I regret your loss of a brother, you have my sympathies.
By reputation: RHB Sound Dezign
That's a simple answer to your post, but I strongly urge you to reconsider. By all accounts, the Mesa Baron is an excellent amplifier as manufactured. A modifier will swap out parts and alter the amplifier's sound, but only you can determine if it has improved. To maximize your chances for satisfaction, you should become well acquainted with the stock amp so you can communicate what you perceive to be the amplifier's opportunities. You should also realize that modifications of this type will likely result in a decrease in the amplifier's value. Good luck.
Mesa will still service the amp. Contact them and inquire what they might suggest. At a minimum you might consider sending it to them and ensuring the amp performs to factory specs, or have it refurbished it so it meets factory specs.
One of these days I will buy one of these amps.
I suggest you keep the amp for sentimental value without modifying it in any way. It will never be the same amp again..you would be moding it so that it in fact wont be.
really, the mesa baron had three versions, which do you have? Each version was set up for the tubes it came with. wanna sell it right now ? anthing that has been modded by some guy in a garage becomes worth near zero imho. ironically, mesa got started by modding fender amps ! youre not too far from where mesa is, so maybe you could drive it over,
FWIW, I've had one of those puppies since they first came out. The amp has great potential but is really system dependent (as is most everything!). Out of the box I think many will find it a bit bright - the critics did for sure, but in an otherwise warmish set up it can be an excellent amp. Mine is up an running as I type. BTW, although the Triode mode is fine, I find the soundstage too diminished and recessed. I run mine in 1/3d triode 2/3d pentode. If I wanted a 'Triode' amp I think I would just buy one designed just for that. I like Triode done right.
I had a factory mod done when it was almost new which changed out the caps to Wima caps, and they help. They also changed out the turn on switches to get them out of the signal path after the unit was running. They subsequently came out with a tri-tube mod which allowed use of 5881's, EL34's, and 6550's.
Right now I'm using it with Silverline Bolero speakers, an ARC SP10 pre, and both a Wadia 302 and a Bat VK D5 CDP's as sources.
I agree with the guys above that recommend that you set your amp up, let it settle in, play with it (all of the options will keep you busy for a while) and see what you think you want to improve.
I wouldn't spend much money on its power tubes but those small tubes make a huge difference, especially if they are the ones furnished by Mesa. Try new production first, like the Mullard re-issues and EI 12AX7E (long grey plates). More importantly, don't overlook the designers comments (in the manual) that you can even use 12AT7's, which have a lower gain. I think this amp works better in a lower gain set up (passive pre-amp or better yet low gain pre-amp). You can even try some in-line attenuators to lower the gain and see if that floats your boat.
Last, but not least, call Mesa and talk to them. They are very service oriented and helpful.
Hope that helps a bit.
There is a local modder in New Jersey that I have used for several projects. He is very knowledgable and has a great ear. His name is Igor. The company is called K-Works. I suggest you contact him with your query. His email is: firstname.lastname@example.org. Tell him Phil Slepian sent you.
no idea about these amps but from fooling with the Audiopax, if you can use 12 AT7's as prior post, try some CV 455s. Some nos Mullard CV455s make the CV4204s? or whatever my Pax came with sound positively broken.
Failing that the engineer I use worked at Abbey Road Studios
and although the only authorised repairer for Audio Note uk,
his real labour of love is band gear.
Get it performing to original spec and leave as is
Talk with Mike at Mesa. The most important upgrade is to replace the 10,00uf 16V brown Sprague electrolytics on the audio board. Highly prone to leakage.
Had my amp set up for EL34s many years ago, much smoother than the 5881. Also replaced the .1uf caps on the outputs to Hovland Musicaps and will soon go to Mundorf silver and oil caps. The original Mesa tubes tended to be a little bright in combination with the orangedrops.
Magnumip205, I also prefer EL34's in the Baron. My original 16V caps did leak, and Mesa replaced them. Would you consider upgrading the replacements Mesa used important? They seem better than the originals, but Mesa would never use an expensive "audiophile" cap. re: the eight .1 uf caps, did you upgrade those from the original Sprague 715's, or had you tried the Wima upgrade Mesa offered?
I have had one since 1998. Mine was modified by Mesa to be a tri tube version with WIMA caps. The speakers are Soundlab Dynastat. Tubes are JJ E34L all matched to 1ma, drivers and splitters are Mazda silver plate or (sometimes) Mullard m8137.
This combo is outstanding. I have had musicians and singers that have appeared at the Kennedy Center and the Metropolitan and 9 of 10 said it sounded as if there were at a live performance.
Since you are in California, Mesa might be the best idea...they are expensive however. The reason I had mine done by them was when I bought it from a California dealer they had already made the arrangements for the work ( otherwise I would have done it). I have been restoring vintage gear and nome new products for over 30 years (and have done work for Joe at Tempo Electric), and intend to rework the amp very soon.
What I will do to it includes, hexfred diodes for the 10 cent 1N4007 line up, Muse electrolytic bypassed with small oil caps and some ATOM caps (if I can't fit film caps in), dump the WIMA and Sprague 715 (which are NOT audio caps)and replace with Obbligato or Ampohm, and resistors in the signal path get replaced with bulk metal type. The output tubes a RCA 12 matched Blackplate 6L6GC.
I could modify yours, but as others have said here, you need to listen to yours first...it may just be what and how your want your amp to sound. Then try a Mullard 12ax7 or a Raytheon/RCA blackplate 12ax7 (very similar to a Mazda in sound) and see what that does. It is very important that your outputs be matched to within/no more than 2ma total spread per set of six.
Farmersre. Truly sorry for your loss. Astrosytomas are mean SOB's! I will give you my 2 cents. Just listen to it for a while in triode mode. Don't just rush right out and have someone mod it. Everybody has their own idea of what it should sound like. Your ears, your audio system is truly unique to you. What sounds good in one person's system might not sound good in yours. I repair ARC in warranty, and sometimes update as well. I'm very careful about mods. After listening to your amp for a while with different material try and determine what you like and what you don't like about the amp. If they're sonic issues it may not be the amp. I also believe calling Mesa is a great idea. Talk to them about it. After all, they designed and voiced it.