Mesa Baron

Not a question, really, just looking to share something with any users of the Mesa Baron all-tube power amp (now sadly discontinued).

I just found THE preamp to match this high-gain amp, after trying for 10 years. It's the Promitheus Audio TVC (passive transformer volume control).

Over the past 12 years, I've used the Baron in 3 phases - back in 96-97, when it first came out, when I reviewed it for a publication; then in 2000-2001 when I bought and then sold one ... and finally, in 2004, which I intend to keep until Hell freezes over.

I've used McCormack's passive TLC-1 preamp (a pretty great match), Audio Research low-gain LS15 and LS16, Quicksilver Linestage and many others ... but something just clicked with the TVC.

Just in case anyone's still in the hunt to optimise their Baron's performance. Do note - all the while, I've been using the stock version. I have, however, messed around with the input driver tubes (AX7) - the onboard Russion Sovteks have the best punch, Tungsols sound cleaner and airier, and Mullards are just too syrupy for me ... :)

Appreciate any thoughts ...

Thanks so much! I am indeed still on that quest, since buying Baron #54 in '96, and will try it. Mesa used to recommend a passive pre. I have also used an AR LS-15 pre (for many years). Would suspect your advice applies to all transformer-based passives preamps. IMHO, if your amp lacks the tri-tube mod (and their capacitor mod) and you are using 6L6's or 5881's, you are missing the boat; EL-34's sound far better in that amp. However, higher voltage, so they are less reliable; it goes in for repair every few years. Like you, I may upgrade everything else, but the Baron will be passed to an heir.
Hi Lloydc ... I'm far away in Malaysia, can't find anyone authorised to do this mod, so have stuck with stock tubes, in 2/3 pentode and 1/3 triode mode. I always regretted selling the previous Baron I had, so this was a bit of luck, getting the very last unit left in the store. I worry about having to get a new set of 12 matched power tubes sometime in the future, hope Mesa stocks them.

When I plugged in the TVC, my jaw dropped ... since then, I've been fine-tuning everything else around this combination (I use JPS Superconductor 2 XLR connects for pre-power - Mesa recommended the original Superconductors back in 1996).

Have fun ... :)
One of the best tube amps for music...
I can only imagine how difficult and expensive it would be to send the amp back to Mesa for the mods, from Malaysia! You might be able to get it done locally with advice from Mesa. The mods cost almost $1000 in 1998; they included better caps and 3-way switches which help prolong tube life. Yes, Mesa does sell (and match) tubes, and they say that the 6l6's they offer now sound much better than the 5881's it originally came with. Depending on whether you got it through the "authorized" retail chain, I suppose, Mesa still honors their promise to sell tubes to original owners for 1/2 price. You have persuaded me to set my sights on a Bent Audio TAP-X (the only passive/transformer-based pre with remote control that I know of; if anyone knows of others, please advise). Recently, the Experience Head One came highly recommended for the Baron by one who should know.
I forgot to add that I have had the best results with old Telefunken input tubes, but the difference was very subtle and I am not sure it is worth the trouble and expense.
If you're looking at something cost effective:

Otherwise, a passive tvc shud work great. I've written to the Mesa people to check on the tubes and upgrades, let's see ...

Yes, I bought the amp from the authorised dealer!
Hi, I also bought a Baron this week just to test. Amp is in great condition but still has first original 5881 tube set. Think is not in excellent condition anymore afer all these years and I think to replace also to avoid damage of the amp or my speakers.

Has anyone listened to TUNG-SOL 6L6 G (bottle) in this amp. Is this tube working/matching with the Baron? Could someone tell me something about the mods you've written? It's possible to use the EL34 tube set without any modification or is amp originally sold with EL34 the same like the 5881 version?

Many questions. Thanks for your help; amp is very rare here in Europe so it's hard to find someone to help me.

The guy I got my Baron from had replaced the 5881s with Russian 6N3CEs. These tubes failed, blew out some resistors and ate one of my tweeters.

I fixed the amp and installed a matched set of 6L6s, but was always worried it would eat some more drivers. Hopefully, the next owner got more enjoyment out of it.

BTW- there's no need to use XLR cables, the input section is not balanced.
Marco, originally the amp was built only for 5881/6L6 tubes, although the manual implies others could be used, but recommended against it. Later, audiophiles convinced Mesa and the designer, Randall Smith, that EL34's would sound better, and a factory modification was offered called the "tri-tube" mod. Mesa then offered tri-tube Barons with E34l tubes, later finding that they were not reliable and robust enough, and finally settling on EL34's. The do sound much better in most ways, in almost everyone's opinion, but are still not as reliable as 6L6, which have a lower bias point and run more conservatively (I think). Almost any good 6L6 probably sounds better than the 5881; Mesa offers some they say sound better than the 5881's.
Hello Lloydc,

do you know how to find out wether my amp has the tri-tube mods or not? Where is difference; other restitors or caps or any other signs? You think there is no problem using the 6L6G (bottle tube) form Tung-Sol? Also think about changing the output caps audiophile Mundorf caps.

Wow man i can't believe it there are some other Mesa Baron fans!!!! Yeah i own 2 with all the upgrades i purchased them directly from Mesa Boogie i have them in my EXTRA small bedroom i currently use a Audio Synthesis Passion that i had modded by Audio Synthesis so that i could bi-amp my B&W Matrix 3's, i use a stock Sony DVP-S9000ES...i also own a pair of BARON M180's that are mint on my secondary system. With regards to preamps i've used 2 Mod Squad Line Drives' and a McCormack Deluxe Line Drive too...but i got rid of all those, i switch between a plexy glass Mod Squad Deluxe Line Drive; the Promitheus sounds interesting...i'm short on cash but i was thinking of a Canary Audio Passive or a First Sound passive...anyway i am totally stoked about all of you that have the Baron BUG i keep mine stock...i love the bi-amping thing i have a BIG problem though i own a pair of KS-Emotion cables that are not bi-ampable anyway there are worse problems to a side note i alternate my Mod Squad Plexy and the AS passion with my 3rd TV rig with a pair of Bryston 3B amps used in mono mode and Dynaco A25's, Clements and Paradigm References Sudio 60's...they COME ALIVE, killer sound stage!!!...Bryston recommoneds their active preamps but a passive pre on the 3b's with a second Sony dvp-s9000-es WOW....sorry for all the verbage...Also, has anyone upgraded their power cables?? Just a thought...oh yeah i had an old Conrad Johnson preamp with my Baron M180's man they sounded awsome i'll post some pics i hope others will closing i picked the Baron's because i believe in their road gear reputation... when i go to audio shops and tell them what i own...some laugh and say "why do you have a guitar amp for audio...try Audio Research" one thing MESA has probably built as many units as other audio companies anyway they rock!!!

Mesa has sent me the schematic to make the necessary changes to my Baron if I want to use other tubes, which Lloydc srongly recommends. But I haven't got around to do this yet ... I was think I'll let the current tubes go first, still have lots of life left in them.
I'm trying to get my Baron to synergise with a pair of Magnepan 1.6 speakers I just got, but not quite hitting the spot so far. I sold my first Baron because, driven by an AR LS16 preamp, it didn't quite do it with my earlier set of Maggies (also the 1.6). Looks like I've come a full circle now, although the bit players are different this time; for one, it's the Promitheus TVC passive pre, and Anti-Cables, and different power cords.
It's been a while, but here's something I finally hit on. I had put the Baron aside for a few months, also sent it for a service (one of the meter bulbs had blown). In the meantime, I got myself a McIntosh MA402 power amp and more recently, a C220 tube preamp.
When the Baron came back, my thought was to sell it, since the Mac pre-power was so musical. Anyway, I hooked the Mac pre to the Baron and voila! I was blown away, sounded like a perfect match for the Baron. I never heard it sound better.
So, it stays ... :)

Just thought I'd share.
Have a Mesa Baron with Tesla EL34 blues, Hovaland Musicaps, hexfreds and Caddocks. Usually run it in triode, still a match for anything around.
I like to run my Baron in 2/3 pentode, 1/3 triode mode. Yes, the triode mode is sweeter sounding, but i need a bit more power to drive the Maggies. In full triode more, bass can be a bit soft ...