Crackling noise

[triode]

Hi

Lately my Stereomour (45 tube config) making some crackling noise. Its not so loud but getting louder now. It was in left side only in the beginning, but now the right side also has the same noise, sometimes even louder.

I changed all the tubes (driver and output tubes) and it still crackling, also change input source, and the noise still there.

Would this because of the MJE5731A going bad ? I used 6829 tubes as driver for some time, would this taxed the MJEs too much and they given up prematurely?

Thank you for your help

Regards

[Paul Birkeland]

Lately my Stereomour (45 tube config) making some crackling noise. Its not so loud but getting louder now. It was in left side only in the beginning, but now the right side also has the same noise, sometimes even louder.

Have you moved any wireless devices close by in the recent past?  Your issue could be external interference.

Would this because of the MJE5731A going bad ? I used 6829 tubes as driver for some time, would this taxed the MJEs too much and they given up prematurely?

Do they looked cooked?  I checked out the data on the 6829 tubes and I don't believe they will cause problems.  A DC voltage check will tell you a lot about the health of those devices, and if they are being worked too hard they will char the PC board.

[triode]

Thanks for the reply

I did check a DC voltage check. All looks good IA/IB around 370-380V, IO/IA around 200V , KReg around 2.5V
I just connect the speaker again and the crackling noise much less now ! Only occasionally in left channel and not so loud.
No Idea what happened !!!

Maybe I'll check solder connections latter in Christmas/New Year break

Thanks

[Paul Birkeland]

Yes, it sounds like perhaps reflowing some joints would be a good idea.

[borism]

I just connect the speaker again and the crackling noise much less now...

I wonder if just cleaning the speaker binding posts, speaker wire connectors and RCA connectors might help with the issue.

[triode]

Paul,

After refreshing some solder joint, the crackling noise happened less time. But still comes back from time to time

I want to check if this comes from power stage or driver stage. Could I turn-on Stereomour without driver tube ? Would this harms the amp?
If there is no noise, then logically the noise comes from driver stage. Would this works?

Thanks

[Paul Birkeland]

You can run the amp with no driver tube, sure.  If the noise does not appear without the driver tube, that doesn't tell you that it's absolutely the driver tube, it just tells you that it's not related to the 2A3 output stage. 

Does the amp do this with nothing plugged into the inputs?  Are you feeding the amp straight from a PC, or are there wireless appliances super close to the Stereomour?

[triode]

Thanks Paul

The amp is connected to the Foreplay III and then the source.
I got no noise when I use Paramount amp instead, so I guess that would rule out the upstream component as source of noise.

I will try if there is no noise when no driver tube installed. At least we know if the noise comes from not the output stage or not.

Next I will try with all tube installed but no source connected

Regards

[Comity]

Not sure whatever happened with Triodes crackling noise but I wanted to let Paul know he nailed my crackling noise / distortion issue. I moved my WiFi router and the noise disappeared.  Strange though it had been on the shelf next to the Stereomour for 6 months and only recently started causing the crackling / distortion to occur.  I wish I had read this before buying a new driver tube!

Thanks again Paul.

[Paul Birkeland]

Hey, any excuse to buy more tubes right?

[Comity]

Well, there is that!