Tube Hum?


Hi Folks.
I just got a NOS pair of RCA Red Base 5692 (for 6SN7 type) tubes and installed them into my Blue Circle BC2 Hybrid monoblocks (they use a single 6SN7 type tube per monoblock). The tubes replaced standard Synvalia 6SN7s and the improvement in quality of sound was readily apparent - great upgrade.

However, there is a significant hum coming from one of the channels - I switched the tubes around to try and isolate the problem and it's definitely because of one of the tubes. The noise is not classic 'noise' like an intermittent hiss or static noise. Rather it is a deep hum. The tubes are NOS and supposed to be matched within 8%. Will this hum disappear as the tubes burn in a bit, is there anything else I can do to get rid of the hum, or am I stuck with it. Also, do you think such a hum is the luck of the draw or should the seller be responsible for providing a tube without such a flaw. Let me know what you think. Thanks!
John.
128x128outlier

Showing 1 response by elevick

I agree, you have a noisy tube. Return it if you can. Don't try to glue it unless you have high heat glue? Last resort, I have an NOS pair of Sylvanias, interested?