SimulClass with all 6L6's

[MesieBooga]

Is there anything I should be aware of or worried about when running all 6L6's in SimulClass Mode?

Can I still use the Class A Mode?

 

[t0aj15]

No
Yes

 

[zosojjc]

I just spoke with Mike B. about this. All the Simul IIC+s were originally shipped with 4 6L6s. He did say that the class A tubes (outer 2) should be cool running 6L6s (red if using Mesa tubes).

 

[Boogiebabies]

You know, I am going to try this in one of mine with 4 STR-415's.
Would you think that I have never ran any of my simul's with 4 6L6's!!!

 

[RussB]

Check how much current the outer pair (of 6L6's) is pulling...it can get quite high! You'd hate to burn up a pair of 415's!

If it's too high, swap the grid resistors (220k, IIRC) with ones of lower value. I'd start with 100k's and re-check

 

[Boogiebabies]

OK then, I will use the Phillips 7581A's !!!!!


The STR-415's are pretty mild and draw 22ma in the 6L6 sockets. I can tweak the bias on the outer sockets, but as you said I dont want toasty high dollar 415's. The GT 6CA7GE's draw 22ma as well in the outer sockets in a # 6 as do the GT 6L6GE's in the inner sockets. I thought it was strange how perfectly matched they were too.

 

[Dasein]

As I said in another thread, my 84 2c+ simul shipped with 4 6l6's.... I have 2 El34's there now, and don't remember the difference anymore.

 

[RussB]

I like the tubes in the outer sockets to run pretty warm...I have the JAN Phillips 7581A's pulling 50mA.

The middle pair pulls 40mA.

I am intrigued by the positive comments about the GT-6CA7's 8)

 

[Joey707]

I've been running 4 STR 415's in my simuls for a long time now. I really like it. It's a nice fat sound. There's nothing wrong with EL 34's, or 6CA7's in the outer sockets but 4 6L6's is like slab bacon, thick, greasy, and fat. Try it, you might like it.

 

[Boogiebabies]

Allright, I am going up to do it. Lets see where we end up.

 

[Boogiebabies]

4 matched STR-415's = 22ma in the 6L6 sockets and 55ma in the Outer Simul sockets. Tons of bottom and and a very nice highs, but way fatter high end with more gain perception. It chunks and shreds very nicely. With lower gain, or even the Volume knob down on a 58 Burst RI, it is seriously fat.

 

[MesieBooga]

4 matched STR-415's = 22ma in the 6L6 sockets and 55ma in the Outer Simul sockets. Tons of bottom and and a very nice highs, but way fatter high end with more gain perception. It chunks and shreds very nicely. With lower gain, or even the Volume knob down on a 58 Burst RI, it is seriously fat.

What I did this weekend. WOW the BEST tone of my life.

 

[Joey707]

So you guys like it faaaatttt. It is a cool sound. Like I said EL's or 6CA7's in the outer sockets are cool too, but if you want beef for dinner 4 6L's is it. Now that you have 6L6's (7581's) try mismatching the impedence. For example, plug an 8 ohm cabinet into the 4 ohm jack. It's like a trip to tweed town. Dark, spongy, and loose. Not something I would use all the time, but an interesting sound similar to using tweed power on a MK IV.

 

[MesieBooga]

4 matched STR-415's = 22ma in the 6L6 sockets and 55ma in the Outer Simul sockets. Tons of bottom and and a very nice highs, but way fatter high end with more gain perception. It chunks and shreds very nicely. With lower gain, or even the Volume knob down on a 58 Burst RI, it is seriously fat.

Do you like running the 4 6L6's better than combining the 34's or the GT 6CA7GE?

 

[Boogiebabies]

4 matched STR-415's = 22ma in the 6L6 sockets and 55ma in the Outer Simul sockets. Tons of bottom and and a very nice highs, but way fatter high end with more gain perception. It chunks and shreds very nicely. With lower gain, or even the Volume knob down on a 58 Burst RI, it is seriously fat.

Do you like running the 4 6L6's better than combining the 34's or the GT 6CA7GE?

I dont know yet. I need more time. I do think I will use the 7581A's though,

 

[MesieBooga]

Today I put some 34's back in the Simul-Class. The amp seems a lot warmer with the combination. I'll see if it works as good as the quartet of 6L6's worked last weekend.

 

[MesieBooga]

I'm back from a gig now....
Dilemma!
The tone with EL34's and 6L6's combined was killer for chords and lead. But I missed the 6L6 chunk when I was palm muting rhythms. I'm not sure what I'll do for next weekend yet. Maybe add an overdrive, or use two amps....?

 

[Boogiebabies]

Add and overdrive !!! Just increase the 80hz fader on the graphic.


Here, steal some settings. My Vol 1 is below 8 becasue this head has more gain than hell. Yours may need to be at 8. Us the lead pull bright and pull shift on the treble. If you want to get real wiggy, use the pull deep, put the treble at 7 and lower the 80hz to taste.


http://homepage.mac.com/mesamac/.Pictures/IIC++/boogiehead2.JPG

 

[MesieBooga]

That looks pretty similar to how I set mine up.

On my newest IIC+ Simul head I found I have to Pull the Vol 1. But otherwise the settings are real similar to below. I've found that the lower I run the Treb the better lead tone I get; as it goes higher it gets into Metallica crunch.

Maybe that's my answer! Just adjust the treble up a notch live! :wink:


Setting IIC+ settings Simul Combo * = Pull

Vol 1- 8
Treb- 6.8*
Bass - 3
Mid -3
Mas 1-2*
Ld Drv- 8 *
Ld Mastr - 3*
Presence - 0

I run the "combo" into a Mesa Standard 4x12 with V30's and a Diezel 4x12 with V30's and Diezel/Eminence speakers in an "X" pattern. The heads 4 ohms outs each send to the seperate cabs 8 ohm input. I use mainly Historic Les Pauls with 57 Classic pick-ups.
My New IIC+ head I got last week (#1330x) sounds best into just the Mesa 4x12 at 8 ohms. It's also not a hot sounding as the combo.

 

[908ssp]

..... Each cab is 4 ohms out into the 8 ohm input.

You made a mistake writing this? :?: You meant both cabs are 8 ohms using the amps 4 ohm output right? :?: Two 4 ohm cabs run in parallel is a 2 ohm load. You could possibly be running the two 4 ohm cab in series for an 8 ohm load but I have never seen a cab wired that way. :roll: