1988 Fender Princeton Chorus amp...

[Jeff Urban]

There is an OP AMP right after the BBD, it is set to unity gain. If you have a scope, it should be putting out the same amplitude as what is going in.

It is nice to have a generator working in those things but you have to usually resistor the output way down. Where I worked I had a guitar next to me, plugged it in and had to strum it periodically. My stuff stays home now.

That print says for a power/gain test go in the return loop jack and you should have equal signal on both sides. You can plug a friggin cassette deck into it really. (one channel) All you have to do is get or make the proper adapter.

 

[Phil Allison]

Jeff Urban wrote:

============================

> First of all Phil is probably right.

** You bet he is...

But then if you want to try things on your own...

** He might start with the Chorus/ straight switching system. In Chorus mode, one channel handles straight signal while the other the delayed/swept version.

Mixing of the two to give the effect occurs in the air beyond the speakers.
If the either channel\'s level is low, he may still think both speakers are workings when one is not.

I use a scope to tell, the delayed signal sounds almost normal until the straight one is added.


...... Phil

 

[Jeff Urban]

Well like you said but in different words, this takes a tech. One speaker could be half blown. And in a guitar amp post people would not notice much if the amp is only pushing one direction.

I say let the guy do it. I think he owns it. If it goes poof then it does.

Maybe the guy will buy a scope. I think novices should always start with a CRO, not a raster based one. No digital no nothing.

That would ell of the speakers. They both had the same power but one (the right one I think right ?) is half fucked up because maybe something got spilled in it. Shit happens.

Well if out OPer here is reading he is probably learning. One of the simplest tests would be to switch the speakers. However we know that is not always feasible. You got two viable choices, mount them reverse. Or just hook it to external speakers. We all have a pair of speakers around.

So without a scope he is not even to that point yet, needs a pair.

 

[Jeff Urban]

Well like you said but in different words, this takes a tech. One speaker could be half blown. And in a guitar amp post people would not notice much if the amp is only pushing one direction.

I say let the guy do it. I think he owns it. If it goes poof then it does.

Maybe the guy will buy a scope. I think novices should always start with a CRO, not a raster based one. No digital no nothing.

That would ell of the speakers. They both had the same power but one (the right one I think right ?) is half fucked up because maybe something got spilled in it. Shit happens.

Well if out OPer here is reading he is probably learning. One of the simplest tests would be to switch the speakers. However we know that is not always feasible. You got two viable choices, mount them reverse. Or just hook it to external speakers. We all have a pair of speakers around.

So without a scope he is not even to that point yet, needs a pair.