Mesa Boogie Alien Buzzing

[CEHMusic]

That is great news! I live in United States (California). I ordered some 440's that I found on eBay that had a great reviewed person and all functional tubes. Out of desperation (and potential EOL status) I purchased them.

That's great to hear any 6L6GC will work!

I would be open to others as these will come by February 9th @.@

[Mick Bailey]

I was saying any Mesa 6l6GC will work, not just any 6l6GC. That's down to the absence of any adjustment of the amp's bias. Without this it's possible that the tubes could draw far too much current at idle and at worse red-plate. The Mesa idea is that they supply tubes that are within an acceptable range that can just be fitted without the need to set the bias - they sell this as a benefit to the owner, but the markup on Mesa tubes makes them far more expensive than regular non-Mesa tubes. There's nothing special at all about them except the current draw. The same tubes can be had from other vendors (such as Doug's tubes, Tubestore etc) without the markup and that are matched to the Mesa spec. Here's a list of where the tubes originate https://www.watfordvalves.com/produc...?id=27&man=182 The STR440 is from the Chinese Shuguang factory.

[CEHMusic]

I see! Thank you for sharing this information. I have done some research regarding the other options here. Non of the Mesa brand tubes seem to be available. I have my tubes I purchased from Netherlands in transit and it seems at that point will I be able to test the problem. Will keep this updated.

[CEHMusic]

Well, I find this issue now resolved. I have replaced both of Mesa Boogie 6L6GC in my amplifier and it is 100% crystal clear again. I have left it on for 20 minutes, then played with it, and the buzzing is completely gone.
Rather than troubleshooting both of the tubes individually, replacing both was my preference. Therefore, the issue lied with 1 or both of the 6L6GC's in the amplifier.

Fixed!