send back to mesa?

[chipaudette]

Hi All,

I've got a Mesa Triaxis and 2:90 rack setup that I haven't used in years. Instead, I've been hanging out here and modifying my Fender Deluxe Reverb Reissue. It's been fun...but I think that I'd like to get the old girl fired up again...

I think that I stopped playing the Triaxis/2:90 both because my tastes ave changed but also because the whole rig lost that certain sound that it had. It just doesn't have that original sound that used to kick me in the rear. I miss that sound. I think that I also stopped playing it because one of the two channels on the 2:90 stopped working. That seems like bad thing to happen to an amp.

Given that the equipment is over 20 years old, maybe the rig needs a good old tune-up. And, since Boogie schematics off the web are unreliable (are they?), I'm not sure that I'm up to the task of getting her sounding sweet again.

My question is, should I take the equipment to the local Mesa authorized repair shop, or should I call Boogie and see if I can send it in to them in California? This stuff is heavy, so it is cheaper to keep it local. But, I want it to sound like it's supposed to sound...maybe I need the experience of the folks in California.

What do you think?

Chip

[Enzo]

I wouldn;t assume the issues with your amp are so cosmic that only the factory will have the skill to handle it. If you have a local Mesa repair shop you trust, I'd bet they would be able to handle it just fine. SOme Mesa products fall into the semi-custom range, and as a particular model went through life on the production line, changes would creep in. SO in that sense schematic might not all match amp chassis. But they will be close most times, and if not, a call to the factory usually gets things straight.

[chipaudette]

Thanks for the reply.

I have no doubt that the local mesa repair shop (or any repair shop) could probably fix the dead channel on the 2:90.

The part that is making me consider sending it to Mesa is the Triaxis. It's not broken...it just doesn't sound great. So, if I bring it to my nearest Mesa shop in Manchester, NH, do they have much experience with the Triaxis to know when one sounds "right". That's my only concern.

I guess the best way to find out is to stop by and ask them. Seems obvious now that I said it out loud. Duh.

I wonder if they're open on Saturdays (ie, today)...hmm...

Chip

[WholeToneMusic]

I use to have this setup and it was very versitile, However rack gear is cumbersome which is a good reason not to ship it to Mesa. I sold mine and sent it to So. Cal and the customer paid around 100 bucks one way. Before you send it in make sure all the filaments are lighting up on all your tubes. I would re-tube the amps before you take it to the shop, both the triaxis and the 2:90, Alot of tubes!! Also there is a 12ax7 inside of the 2:90 chassis.

[tim]

Thanks for the reply.

I have no doubt that the local mesa repair shop (or any repair shop) could probably fix the dead channel on the 2:90.

The part that is making me consider sending it to Mesa is the Triaxis. It's not broken...it just doesn't sound great. So, if I bring it to my nearest Mesa shop in Manchester, NH, do they have much experience with the Triaxis to know when one sounds "right". That's my only concern.

I guess the best way to find out is to stop by and ask them. Seems obvious now that I said it out loud. Duh.

I wonder if they're open on Saturdays (ie, today)...hmm...

Chip

Hi Chip... I used to work in that shop for about 6 years and I repaired 99% of the Boogie stuff that came in. In the six years that I worked there I only saw one Triaxis and the problem, as I remember, was a noisy plate resistor. Those preamps are well known as switching nightmares.

I know they have a couple of sharp techs down there (or did, I haven't been in contact with them much since I left about 4 years ago). At least one of them that was there when I left would be up to the task if there was a switching issue...

and no, the repair shop isn't open Saturdays. Only M-F 8:00-5:30 I believe...although their stores are open 7 days a week I think (there's one in Vermont somewhere) and you can drop it off there and they'll send it down to Manchester to be repaired.

As far as it sounding "right"..."right" is sometimes in the ears of the beholder... unless there is something obviously wrong with it, it will be checked out for nominal operation and if it meets that, it's sent on it's way and fixed if it's not nominal.

[Enzo]

The difference between a one channel amp and a 17 channel amp is just the amount of stuff inside and the switching circuits. Channels themselves all tend to be very similar. They may not sound alike, but they are full of triodes and the occasional pentode. They all have plate load resistors and cathode resistors, and coupling caps between stages. That there are multiple ones is not much of an issue to a technician of any competence. If a problem affects all the channels it probably isn;t in one of them anyway, it is more likely in the circuits they have in common, like the power amp or power supply. And if the problem is only in one channel then we can ignore the other 16 or however many there may be.

What am I babbling about? The amp may seem real complex to you, but it is just another amp to a competent repair tech. Electronics doesn;t change with the brand. I find the main problem servicing Mesa amps is the poorly drawn schematics and the cramped circuit boards where we find such things as four LDRs stacked. That is a matter of inconvenience, not a technical challenge.

[chipaudette]

Hey Tim! Thanks for the inside info!

The lack of experience with the sound of the Triaxis is exactly what I'm worried about. It seems to me that all the functions work properly...it's just a matter of the sound being not the way that it was. If I were the repair tech, I wouldn't want to take this kind of job...it's too amorphous...there's no actual problem that can be pointed to and debugged. I can only assume that's it's really hard to please the customer (me) in this situation -- if you can't find the "problem", he's pissed -- if you do find the problem, it took you four hours of bench charges ($$$), and he's still pissed. No win. How annoying for the tech.

So, to me, the pre-amp sounds like the tone shaping is wrong somewhere near the tail end of system. The gain and distortion have the right feel (more or less) so the problem isn't early in the chain. It's just that the sound of it is wrong once it comes out the speakers...like it's missing most of it's low-mids and all of it's bass. Weird. So, maybe some caps are going...or maybe something isn't switching into the circuit (the two clean channels sound fine...it's all the lead channels that are lacking)...who knows.

If I had a decent schematic (the one I got off the web is hard to read and doesn't have all the cap values), I could probably start myself. Bummer.

Thanks for all your thoughts.

Chip

[pdf64]

Mesa will almost certainly email you a schematic if you provide them with a model and serial #.
The LDRs, as noted above, age badly. So consider just replacing them all.
Mesa use tantalum signal caps which can be unreliable, but with a schematic and a sig gen it should be possible to track it down.
Peter.

[chipaudette]

Good info. Can one buy new LDRs? I thought that there was a thread a few years ago discussing the impossibility of getting suitable parts.

I've never contacted Mesa before. Are they open to sending schematics to nobodies like me? Do they require some sort of NDA or "authorized repair shop" agreement? Will they sell replacement parts to individuals?

Thanks,

Chip

[tim]

Chip, one thing you could do is swap all the tubes from one channel to the other and vice versa and see if the quality of your sound moves with the tubes. If so, then you know you most likely have an issue with a tube. Start swapping them back one at a time (process of elimination) until the sound moves to the other channel and that's the tube...it's a fairly involved process to do it that way but may be the only way...if the objectionable sound stays in the same channel no matter what tubes are where, then there is a deeper issue and what you're hearing may indeed be a distortion problem which can be seen on a scope and a competent tech's eyes.

I don't claim to have "golden ears" (been playing too long in loud bands and working on aircraft carrier decks in my younger days) but I always believe the owner when he says that he/she is hearing something out of the ordinary. After all, they listen to the amp more than I do and they most generally know when someting is amiss...then again, there is that minority that will bring an amp in and say...."I am looking for more of a "purple" tone "

BTW, I sent you a PM.