Inexpensive Russian tubes

neon333 · Post by **neon333** » Mon 04/12/10 9:56 pm

I've been thinking about using the 6p14-ev's and 6n2p's in my next build. My only concern is they draw more current than el84's and 12ax7's. Here are some specs I found:

http://www.russiantubes.com/prop.php?t=12&p=245
http://www.russiantubes.com/prop.php?t=12&p=246
http://www.russiantubes.com/prop.php?t=12&p=197
I think I'm probably ok with the 6n2p-er.

What changes to a power supply and or transformer would I have to make to use these tubes in a 18wattish type circuit?

pax,
neon

Post by **rock_mumbles** » Mon 04/12/10 10:09 pm

In an 18 Watt with a decent power supply I don't think there's an issue, as far as heater current it's like powering an extra 12AX7 or so.

Plate current is 48mA and cathode current is 65mA for both an EL84 and a 6p14p-EV. I'd think that most power supplies should be able to handle that no problem. A Baby Will 18W VJr conversion maybe not...

Older NOS 6p14p tubes are a bit darker sounding than a current Sovtek, the 6p14p-EV are a bit brighter and more hifi sounding...

I had an amp that sounded bad with the 6p14p-EV's but it had a questionable power supply.

dotfret · Post by **dotfret** » Thu 04/15/10 5:06 pm

It's only sums.

The power transformer ratings for the heater supply are specified - so you know they will deliver up to whatever the spec says.

For example, SteveSUK sells transformers that deliver 1 X 6.3V CT @ 2.5A and 1 X 6.3V @ 1A for heater supplies.

The 1A line is taken up by the EZ81, leaving 2.5A for the other valves.

Two EL84 nominally draw 0.76A each = 1.52A.
Three ECC83 draw 0.9A. That leaves 80mA as a safety margin - which is too near the bone for using Russki valves.

For 6n2p, allow 350mA each, and 800mA each for 6p14p. That should be enough for whatever variants you buy - some of the mil spec (V) versions draw more current. Don't trust the specs, the valves vary from factory to factory.

So, to run 3 x 6n2p and a pair of 6p14p you want about 2.65A available. Plus another 1A for the EZ81 - then you might want more for the trem circuit...

There are transformers easily available which will give the extra on the heater line - or you could get the extra from using a small supplementary heater transformer to power one or two valves.

People often say these valves sound "dark", when the truth is they are not getting enough juice in the heaters.

You'll be very lucky if you can find any valves with the R suffix cheaply. R means Space Agency spec - not exactly common, although sometimes available.

alonso · Post by **alonso** » Fri 04/16/10 9:08 am

OK, trying to understand this. I have a Marshall 1974x, it had cheap sovtek power tubes. I was dissapointed with the volume of the amp and so I searched for more powerful power tubes. In comes "The Sargent" Terry Kilgore and so I got from him some powerful NOS Saratov's 6N14N-K.

Now considering the Transformer problems with my model amp, am I pushing it too close to limit with these tubes?
If I had enough money right now to change the PT and OT, I would push it hard with these with no worry, but for now, I need to work with what I have.

dotfret · Post by **dotfret** » Sat 04/17/10 10:16 pm

I don't think you should have any problems with those 6p14p-k (the k means "vibration resistant"). They are standard spec, but tested to avoid microphony.

Putting it simply, if you increase the heater current in a valve design, it is an easy way to reduce noise. A lot of Russki military designs (V suffix) exploit this, so they are designed to draw more heater current than the standard versions.

Or, in the Sarge's style,
IT IS MY HONEST BELIEF THAT MR KILGORE WOULD NEVER EVER EVER SELL YOU ANYTHING (BUT ANYTHING) THAT IN ANY WAY SHAPE OR FORM COULD DO ANYTHING DETRIMENTAL TO YOUR EQUIPMENT AND WHATEVER HE SELLS IS GOING TO MAKE IT SOUND BETTER AS REPORTED BY SO MANY SATISFIED CUSTOMERS ON THIS HERE FORUM AND YOU AINT HAD ANY TROUBLE YET SO DONT WORRY JUST DONT TRY USING THOSE 6N2P THINGS.

My comments were merely to draw attention to the fact that over-rating the heater supplies helps a lot when using Russki valves as substitutes, and guide people towards an easy solution to using almost any variant of 6p14p and 6n2p.

StarGeezers · Post by **StarGeezers** » Sun 04/18/10 6:48 am

Gentlemen, I just finished an amp using 6U8> 6N2P > 6P1P (quad)... The "Dog Sled" ... Discussed here http://www.wattkins.com/node/15993
Used the Antec T200 "donut" PT , which has parallel htr. windings that allow for 4A fils. Perfect for these Russian tubes , inexpensive , and cool running... Set up this way , these Russian tubes sound GREAT !!!
But I would hesitate to adapt a "factory" amp to use Russian tubes , unless there was a PT change , or possibly another fil. Tx added to split the load ... crumbs for thought...

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Dustpuppy · Post by **Dustpuppy** » Fri 07/30/10 12:31 pm

I have a superlite tmb running a pair of Reflektor 6p2p's and Saratova 6n14p's. I didn't make any changes to accommodate them, using a 270DX and 1750E from Hammond. They sound great!

StarGeezers · Post by **StarGeezers** » Fri 07/30/10 4:40 pm

Lets not spread this around too much , or some fools will be buying them all up and selling them for much higher prices on Flea Bay ...

Just like they did with those greenie pio caps ... grrrrrrr!!!!
Let it be our secret source of good cheap tubes !!!

Dustpuppy · Post by **Dustpuppy** » Fri 07/30/10 6:34 pm

Oh yeah, those tubes are actually known to explode, steal children and wear muddy shoes in your house! I would steer clear!

demonufo · Post by **demonufo** » Sat 07/31/10 3:51 am

Dustpuppy wrote:Oh yeah, those tubes are actually known to ... steal children

Perfect. Think I just found the next purchase for my household.

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Inexpensive Russian tubes

Inexpensive Russian tubes