2. amps-preamps
  3. 1352419247

Tube pre amp problem?? Help??

Hi all, I have a New Dared MC-7p preamp and to make a long story short, went to roll in a 12AX7 and when I turned it on, a loud squelching shrill noise came out of the right speaker then nothing, silent out of the right speaker. I quickly turned it off and put the stock tube back in and again, nothing out of the right speaker. I was horrified that I may have blew up the speaker X-Over or something as no sound at all was coming out. So I hooked up my Dac/pre to see where the problem lies, and thank goodness all plays well. So something happened to the preamp I guess but what?? I took the bottom cover off to look for fuses but only see about three tiny ones that look to be hard wired in, and they don't look blown but cant tell. I'm so mad I am ready to fire sale the pre. Any idea of what it could be if not a fuse?? I sure am not going to send it back to China. Look for a good deal on the Gon. I'm going to stick with SS.
telescope_trade

Showing 2 responses by telescope_trade

telescope_trade OP
555 posts
 
Thanks Nglazer for the reply, but I already figured out the problem, and in fact emailed A-Gon to kill the thread before it came out so as not to get replies from thoughtless bone heads like above. They told me they took care of it, but here it is.
telescope_trade OP
555 posts
 
If RL was trying to be funny, my apologies :o) But I was really frustrated and looking for real help and did not read that as very funny. I do not know what happened for sure.

Here was the scenario...I got home with some tubes I got from a friend, and before I turned on the pre (obviously)
I pulled one 12AX7 to start, and upon firing up the pre, it
made the big loud noise out of the right speaker and it went away and left only he left speaker playing,right side totally dead. I turned it off and put the stock tube back in and turned it on and still...right side totally dead. In a fast panic, I turned every thing off and plugged every thing back into my Emotiva XDA which can be used as a preamp also, and everything was fine. WHEW!!! Anyway, I thought the pre either blew a fuse and did not think it was a tube issue since the stock one did not make a difference either. So I was bummed of coarse and posted my post.

About 4-5 hours later, I decided I would hook it all back up and try the left side tube (which is an AT7 tube) just to see if for some reason it controlled the right ch, and "it" had gone south. But when I turned it back on, everything was fine like nothing had happened??? Been sounding great from that moment on last night and all through the day today. No issues, not problems and sounding fantastic. I put in another AT7 tube and been enjoying it.

So, bottom line is, I think the AX7 tube was bad (lost it's vacuum??) and not sure it makes sense, but something in the pre "reset" itself??? A protection circuit??

Your guess???

Again, to RLwainright...I'm sorry if I read your reply wrong. Long week. :o)
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