|
|
Post by akadave on Mar 10, 2012 0:23:55 GMT -5
I picked up a pair of Cryoset Svetlana EL34s to re-tube my SR. They are rated by the seller at 35ip which is supposed to be a medium on a scale of soft to hard. So I put them in and let them heat up for a bit, They showed 52mA on the multimeter with probe. So, I crank down the bias pot as far as it will go. It start to click when you reach the limit of bias, and the tubes still read 45mA. The amp sounds AWESOME with that setup but Scott says dont go over 40mA with the SR....I guess I will have to just use Sinos in this thing? I dont like soft tubes either so this is a problem.
What to do?
|
|
|
|
Post by Ayton(e) on Mar 10, 2012 14:00:50 GMT -5
Wouldn't it just be a resistor swap to shift your bias range higher?
|
|
|
|
Post by akadave on Mar 12, 2012 12:00:01 GMT -5
Wouldn't it just be a resistor swap to shift your bias range higher? I suppose. Dont mod my amps really and I dont even know where the resistor is..and this is a new amp. I did get the tubes to bias a 44mA and Scott said aside from the tubes not lasting as long there wouldnt be any damage to the amp and I have to say the Svets running hot sound really good! I cant send the tubes back so Im going to run them and order another set in the range that will bias at 40mA or under. |
|
|
|
Post by akadave on Mar 12, 2012 19:10:07 GMT -5
I will say this. The Svetlana EL34s sound great! More bottom and mids than the Sinos. Still stays tight and articulate though. Definitely good for rounding out the sound a bit. I will have NOS RCA 12AX7 to try this week. I have JJs in V1 V3 and a balanced 12ax7 in V4 and a Sino in V2 which is the first gain stage of the gain channel. Sounds very good!
|
|
|
|
Post by lonestar on Jul 25, 2014 19:20:06 GMT -5
I ran into that problem with some Svetlana el34's. I couldn't get the bias pot to crank below 44MA. I sent them back to KCA and explained my problem, so he sent me back some Svet's that were rated to match the amp. Ironically, they were rated "26", the same rating the stock splawn sino's have on them. I got them to bias in the correct range. I saw some posts about this in the quick rod forum also. When buying power tubes, make sure to specify the rating(the current different tubes draw varies).
|
|
