I think I like EL-34's best in my Mark I Re-Issue

[yettoblaster]

I tried and liked the 6V6's a lot.
Then I even tried a 12AT7 in V3 just so I could see the Master Vol above 2, for the experience.
The 6L6's (str440) that came with are ok, but rattle and make bass farts through the C-90 on anything more than 1&1/2 on the bass pot.

The EL-34's (just Mesa brand) have a more aggressive tone even though Mark I's are mostly pre-amp distortion. There's still some EL-34 sizzle even turned down.
Seems to be a good match for the C-90 too.

The sweet spots are broadest with the 6V6's, but that aggressive tone is easy enough to find with the EL-34's with just a bit of twiddling.

I also put a DiMarzio Evolution in the bridge spot on my partsocaster, so the combination is REALLY FILTHY, NASTY, and LOUD! 8)

I'm ready for our next outdoor (in the park) blast. But that's not until Oct 14th. The park's ducks will be heading South immediately.

 

[srf399]

What does the 12AT7 do? How does it effect the tone? I am also running the EL34's in my MKIV and prefer the tone over the 6L6's If you could describe the 6V6's? Blackface with attitude? How does the tone compare with the 6L6's and the EL34's respectively. I also want to try using the yellowjackets with EL84's and the EL34 combo. Thanks for sharing.

 

[yettoblaster]

What does the 12AT7 do? How does it effect the tone?...

It's a lower gain factor than a 12AX7. In the V3 position it's supposed to offer less pre-amp gain to the power amp section, so its affect on tone is mostly changing the sweet spot a bit in the gain stages.

I allows the Master volume pot to be turned up a bit so it's not right at that notchy minimum setting which is hard for me to get where I want it at low volume venues.
The amp is still plenty loud, just doesn't blow your earlids off with the Master on 7 - 8.

The 6V6's give the overall tone a bit more "tweed" sound, to my ears. I can pretty much find what I like about tweed Deluxes and Bassmans by carefully contouring the midrange with a couple 6V6's on the tweed power setting.

I think 6L6's give my Mark I more of the Blackface with attitude (when I'm in the #2 input - which on Mark I's drops off a gain stage) sound.

The 6V6's don't get really spongey sounding like a small tweed amp with tube rectifier, like a tweed Champ or Deluxe. So it does react a bit more like a Blackface in that regard (ss diodes are what Mark I's have).

So probably by contouring the midrange (down) it would be possible to get some in-between BF and Tweed sound, but I'm usually after more mids (tweed). It won't get all the chime and high end sweetness of a say, 5E3 circuit (I had a Victoria 20112 that was a nice version of a 5E3 tweed Deluxe Fender). More like a tweed Deluxe with tired tubes.
But at least it gives an overall impression of tweed tone - just without the sheen.

The EL-34's give me a nice so-called "British" sensibility, but fatter. And the bass doesn't fart out the C-90 (stock) speaker. Sometimes the Vox sound is closer, but it's got more oomph like a Marshall, but I can tune out that high midrange and fill in more bass than Vox or Marshall get.

The 12AT7 in the V3 spot just lowers the overall volume with any of the different power section tubes I use.
If I was trying to get more power tube crunch (again, at higher volumes than I'm usually asked for), I'd definitely put the 12AX7 back in V3 and throw a blanket over the amp. :wink:

In mid Oct we have another outdoor concert in a park, so I will be putting the EL-34's in for that, and possibly the 12AX7 in V3, depending...

 

[srf399]

Thanks for your description. I love the fact that we can switch tubes in our Boogies... Makes versatile amps even more so.

 

[yettoblaster]

have you tried KT77's with the Mark I? I have 2 of them in my Mark IV and love them. I'll be posting an update in the tubes section shortly...

No. I've never seen them for sale in a store that handles Mesa tubes. Do you have to get 'em online?
I'll look for your review.