-> audio/diy -> 30somethang

(click photo to see pp-schematic - ~50kB)

( click to see the Power Zupply schematic ~ 50KB)

April, 2nd. 2007
Ever wondered why there are the UX4 sockets on the BaRBaR Chassis ???
I'm pretty sure that you now know why.
As I told already, my first "ZERIOUS" Line Amp was a copy
 of Doede Doumas DDPRE (a 30 Tube in a mu-follower configuation).
Ever since I own 2 pairs of 30's - one pair of 230 Silvertone's and one pair of RCA 30's
and wanted to know how they are going to sing in a LC-coupled configuration.
Bad newZ iZ: I burned the RCA's due to an error in the connection
 of the current source for the heaters (:-(
(You know - one kind of the mistakes: May happen to anyone - dumbest first)
Really GOOD newZ iZ: after getting the circuit right,
the Silvertones really ZZZZZZZZANG.

The circuit is basically the "BaRBaR" circuit, with the Ba's substituted by the 30's.
Don't know if they're really same level - or if one can beat the other. I need to "investigate" that..

Addendum April, 21st. 2007
The 1H4G won.
No really, the 1H4G is the octal-socket successor of the 30 established in the late 1930's.
The advantage of this tube is that it is relatively cheap to get as NOS in the US.
So I ordered some for $5 each :-) and tried 'em.
I think that tube has the best price-performance ratio of all tubes
 I ever bought (griiiiiiiiiiiiiiiiin) especially with the nowadays really
 FAT EURO (griiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiin) it costs me less than €5 per tube incl. shipping.
And the sound is in my setup better than with the Ba.
New schematic version is 1.1. because the 1H4G needs other B+ than the 30.
Don't ask me, I don't understand it.
The datasheets tell you that these tubes are more or less identical beside of the capacitances.
Maybe that the root cause is that I always dealed with used 30's and the now installed 1H4G is NOS.

Have a nice weekend

Feel free to contact me, if you have any questions, suggestions, comments etc.