2:90 cap job and gut shots

[Triaxstasy]

Just did a cap job on my 2:90 replacing all electrolytic power caps with new ones (the sig on the board says 9-1-92, so the parts were almost 20years old....about time for some maintenance).
While I was "in there" I also replaced all tube sockets with higher quality Belton Micalex ones.....
Here´s some gut shots:

Next up (and already on the way) is a matched integrated set of TungSol 6L6GC-STR and TungSol EL34B power tubes as well as 3 TubeTown E83CC bottles for the driver and PI slots. Thanks Dirk Munzinger of Tube-Town for matching iaw Mesa specs.

*Edit*: Just got this awesome collection of glassware in the mail today:

 

[ando]

Sweet, you're ready for the next 20 years now!

 

[kranog]

Does the board move?
I'm having trouble fixing my Pilot Light and Fan as I might have to unsolder a load of wires just to raise the board so that I can get to the Pilot Light and Fan cables.
Any help?

 

[snorkel54]

I realize that it's and old thread but...

The second last picture, why didnt you change the two upright electrolytic caps?
I thought that these also have to be changed...

 

[Triaxstasy]

Sorry for the late reply....been away for some time...

...you mean C41 and C42 in the mode switching circuitry (lower left in this schematic)?!?
I changed them as well ;-)

 

[BlackBart]

I have a 2:90 as well and it has the same tube layout sticker in the back, 4x 6L6 for A and 4x 6L6 for B.

How/what do you have to do to use EL34s?

 

[Triaxstasy]

Hi BlackBart,

There's no modification necessary....
Just get a matched quad 6L6 and a matched quad EL34.... And tell the vendor/shop that you need the tubes to be within Mesa specs.
I got mine (TungSol 6L6GC-STR and TungSol EL34B) from Tube-Town in Germany...awesome customer service

 

[BlackBart]

Thanks Triaxstasy,

Which tube sockets do the EL34s go in?

 

[Triaxstasy]

The EL34s go in the outer pair of sockets on the left and right, 6L6 in the inner quad.

 

[BlackBart]

The EL34s go in the outer pair of sockets on the left and right, 6L6 in the inner quad.

Thanks for the info! I'll have to try the 6L6/EL34 mix sometime.

 

[JMMP]

Just for clarification, Triaxtasy is correct for the blue light 2:90s. The layout for red light 2:90s is different and given below (as well as a pictorial version of Triaxstasy's statement) :

http://s992.photobucket.com/user/MagnusBausW/media/290integrated.png.html

 

[BlackBart]

I must have an older 2:90.

The layout for speaker/input/mode-switching jacks do not match the illustrations and the power cord is hardwired.

Are there any EL34 options for older 2:90s?

Thanks!

 

[JMMP]

The older 290 is the blue light model. The newer model has a detachable red light. The picture uses the red light model for both illustrations, but the layouts are correct. The blue light picture is on top, and the red light photo is below it. If your 2:90 does not look like the picture, it is a blue light and the top picture is your ticket, and the same as Triaxtasy's.

 

[BlackBart]

Thanks for the clarification JMMP!

 

[Corporal]

Excellent job, Triaxstasy :shock:

Any tips on how to get to the underside of that pcb ? Do you have to unsolder everything ?

 

[MesaMad1378]

Yep, take photos, unsolder everything and solder back up. Good fun!

 

[xcpointx]

Just curious to know if you noticed a tone difference after the cab job (hopefully you tested before the new tubes were put in)

 

[Henz]

Great work!! I have to do that. Hey, on your first pict, upper right, Where or what do those orange and red wires supply? near caps 26 and 27? Thanks.

 

[Henz]

Are those F & T caps?

 

[Henz]

Greetings. I just did everything too, along w/ two orange drop caps, 2 new LDR's and hard wired PT wires to pcb. Everything works great. Yes , the board shud be lifted. Take many picts and take your time. Make sure that your solder skills are good. Blessings, James.