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Crate G120CXL Rebuild 
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New Member

Joined: Sun Dec 18, 2016 3:34 am
Posts: 2
Hello,

So in my infinite wisdom i decided i wanted a project to play with. I found a cheap crate amp and decided to rebuild it. I have spared no expense, upgraded every component and generally spent a whole lot of time soldering. I finally got the thing back together yesterday and to my surprise it didn't burn up when i powered it up. Everything works but the chorus. So i have spent a bunch of time trying to hunt down that problem. I can't figure it out. It's been a very long time since electronics class. If anyone can take a peek at the schematics and give me an idea of where and how to figure out what's wrong i would really appreciate it.

All i have for test equipment is a DMM. So far i have checked that i have proper voltage with the switch on and off at the designated test point. I have checked for power from IC7 through IC12. Other than that i don't have a scope to check for wave forms. My biggest issue is the schematic confuses me. I would have thought the chorus effect would be isolated more than it is. i can't tell where the effect circuit starts or ends.

Anybody want to help?

I tried to attach the schematics to the post but the forum won't allow a pdf and if i make it an image it is too big. So here is a link to the schematics.

https://www.dropbox.com/s/hfhow39bkq3ni ... c.pdf?dl=0


Sun Dec 18, 2016 4:06 am
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Registered Member

Joined: Sun Feb 03, 2013 2:33 pm
Posts: 36
Looked the print quick, without a scope it will be tough. You can check and see that there is some continuity through the reverb tank and connections with a DMM.


Sun Dec 18, 2016 5:37 am
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New Member

Joined: Sun Dec 18, 2016 3:34 am
Posts: 2
Hi Petee,

Thanks for the help. The reverb tank is new and works great. What i have found is that both channels work on clean and overdrive but i lose the right channel when i switch on the chorus.


Sun Dec 18, 2016 5:51 am
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Registered Member

Joined: Sun Feb 03, 2013 2:33 pm
Posts: 36
There ya go, at least your narrowing it down. Tough to troubleshoot without a scope though.


Mon Dec 19, 2016 2:46 pm
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