Safe Tube Replacements Chart along with Recommendations

I've been trying to find come recommendations to upgrade a tube amp I just bought that has a stock 6N1.  I read that there are ones that will fit but are not made for it due to various differences.

They post a link to an article that is dead, so I used the wayback machine to post it in the forums preparing for the post-apocalyptic future!

Original thread:

http://www.head-fi.org/forum/thread/191958/recommend-tubes-for-xiangsheng

The page is no longer in service so here is what it used to contain:

6DJ8, 6922, 6N1P etc. compared

Per: http://www.geofex.com/tubeampfaq/taffram.htm

*** SAFETY WARNING *** READ THIS FIRST!!!!!

Working inside a tube amplifier can be dangerous if you don't know the basic safety practices for this kind of work. If you aren't prepared to take the time to learn and apply the right precautions to keep yourself safe, don't work on your own amp. You can seriously injure yourself or get yourself killed. This section is not intended to be a complete guide to safety in tube equipment, just to hit the high points as refresher for those of you who have some experience. The best way to learn the requirements and practices for safety in tube equipment is to find someone who will teach you one on one.

BASIC REQUIREMENTS

• • UNPLUG IT FIRST Pretty self explanatory. Do not, ever, ever, leave the equipment plugged in and start work on it unless you specifically intend to make some live-voltage measurement. Leaving it plugged in guarantees that you will have hazardous voltages inside the chassis where you are about to work. This is like setting a trap for yourself.
  • LET IT DRAIN If the amp has been turned on recently, the caps will still have some high voltage left in them after the switch is turned off. Let it sit for five minutes after you turn it off.
  • SUCK IT DRY When you open up an amp, you need to find a way to drain off any residual high voltage. A handy way to do this is to connect a shorting jumper between the plate of a preamp tube and ground. This jumper will drain any high voltage to ground through the 50k to 100K plate resistor on the tube. To do this successfully, you will need to know which pins are the plate pins. Look it up for the amp you're going to be working on. You'll need to know this for the work anyway. Leave the jumper in place while you do your work ( high voltage electrolytics caps can "regrow" voltage like a battery sometimes. Really. ) Remember to remove it when you finish your work.
  • TEST IT Take your multimeter and ground the (-) lead. Probe the high voltage caps and be sure the voltage across them is down, preferably to less than 10V.
  • BUTTON IT BACK UP FIRST Take the shorting jumper out. Put the chassis back in the cabinet, making sure all of your tools, stray bits of solder, wire, etc. are out of it. You don't have to actually put all the screws and so forth back in if you believe more work might be needed, but make sure that the chassis is sitting stably in the cabinet and won't fall out. At the end of a listening test, either continue buttoning up if you're done, or go back to UNPLUG IT FIRST.

Here is another set of info of drop in replacements from:

http://giaime.altervista.org/china_eng.html

Refer to each row for set of similar tubes:

Tubes in italic, like this text, are not "direct replacement" types. However they may work in some circuits, and some of them are known to work.

* Note: ECC40 is only electrically equivalent to 6N1P, its socket is different so a direct replacement is impossible.

Find some other references for your tubes here!

Some known problematic tubes to replace:

• 6N6 (chinese), 6N6P (russian). This tube has NO known direct replacement: the best replacement is another 6N6 - 6N6P. However if you are experienced, and with the proper tools, it could be replaced (given socket rewiring and maybe some circuit tweaks) with 5687, 12BH7, ECC99 or E182CC. This last tube seems to be the closest equivalent.

• 6N2 - 6N2P: the question here is, can I replace it with ECC83/12AX7? Yes you can, but you HAVE TO REWIRE THE SOCKET. Refer to the tube datasheets for this: as always I suggest to have this work done from experienced people, don't try poking inside dangerous tube amplifiers if you haven't done this before!

• 6N1: not much info. Best replacement is still another 6N1. ECC88 and its various cousins might work, but be careful of the much higher filament current for the 6N1, and muchlower allowed plate voltage for the ECC88. If the amp runs the 6N1 at less than 130V you can safely replace 6N1 with ECC88 (don't know how it will sound...), but if the quiescent plate voltage is more, ECC88 might fail and ruin your amp. See also here for deeper information.

• 6N30 - 6N30P - 6N30PI - 6N30PI-DR. Absolutely no western equivalence: the only known source for these is Sovtek that still makes them. However, russian NOS ones are even better but they're becoming scarce and expensive. 

I hope I'm not going against some forum rules or something - just had a little trouble finding this info in a concise way.  I hope it is useful to others like myself.

Feel free to leave recommendations for your particular tube types (music enjoyment/amp/cans/ -> tube recommendation)