According to the following website the P designation is for Chinese.
I have a dared sl-2000A
Get in touch with audiogon member "chelseawin" His name is Tyler and he's a great guy.
He is a A+ tube dealer also.
I bought a BIG ass NOS RCA 5Z4G from him for a very fair price.Its a good substitute for the Chinese 5Z4P.
A huge,flared tube looks very cool in this preamp.
Sounds better also than the supplied Chinese rectifier.
If you still have the Chinese 12AT7 input tubes,get some decent NOS for it instead.
I've had several tube preamps but the difference in a good NOS tube with this dared, was the most shocking tube rolling experience I have had.
I have a pair of NOS Mullard 'bugle boy' and a pair of NOS RCA's.
The Mullards are sweeter sounding,the RCA's cleaner sounding.
Im using the Mullards at the present.
If any owners of this preamp are still using the supplied Chinese 12AT7's,get some good NOS's in there and you will be in for a shock.
HUGE improvement.I've been messing w/tubes for a long time but never had this type of positive sound change from tubes.
You can get some good 12AT7's off eBay for a low price.
The 12AT7 isnt in much demand, so they go at a lower price.
Just make sure the seller has a few + tube selling feedbacks.
Also,I would get a hold of Tyler who I mentioned above.He's a great tube dealer and has a huge stash.