(Jay-Z© - Thirty Something)
(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
v.
Feel free to contact me, if you have any questions, suggestions, comments etc.
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valviac 20xx