Hello,
I have a ML 33H that has been shutting down indiscriminately and neither United Radio nor Pyramid Audio has been able to reproduce the fault and fix it on their benches. The full description follows below, if anyone has seen a similar fault and has an idea of what might be causing it, I would greatly appreciate the insight.
I have a 33H that was refurbed by United Radio starting back in late 2020, replacing nearly all the electrolytic capacitors and the large filter caps, regulator and power supply caps with Cornell Dublier DCMC items. When it first arrived, it would not come out of standby. I just got a loud pop and it shut off with a slight ozone smell. I swapped outlets and speakers with its mate to make sure the problem was not with either the power or load, and even tried another speaker. It still would not turn on, and was sent back to United radio. If I remember correctly, Frank Rolince replaced a circuit board and sent the amp back and it worked fine for several months. Over time it started shutting down indiscriminately while in use as if there had been a power outage. It would go to the pre-standby mode where the LED was on and not flashing, but dimmer in brightness than when full on and operating. Sometimes, this would happen when the amp was in standby mode. Over time the frequency of this occurrence went from once every one or two months to no more than 40 minutes of use. The amp was sent back to United Radio again and it took several months for the fault to repeat itself on their bench.when it finally did show up, Frank found some “goo” on one of the boards that he cleaned up. The amp worked perfectly for a few weeks and then the fault started to to appear again and got to the point where it would not stay on for longer than 10 to 15 minutes. I noticed that if the ambient temperature was in the mid 60’s the amp operated longer than if the temperature was in the seventies. After calling Frank again, he was out of ideas, so I sent it to Pyramid Audio this past June. They have not seen the fault this entire time. The amps mate has not had any issues, nor has the newer production 33H that I got from Rick Castle. For reference, the speakers are JM Lab Grande Utopia’s, first generation, preamp ML 32. The LED on the failing amp is significantly brighter than on its mate, so that when it is in the pre-standby mode, it is the same level of brightness as the other amp is when fully on. The amps are in a well ventilated space. I cannot think of any other relevant information, but if you have questions, feel free to ask.
I have a ML 33H that has been shutting down indiscriminately and neither United Radio nor Pyramid Audio has been able to reproduce the fault and fix it on their benches. The full description follows below, if anyone has seen a similar fault and has an idea of what might be causing it, I would greatly appreciate the insight.
I have a 33H that was refurbed by United Radio starting back in late 2020, replacing nearly all the electrolytic capacitors and the large filter caps, regulator and power supply caps with Cornell Dublier DCMC items. When it first arrived, it would not come out of standby. I just got a loud pop and it shut off with a slight ozone smell. I swapped outlets and speakers with its mate to make sure the problem was not with either the power or load, and even tried another speaker. It still would not turn on, and was sent back to United radio. If I remember correctly, Frank Rolince replaced a circuit board and sent the amp back and it worked fine for several months. Over time it started shutting down indiscriminately while in use as if there had been a power outage. It would go to the pre-standby mode where the LED was on and not flashing, but dimmer in brightness than when full on and operating. Sometimes, this would happen when the amp was in standby mode. Over time the frequency of this occurrence went from once every one or two months to no more than 40 minutes of use. The amp was sent back to United Radio again and it took several months for the fault to repeat itself on their bench.when it finally did show up, Frank found some “goo” on one of the boards that he cleaned up. The amp worked perfectly for a few weeks and then the fault started to to appear again and got to the point where it would not stay on for longer than 10 to 15 minutes. I noticed that if the ambient temperature was in the mid 60’s the amp operated longer than if the temperature was in the seventies. After calling Frank again, he was out of ideas, so I sent it to Pyramid Audio this past June. They have not seen the fault this entire time. The amps mate has not had any issues, nor has the newer production 33H that I got from Rick Castle. For reference, the speakers are JM Lab Grande Utopia’s, first generation, preamp ML 32. The LED on the failing amp is significantly brighter than on its mate, so that when it is in the pre-standby mode, it is the same level of brightness as the other amp is when fully on. The amps are in a well ventilated space. I cannot think of any other relevant information, but if you have questions, feel free to ask.
