Mixing Str420 and Str440 6L6 GC tubes

Quick question...I've search this board and can't find an answer so I hope to find some help asap. I needed to replace tubes 2 and 3 on my DR. Just went to the store and bought a matched set of 6L6 GC STR440. Come home to put them in and see that the other 2 tubes in the amp are 6L6 GC STR 420. Now I'm somewhat afraid to throw these in thinking it'll be disatorous...can anyone give me some insight? Like maybe a yes or a HELL NO!!! Thank you!!!

It won't be a problem. All the Mesa tubes are in the same range.

Put them in pairs....inside and outside pairs.

TriggerRob said:

Quick question...I've search this board and can't find an answer so I hope to find some help asap. I needed to replace tubes 2 and 3 on my DR. Just went to the store and bought a matched set of 6L6 GC STR440. Come home to put them in and see that the other 2 tubes in the amp are 6L6 GC STR 420. Now I'm somewhat afraid to throw these in thinking it'll be disatorous...can anyone give me some insight? Like maybe a yes or a HELL NO!!! Thank you!!!

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What was the ‘need’ to replace the tubes?

The STR-420 has not been used by Mesa for decades. If the tubes that needed to be replaced failed, I would surmise the other two are not too far behind.

While mixing the 420 & 440 series is not a problem, IMO I would get another matching pair of 440’s, and keep the working 420’s as spares.

My $0.02

Yes absolutely....replacing all 4 was the end result but here's what happened that led to the post. I purchased a DR the night my band was playing a show. Guy shows up with the amp...2 middle tubes missing...outer tubes are in place (6L6GC STR420)...So...I'd like to test it...buy it, so we hit a close music store and I got the set of 2...thinking they were an exact match till I saw the 420/440 difference. Now I'm freaking out so I hit this board with my concerns...thanks for the help BTW. I was looking online everywhere and read that the 440 was the replacement of the no longer made 420..and I saw many posts of people replacing all the tubes but not just 2 of the 4. I bought the matched set and left the store as it was closing and I knew they weren't open till the following Monday...so yeah...all is well now. The guy I bought it from had no clue what he really had. He purchased a storage at an auction from someone who lost they're belongings for failing to pay there monthly rental. Thanks again for the reply...thanks for the help!!!