Teflon Cap upgrade or new set of NOS tubes for conrad johnson PV12A Preamp?

Well, the NOS tubes could be worse than what you have and the teflon caps might be worse than what’s in there already. It would be easier, safer, and less of a drag to try tubes. 

Depends how cheap the teflon is.

There's a wide variety of caps out there though.  I might suggest a compromise, try out some Audyn TC bypass caps, in the 0.1 to 1uF range. They're pretty big, so you may have to go small, but less expensive than pure teflon in those sizes (~ 4uF each or higher, right?) .

@erik_squires ,

I believe the OP wants Conrad-Johnson to do it.  The Teflon caps are made by CJ or are branded as such and everyone who has bought the unit with the better caps says it is worthwhile.  They also take a few hundred hours to break in.

Teflon caps.

I recently had new Teflon caps installed in my CJ PV 11.  It certainly was worth it.
 It’s like acquiring a new premium preamp. If yours has a phono section, it’s especially worth it. Probably superior to any stand alone phono preamp out there,
the CJ phono section is very special.
Btw, two Telefunken NOS 12 AU7s are not too expensive and sound wonderful in the line stage.

Sorry, didn't understand CJ was offering this as an upgrade! :)

I have a humble c-j Classic 2SE with the teflon caps....   it is such a great sounding pre.  It was a $500 premium over the base Classic but well worth it.  I auditioned it against a base  ET3 in what had to be a $50k system and liked the Classic 2SE better. 

If you really like it, why not do the caps ?   It's a great preamp that is worth the upgrade.  Outfit it with the best new production tubes , or NOS if you have a reliable source like Brent Jessee or Jim McShane and have the $$$ .    The teflon upgrade isn't cheap , but it's a fraction of a new preamp.

You have loved the preamp, plan on keeping it in any case?

BOTH!

Why not? Money? I can understand that, not to mention packing/shipping/return shipping. I would do tubes first.

Tubes: can you bias them yourself?

many tubes last 10,000 hours. Buying new tubes, original, or, a different type/breed. Someone like Brent Jesse will take them back, let you try a different brand if you don't like them after a 60 hour burn-in.

i.e. I bought new KT88's, liked them better than my 6550's. I have the 6550's as spares, so I will never be in a hurry in the future.

i.e. I bought sylvania for pre-amp, didn't like them as much as original, burnt them in 60 hrs, sent them back, tried some GE's, half the price, sound great.

You can always do the caps later.