[mistyfud]

I've had my little dot i+ for a few days now. I upgraded the stock tubes with NOS sylvania 408a's. The tubes sound great, but there is some hissing and crackling noise in the left channel only. The hissing sound is a constant volume, so increasing the volume on the amp does not increase the volume of the distortion. I switched the tubes around, but with no success. Is this a problem with the amplifier or the tubes?

 

[HeatFan12]

Quote:

Originally Posted by mistyfüd /img/forum/go_quote.gif I've had my little dot i+ for a few days now. I upgraded the stock tubes with NOS sylvania 408a's. The tubes sound great, but there is some hissing and crackling noise in the left channel only. The hissing sound is a constant volume, so increasing the volume on the amp does not increase the volume of the distortion. I switched the tubes around, but with no success. Is this a problem with the amplifier or the tubes?

Did you set the jumpers to use the 408As? If you purchased the starting version (6J1), jumpers must be set accordingly. If you purchased the 408a version then it should be set to use those tubes.

 

[mistyfud]

Yes, I removed both jumpers from J1 and J2, and adjusted K1 and K2 to the correct side.

 

[HeatFan12]

Yes, that is correct..

When you switched the tubes, did the distortion follow to the right?

 

[mistyfud]

Oddly enough, the distortion stayed on the same side :/

 

[wallace]

It could be dirt on the gain jumpers,the early ones used switches that needed the odd flick from time to time.you could try reseating the jumpers.I also had a similar hiss on an op amp i tried. If you put the same post on little-tube.com ,i am sure David will come up an answer quickly. Good luck.

 

[lazpete]

Could also be some dirt on in the sockets. Try to use some good cleansing solution and clean the tubes as good as possible.