Wow...what a difference some preamp tubes make in a C+.....

[floridamike]

Holy crap. Some of you know about the C+ I recently obtained from a buddy who had it hidden away in a closet for years. Anyway, the amp had the original number Mesa preamp tubes that all checked out fine with my amp tech. However, it was still a bit icy.

Finally bit the the bullet and replaced the existing ones with an Old 60's Mullard in V1, a NOS Jan GE 5751 in V2, a 60's RCA 12ax7a in the lead channel and a 60's RCA 12at7 in the Reverb.

The clean channel was freaking phenomenal but the lead was a bit dark. I swapped out the RCA 12ax7a with the 5751 and voila......just a different sounding amp. I now run the first volume at 10 and the lead channel around 5 and I get just a killer alt.country twang in the clean channel (that can be popped with an OD for a nice sound and an Atlanta Rhythm Section-like lead tone that is smooth as silk. This amp is the sh$%. Most versatile amp I've ever owned.

 

[dodger916]

Try a new Mullard 12at7wa (balanced triodes) in the phase inverter. It really smoothed out my C+. I got the balanced triode tube from Doug's.

 

[stokes]

The 5751's are great in that amp,I've had 2 in mine for years,but I like it better in V1 and the lead channel.A 12AT7 is nice in the PI,as dodger pointed out,but not meaning any offense,I think the balanced triode thing is lot of hype when it comes to guitar amps.In hi-fi it makes more sense.Look at it this way,in a guitar amp,including the C+,all the components are +/- 10% or more,when you put your balanced triode in the circuit,it aint balanced anymore.In hi-fi use you want super clean,lin ear sound repro,but in guitar amps a little non-linearity is very desireable.Not looking to argue,dodger,if it works for you,thats great,after all tone is totally subjective,but when you look at the overall circuit,the balanced thing just doesnt make sense.
Mike,if that amp was sitting unused for years,like you say,it would be a good idea to re-cap the power supply,you will be amazed at the improvement in that amps response with fresh caps.I've done about 100 Booogies over the last couple of years and every owner was blown away with the results.

 

[dodger916]

A 12AT7 is nice in the PI,as dodger pointed out,but not meaning any offense,I think the balanced triode thing is lot of hype when it comes to guitar amps.

Hi Stokes. No offense taken! I've heard both sides of the argument. Frankly I don't have the techincal knowledge to determine which is "correct", so for the extra $4 (for balanced triodes), I figure better safe than sorry.

 

[MusicManJP6]

Actually, the balanced triode does hold some value. If you use an unbalanced tube in the PI slot you will have less sustain for some notes due to the phasing not being identical for both positive and negative signals. This info came straight from Bob at Eurotubes...

 

[floridamike]

Yeah, I really like the 5751. I may put one in the V1 and move the Mullard to V2. It's cool experimenting anyway and there is still PLENTy of gain in the lead channel with the 5751 in it.

The 5751's are great in that amp,I've had 2 in mine for years,but I like it better in V1 and the lead channel.A 12AT7 is nice in the PI,as dodger pointed out,but not meaning any offense,I think the balanced triode thing is lot of hype when it comes to guitar amps.In hi-fi it makes more sense.Look at it this way,in a guitar amp,including the C+,all the components are +/- 10% or more,when you put your balanced triode in the circuit,it aint balanced anymore.In hi-fi use you want super clean,lin ear sound repro,but in guitar amps a little non-linearity is very desireable.Not looking to argue,dodger,if it works for you,thats great,after all tone is totally subjective,but when you look at the overall circuit,the balanced thing just doesnt make sense.
Mike,if that amp was sitting unused for years,like you say,it would be a good idea to re-cap the power supply,you will be amazed at the improvement in that amps response with fresh caps.I've done about 100 Booogies over the last couple of years and every owner was blown away with the results.

 

[Platypus]

Would you say the 5751 is a brigther tube? I am running SPAX7's in V1/V2 in my simul C+ right now and to be honest I'm not entirely impressed with this amp yet as compared to my other C+ running russian 12ax7s.

I don't really like the idea of a 'gain reduction' that the 5751 totes but I've heard it mentioned a ton lately so I'm willing to give it a shot. I am looking for the heinous tight/brightness crunch without fizz out of it.

 

[Boogiebabies]

I think there is a fundamental difference in tone when using a NOS versus a current production preamp tube. The NOS tubes, to me, offer a thicker tone with a wider range of harmonics and sound dimension. The tone is fatter and has a different feel and touch response that lends itself to tones different than the amp is commonly accepted to have. In relation to tone, I think tube advice relates heavily on ones personal preference or genres. The amp covers ground for tones from different generations. Like floridamike has mentioned in the past that he can get his C+ to give him a great David Lindley tone, while others are seeking a more modern tone like Metallica or John Petrucci. In either case, the tonal advise would be lost on the other. For some, lowering the gain factor with preamp tubes will help get that Dumble or boosted Fender tone, while for others, a full set of Chinese pre's will be more apt to help with modern tones. At any rate, the Grail is versatile enough to have a generation gap. It's pretty awesome.

 

[Platypus]

Ed, very true. I guess it's hard to quantify what I'm after.

I have my 60/100 that does the petrucci/metallica trip for hours, I am definitely going to go the NOS route with the simul. I am putting in an order for some JP 5751

 

[stokes]

Ed, very true. I guess it's hard to quantify what I'm after.

I have my 60/100 that does the petrucci/metallica trip for hours, I am definitely going to go the NOS route with the simul. I am putting in an order for some JP 5751

If you are looking for the Metallica thing the 5751 may not be for you.I use it specifically to get away from the mega gain thing.In your previous post you mention looking to get rid of the "fizz",I think a NOS AX7 will get you where you want.I got into the NOS tubes years ago to get rid of that harsh,fizzy distortion that most current production tubes have.
MusicMan-when you use a balanced triode in the PI in a guitar amp,it aint balanced anymore,since the circuit itself isnt balanced.For years nobody but HI-FI guys even considered a balanced PI,since their circuits have tighter tolerances.Now I aint saying Bob at Eurotubes isnt knowledgeable,but he sells tubes,and I havent heard anyone pushing balanced triodes except tube dealers.Like dodger says its only $4 more so it aint that big a deal,but to a guy who sells thousands of tubes......Which is another thing that pisses me off-if a dealer is testing his tubes and sorting them anyway,why does he have to charge $4 more for a balanced tube if it has gone thru the same testing as the one that costs $4 less?Believe me,the test for a balanced triode is exactly the same as the test to make sure both sides are working,they just put them in a different pile and charge more for it.Leo Fender would laugh at us for even talking "balanced triode".

 

[floridamike]

Dead on BB...and to take it a step further once I got the gain smoothed out a bit a simple change from a G&L ASAT classic to an SG w/Lollar P90s is a lot more noticeable and usable. It is nice to find an amp that has so many different variations available both through the basic settings of the amp itself and through the available tube types. Not to mention the differences between speakers and cabs.


As to the 5751 being brighter...I haven't had a chance to put it in the circuit without the Mullard as they both arrived at the same time and I only had about 45 minutes to play. I did pop the Mullard into an old '64 Champ and '92 SC30 and it made a significant difference in the musicality of the amps. Just phenomenal...like a new set of strings after a year of heavy playing. Of course, it should for $145. Hell, I may buy another.

 

[Boogiebabies]

My favorite gear related Lindley article...

Amp Wizard Howard Dumble

by Dan Forte

Jackson Brown is wandering the back stage caverns of San Francisco's Cow Palace looking a bit worried. "Where's Lindley?" he asks his road manager [...] "We're onstage in 15 minutes!"

A door at the end of the hallway is seeming blasted open by a torrent of beefy sustained lap steel licks. Inside, Lindley is squatting precariously, his Hawaiian guitar balanced on his knees. Crunching chords and crystal-clear single notes are pour out of a crude-looking amplifier about a foot in front of his face.

"I want this one, Howard," David says to a large man who is smiling like a proud father. "Not this model, not one like this, but this one, OK?"

"It's just a prototype." Howard Dumble points out.

"Fine," nods Lindley. "I'll take it."

 

[lesterpaul]

helluva story...!