Hi Everyone !
I just registered onto this forum although I have followed some of the discussions on this forum since I have owned a pair of Aerius i for about 10 years.
I thought I would share a recent experience in fixing my left speaker high voltage pathway , as well as seek some advice on a long term repair.
A few months ago, my left Aerius unit sound dropped substantially. When I disconnected the speaker cable from the speaker bass nuts, the sound from the electrostatic panel was barely audible and severely distorted. My right speaker went merrily on with that sweet clear panel sound that I have grown accustomed to all these years. Last week I finally got the time to work the problem:
1) I switched around the left and right speaker cables but .. no change to problem. I used different power supply cables but the problem persisted. I concluded that something is wrong inside the left speaker.
2) Using instructions that I read on this forum, I disassembled the electrostatic panel to check the connections but everything seemed to be in order. Anyway, I re-tightened all the leads to and from the plastic connector grid just below the panel but there was no improvement in sound.
3) I bit the bullet and opened up the back wooden panel of both speakers and compared visually the two sets of electronics and the various wirings. I could detect no visual difference between the two sides. Sweet music continued from the right but the left panel was basically mute. I got desperate and although many on the forum have warned about the danger of high voltage, I pulled out my multimeter and began to check first circuit path continuity with power off ( such as the 15M Ohm resistors that Roberto of this Forum have repeatedly mentioned ) and then some selected voltages with power on. I was sweating quite a bit during the latter operation but I guess I must have been careful enough to avoid some nasty situations. Also I am unfamiliar with the circuitry such that I had to guess bit by bit the function of the different sections. I checked back on many forum discussions and that's when I learned about the voltage multipliers and the 15M resistors. I concluded that the 15M resistors are OK but that no high voltage was being fed to the panel even when the signal-detect LED was on. The right channel circuit board acted as a valuable reference and I was finally able to establish that the gate transistor after the high voltage transformer but before the voltage multiplier is mal-function. It stayed open irrespective of whether there is signal input ( ie whether the LED lights up or not).
4) As a remedy, I soldered a short bypass wire around the transistor. The high voltage transformer output was fed directly to the input point of the voltage multiplier, and beautiful music returned once again to the left channel panel !
5) The bypass has disabled the automatic HT switch . I have to unplug the power line to the left channel every time I switch off my amplifier now.
I hope this experience can be for reference to those that might have similar issues with their Aerius i.
I would appreciate anyone who can tell me the numbering of the gate transistor such that I can try to buy a replacement. There is none printed on the component itself. Also does anyone have a circuit diagram of the electronics of this model ?
Happy listening to all !
I just registered onto this forum although I have followed some of the discussions on this forum since I have owned a pair of Aerius i for about 10 years.
I thought I would share a recent experience in fixing my left speaker high voltage pathway , as well as seek some advice on a long term repair.
A few months ago, my left Aerius unit sound dropped substantially. When I disconnected the speaker cable from the speaker bass nuts, the sound from the electrostatic panel was barely audible and severely distorted. My right speaker went merrily on with that sweet clear panel sound that I have grown accustomed to all these years. Last week I finally got the time to work the problem:
1) I switched around the left and right speaker cables but .. no change to problem. I used different power supply cables but the problem persisted. I concluded that something is wrong inside the left speaker.
2) Using instructions that I read on this forum, I disassembled the electrostatic panel to check the connections but everything seemed to be in order. Anyway, I re-tightened all the leads to and from the plastic connector grid just below the panel but there was no improvement in sound.
3) I bit the bullet and opened up the back wooden panel of both speakers and compared visually the two sets of electronics and the various wirings. I could detect no visual difference between the two sides. Sweet music continued from the right but the left panel was basically mute. I got desperate and although many on the forum have warned about the danger of high voltage, I pulled out my multimeter and began to check first circuit path continuity with power off ( such as the 15M Ohm resistors that Roberto of this Forum have repeatedly mentioned ) and then some selected voltages with power on. I was sweating quite a bit during the latter operation but I guess I must have been careful enough to avoid some nasty situations. Also I am unfamiliar with the circuitry such that I had to guess bit by bit the function of the different sections. I checked back on many forum discussions and that's when I learned about the voltage multipliers and the 15M resistors. I concluded that the 15M resistors are OK but that no high voltage was being fed to the panel even when the signal-detect LED was on. The right channel circuit board acted as a valuable reference and I was finally able to establish that the gate transistor after the high voltage transformer but before the voltage multiplier is mal-function. It stayed open irrespective of whether there is signal input ( ie whether the LED lights up or not).
4) As a remedy, I soldered a short bypass wire around the transistor. The high voltage transformer output was fed directly to the input point of the voltage multiplier, and beautiful music returned once again to the left channel panel !
5) The bypass has disabled the automatic HT switch . I have to unplug the power line to the left channel every time I switch off my amplifier now.
I hope this experience can be for reference to those that might have similar issues with their Aerius i.
I would appreciate anyone who can tell me the numbering of the gate transistor such that I can try to buy a replacement. There is none printed on the component itself. Also does anyone have a circuit diagram of the electronics of this model ?
Happy listening to all !
