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AUDIO FORUMS >> General Discussion and Support >> SE84UFO - Sudden Volume Loss
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Message started by benzxc on 08/29/22 at 17:05:15

Title: SE84UFO - Sudden Volume Loss
Post by benzxc on 08/29/22 at 17:05:15

Hi all,

I've been using and enjoying my SE84UFO very much over the past two to three years that I have had it. Until very recently, I've usually listened to music with the volume knob at around 9 o'clock or 10 o'clock, rarely exceeding that level.

About two days ago, I turned up my system and started listening to music but noticed that the volume didn't seem correct. I had to turn it up to around 12 or 1 o'clock to get the same volume that I was used to. I took my preamp and other equipment out and only used my phone as my source. The volume level remains the same so it is not my other equipment.

I visually observed the tubes on my SE84UFO and they seem to be fine. So I'm really wondering what is going on? To my ears, once I turn up the volume to 12 or 1 o'clock it still sounds good but I'm just curious what's going on here.

Not sure if this is related, but I also noticed that there is no "popping" sound when I change the bias switch when listening to music.

Any suggestions would be most welcome!

Ben

Title: Re: SE84UFO - Sudden Volume Loss
Post by CAJames on 08/29/22 at 17:15:53

Quote:

Posted by: benzxc Posted on: Today at 17:05:15

...About two days ago, I turned up my system and started listening to music but noticed that the volume didn't seem correct....

I visually observed the tubes on my SE84UFO and they seem to be fine...

This is almost certainly a bad tube and unfortunately visually observing the tubes usually isn't going to tell you much. Only way to know is to swap in known good tubes.

Title: Re: SE84UFO - Sudden Volume Loss
Post by benzxc on 08/29/22 at 17:42:15

I was hoping my tubes were still good... Oh well this was bound to happen! I will try swapping in known good tubes and see the results.

Thanks!

Title: Re: SE84UFO - Sudden Volume Loss
Post by CAJames on 08/29/22 at 17:46:25

Replacing tubes are a whole lot easier (and cheaper) than fixing something inside the amp, so good news - bad news I guess.

Title: Re: SE84UFO - Sudden Volume Loss
Post by benzxc on 09/04/22 at 09:51:46

So I purchased new tubes for the SE84UFO and swapped them one by one. The issue remains. Any ideas on next steps?

Title: Re: SE84UFO - Sudden Volume Loss
Post by CAJames on 09/04/22 at 15:07:33

Just to be clear, you have 4 new tubes in the amp now, right? And the both the left and right channel are equal volume?

Hum, I guess the only other thing I can think of is maybe one of the internal fuses has blown. You can open up the amp and check the fuses (I think they are 5 amp and 2x 0.5 amp but I'm not sure) or you can call Steve, which is never a bad idea.

Title: Re: SE84UFO - Sudden Volume Loss
Post by benzxc on 09/04/22 at 15:59:03

Yes, 4 new tubes and both channels have the same volume. Guess I'll have to write Steve. Thanks for your help!