Curious Sequel II event...

[jvitez]

I was exchanging interconnects between my pre and power amps. I turned off the preamp, not the power amp. I unplugged the cable from the preamp, and heard a pop from the speakers, and a double click from my amp. Doh!

I shut off my Furman, and proceeded to install the new interconnect. I powered up everything, and huh? Everything shifted to the left of the soundstage, and the treble was very muted. I replaced the old interconnect, no change. I then switched the cable pre to power amp channels, ie left to right & vice versa. No change. Thinking I fried my amp, I went to bed, peeved at myself.

After work the next day, I turned on my stereo, and voila! Everything was back as before. Gremlins? It wasn't after midnight after all.

So, did the pop demonstrate the preamp's capacitors discharging a surge into the speaker which resulted in a prolonged refractory period after the action potential , for you physiologically trained folks It was the right channel's cable I was removing, and it was the right speaker that went flat.

I vacuumed the panels just recently. I bought a pair of Nordost Baldur RCA's which is what I was playing with. They give fabulous air and exhilarating crescendos to the top end, but after listening for a while, I'm now finding them too bright. The weaker bass of the Sequel II's are now more evident. The Baldur's kind of "unbalanced" the sound. So now, I have a line on two used Nordost Frey's, or maybe I should just go back to my pleasant sounding and well balanced Signal cable. But I digress.

Anyone care to explain what happened? I'm very curious.

 

[roberto]

I was exchanging interconnects between my pre and power amps. I turned off the preamp, not the power amp. I unplugged the cable from the preamp, and heard a pop from the speakers, and a double click from my amp. Doh!

I shut off my Furman, and proceeded to install the new interconnect. I powered up everything, and huh? Everything shifted to the left of the soundstage, and the treble was very muted. I replaced the old interconnect, no change. I then switched the cable pre to power amp channels, ie left to right & vice versa. No change. Thinking I fried my amp, I went to bed, peeved at myself.

After work the next day, I turned on my stereo, and voila! Everything was back as before. Gremlins? It wasn't after midnight after all.

So, did the pop demonstrate the preamp's capacitors discharging a surge into the speaker which resulted in a prolonged refractory period after the action potential , for you physiologically trained folks It was the right channel's cable I was removing, and it was the right speaker that went flat.

I vacuumed the panels just recently. I bought a pair of Nordost Baldur RCA's which is what I was playing with. They give fabulous air and exhilarating crescendos to the top end, but after listening for a while, I'm now finding them too bright. The weaker bass of the Sequel II's are now more evident. The Baldur's kind of "unbalanced" the sound. So now, I have a line on two used Nordost Frey's, or maybe I should just go back to my pleasant sounding and well balanced Signal cable. But I digress.

Anyone care to explain what happened? I'm very curious.

Hola. If you had only one panel working, then I suspect a faulty contact at the speaker's wire connector. The Sequel II are bi-wired and sometimes you might have a loose connection between the panel and the woofer. Because the woofer at the right is working, and the panel is not, this is the reason why everything went to the left side, then you did made changes, moving cables everywhere, and this could make to have a good panel contact again. Check for loose connection at the speaker connectors or power amplifier if you are bi-wired. Happy listening,
Roberto.

 

[jvitez]

Boa tarde Senor! Your advice is good, and appreciated. But I might not have been clear enough in my explanation. It was only the RCA interconnect between the pre-amp and the power amp I was exchanging when the "pop" occurred. More precisely, I was pulling out the interconnect from the pre-amp right channel, with that interconnect still being connected to the power amp. I touched no other wires.

My uneducated assumption is that pulling out the cable caused some type of short/voltage surge down the interconnect, into the power amp which was still energized, which then fed a blast of current to the right speaker, which led to audible "pop." I can make sense of that. What leaves me perplexed is why it seems the panel was not working properly for the rest of the day, and then be back to normal the next day.

So, did the "pop" mean enough current was fed into the electrostat panel to demagnetize it, even though that speaker was still connected to power? I'm not an engineer, so I'm only guessing here. If it did get demagnetized, why couldn't the speaker's power supply simply remagnetize the panel in a short time? I find this whole episode very interesting. I hope I've clarified what happened. My apologies if I wasn't clear initially.

 

[roberto]

Boa tarde Senor! Your advice is good, and appreciated. But I might not have been clear enough in my explanation. It was only the RCA interconnect between the pre-amp and the power amp I was exchanging when the "pop" occurred. More precisely, I was pulling out the interconnect from the pre-amp right channel, with that interconnect still being connected to the power amp. I touched no other wires.

My uneducated assumption is that pulling out the cable caused some type of short/voltage surge down the interconnect, into the power amp which was still energized, which then fed a blast of current to the right speaker, which led to audible "pop." I can make sense of that. What leaves me perplexed is why it seems the panel was not working properly for the rest of the day, and then be back to normal the next day.

So, did the "pop" mean enough current was fed into the electrostat panel to demagnetize it, even though that speaker was still connected to power? I'm not an engineer, so I'm only guessing here. If it did get demagnetized, why couldn't the speaker's power supply simply remagnetize the panel in a short time? I find this whole episode very interesting. I hope I've clarified what happened. My apologies if I wasn't clear initially.

Hola...now I do understand what was on better...some amplifiers and also preamps have an overload protection circuit that "mutes" for certain time a section if an overload happened. Also, ML Sequel model has a power sensing circuit, that when the signal is present, then goes to on, and when there is no signal, turns the high voltage power supply to off. Also this power supply might detect an abnormal signal and could protect your speaker...as an example, too much dc voltage present at the speaker terminal, will cut down the high voltage power supply. You had a heavy pop, and that is a big transient with a lot of power that you did generate when you unplugged the cable. Your amp could be under protection too. Just my thoughts too...happy listening,
Roberto.