Notice that the current bias point is not likely optimal for the 6922. This means that you will need to adjust the cathode resistor as well. I suggest to get a schematic before attempt doing any mod. You don't want unpleasant surprise :-)

[singleended40]

Anybody have tried to replace 6922s with PCC189s? Thanks.

[Yvesm]

The nearest equivalent for 6N1pi is the 6BQ7, not the 6DJ8 !

Yves.

[kathodyne]

the 'real' russian e88cc/6922 is:


6n23p: 6,3/310mA S:12,7mA mu=34
e88cc: 6,3/300mA S:12,5 mA/v mu:33

also available in the -EV version...

best,

Henk

[kstagger]

In the one application I've used the 6N1P it has been a fine performer. The guy who has it now is a big time tube roller and he preferred the 6N1P (in a white cathode follower circuit mind you) over most of his 6922/6DJ8 collection. What does that mean? Dunno - other than the 6N1P is cheap and sounds good - why change it?

[L700]

hi kstagger yeah agree with that 6N1P-EB is very good n cheap i using the Rocket logo one i bought from ebay for GBP 10.00 some more is match pair
i found 6n1p are more sound more airy and open ... compare with 6922 and 6N23P sound laid back n mellow