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LEAK Stereo 50 Restore

H

Hi-FiGuy

AK Subscriber
Subscriber
I have a Leak Stereo 50 on my bench and I was able to find the schematic, but I am looking for more information like the manual with the specs and possible tube substitutions. I replaced the capacitors and checked the values of the resistors and I ran the amp with a GE 5AR4 and found that the rectifier was red plating!! The amp sounds good and is running fine otherwise. I plugged in a Sylvania 5AR4 (Fat Boy) and got no red plating. Im thinking the GE did not like this amp because the rectifier is run right at its limit. Could I safely use a 5U4 or GZ33 in this amp? Thanks!
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If i am not mistaken, that amps is supposed to have el34 output tubes. I dunno if that was why you had a problem wiht the GE tube but, it would make a difference in the biasing. I believe that it is also cathode biased. But, the differences between the el34 and 6l6 is not so great that the unit would not work . But using the 5u4 would be "iffy" since that draws 3 amps current. I doubt if the PT is spec'd at 3A for the 5v circuit. Leaks are sweet sounding amps though.
 
Beautiful amp! Does the amp have the voltage selector set for 124v? according to the schematic for the stereo 60, and stereo 50, it can take 5881, 6ca7, KT-66, EL-34.
Are the cathode resistors 440 ohm?
 
Line Voltage here is about 120V so I have the amp set for the 124V setting. I have tried this amp with 6L6 and EL34 tubes. The cathode resistors are just above 440 ohms. I was thinking that since this cathode bias and the power tubes are drawing a lot of current, that the 5AR4 would need to be very beefy. I wanted to use a GZ33 but I didnt want to tax the 5V filament winding. I was thinking of using a Weber CopperCap with the inrush limiter and the voltage drop that simulates a GZ34 (WZ34), they also have one that simulates a pair of GZ34 tubes in parallel (WZ68). This amp sounds amazing!! I have been using it with my Sylvania Fat Boy and its running fine. I was doing some tube rolling and put a Mullard mC1 in the front end, Using Sylvanias as drivers, and a set of 6889 for power (With Adapters). This combo is AMAZING!!!!
 
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