Mesa/Boogie Titan V12 megathread!

[Camix]

My Mesa Boogie Titan V12 is finally repaired and working flawlessly again. My guitarist and I repaired the entire unit ourselves, but unfortunately, the component of the DI box that we replaced failed again on its first use. We plan to fix that as well. Additionally, I bought four Mosfets as spares and fitted a new fan to the Titan to be prepared for the future. I'm overjoyed to be playing on my Big Block again, which is almost irreplaceable to me.

This weekend, my Big Block had its first outing at an open-air concert, and it performed brilliantly. Thanks to the spacious stage, I was able to borrow a BigBlock 750 and a Powerhouse 1000 from a friend who plays bass. I connected the two amps via the slave-out port. The result was a fantastic setup!

 

[baxter_x]

My guitarist and I repaired the entire unit ourselves, but unfortunately

What did you guys do exactly?

 

[Camix]

What did you guys do exactly?

We replaced all the Mosfets since one was defective and tried to repair the DI out. Check out posts #971 to #975.

 

[baxter_x]

We replaced all the Mosfets since one was defective and tried to repair the DI out. Check out posts #971 to #975.

Good job!
All you did was just replacing the MOSFETs ?
Nothing else on the amp like bias?

 

[Camix]

Good job!
All you did was just replacing the MOSFETs ?
Nothing else on the amp like bias?

Thank you! We measured the resting voltage of all the old MOSFETs (except for the disconnected defective one) and then adjusted the bias of the new MOSFETs so that it is not higher in any of them compared to the old ones.

 

[baxter_x]

Ok, so that requires a certain knowledge.

 

[Camix]

Ok, so that requires a certain knowledge.

Yes, absolutely. Without the necessary knowledge, this can be life-threatening, such as when discharging capacitors. We have basic knowledge in electronics but are not specialists in amplifiers.

 

[Vilhelm82]

Thank you! We measured the resting voltage of all the old MOSFETs (except for the disconnected defective one) and then adjusted the bias of the new MOSFETs so that it is not higher in any of them compared to the old ones.

Hi, any chance you could provide the new MOSFET part numbers? I'm currently fault finding my 2006 silver face unit and might need to replace them.

 

[Vilhelm82]

While going over my amp i noticed some strange "mods". No idea what the previous owner might have had done to it, unfortunately i cant contact him. Does this make any sense to anyone? View attachment PXL_20250125_075135081.jpg
View attachment PXL_20250125_075142768.jpg
The first mod appears to be added to the solo function. Never heard anything wild before when engaging the solo, but since I bought it like this, I wouldn't even know the difference from a stock one to know if it sounded "off".
There's also a wire that runs from near the input area of the PCB to a resister beneath the gain bots, plus an additional zener diode and jfet j112 transistor. I think based on the location and the components that its a distortion mod. What you guys think?
View attachment PXL_20250107_072543182.jpg

 

[baxter_x]

I think this is extremely weird.

 

[detracti]

So, I just scored a Titan V12 off of Reverb. The seller said it has the updates, but I called MB and confirmed that they have no record of it. That kind of bummed me out... The right rack handle turned out being bent. I am in the process of doing a cosmetic refurbish on it.

...have you ever discovered a bent rear output level knob on one of these? Well, I fixed this one using a long bolt some washers and a socket (see the pic) -- worked perfectly. When I cinched it, the dent in the case popped flat - very satisfying.

Yes, the rack case does not have space on top for airflow, but on this one, the case is not vented on top... it is vented to the sides, and the case has plenty of airspace on either side. I'm not looking for stage crushing volume. I just love the voicing and punchiness, and the weight is a small price to pay. The Subway 2x15 is only rated for 800 RMS, but I'm careful with the volume and would keep it on the 2-ohm switch for this setup.

I have a second black-front Titan V12 on the way - one of those ones that is VERY vented, that I will rack similarly, except in a 4U with some space on top and a vent on the front.

Love the Big Blocks!

...also, if you're looking for replacement rack handles, this place has what sounds like a perfect match.. I have four on the way, sounds like they have 30 more:

Handles Unlimited | Manufacturer of Standard & Custom Handles

Handles Unlimited (ISO 9001) manufacturers standard and custom handles, pulls and knobs for commercial, military, electronic and medical use.

handlesunlimited.com

Part # ER680-1

 

[MentalBass]

Question for @agedhorse: Where can I find a definitive answer on the Titan’s Active Freq dial markings / taper? The manual says 340 Hz is at noon, while on the amp it’s labeled 1.2 kHz.

 

[agedhorse]

Question for @agedhorse: Where can I find a definitive answer on the Titan’s Active Freq dial markings / taper? The manual says 340 Hz is at noon, while on the amp it’s labeled 1.2 kHz.

I have no idea, I don’t have one to test either. There may have been two versions as well, so be aware of this possibility.

 

[BassDaddySky]

Wow! 50 something pages...
Im looking for service diagrams to give my repair technician.
Unfortunately my (new to me) Titan cut out after only thee practice sessions at moderate volume.
Had it going into a 1000w 4ohm cab too.
Opened her up, saw and smelled nothing out of the ordinary.
Had a spare tube. So I swapped them around to no avail.
Which brings me back to my opening question;
Local Tube Amp guru asked me if I could find the "service diagrams"
Are they buried somewhere in this thread?
Or can somebody post a link?
Thanks

 

[BassDaddySky]

Ok, I skimmed through the thread only to discover Mesa "no longer supports" this amp, but won't give up the schematics?
Isn't there some "right to repair" policy or something?
Serious bummer.
Is there any hope of resurrecting this beast?
And I hope the Swiss guy got the correct mosfets he was looking for

 

[agedhorse]

Wow! 50 something pages...
Im looking for service diagrams to give my repair technician.
Unfortunately my (new to me) Titan cut out after only thee practice sessions at moderate volume.
Had it going into a 1000w 4ohm cab too.
Opened her up, saw and smelled nothing out of the ordinary.
Had a spare tube. So I swapped them around to no avail.
Which brings me back to my opening question;
Local Tube Amp guru asked me if I could find the "service diagrams"
Are they buried somewhere in this thread?
Or can somebody post a link?
Thanks

Local tube amp guru will be in WAY over his head on this amp.

We really can't support this amp at the factory anymore, we can't get the parts needed to perform most repairs and we don't have the time to walk unqualified techs who are in over their heads through hours of learning experiences.

We had too many amps at the factory that we performed diagnostics on (they take quite a bit of time to diagnose PROPERLY), weren't able to repair due to parts unavailability, then got stuck with unrepairable amps and unpaid labor charges. The customers were generally pretty disappointed... even after stiffing us. It's just unsustainable.

A truly qualified service tech will already know how the amp is supposed to work, if they are a Mesa authorized service center they will have access to the service docs. and our service center tech support. That said, many of these techs have already been down the "unavailable parts road" and may not be willing to work on them. Many of the discontinued parts are from suppliers that discontinued the parts or went out of business. The lateral MOSFETs have been out of production for about 5 years, Exicon bought up some wafers on a lifetime buy and have been re-packaging them, but they do not have production quantities and the parts have the same quirks and reliability issues that caused us to discontinue MOSFET based amps. I see that Exicon is now slowly discontinuing these parts too.

I was considering a new design based on lateral MOSFETs but even in 2014 there were constant supply and reliability issues so I went a different direction.

 

[blong1]

I had a V12 for several years...best amp I have ever owned, I have thought about purchasing another one, but just can't pull the trigger for the exact reasons agedhorse mentioned. They don't make the parts anymore that Mesa Boogie used for the factory update repairs and I didn't want to be stuck if something ever went wrong. Unfortunate.

 

[inazone]

I played a Titan for years. I sold it only due to not playing live so I could concentrate on coaching and family. The amp never had an issue but it died a week after I sold it so I paid for the repair. Years later and back to playing live again, I'm now a very happy owner of Subway amps but the Titan is my favorite amp of all time.

 

[BassDaddySky]

That does make sense .
Still bummed
Is there a lesser amp i might find worth scavenging parts from?
As in what other amps utilize the Mesa misfits?
Assuming that is what mine might need.

Also, Mesa's service and repair finder age is busted...
Gonna call them on my lunchbreak
I know im probably beating a dead horse ( no offense intended AgedHorse lol )
But like has been said, its a damn fine sounding Amp, when it makes sound, that is

 

[Soundworks]

all this just makes me appreciate my time with my Titan more! it's a sweet machine.