JL e4300

[m4ick]

Really strange issue with this one, not sure where to start.

It powers up and produces audio fine from channels 2 and 4 but when you apply signal to channels 1 or 3 with a load it protects and you hear the transformer buzz a little. It does produce a split second of distorted audio before protect kicks. There is no significant DC offset on any channels and the two channels seem to have identical symptoms.

[Perry Babin]

Are any of the emitter resistors broken or out of tolerance?

[m4ick]

Not sure of the accuracy of my meter but all emitter resistors are definitely below one ohm and ALL of them give the same readings including the known good ones.

As a side note, channels 3 and 4 are NOT getting their input from the channel 1 and 2 rcas (there is a switch for that).

[Perry Babin]

If the switch is switching DC instead of an audio signal, the switching is done through the DG201s (if they're used in this amp)

Do you have a scope?

[m4ick]

Yes I do. I get the same results with the ch 3/4 switch in either position, the point I was making is that the ch 3/4 signal is coming from the ch 3/4 rcas and the switch is not set to get the input from ch 1/2. Still ch 1 and ch 3 have the same symptoms.

[Perry Babin]

Do you see a clean signal on 1 and 3 with no load?