Can weird tube combos screw my amp?

[enuenu]

If you get it wrong can using the wrong tubes screw your amp?

The reason I ask is I am thinking of putting my faith (as I have no knowledge) in Eurotubes' re tube sets for DRs as detailed here. I was interested in the "Mesa Dual Rec My Personal Fave" near the bootom of the linked page. It reads as follows;

Mesa Dual Rec My Personal Fave
Price: $176.75
Description: A lot of my customers know that I own a Dual Rec and quite often ask me "What is your favorite tube lineup?" So here it is! This is what I run in my DR. After a lot of experimenting with different grades I came up with the perfect grades to do this and get the bias just right. For power I run an Integrated quad of two KT77's in the outside sockets with a pair of 6V6's in the inside sockets and two GZ34 rectifiers. For the front end a Gold Pin ECC803S in V1, a Gold Pin ECC83S in V2, a high gain ECC83S in V3, a standard ECC83S in V4 and a balanced ECC83S in V5. These get a killer clean and a smooth rich tone with plenty of distortion and the warmest tone I've heard yet from a DR. I run these in the tube rec and EL34 mode in the bold setting.

Does such a combination of tubes push the amp beyond what Mesa designers would recommend in any way? To someone like me who knows nothing of the electronics it sounds plain dangerous. But if it is safe as houses and gets me closer to tonal Nirvana, I'm there.

 

[enuenu]

It seems you have ensure you select "bold" and "tube rectifier" settings or maybe something bad could happen. This indicates that maybe the combination of tubes pushes the envelope a bit.

Are some of the other DR cocktails that Eurotubes have on offer "safer" than the "personal fave"? I have no intereest in anything that has the slightest chance of damaging my amp.

 

[mikey383]

Typical 6V6s handle less than 400 plate volts. A Recto typically puts out 475 in bold/diode mode. Although, the JJ 6V6 is said to handle voltages in excess of 450 watts rather well, and acts more like a 6L6.

You could run them, but I think Bob likes to push the envelope a little further than most people, and I really wouldn't try it. But that's just me. Chances are, the tonal change you'll hear isn't something that most other people will hear.

 

[94Tremoverb]

As long as you're using 6V6s that will take the voltages (pretty much only JJs, which as mikey said are really halfway to a 6L6) I can't see any reason it shouldn't be fine. If the tubes will take the voltage and don't draw too much current (which will be true with this set in a DR) and bias at the right point to work correctly (which they will, since surprisingly 6V6s and EL34/KT77s need about the same bias voltage for a given plate voltage) then it's safe and should sound OK. The only remaining issue is that the impedance of 6V6s is around double that of 6L6s or EL34s, so probably there will be a slight loss of power due to the mismatch, but I doubt you'll notice.

 

[enuenu]

Thanks. I think I will stick with some SED 6L6s, SED EL34s and some JJ or Tungsol 12AX7s. I have standard issue Mesa tubes in now and I think the amp sounds pretty good. I want to keep everything nice and safe as I just don't have the technical knowledge to stray from the tried and true.

I hear a lot about KT77s being good in a DR, but again I think they maybe fall outside the "tubes for noobs" category.

I also want my tubes to have a reasonably long life, no live fast die young for me.