Question about Amperex tubes and a preamp

[JPeitzman]

I know two different things, but a couple of questions.

1. I have been cataloging tubes I got from my dad from when he used to service theater amps for RCA. I have 5 Amperex 807's that are totally brand new. In Amperex boxes still wrapped in paper, beautiful crystal clear glass, beauties. Anyways they are stamped Amperex 807 Made in England...are they re-branded Mullard's? Just curious, I don't know for sure what I will do with them, if anything. Maybe PP amp made using one of his theater schematics to pay homage to the God's for blessing my with his old tube stock, maybe leave them in the box to sit out another 40+ years.

2. I am going to build a tube preamp, I am thinking 6SN7's or 6SL7's, I have 4 of each that are NOS RCA's and some other's that are random brands...Tung Sol, Ken Rad, etc... I was thinking ½ of the 6SL7 and a 6SN7 in SRPP. Is the 6SL7 needed, or can I just do 6SN7 in SRPP? Would 6DJ8, 6H30, or 12AX7's be a better choice, I have the 12AX's...a pair of RCA's... but the others I would have to buy, though that is no biggie. Oh, and no I don't have a schematic as of yet.

Still have no idea what to do with my one lone gray plate RCA 2A3.

Thanks and happy listening!

 

[planet10]

Anyways they are stamped Amperex 807 Made in England...are they re-branded Mullard's?

After Philips bought Amperex many (if not most) Amperex tubes were rebranded out of the various Philips factories.

Look for the little codes (2 rows of 3 charachters). If the 1st on the 2nd line is a B, then they were made in the Mullard Blackburn factory.

http://www.audiotubes.com/mullcode.htm

dave

 

[JPeitzman]

Thanks for the info, I will have to check it out!

BTW I really like "The Seraphim" 's on your site. Very very cool, very imaginative, a great combo of kid-friendly art and sound. Hats off to Mr. Duke.