The high capacitance (ie th e 150uF reading 177uF) should be a warning as it indicates high leakage. The tester thinks it's still charging but it's leaking DC. A high voltage cap test with a 100mR or 1R resistor to test the leakage would show the leakage. Great job.
Apparently the designers never read the memo about turning transformers at right angles to each other so you don't have cross coupling of magnetic fields....
The inductive surge at turn on can often exceed the 1KV peak inverse voltage of ordinary diodes, which is why you often see two or three of them wired togther in series. On a high-power amp like this I would have used 2 1N5408 diodes in series on each leg of the power transformer secondary. The blackened leads on the original diodes is due to the plating which is probably silver or a silver alloy. I haven't seen it to be problematic for diodes, but in older plastic- body transistors, that oxidation product can creep right up into the plastic case and cause the transistor to become intermittent and noisy.
An appropriate spec'd MOV can also be used used, when the inductive spike goes above it provides a path to short the spike. It also protects for spikes like lightning strikes etc.
Would be a good idea to put in some good quality coupling caps coming from the phase inverter to the power tubes, just saying.... And not orange drops. Oil filled caps for that are great. Good job
I'm positive you're right! I haven't gotten competent testing caps for leak - but thats the next thing I intend to really learn. I have a G-2000 that's awesome sounding but the reverb is weak and the trem strength is also weak. I need to get better versed and see of I have some DC leaking and throwing things off. All the easy normal stuff is checked and good!
@char7138 Eminence squarebacks! I had never used them before, they are surprisingly great guitar speakers. Solid for bass as well but not as mellow as any others kf the era. I feel like the midrange and allowing the treble to sparkle is their strong point!
The high capacitance (ie th e 150uF reading 177uF) should be a warning as it indicates high leakage. The tester thinks it's still charging but it's leaking DC.
A high voltage cap test with a 100mR or 1R resistor to test the leakage would show the leakage.
Great job.
Apparently the designers never read the memo about turning transformers at right angles to each other so you don't have cross coupling of magnetic fields....
The inductive surge at turn on can often exceed the 1KV peak inverse voltage of ordinary diodes, which is why you often see two or three of them wired togther in series. On a high-power amp like this I would have used 2 1N5408 diodes in series on each leg of the power transformer secondary. The blackened leads on the original diodes is due to the plating which is probably silver or a silver alloy. I haven't seen it to be problematic for diodes, but in older plastic- body transistors, that oxidation product can creep right up into the plastic case and cause the transistor to become intermittent and noisy.
An appropriate spec'd MOV can also be used used, when the inductive spike goes above it provides a path to short the spike. It also protects for spikes like lightning strikes etc.
Would be a good idea to put in some good quality coupling caps coming from the phase inverter to the power tubes, just saying.... And not orange drops. Oil filled caps for that are great. Good job
I'm positive you're right! I haven't gotten competent testing caps for leak - but thats the next thing I intend to really learn. I have a G-2000 that's awesome sounding but the reverb is weak and the trem strength is also weak. I need to get better versed and see of I have some DC leaking and throwing things off. All the easy normal stuff is checked and good!
Awesome amp with jbls or alters for bass
@@timedwards5600 , "alters"? *Altecs*, I presume! (Autocorrect did the same exact thing to me here!)
Whats in the cab, Celestion G15M speakers???
@char7138 Eminence squarebacks! I had never used them before, they are surprisingly great guitar speakers. Solid for bass as well but not as mellow as any others kf the era. I feel like the midrange and allowing the treble to sparkle is their strong point!