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Hi, my name is Greg. I come here seeking knowledge.
I have given up getting any support from Ampeg/Loud on this amp, so I turn to strangers on the internet. I have found a few threads here regarding the SVT 7 Pro (but different than my issue) and folks seemed very knowledgeable and helpful so I though I would throw this out here.
The amp is a rev B unit that had the main board changed to rev G prior to me buying it. I bought it as a fixer with it cutting out almost continuously. I had found the rev H rework instructions and figured it might be an easy flip (yeah, I know
)
After doing the rework the amp works but 1.) it still cuts out but much less than before and 2.) it doesn't have the volume it should. It seems like it is maybe putting out a couple hundred watts. Patching into the power amp from a different pre yields the same result. Output sounds fine, no distortion. Cutting out is much reduced by cooling the replaced U2 chip with airflow and a small heatsink.
I have probed the voltage rails and they seem fine (I am using the schematic from this thread post #21 http://music-electronics-forum.com/t28440/#post307936, which seem pretty much identical even though it is an earlier rev than my board). I need to go measure the voltages at U17 and U300 and on the output FETs, but wanted to throw out the question in case someone had a thought. This thing seems to have a whole slew of different mutes and protections that might be screwing me up.
Thanks in advance.
Greg
I have given up getting any support from Ampeg/Loud on this amp, so I turn to strangers on the internet. I have found a few threads here regarding the SVT 7 Pro (but different than my issue) and folks seemed very knowledgeable and helpful so I though I would throw this out here.
The amp is a rev B unit that had the main board changed to rev G prior to me buying it. I bought it as a fixer with it cutting out almost continuously. I had found the rev H rework instructions and figured it might be an easy flip (yeah, I know
)After doing the rework the amp works but 1.) it still cuts out but much less than before and 2.) it doesn't have the volume it should. It seems like it is maybe putting out a couple hundred watts. Patching into the power amp from a different pre yields the same result. Output sounds fine, no distortion. Cutting out is much reduced by cooling the replaced U2 chip with airflow and a small heatsink.
I have probed the voltage rails and they seem fine (I am using the schematic from this thread post #21 http://music-electronics-forum.com/t28440/#post307936, which seem pretty much identical even though it is an earlier rev than my board). I need to go measure the voltages at U17 and U300 and on the output FETs, but wanted to throw out the question in case someone had a thought. This thing seems to have a whole slew of different mutes and protections that might be screwing me up.
Thanks in advance.
Greg
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