petehall347
the brandy coffee man
did you look for oscillations on pre out ?
If the c1451's are still in place, replace them with KSC3503 ASAP.
did you look for oscillations on pre out ?
They are know to be ticking time bombs. If the BE junction is failing, it will affect Q1 and the operation of the differential amplifier.I'm guessing these are a known failure point?
would that not affect the bias current of the outputs ?They are know to be ticking time bombs. If the BE junction is failing, it will affect Q1 and the operation of the differential amplifier.
They are know to be ticking time bombs. If the BE junction is failing, it will affect Q1 and the operation of the differential amplifier.
Entirely possible. Also, if the diff amp is being thrown out of balance by the C1451, the DC offset could go high which would trigger protection. Either way, the C1451's need to go.would that not affect the bias current of the outputs ?
KSC3503DSTUMan, electronics are wierd. I'll get some KSC3503's on order now hopefully they'll be here within the week. Any specific suffix I should go with?
KSC3503DSTU
2SC1451 is the work of the devil.
They did all kind of things on my 7500 too.
As long as you're going to be right there, replace the trimmers (VR1/2) and sleep better.
I always suggest to put some glue on the leads/covers for the STK diodes, where they enter the package = cheap insurance.
Also good to have ksc3503 and its complement ksa1381 in your stash, as they are used on so many units.