Which Valves for Mark II ???

[MarkIIc+]

Hello I read a thread about tubes colors but ain't really sure about the tubes I can buy. thomann is selling many 6L6 tubes with different colors and different references!!!!

I have four Groove tubes GC that need to be replaced.

the head is smoking blue, the eq is dead...


as for the 12AX7 or Ecc83 tried them all with Mesa and groove tube but don't seem to find a way out... if you could just give me advice

thanks

Ps how can I attach the pic of my amp?!

 

[mark2boogie]

Well...

There is much hype about all that tubes mojo mystic and Co...

1 - Most of the tubes (nearly all) come from Russia or China, and some from Eastern Europe or other rare countries.
2 - AFAIK, Dave Matthews (EH) owns Sovtek and Svetlana, and sells directly its products under the Sovtek, Svetlana, EH brands, others being sold to Mesa-Boogie, GrooveTubes, RubyTubes, etc... Which use a more or less elaborated tube sorting process of their own (no ISO there...).
3 - NOS (New Old Stock) tubes must incitate to suspiscion : NOS doesn't imply GOOD - I mean complying with its original manufacturer's specs. You can find lots of brand-new-sealed-military-NOS tubes that are not usable : I have many JAN-6L6GAY lots to say that, and the equipment to check them versus the official manufacturer's datasheets.
4 - No matter what the tube sellers says, the performances of a tube varies more or less from a sample to another, even when sorted, during its life expectancy. According to the RCA manuals, none other than +/- 30% of variation from the datasheet remains correct...

So...

I would stay with Mesa, EH, Sovtek tubes, which are more affordable than other "hype" brands, and change them more often...

A+!

 

[mark2boogie]

Yes, druckpig is right - what do you mean by :

the head is smoking blue, the eq is dead...

A+!

 

[MarkIIc+]

@ mark II thanks for the info, I have found a great description on google! I have to find a way to get it over here

I had Sylvania tubes in my Marshall and loved them. I had many tubes in the boogie from groove tubes to marshall to ruby to Pm....
actually I realised it sounded cool with different brands. Having only Goove tubes or Mesa seems to flaten the sound and get it too dry/deadly

The problem is changing them as they seem to work together and they are nine of them! Mesa manual says changing the 6l6 often but actually I keep changing the 12ax7 as they don't keep life long. Since they die one to another it's difficult to keep up with changes.

@drykup the EQ when switched on make a big mass sound like something 's wrong. It certainly is a 12AX7 dead as suggested by Mesa. (just need to find the one)

about the 'blue smoke' well actually I realised this while playing with the heat it gives and the groove tubes amp there is a slight electronic smell and slight blue smoke.

I guess it comes out from the tubes ?!

cheers n to be continued

 

[boogiemon]

smoke (of any color) = damage

don't turn it on until you've taken it to a technician

 

[MarkIIc+]

@boogiemon

cheers i didn't think it was that bad...