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Acoustic 360 (2011-12) problem with cutting out

A

Alembic298

Nov 18, 2015
4
1
63
#1
Hello, I recently purchased an Acoustic 360/361m. The last few outdoor gigs it has cut out a few times in the beginning of the show then is stable ( something to do with the Play/Mute circuit)? I didn't receive a manual and was unable to figure out how to access the 360 to go through it with contact cleaner and check the circuit for problems. I have "rocked" the Play / Mute switch and "spun" the volume knob to hopefully clear any etching. I don't have any problem in the room where I keep it and it had the problem once at an indoor gig. I was able to find the manual online for the Acoustic Control Corp. version ( I have a 1972 360/361 which I don't gig with anymore) but haven't found any information on how to take apart the 360 so I can fix it. thanks in advance for any help
 
#2
Probably not, I think it's going to be something a little more challenging than this.

If you choose to "clean the pots" (also not a likely problem), be sure to use DeOxit D5, and only the tiniest amount possible into the slots that the terminals exit from. I don't believe these posts are still available though there may be suitable substitutes that are not mechanically identical (which could be an issue with mounting or the knobs)

Given the age of these amps, the first thing I would do is measure the critical voltages throughout the circuit when the amp is malfunctioning. Since there are multiple bias and offset (level shifting) circuit elements throughout the preamp and amp, this is unfortunately the most effective way to identify the problem. Once you correctly identify the cause, the repair will be infinitely easier and more effective.

Have you identified if the fault is in the preamp or power amp? That's a first step.
 
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#3
agedhorse, thanks I have not had the cutting out happen except when at a gig where I don't have the ability to do anything. I have had it come back by rocking the play/mute switch and spinning the gain knob, after one or two more times of it cutting out then it is stable for the rest of the gig, I am thinking it is in the preamp but need it to malfunction when I can take the time to go through it
 
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#5
agedhorse said:
Probably not, I think it's going to be something a little more challenging than this.

If you choose to "clean the pots" (also not a likely problem), be sure to use DeOxit D5, and only the tiniest amount possible into the slots that the terminals exit from. I don't believe these posts are still available though there may be suitable substitutes that are not mechanically identical (which could be an issue with mounting or the knobs)

Given the age of these amps, the first thing I would do is measure the critical voltages throughout the circuit when the amp is malfunctioning. Since there are multiple bias and offset (level shifting) circuit elements throughout the preamp and amp, this is unfortunately the most effective way to identify the problem. Once you correctly identify the cause, the repair will be infinitely easier and more effective.

Have you identified if the fault is in the preamp or power amp? That's a first step.
Click to expand...
 
#6
It seems to be that the Play/Mute switch connections were oxidized ( there was bleed when on mute that started to happen after I posted) after cleaning and re seating the connections the bleed went away and I have not experienced and cutting out since. Since the site no longer exists I was wondering about if the 360 preamps are interchangeable ( 2010 360 on 1972 361- 1972 360 on 2010 361m)? I am keeping an eye on it and hoping that that resolved it. Thanks for the help
 

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