Hello all,
Working on a Crest CA9 amplifier.
This is on the preamp board which also has the input jacks.
I can see someone has been in here before…
Can anyone help me understand the purpose of the two 10k resistors which were added in?
If you look close, you’ll see the left one is broken away, but that happened after moving it around.
I’d really like to get them out, but I’m hesitant to do that until their purpose is known.
They are not on the schematic, but I have drawn them in on the second photo, for easier reference.
I’m guessing they bypass part of the IGM circuit, but I don’t understand this well enough to be sure.
C17 and C18 were both bad, as were C21 and C22.
Everything else seems ok, but I don’t know exactly what IC4 does.
Hoping someone here has experience with this amplifier.
BTW, prior to replacing those 4 caps, the symptom was no audio, slight hum at the output. Active light lit, and no protect light on.
Thanks in advance!
Working on a Crest CA9 amplifier.
This is on the preamp board which also has the input jacks.
I can see someone has been in here before…
Can anyone help me understand the purpose of the two 10k resistors which were added in?
If you look close, you’ll see the left one is broken away, but that happened after moving it around.
I’d really like to get them out, but I’m hesitant to do that until their purpose is known.
They are not on the schematic, but I have drawn them in on the second photo, for easier reference.
I’m guessing they bypass part of the IGM circuit, but I don’t understand this well enough to be sure.
C17 and C18 were both bad, as were C21 and C22.
Everything else seems ok, but I don’t know exactly what IC4 does.
Hoping someone here has experience with this amplifier.
BTW, prior to replacing those 4 caps, the symptom was no audio, slight hum at the output. Active light lit, and no protect light on.
Thanks in advance!
