stereomour turnon

[kevner21]

does the stereomour always have a hum in both channels at turnon ,or power up then disappears. this I take it is a normal procedure?

[M42]

Mine does exactly the same thing, it lasts about five or six seconds then dissipates!

Jeff

[Doc B.]

Yes, that is normal for the startup with AC filaments and solid state rectifiers.

[kevner21]

Thanks you all ,and have to say am very pleased with the sound of this 2A3 amp. Been listening to el84 and el34 amps and find  this 2A3 amp to be more open and pleasing to my ears. Thanks again

[kevner21]

after the turnon of the amp and the hum subsides i'm getting a scratching noise  and after it warms up it also seems to subside, in the right channel, don't worry about it, ??, check solder joints. JJ2A3's and RCA black plate 12AT7. outstanding sound!!!

[Natural Sound]

after the turnon of the amp and the hum subsides i'm getting a scratching noise  and after it warms up it also seems to subside, in the right channel, don't worry about it, ??, check solder joints. JJ2A3's and RCA black plate 12AT7. outstanding sound!!!

My Paramour II mono-blocks which is the precursor to the Stereomour has the same hum on warmup. If it goes away after a few seconds then its normal. If it didn’t go away then we'd need to do a little troubleshooting. The scratching thing might be related to a connection as Grainger suggests but since that goes away too perhaps its just the cathode forming. Give it some time and let it burn in. Most importantly, enjoy the beautiful music that the Stereomour is capable of.

[kevner21]

Hi Natural Sound    Have had the stereomour since June 10th and in the beginning  the amp would just produce the hum for a few seconds (which is normal ) at turn on . now I get the scratching for a few seconds also after the hum only in the right channel. Just want to see if I can correct it.

[Natural Sound]

Hi Natural Sound    Have had the stereomour since June 10th and in the beginning  the amp would just produce the hum for a few seconds (which is normal ) at turn on . now I get the scratching for a few seconds also after the hum only in the right channel. Just want to see if I can correct it.

I had a 6SN7 in my Crack headphone amp that had a scratching sound like that. It too was only happening in one channel. If I gently tapped the tube the scratching would go away. I replaced the tube and the problem went away. I assume that one of the two triodes was noisy. Some tubes that show up on eBay are noisy like this. Do you have another 12AT7 to try? If that doesn't work you might want to take the JJ's out and install the stock Sovtek's. If none of that works then start looking / re soldering connections. Unplug the amp before you do.

Good luck and let us know how it works out.

[Doc B.]

First try removing and replacing the tubes in the sockets. Sometimes it's just a little corrosion on the pins that creates the scratching sound. Next, once it is warmed up be sure the hum balance is optimized. The setting can drift a bit as the tubes break in.

[kevner21]

turned the amp on today and dead quiet, so maybe there was something on that old RCA tube , the GE sounds better anyway. another fire put out..... Thanks