Mesa power section is killing me!

[Anonymous]

I'm wondering how many people have similar thoughts in mind as me in posting this. Lately I've been doing some amp shopping and finally finished my tone quest with an Uberschall Twin Jet. I've got some nice amps and had quite a bit of cash to lay down, and so in finding the amp, I was looking for the best of something. IMO, the Uberschall does metal the way it's supposed to be done: with balls like nothing else.

I owned a Mark V for a brief period and also tested out a whole bunch of other gear including other Mesa stuff, Diezel, Engl, and a Bogner Fish. The Engl stuff sounded a little, for lack of a better word, constipated. The Diezel stuff was very good, but not really organic enough; I liked it a lot, but wasn't ready to drop $4k on one. The Bogner stuff sounds amazing to me; I have instantly loved every amp I've heard of his that's set up properly.

This leaves Mesa. Please understand that I love what mesa does; they're the only company that's able to pack so much into one amp, and the Mark V looks like one of the most well-designed, logical amps I've ever seen. I love the Rectifiers as well; I know the Uber will cover similar ground, but I wouldn't be surprised if I liked them both about the same in terms of tone. However, what I can't get my head around is the cold bias for anything other than clean tones or Rectifiers.

To me it means one of two things: either they actually believe the cold bias sounds best, or they realize it doesn't sound best and are alright with that because of the added reliability. What I'm curious to hear about - my point in writing this - is to ask what people have either to add to this, or what might you say to defend this design. Unless I'm missing something, at this point, it's unlikely I'll ever buy another Mesa unless it's only for high gain application.

Thanks in advance for your replies!

 

[emperor_black]

This is what I understand about cold vs hot bias...if it feels "stiff" and tight sounding, I assume the amp is cold biased. That could probably be why I never fell in love with my 5150? My bandmate's carvin ts100 used to feel like that. I had the exact same amp but to my ears, mine sounded warm, loose and punchier than his.

That said, I feel my mark iv is either biased just right or hotter. But not colder. In my guitar life, I've biased only one amp.

 

[Anonymous]

This is what I understand about cold vs hot bias...if it feels "stiff" and tight sounding, I assume the amp is cold biased. That could probably be why I never fell in love with my 5150? My bandmate's carvin ts100 used to feel like that. I had the exact same amp but to my ears, mine sounded warm, loose and punchier than his.

That said, I feel my mark iv is either biased just right or hotter. But not colder. In my guitar life, I've biased only one amp.

Sounds about right to me. I bias my own amps and find that I set them up to be a little hotter than the recommended "optimal" setting. Basically all it is for me is turning the bias control to where I think it sounds best, then checking it to make sure I'm not running the tubes so hot that they'll only last for a month.

Has anyone ever taken a reading on the Stiletto? An amp like that - I think - needs to be biased hot; otherwise it will never sound as good as other EL34 - based, mid heavy amps. I'll bet the Lone Star would sound better too - for SRV tones - with hotter bias. Guess I'm just a little frustrated because I like the Mesa product range so much, not to mention their prices are a hell of a lot more attractive than Bogner, Fryette, Diezel, etc.

 

[Monsta-Tone]

Well.....
I think that they are biased coldly for the maximum amount of tube longevity and clean headroom in the power amp section. The reason I think the headroom is a factor is that most of the gain in a Mesa is acquired in the preamp section.

That being said, I have installed bias pots in over 100 Mesa amps and everyone of them sound better to me and my customers!

And, the final reason, they make butt loads of money on tube sales. "Fixed bias for consistant, maintenance free performance." Reads like a presidential speech. In fact, if Mesa's PR people started campaining for someone, they would make a hell of a difference.

Even the mighty Rectifier can benefit from an adjustable bias pot.

 

[MrMarkIII]

Without the "maintenance-free" performance, many "tube noobs" would blow up their amps, blame Mesa for a faulty product, and go back to their "reliable" Crates. There's a learning curve with tube amps, and who's got time in this short-attention-span world?
Tube amps are a dinosaur hold-over from a bygone era when you fixed your own stuff. No hassle but less adjustable is more marketable to teenagers and other mass consumers.

 

[JOEY B.]

Has anyone ever taken a reading on the Stiletto? An amp like that - I think - needs to be biased hot; otherwise it will never sound as good as other EL34 - based, mid heavy amps. I'll bet the Lone Star would sound better too - for SRV tones - with hotter bias. Guess I'm just a little frustrated because I like the Mesa product range so much, not to mention their prices are a hell of a lot more attractive than Bogner, Fryette, Diezel, etc.

I tested a Stiletto ACE with STR-447 "Blue" tubes and found it was biased hotter than 70% MPD with Full Power and diode rectifier.

I also tested the MkV with a quad of ST-450's. Most definately not cold either. http://forum.grailtone.com/viewtopic.php?f=33&t=38013&p=280385&hilit=blend#p280385

I think the EL-34 bias on the newer MESA amps breaks the "cold as ice" tradition.

 

[Anonymous]

Well.....
I think that they are biased coldly for the maximum amount of tube longevity and clean headroom in the power amp section. The reason I think the headroom is a factor is that most of the gain in a Mesa is acquired in the preamp section.

Meh...the same can be said about my Bogner. I'd take warmth and life over clean headroom any day. With all the technology over at Mesa, they'd have a way to set the clean channel up to be colder if they wanted, but I even prefer a warmer clean tone; I know others don't though.

That being said, I have installed bias pots in over 100 Mesa amps and everyone of them sound better to me and my customers!

That's good to know. I'd imagine it wasn't too difficult to do, right? Should just be switching out a resistor for a pot? Do you find that it sounds at all awkward since Mesa preamps are built around the cold power section?

And, the final reason, they make butt loads of money on tube sales. "Fixed bias for consistant, maintenance free performance." Reads like a presidential speech. In fact, if Mesa's PR people started campaining for someone, they would make a hell of a difference.

Even the mighty Rectifier can benefit from an adjustable bias pot.

If I have enough $$$ to keep a Rectifier and the Uberschall, I think I'll do that. Worst that can happen is it doesn't sound as good and I put the resistor back...

Without the "maintenance-free" performance, many "tube noobs" would blow up their amps, blame Mesa for a faulty product, and go back to their "reliable" Crates. There's a learning curve with tube amps, and who's got time in this short-attention-span world?
Tube amps are a dinosaur hold-over from a bygone era when you fixed your own stuff. No hassle but less adjustable is more marketable to teenagers and other mass consumers.

I'm 19. I have no electronics training nor have I had anyone go through an amp and show me how it worked; I just read a **** load of forums and a couple of books. That said, I know where you're coming from; it's really too bad people don't care more about what happens in the amp. I'd think if you're willing to spend that much money on something, you ought to know. At the same time though, Marshall seems to be doing alright with their adjustable bias amps, though if you blow up a Marshall, you really can blame them for a faulty product nowadays. :lol:

Has anyone ever taken a reading on the Stiletto? An amp like that - I think - needs to be biased hot; otherwise it will never sound as good as other EL34 - based, mid heavy amps. I'll bet the Lone Star would sound better too - for SRV tones - with hotter bias. Guess I'm just a little frustrated because I like the Mesa product range so much, not to mention their prices are a hell of a lot more attractive than Bogner, Fryette, Diezel, etc.

I tested a Stiletto ACE with STR-447 "Blue" tubes and found it was biased hotter than 70% MPD with Full Power and diode rectifier.

I also tested the MkV with a quad of ST-450's. Most definately not cold either. http://forum.grailtone.com/viewtopic.php?f=33&t=38013&p=280385&hilit=blend#p280385

I think the EL-34 bias on the newer MESA amps breaks the "cold as ice" tradition.

That's some good news! Now I've got to find one to play....

 

[Monsta-Tone]

Most amps are pretty easy to add a bias pot too.

 

[mikey383]

Well.....
I think that they are biased coldly for the maximum amount of tube longevity and clean headroom in the power amp section. The reason I think the headroom is a factor is that most of the gain in a Mesa is acquired in the preamp section.

That being said, I have installed bias pots in over 100 Mesa amps and everyone of them sound better to me and my customers!

And, the final reason, they make butt loads of money on tube sales. "Fixed bias for consistant, maintenance free performance." Reads like a presidential speech. In fact, if Mesa's PR people started campaining for someone, they would make a hell of a difference.

Even the mighty Rectifier can benefit from an adjustable bias pot.

This.

The hotter a tube is biased, the quicker it will breakup. If you take a look at most high gain amps, they are biased cold. Simply because they get their gain from the preamp section and not the power amp. Unlike an amp like a JCM800 where you get most of the gain from cranking the power section and driving the power tubes into distortion.

Bias pots are a good idea if you are running at low to moderate volumes, which most of us are. Very few of us are driving our amps to their full potential, even in live settings, so adding a bias pot helps us get there without the sheer volume involved with cranking the hell out of our amps.

One of the best tones I got was with a set of EL34s in my Dual Rec that were running at around 95% dissipation! I installed a bias pot in that same amp and set them to where they should be, and the tone got thinner.

 

[Monsta-Tone]

One of the best tones I got was with a set of EL34s in my Dual Rec that were running at around 95% dissipation! I installed a bias pot in that same amp and set them to where they should be, and the tone got thinner.

Yeah, it's a shame that you reach a trade off point. Great tone vs. tube life. Even still....at 60%, 70% or even 80% I find I like the tone much better.
The real catch is to find the middle ground between all of the power supply settings. The bias will completely change when you switch to Tube Rectifier or Tweed Power. I usually set the bias at 70-75% in the highest power settings, but some amps have sounded much better if I set it a little hotter and this kept the bias fairly correct in the lower power settings.
I usually ask the owner what features they use, and then I set the bias correctly for those settings.

 

[jaquetapus]

Yeah, I'd say definitely listen to these guys, bias adjustments can make it "feel" and sound a lot better in quieter applications. Plus if you ask me, a bias pot is a good selling point if/when the time comes!

-dave

p.s. Congrats on being a well spoken, intelligent 19 year old! Always good to have your kind here!

 

[Monsta-Tone]

p.s. Congrats on being a well spoken, intelligent 19 year old! Always good to have your kind here!

What he said!

 

[mrd]

Does anyone know where I could find a good schematic for a bias pot mod for either a MKIV or a RKII or possibly both? Or is it so easy that anyone with an ounce of electronics knowledge could do it? I have a buddy who is in 4th year electrical engineering who could likely do it... any ideas? Thanks!

 

[Anonymous]

p.s. Congrats on being a well spoken, intelligent 19 year old! Always good to have your kind here!

What he said!

Thanks guys; always nice to get a bit of encouragement!

I'm going to mod my Recto so that I can A/B the factory 6L6 setting with an adjustable bias I set myself. Will report back and possibly have some clips!

 

[ibanez4life SZ!]

Let us know how it turns out...I'm thinking about doing the same for my Mesas.

Eric

 

[Anonymous]

Let us know how it turns out...I'm thinking about doing the same for my Mesas.

Eric

Unfortunately, it didn't go as well as I had hoped. I did the mod so that in 6L6 mode, bias was unaffected and when in EL34, I could use the bias pot to set it where I thought sounded best. To me, there wasn't really an improvement over stock bias. I think because the amp is designed with a cold bias in mind, when you turn it up the bass becomes too much. You lose definition, and though lead playing sounds better and is more full, rhythm takes a pretty hard hit.

For me, it's just not working out. My Uberschall Twin Jet does everything my Rectifiers can do, plus so much more. No, it doesn't sound like a Rectifier, but I like the Bogner's tone equally as much; the added versatility makes the Uber a winner.